Earth & Environmental Sciences and Geography & Sustainable Development (Schools of)
https://hdl.handle.net/10023/24
2024-03-28T11:56:14Z
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The co-evolution of Earth's crust and hydrosphere : a silicon isotope perspective
https://hdl.handle.net/10023/29543
The silicon isotope system is a well-established geochemical tool for tracing processes influenced by the interplay of Earth’s present-day crust and hydrosphere. While there is good understanding of stable silicon (Si) isotope systematics for high- and low-temperature processes in the Phanerozoic eon, these are poorly constrained for early Earth processes. Particularly, the Si isotope
composition of Archaean and Proterozoic crustal materials is a scarce record mainly consisting of silica precipitates. However, recent investigations of Si isotopes in Archaean granitoids linked heavy isotopic signatures to seawater-derived sources, invoking the hydrosphere in forming Earth's earliest continental crust.
Motivated by recent research gaps, this thesis aims to explore crust-hydrosphere interactions by establishing the Si isotope compositions of Archaean granitoids, specifically tonalite-trondhjemite-granodiorites (TTGs), and other lithologies representative of more than one-third of Earth history. This thesis presents outcomes from five Si isotope studies on globally diverse, ancient silicates. Here we find Eoarchaean igneous rocks from Greenland were influenced by supracrustal fluids, necessitating a primeval hydrosphere in forming early continents. We explore Si isotope behaviour during ancient partial melting from an Archaean migmatite from Ontario and find that TTG sources were likely seawater-silicified.
This thesis records a secular homogenising of Si isotopes in the ancient upper continental crust from global glacial diamictites, supporting craton stabilisation after ~3.0 Ga. We also show Archaean –Proterozoic Fennoscandian weathering crusts imply no significant Si isotope trends at the Great Oxidation Event and highlight local controls instead. Finally, this thesis explores the Archaean marine silica cycle with a model for the Si isotope evolution of seawater, aligning with data that require a heavy Si isotope signature in the early oceans.
In total, this thesis contributes a more robust temporal Si isotope record of ancient crustal materials and provides a greater understanding of the connection between Earth’s earliest crust and hydrosphere.
2024-06-13T00:00:00Z
Murphy, Madeleine
The silicon isotope system is a well-established geochemical tool for tracing processes influenced by the interplay of Earth’s present-day crust and hydrosphere. While there is good understanding of stable silicon (Si) isotope systematics for high- and low-temperature processes in the Phanerozoic eon, these are poorly constrained for early Earth processes. Particularly, the Si isotope
composition of Archaean and Proterozoic crustal materials is a scarce record mainly consisting of silica precipitates. However, recent investigations of Si isotopes in Archaean granitoids linked heavy isotopic signatures to seawater-derived sources, invoking the hydrosphere in forming Earth's earliest continental crust.
Motivated by recent research gaps, this thesis aims to explore crust-hydrosphere interactions by establishing the Si isotope compositions of Archaean granitoids, specifically tonalite-trondhjemite-granodiorites (TTGs), and other lithologies representative of more than one-third of Earth history. This thesis presents outcomes from five Si isotope studies on globally diverse, ancient silicates. Here we find Eoarchaean igneous rocks from Greenland were influenced by supracrustal fluids, necessitating a primeval hydrosphere in forming early continents. We explore Si isotope behaviour during ancient partial melting from an Archaean migmatite from Ontario and find that TTG sources were likely seawater-silicified.
This thesis records a secular homogenising of Si isotopes in the ancient upper continental crust from global glacial diamictites, supporting craton stabilisation after ~3.0 Ga. We also show Archaean –Proterozoic Fennoscandian weathering crusts imply no significant Si isotope trends at the Great Oxidation Event and highlight local controls instead. Finally, this thesis explores the Archaean marine silica cycle with a model for the Si isotope evolution of seawater, aligning with data that require a heavy Si isotope signature in the early oceans.
In total, this thesis contributes a more robust temporal Si isotope record of ancient crustal materials and provides a greater understanding of the connection between Earth’s earliest crust and hydrosphere.
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Development of a 1-D oxygen isotope photochemical model and its application to atmospheric O₂
https://hdl.handle.net/10023/29486
Oxygen is the second most abundant gas in the Earth’s atmosphere, but this has not always been the case. A suite of geochemical, palaeobiological, and geological proxies have been presented over the last few decades to better constrain the evolution of pO₂ over the history of our planet, but uncertainty remains. Here, we use numerical modelling with the 1-D photochemical model Atmos, firstly by exploring the boundary conditions of the model, and secondly by developing it to predict ∆¹⁷O values – a fairly novel proxy for Proterozoic and Phanerozoic pO₂. Our study of boundary conditions highlights the importance of choosing and describing boundary conditions carefully, as our flux-driven models produce somewhat different results to previous fixed mixing ratio-driven models. Our results provide a potential constraint on pO₂, suggesting that atmospheres with 6×10⁻⁷ < pO₂ < 2×10⁻³ may have been unlikely to exist for long periods of Earth history. We review these conclusions using our newly-developed oxygen isotope model, tuned to predict modern atmospheric ∆¹⁷O. Preliminary results predict the production and preservation of non-zero ∆¹⁷O in the geological record can occur for palaeo-atmospheres with pO₂ > 10⁻⁴, but even the minimum values observed at 1.4 Ga and 635 Ma do not require such low concentrations, especially if pCO₂ is higher than modern. The development of the oxygen isotope model allows the better prediction of ∆¹⁷O under various atmospheric conditions, and will be a useful tool in the interpretation of anomalous oxygen isotope compositions in the geological record.
2021-06-30T00:00:00Z
Gregory, Bethan Sarah
Oxygen is the second most abundant gas in the Earth’s atmosphere, but this has not always been the case. A suite of geochemical, palaeobiological, and geological proxies have been presented over the last few decades to better constrain the evolution of pO₂ over the history of our planet, but uncertainty remains. Here, we use numerical modelling with the 1-D photochemical model Atmos, firstly by exploring the boundary conditions of the model, and secondly by developing it to predict ∆¹⁷O values – a fairly novel proxy for Proterozoic and Phanerozoic pO₂. Our study of boundary conditions highlights the importance of choosing and describing boundary conditions carefully, as our flux-driven models produce somewhat different results to previous fixed mixing ratio-driven models. Our results provide a potential constraint on pO₂, suggesting that atmospheres with 6×10⁻⁷ < pO₂ < 2×10⁻³ may have been unlikely to exist for long periods of Earth history. We review these conclusions using our newly-developed oxygen isotope model, tuned to predict modern atmospheric ∆¹⁷O. Preliminary results predict the production and preservation of non-zero ∆¹⁷O in the geological record can occur for palaeo-atmospheres with pO₂ > 10⁻⁴, but even the minimum values observed at 1.4 Ga and 635 Ma do not require such low concentrations, especially if pCO₂ is higher than modern. The development of the oxygen isotope model allows the better prediction of ∆¹⁷O under various atmospheric conditions, and will be a useful tool in the interpretation of anomalous oxygen isotope compositions in the geological record.
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An environmental cost-benefit analysis of LNG as a maritime fuel in the Arctic
https://hdl.handle.net/10023/29479
As environmental regulations continue to drive a transition away from the extremely polluting heavy oil based fuels traditionally utilized for maritime transport towards alternative fuels, liquefied natural gas is emerging as a viable compliance option. This transition is of particular importance to the Arctic region, where escalating interest in development activities pose significant risks to a relatively undeveloped, yet particularly environmentally vulnerable area. Due to the importance of the Arctic region to the global environment, the prospect of increased development activity and associated maritime traffic within the area has wide ranging implications extending well beyond the region. By taking into account the perspectives of governance actors at varying levels and through the use of cost-benefit analysis, this study will provide an evaluation of the environmental, political and economic implications of a transition towards liquefied natural gas being utilized as a maritime transport fuel in the Arctic region.
2020-07-29T00:00:00Z
Holmes, Ryan Thomas
As environmental regulations continue to drive a transition away from the extremely polluting heavy oil based fuels traditionally utilized for maritime transport towards alternative fuels, liquefied natural gas is emerging as a viable compliance option. This transition is of particular importance to the Arctic region, where escalating interest in development activities pose significant risks to a relatively undeveloped, yet particularly environmentally vulnerable area. Due to the importance of the Arctic region to the global environment, the prospect of increased development activity and associated maritime traffic within the area has wide ranging implications extending well beyond the region. By taking into account the perspectives of governance actors at varying levels and through the use of cost-benefit analysis, this study will provide an evaluation of the environmental, political and economic implications of a transition towards liquefied natural gas being utilized as a maritime transport fuel in the Arctic region.
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What drives the community acceptance of onshore wind energy? Exploring the link between ownership, energy justice, and place in Scotland and Newfoundland
https://hdl.handle.net/10023/29461
This thesis investigates the key factors influencing community acceptance of onshore wind energy, specifically examining the argument that fair involvement in decision-making and fair financial benefits are powerful determinants. The thesis examines this claim through various methodologies and across two different contexts: Scotland and Newfoundland. The initial papers, focusing on Scotland, employ quantitative surveys to investigate the significance of community ownership and energy justice in determining acceptance. By comparing communities which have different degrees of ownership, that is, community, shared, and private, the first paper highlights the characteristics of ownership that foster community acceptance. Notably, it emphasises the importance of fair involvement and financial benefits, providing evidence that a co-operative can achieve a similar degree of acceptance and energy justice as a fully community-owned project. Building on the findings of the first paper, the Scotland second paper employs multigroup structural equation modelling to empirically test the influence of energy justice factors (fair involvement, fair financial benefits, and perceived turbine impacts) on social acceptance and how these relationships vary according to projects with different ownership structures. The chapter demonstrates that while energy justice factors influence acceptance, their relative importance depends on ownership. For instance, residents near the community-owned project placed greater emphasis on fair involvement, while those near the privately-owned project valued fair financial benefits and perceived impacts. The final paper, focusing on Newfoundland, uses semi-structured interviews to examine how place shapes acceptance and justice perceptions for onshore wind, analysed through sociotechnical imaginaries and a political economic analysis of successive industries in the province. The findings reveal that a shared narrative of struggle stemming from the cod fishery collapse has emerged in local discourses around wind projects, promoting acceptance. Taken together, this research demonstrates that the challenging process of negotiating just, sustainable energy transitions requires an understanding of geographical context.
2024-06-14T00:00:00Z
Hogan, Jessica
This thesis investigates the key factors influencing community acceptance of onshore wind energy, specifically examining the argument that fair involvement in decision-making and fair financial benefits are powerful determinants. The thesis examines this claim through various methodologies and across two different contexts: Scotland and Newfoundland. The initial papers, focusing on Scotland, employ quantitative surveys to investigate the significance of community ownership and energy justice in determining acceptance. By comparing communities which have different degrees of ownership, that is, community, shared, and private, the first paper highlights the characteristics of ownership that foster community acceptance. Notably, it emphasises the importance of fair involvement and financial benefits, providing evidence that a co-operative can achieve a similar degree of acceptance and energy justice as a fully community-owned project. Building on the findings of the first paper, the Scotland second paper employs multigroup structural equation modelling to empirically test the influence of energy justice factors (fair involvement, fair financial benefits, and perceived turbine impacts) on social acceptance and how these relationships vary according to projects with different ownership structures. The chapter demonstrates that while energy justice factors influence acceptance, their relative importance depends on ownership. For instance, residents near the community-owned project placed greater emphasis on fair involvement, while those near the privately-owned project valued fair financial benefits and perceived impacts. The final paper, focusing on Newfoundland, uses semi-structured interviews to examine how place shapes acceptance and justice perceptions for onshore wind, analysed through sociotechnical imaginaries and a political economic analysis of successive industries in the province. The findings reveal that a shared narrative of struggle stemming from the cod fishery collapse has emerged in local discourses around wind projects, promoting acceptance. Taken together, this research demonstrates that the challenging process of negotiating just, sustainable energy transitions requires an understanding of geographical context.
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Marine protection in the European Union : how do social constructions of marine wilderness and nature influence policy?
https://hdl.handle.net/10023/29438
Marine biodiversity is diminishing globally. Due to the extent and transboundary nature of the seas, effective conservation can best be achieved through international cooperation and policies. The European Union (EU) has developed some of the most stringent, but also complex marine environmental policy frameworks in the world. However, their implementation has remained inconsistent and poorly coordinated. The gravity of the biodiversity crisis requires better implementation of policy objectives, if current targets are to be achieved. While most previous research has focussed on provision of better data and on supporting coordination activities, this study focusses on the social constructions held by key actors involved in EU policy interpretation and implementation. The new generation of ambitious EU conservation targets often provokes contentious ideas linked to the resurgence of wilderness discourses. This study combined three major phases of research to understand these issues. Firstly, a combination of interviews, literature and EU policy analysis were used to explore how key EU policy actors perceive the concepts of marine nature and wilderness, what their personal policy priorities are and why. Secondly, a Q methodological study identified the prevailing social constructions among policy actors. Thirdly, the identified social constructions were subsequently explored and validated further in Living Q workshops with key actors representing all EU Regional Seas. The thesis explores the differing social constructions of marine wilderness and nature amongst policy actors, and how these shape and are shaped by EU policies designed to achieve strict or effective protection of marine nature. The research revealed six distinct social constructions, and considerable divergence between the discourses used in policy texts and those employed by the key actors. The influence of these six social constructions on the understandings of science-policy interfaces and policy implementation are discussed. The results highlight a considerable challenge for the future implementation of EU marine conservation policies, and the thesis argues that this underlying diversity of perceptions needs to be recognised and engaged with.
2024-06-14T00:00:00Z
Gorjanc, Sašo
Marine biodiversity is diminishing globally. Due to the extent and transboundary nature of the seas, effective conservation can best be achieved through international cooperation and policies. The European Union (EU) has developed some of the most stringent, but also complex marine environmental policy frameworks in the world. However, their implementation has remained inconsistent and poorly coordinated. The gravity of the biodiversity crisis requires better implementation of policy objectives, if current targets are to be achieved. While most previous research has focussed on provision of better data and on supporting coordination activities, this study focusses on the social constructions held by key actors involved in EU policy interpretation and implementation. The new generation of ambitious EU conservation targets often provokes contentious ideas linked to the resurgence of wilderness discourses. This study combined three major phases of research to understand these issues. Firstly, a combination of interviews, literature and EU policy analysis were used to explore how key EU policy actors perceive the concepts of marine nature and wilderness, what their personal policy priorities are and why. Secondly, a Q methodological study identified the prevailing social constructions among policy actors. Thirdly, the identified social constructions were subsequently explored and validated further in Living Q workshops with key actors representing all EU Regional Seas. The thesis explores the differing social constructions of marine wilderness and nature amongst policy actors, and how these shape and are shaped by EU policies designed to achieve strict or effective protection of marine nature. The research revealed six distinct social constructions, and considerable divergence between the discourses used in policy texts and those employed by the key actors. The influence of these six social constructions on the understandings of science-policy interfaces and policy implementation are discussed. The results highlight a considerable challenge for the future implementation of EU marine conservation policies, and the thesis argues that this underlying diversity of perceptions needs to be recognised and engaged with.
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Whodunit? Determining the source and eruptive characteristics of unidentified volcanic eruptions from ice and sediment core archives
https://hdl.handle.net/10023/29279
The most complete records of explosive volcanism from the last 100,000 years are preserved in polar ice cores as deposits of sulfate aerosol and microscopic ash (tephra). These records are essential for reconstructing the history of past eruptions, including their stratospheric sulfur loading, as well as understanding the climatic impact of eruptions. However, few of these deposits have been linked with volcanic sources, leading to assumptions of eruptive source latitude, plume height and stratospheric sulfur loading, which are all essential for interpreting the climate forcing potential of eruptions. A fundamental limitation preventing the correlation of ice core volcanic deposits to eruptive sources is the difficulty of geochemically characterising extremely fine-grained (<10 μm) tephra with conventional analytical methods. This thesis provides a thorough assessment and recommended workflow for analysing <10 μm tephra, increasing potential for characterising cryptotephra from distant eruptions in ice. These tephra method developments are then used alongside sulfur isotope analysis to improve source attributions of major Common Era eruptions recorded in Greenland ice during the 7th century. This allows testing of previous source latitude assumptions for eruptions associated with large climate anomalies and contributes to ongoing efforts to understand climate sensitivity to extra-tropical versus tropical eruptions. Finally, the identification of Atitlán Los Chocoyos supereruption tephra in both Greenland and Antarctic ice ~79,500 years ago suggests even volcanic stratospheric sulfate injection several times greater than any Common Era eruption does not have a long-term (greater than decadal) impact on climate. Grainsize analysis of Los Chocoyos ash in marine sediment cores provides further insights into the physical characteristics of the supereruption, suggesting mechanisms that accelerate fine ash and sulfate fallout from the atmosphere may limit stratospheric sulfur loading. By better constraining source and stratospheric sulfate estimates for both major eruptions of the Common Era and one of the largest supereruptions of the last 100,000 years, this thesis contributes to ongoing efforts to understand the history and global impacts of explosive volcanism.
2024-06-13T00:00:00Z
Innes, Helen Mary
The most complete records of explosive volcanism from the last 100,000 years are preserved in polar ice cores as deposits of sulfate aerosol and microscopic ash (tephra). These records are essential for reconstructing the history of past eruptions, including their stratospheric sulfur loading, as well as understanding the climatic impact of eruptions. However, few of these deposits have been linked with volcanic sources, leading to assumptions of eruptive source latitude, plume height and stratospheric sulfur loading, which are all essential for interpreting the climate forcing potential of eruptions. A fundamental limitation preventing the correlation of ice core volcanic deposits to eruptive sources is the difficulty of geochemically characterising extremely fine-grained (<10 μm) tephra with conventional analytical methods. This thesis provides a thorough assessment and recommended workflow for analysing <10 μm tephra, increasing potential for characterising cryptotephra from distant eruptions in ice. These tephra method developments are then used alongside sulfur isotope analysis to improve source attributions of major Common Era eruptions recorded in Greenland ice during the 7th century. This allows testing of previous source latitude assumptions for eruptions associated with large climate anomalies and contributes to ongoing efforts to understand climate sensitivity to extra-tropical versus tropical eruptions. Finally, the identification of Atitlán Los Chocoyos supereruption tephra in both Greenland and Antarctic ice ~79,500 years ago suggests even volcanic stratospheric sulfate injection several times greater than any Common Era eruption does not have a long-term (greater than decadal) impact on climate. Grainsize analysis of Los Chocoyos ash in marine sediment cores provides further insights into the physical characteristics of the supereruption, suggesting mechanisms that accelerate fine ash and sulfate fallout from the atmosphere may limit stratospheric sulfur loading. By better constraining source and stratospheric sulfate estimates for both major eruptions of the Common Era and one of the largest supereruptions of the last 100,000 years, this thesis contributes to ongoing efforts to understand the history and global impacts of explosive volcanism.
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Asylum as artifice : the role of the 'asylum seeker' and the production of the space-time of asylum accommodation in Glasgow, Scotland
https://hdl.handle.net/10023/29204
This thesis explores the relationship between the legal category of the ‘asylum seeker’ and production of asylum accommodation as space-time, through a localised empirical case study in Glasgow, Scotland. Administered by the UK Home Office and delivered by a private contractor, the Mears Group, asylum accommodation is here theorised as being a logistically defined and value-creating carceral space-time. This is constituted relationally and performatively, a theoretical composite of the work of Massey (2001), Delaney (2010) and Butler (1988). Such a theorisation is arrived at through a novel conceptualization of the ‘asylum seeker’ as an artifice, the site of a double real abstraction of legal categorization and commodity exchange, drawing on the work of Toscano (2008, 2012, 2014), Thomas (2021) and Sohn-Rethel (2021). The category of the ‘asylum seeker’ – the legal double of the real asylum-seeking individual – is constituted through three different levels of discourse: 1) successive rounds of asylum legislation since 1993, which has stripped away access to employment and welfare; 2) contracts for the delivery of asylum accommodation, which recast the ‘asylum seeker’ as a ‘service user’; 3) relationality and performativity of roles, which in turn constitute the space-time of asylum accommodation itself. Analysis of all three levels of discourse, understood to be in a dialectical, co-constitutive relationship with one another, contributes a formulation of asylum accommodation as a ‘parallel world’: a qualitatively distinct modality of space-time, ruled by legal and commodity exchange abstraction, which has the capacity to distort the semantic constructions used to describe it. This formulation in turn enables propositions concerning the role of asylum accommodation in wider migration management to be made, problematizing not only the organization of authority between the Home Office and private accommodation providers, but the nature of power itself in such contractual arrangements.
2024-06-14T00:00:00Z
Pearce, Anna Valeria
This thesis explores the relationship between the legal category of the ‘asylum seeker’ and production of asylum accommodation as space-time, through a localised empirical case study in Glasgow, Scotland. Administered by the UK Home Office and delivered by a private contractor, the Mears Group, asylum accommodation is here theorised as being a logistically defined and value-creating carceral space-time. This is constituted relationally and performatively, a theoretical composite of the work of Massey (2001), Delaney (2010) and Butler (1988). Such a theorisation is arrived at through a novel conceptualization of the ‘asylum seeker’ as an artifice, the site of a double real abstraction of legal categorization and commodity exchange, drawing on the work of Toscano (2008, 2012, 2014), Thomas (2021) and Sohn-Rethel (2021). The category of the ‘asylum seeker’ – the legal double of the real asylum-seeking individual – is constituted through three different levels of discourse: 1) successive rounds of asylum legislation since 1993, which has stripped away access to employment and welfare; 2) contracts for the delivery of asylum accommodation, which recast the ‘asylum seeker’ as a ‘service user’; 3) relationality and performativity of roles, which in turn constitute the space-time of asylum accommodation itself. Analysis of all three levels of discourse, understood to be in a dialectical, co-constitutive relationship with one another, contributes a formulation of asylum accommodation as a ‘parallel world’: a qualitatively distinct modality of space-time, ruled by legal and commodity exchange abstraction, which has the capacity to distort the semantic constructions used to describe it. This formulation in turn enables propositions concerning the role of asylum accommodation in wider migration management to be made, problematizing not only the organization of authority between the Home Office and private accommodation providers, but the nature of power itself in such contractual arrangements.
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Investigating the dynamics of Greenland's glacier-fjord systems
https://hdl.handle.net/10023/29146
Over the past two decades, Greenland’s tidewater glaciers have dramatically retreated, thinned and accelerated, contributing significantly to sea level rise. This change in glacier behaviour is thought to have been triggered by increasing atmospheric and ocean temperatures, and mass loss from Greenland’s tidewater glaciers is predicted to continue this century. Substantial research during this period of rapid glacier change has improved our understanding of Greenland’s glacier-fjord systems. However, many of the processes operating in these systems that ultimately control the response of tidewater glaciers to changing atmospheric and oceanic conditions are poorly understood. This thesis combines modelling and remote sensing to investigate two particularly poorly-understood components of glacier-fjord systems, with the ultimate aim of improving understanding of recent glacier behaviour and constraining the stability of the ice sheet in a changing climate.
The research presented in this thesis begins with an investigation into the dominant controls on the seasonal dynamics of contrasting tidewater glaciers draining the Greenland Ice Sheet. To do this, high resolution estimates of ice velocity were generated and compared with detailed observations and modelling of the principal controls on seasonal glacier flow, including terminus position, ice mélange presence or absence, ice sheet surface melting and runoff, and plume presence or absence. These data revealed characteristic seasonal and shorter-term changes in ice velocity at each of the study glaciers in more detail than was available from previous remote sensing studies. Of all the environmental controls examined, seasonal evolution of subglacial hydrology (as inferred from plume observations and modelling) was best able to explain the observed ice flow variations, despite differences in geometry and flow of the study glaciers. The inferred relationships between subglacial hydrology and ice dynamics were furthermore entirely consistent with process-understanding developed at land-terminating sectors of the ice sheet. This investigation provides a more detailed understanding of tidewater glacier subglacial hydrology and its interaction with ice dynamics than was previously available and suggests that interannual variations in meltwater supply may have limited influence on annually averaged ice velocity.
The thesis then shifts its attention from the glacier part of the system into the fjords, focusing on the interaction between icebergs, fjord circulation and fjord water properties. This focus on icebergs is motivated by recent research revealing that freshwater produced by iceberg melting constitutes an important component of fjord freshwater budgets, yet the impact of this freshwater on fjords was unknown. To investigate this, a new model for iceberg-ocean interaction is developed and incorporated into an ocean circulation model.
This new model is first applied to Sermilik Fjord — a large fjord in east Greenland that hosts Helheim Glacier, one of the largest tidewater glaciers draining the ice sheet — to further constrain iceberg freshwater production and to quantify the influence of iceberg melting on fjord circulation and water properties. These investigations reveal that iceberg freshwater flux increases with ice sheet runoff raised to the power ~0.1 and ranges from ~500-2500 m³ s⁻¹ during summer, with ~40% of that produced below the pycnocline. It is also shown that icebergs substantially modify the temperature and velocity structure of Sermilik Fjord, causing 1-5°C cooling in the upper ~100 m and invigorating fjord circulation, which in turn causes a 10-40% increase in oceanic heat flux towards Helheim Glacier. This research highlights the important role of icebergs in Greenland’s iceberg congested fjords and therefore the need to include them in future studies examining ice sheet – ocean interaction.
Having investigated the effect of icebergs on fjord circulation in a realistic setting, this thesis then characterises the effect of submarine iceberg melting on water properties near the ice sheet – ocean interface by applying the new model to a range of idealised scenarios. This near-glacier region is one which is crucial for constraining ocean-driven retreat of tidewater glaciers, but which is poorly-understood. The simulations show that icebergs are important modifiers of glacier-adjacent water properties, generally acting to reduce vertical variations in water temperature. The iceberg-induced temperature changes will generally increase submarine melt rates at mid-depth and decrease rates at the surface, with less pronounced effects at greater depth. This highlights another mechanism by which iceberg melting can affect ice sheet – ocean interaction and emphasises the need to account for iceberg-ocean interaction when simulating ocean-driven retreat of Greenland’s tidewater glaciers.
In summary, this thesis has helped to provide a deeper understanding of two poorly-understood components of Greenland’s tidewater glacier-fjord systems: (i) interactions between subglacial hydrology and ice velocity, and; (ii) iceberg-ocean interaction. This research has enabled more precise interpretations of past glacier behaviour and can be used to inform model development that will help constrain future ice sheet mass loss in response to a changing climate.
2021-11-30T00:00:00Z
Davison, Benjamin Joseph
Over the past two decades, Greenland’s tidewater glaciers have dramatically retreated, thinned and accelerated, contributing significantly to sea level rise. This change in glacier behaviour is thought to have been triggered by increasing atmospheric and ocean temperatures, and mass loss from Greenland’s tidewater glaciers is predicted to continue this century. Substantial research during this period of rapid glacier change has improved our understanding of Greenland’s glacier-fjord systems. However, many of the processes operating in these systems that ultimately control the response of tidewater glaciers to changing atmospheric and oceanic conditions are poorly understood. This thesis combines modelling and remote sensing to investigate two particularly poorly-understood components of glacier-fjord systems, with the ultimate aim of improving understanding of recent glacier behaviour and constraining the stability of the ice sheet in a changing climate.
The research presented in this thesis begins with an investigation into the dominant controls on the seasonal dynamics of contrasting tidewater glaciers draining the Greenland Ice Sheet. To do this, high resolution estimates of ice velocity were generated and compared with detailed observations and modelling of the principal controls on seasonal glacier flow, including terminus position, ice mélange presence or absence, ice sheet surface melting and runoff, and plume presence or absence. These data revealed characteristic seasonal and shorter-term changes in ice velocity at each of the study glaciers in more detail than was available from previous remote sensing studies. Of all the environmental controls examined, seasonal evolution of subglacial hydrology (as inferred from plume observations and modelling) was best able to explain the observed ice flow variations, despite differences in geometry and flow of the study glaciers. The inferred relationships between subglacial hydrology and ice dynamics were furthermore entirely consistent with process-understanding developed at land-terminating sectors of the ice sheet. This investigation provides a more detailed understanding of tidewater glacier subglacial hydrology and its interaction with ice dynamics than was previously available and suggests that interannual variations in meltwater supply may have limited influence on annually averaged ice velocity.
The thesis then shifts its attention from the glacier part of the system into the fjords, focusing on the interaction between icebergs, fjord circulation and fjord water properties. This focus on icebergs is motivated by recent research revealing that freshwater produced by iceberg melting constitutes an important component of fjord freshwater budgets, yet the impact of this freshwater on fjords was unknown. To investigate this, a new model for iceberg-ocean interaction is developed and incorporated into an ocean circulation model.
This new model is first applied to Sermilik Fjord — a large fjord in east Greenland that hosts Helheim Glacier, one of the largest tidewater glaciers draining the ice sheet — to further constrain iceberg freshwater production and to quantify the influence of iceberg melting on fjord circulation and water properties. These investigations reveal that iceberg freshwater flux increases with ice sheet runoff raised to the power ~0.1 and ranges from ~500-2500 m³ s⁻¹ during summer, with ~40% of that produced below the pycnocline. It is also shown that icebergs substantially modify the temperature and velocity structure of Sermilik Fjord, causing 1-5°C cooling in the upper ~100 m and invigorating fjord circulation, which in turn causes a 10-40% increase in oceanic heat flux towards Helheim Glacier. This research highlights the important role of icebergs in Greenland’s iceberg congested fjords and therefore the need to include them in future studies examining ice sheet – ocean interaction.
Having investigated the effect of icebergs on fjord circulation in a realistic setting, this thesis then characterises the effect of submarine iceberg melting on water properties near the ice sheet – ocean interface by applying the new model to a range of idealised scenarios. This near-glacier region is one which is crucial for constraining ocean-driven retreat of tidewater glaciers, but which is poorly-understood. The simulations show that icebergs are important modifiers of glacier-adjacent water properties, generally acting to reduce vertical variations in water temperature. The iceberg-induced temperature changes will generally increase submarine melt rates at mid-depth and decrease rates at the surface, with less pronounced effects at greater depth. This highlights another mechanism by which iceberg melting can affect ice sheet – ocean interaction and emphasises the need to account for iceberg-ocean interaction when simulating ocean-driven retreat of Greenland’s tidewater glaciers.
In summary, this thesis has helped to provide a deeper understanding of two poorly-understood components of Greenland’s tidewater glacier-fjord systems: (i) interactions between subglacial hydrology and ice velocity, and; (ii) iceberg-ocean interaction. This research has enabled more precise interpretations of past glacier behaviour and can be used to inform model development that will help constrain future ice sheet mass loss in response to a changing climate.
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Air pollution, health, mortality, and ethnicity: analysis of individual-level longitudinal and census data linked to high-resolution spatial data from the United Kingdom
https://hdl.handle.net/10023/28632
This thesis investigates the association between air pollution and health in the UK and examines how this association varies by ethnicity and country of birth. It links high-resolution spatial data on air pollution to individual-level longitudinal data at different geographical scales. The thesis shows that higher concentrations of NO₂, SO₂, CO, PM10, and PM2.5 ambient air pollutants are associated with limiting long-term illness, poor self-reported health, lower ratings of mental well-being, and increased mortality rates and hospital admissions. Particulate matter is mainly associated with all-cause, respiratory, cardiovascular, infectious and cancer mortality and hospital admissions, while SO₂ is mostly related to mental/behavioural disorders/suicide mortality and respiratory hospital admissions. NO₂ is associated with all mortality and hospital admission causes. The analysis further shows that non-UK-born and ethnic minorities report poorer health with higher exposure to air pollution than UK-born and British-white individuals. Ethnic differences are not observed in the association between air pollution and mental well-being. This thesis supports the association between long-term exposure to air pollution and poor health and increased mortality and hospital admissions and shows that the effect of air pollution on health is exacerbated for ethnic minorities in the UK.
2023-11-28T00:00:00Z
Abed Al Ahad, Mary
This thesis investigates the association between air pollution and health in the UK and examines how this association varies by ethnicity and country of birth. It links high-resolution spatial data on air pollution to individual-level longitudinal data at different geographical scales. The thesis shows that higher concentrations of NO₂, SO₂, CO, PM10, and PM2.5 ambient air pollutants are associated with limiting long-term illness, poor self-reported health, lower ratings of mental well-being, and increased mortality rates and hospital admissions. Particulate matter is mainly associated with all-cause, respiratory, cardiovascular, infectious and cancer mortality and hospital admissions, while SO₂ is mostly related to mental/behavioural disorders/suicide mortality and respiratory hospital admissions. NO₂ is associated with all mortality and hospital admission causes. The analysis further shows that non-UK-born and ethnic minorities report poorer health with higher exposure to air pollution than UK-born and British-white individuals. Ethnic differences are not observed in the association between air pollution and mental well-being. This thesis supports the association between long-term exposure to air pollution and poor health and increased mortality and hospital admissions and shows that the effect of air pollution on health is exacerbated for ethnic minorities in the UK.
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A quantitative classification tool for porphyry Cu alteration systems
https://hdl.handle.net/10023/28590
Porphyry copper deposits form from upper crustal H₂O saturated magmatic systems, along ancient and active convergent margins. As the world’s major source of copper, gold and molybdenum, along with minor quantities of other base and precious metals, they are an increasingly important source of raw material, essential to the ongoing clean energy transition and in hitting key targets set by global societies today. Driven by the transition to renewable energy sources and electric vehicles, dependent on substantial quantities of iron ore, copper and aluminium, it has been estimated that the demand for copper alone will increase by over 20 times. With current reserves not expected to meet future demand, extensive additional exploration is anticipated. Furthermore, with the depletion of near-surface deposits in mature exploration terranes, there is a clear need for the development of new techniques to identify and unearth deeply buried reserves. Exploration programs rely on many techniques for the identification of the large, distal alteration systems associated with porphyry style mineralisation, which currently focus on pathfinding geochemical indicators. Alongside these techniques, infrared spectroscopy and magnetic susceptibility data is often collected but underutilised, despite providing a rapid and low-cost source of mineralogical information.
Using samples collected form the Aktogay porphyry Cu deposit in the Central Asian Orogenic Belt, an extensive Palaeozoic subduction-accretion complex, the ability of magnetic and infrared spectroscopy to quantifiably define and characterise alteration, when used in conjunction with a specifically developed, unsupervised deep learning algorithm, has been examined. Our findings demonstrate that the resulting subdivision around porphyry mineralisation into twelve discrete domains, can uniquely identify otherwise hidden mineral assemblages. Through examining the consistency of key parameters within each domain such as ore grade and geochemical signatures, their statistical significance has been tested, indicating an increased consistency of between 60 and 70% when compared to traditional alteration zones classified by on-site mining geologists. In addition, detailed petrological and magnetic characterisation independently confirms the validity of the newly defined alteration domains, whilst also demonstrating the importance of magnetic characterisation as a new tool, which can improve our understanding and partial quantification of the magnetic effects during hydrothermal fluid-rock interactions throughout ore deposit formation. Quantifiably defining alteration domains provides a reproducible, rapid and non-destructive method that can be deployed in a wide variety of settings, leading to the consistent separation of domains which can be used as a superior proxy for ore distribution and grade.
2023-11-28T00:00:00Z
Dixon, Oliver James
Porphyry copper deposits form from upper crustal H₂O saturated magmatic systems, along ancient and active convergent margins. As the world’s major source of copper, gold and molybdenum, along with minor quantities of other base and precious metals, they are an increasingly important source of raw material, essential to the ongoing clean energy transition and in hitting key targets set by global societies today. Driven by the transition to renewable energy sources and electric vehicles, dependent on substantial quantities of iron ore, copper and aluminium, it has been estimated that the demand for copper alone will increase by over 20 times. With current reserves not expected to meet future demand, extensive additional exploration is anticipated. Furthermore, with the depletion of near-surface deposits in mature exploration terranes, there is a clear need for the development of new techniques to identify and unearth deeply buried reserves. Exploration programs rely on many techniques for the identification of the large, distal alteration systems associated with porphyry style mineralisation, which currently focus on pathfinding geochemical indicators. Alongside these techniques, infrared spectroscopy and magnetic susceptibility data is often collected but underutilised, despite providing a rapid and low-cost source of mineralogical information.
Using samples collected form the Aktogay porphyry Cu deposit in the Central Asian Orogenic Belt, an extensive Palaeozoic subduction-accretion complex, the ability of magnetic and infrared spectroscopy to quantifiably define and characterise alteration, when used in conjunction with a specifically developed, unsupervised deep learning algorithm, has been examined. Our findings demonstrate that the resulting subdivision around porphyry mineralisation into twelve discrete domains, can uniquely identify otherwise hidden mineral assemblages. Through examining the consistency of key parameters within each domain such as ore grade and geochemical signatures, their statistical significance has been tested, indicating an increased consistency of between 60 and 70% when compared to traditional alteration zones classified by on-site mining geologists. In addition, detailed petrological and magnetic characterisation independently confirms the validity of the newly defined alteration domains, whilst also demonstrating the importance of magnetic characterisation as a new tool, which can improve our understanding and partial quantification of the magnetic effects during hydrothermal fluid-rock interactions throughout ore deposit formation. Quantifiably defining alteration domains provides a reproducible, rapid and non-destructive method that can be deployed in a wide variety of settings, leading to the consistent separation of domains which can be used as a superior proxy for ore distribution and grade.
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Patterns and timing of Holocene environmental change and carbon accumulation at Bankhead Moss, Scotland
https://hdl.handle.net/10023/28485
Abstract redacted
2023-11-28T00:00:00Z
Wang, Li
Abstract redacted
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Legislation, governance, and ecology of aguaje palm fruit harvest in lowland Peruvian Amazonia
https://hdl.handle.net/10023/28483
Abstract redacted
2023-11-28T00:00:00Z
Macphie, Anna Jane
Abstract redacted
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Investigating calving dynamics through the development of a new 3D full-Stokes calving model and its application at Jakobshavn Isbrae, West Greenland
https://hdl.handle.net/10023/28390
A new calving algorithm was developed in the finite element model Elmer/Ice that allows unrestricted calving and terminus advance in 3D. The algorithm used the meshing software Mmg to implement anisotropic remeshing and allow for adaptive meshing at each timestep. The development of the algorithm along with the implementation of the crevasse depth calving law produced a new full-Stokes calving model in Elmer/Ice that is laid out in detail in Chapter 4. The new model is shown to be robust and capable of simulating calving across an array of complex geometries. Using a synthetic geometry, the model is applied in Chapter 5 to test a comprehensive list of variables that affect calving dynamics. The simulations show that calving dynamics are predominately altered by fjord or bed geometry, but other factors such as lateral friction or temperature can also alter the simulated calving. Other non-physical model parameters such as mesh resolution or timestep are also shown to have a large impact on modelled calving. Finally, in Chapter 6, the calving model is applied at Jakobshavn Isbrae (Sermeq Kujalleq), Greenland’s largest glacier. This is the first time that the calving dynamics at Jakobshavn Isbrae have been modelled in 3D. This has been a challenge previously due to the large outlet glacier’s dynamic nature. The model is shown to be robust and capable of simulating the calving, but the prediction of calving is underestimated. The crevasse penetration requirement of the crevasse depth calving law needed to be optimised in order for simulations to match observations of advance and retreat, with the optimal crevasse penetration requirement being 94.5\%. Ice-melange back stress was key to winter readvancement and essential for the model to match observations. However, the ultimate position of the terminus was determined by the geometry at the glacier bed. Importantly, this showed a large step forward in modelling capabilities, where unrestricted 3D calving was modelled at a large dynamic tidewater glacier in a continuum. This work is vital to improving our understanding of calving dynamics at tidewater glaciers and therefore enabling calving to be better constrained in future climate projections.
2023-11-28T00:00:00Z
Wheel, Iain
A new calving algorithm was developed in the finite element model Elmer/Ice that allows unrestricted calving and terminus advance in 3D. The algorithm used the meshing software Mmg to implement anisotropic remeshing and allow for adaptive meshing at each timestep. The development of the algorithm along with the implementation of the crevasse depth calving law produced a new full-Stokes calving model in Elmer/Ice that is laid out in detail in Chapter 4. The new model is shown to be robust and capable of simulating calving across an array of complex geometries. Using a synthetic geometry, the model is applied in Chapter 5 to test a comprehensive list of variables that affect calving dynamics. The simulations show that calving dynamics are predominately altered by fjord or bed geometry, but other factors such as lateral friction or temperature can also alter the simulated calving. Other non-physical model parameters such as mesh resolution or timestep are also shown to have a large impact on modelled calving. Finally, in Chapter 6, the calving model is applied at Jakobshavn Isbrae (Sermeq Kujalleq), Greenland’s largest glacier. This is the first time that the calving dynamics at Jakobshavn Isbrae have been modelled in 3D. This has been a challenge previously due to the large outlet glacier’s dynamic nature. The model is shown to be robust and capable of simulating the calving, but the prediction of calving is underestimated. The crevasse penetration requirement of the crevasse depth calving law needed to be optimised in order for simulations to match observations of advance and retreat, with the optimal crevasse penetration requirement being 94.5\%. Ice-melange back stress was key to winter readvancement and essential for the model to match observations. However, the ultimate position of the terminus was determined by the geometry at the glacier bed. Importantly, this showed a large step forward in modelling capabilities, where unrestricted 3D calving was modelled at a large dynamic tidewater glacier in a continuum. This work is vital to improving our understanding of calving dynamics at tidewater glaciers and therefore enabling calving to be better constrained in future climate projections.
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A thermodynamic modelling approach to predict the outcome of carbonaceous fluid metasomatism on Earth and Mars
https://hdl.handle.net/10023/28234
The carbon flux between the atmosphere and the geosphere is linked by a broad range of geodynamic and magmatic processes which govern the deep carbon cycles on all telluric planets, asteroids, and moons. On Earth, carbon is introduced into the mantle by subduction. On Mars, deep carbon is mobilised by magmatism and mantle convection, with delamination the only likely mechanism to recycle crustal carbon. The mobilisation and transportation of phases across P-T-X gradients result in the destabilisation of carbon-bearing and hydrated minerals leading to the formation of melts and fluids. Both act as mass-transfer agents, mobilising and transferring carbon. The interaction of fluids and magmas with surrounding rocks results in metasomatism. The role of carbon-rich fluids in the formation of metasomatic minerals and methane reservoirs on Earth and Mars has been studied via thermodynamic modelling. Here I present the results of predictive simulations to express the evolution of metasomatic systems at different P-T-fO₂ conditions.
This study finds that the traditional distinction of diamonds through paragenetic groups cannot be used as a genetic classification because fluid-rock metasomatism can produce the compositional range of garnet and clinopyroxene found as inclusions in diamonds. The amount of carbon in the system – and its speciation – controls the geochemistry of metasomatic silicates, highlighting how carbon is even more influential than previously thought. Furthermore, fluid metasomatism can convert depleted mantle rocks into fertile websterites without championing a mechanism involving partial melting. Fluids have all the rock-forming elements to precipitate anhydrous silicates, and the presence or absence of hydrated minerals is no reliable evidence to distinguish melt and fluid metasomatism. Finally, the reduced conditions of Mars favour the formation of methane, which can be stored in geological reservoirs and then transported to the surface, sustaining the CH₄-based greenhouse required for liquid water on the surface of Early Mars.
2023-11-28T00:00:00Z
Rinaldi, Michele
The carbon flux between the atmosphere and the geosphere is linked by a broad range of geodynamic and magmatic processes which govern the deep carbon cycles on all telluric planets, asteroids, and moons. On Earth, carbon is introduced into the mantle by subduction. On Mars, deep carbon is mobilised by magmatism and mantle convection, with delamination the only likely mechanism to recycle crustal carbon. The mobilisation and transportation of phases across P-T-X gradients result in the destabilisation of carbon-bearing and hydrated minerals leading to the formation of melts and fluids. Both act as mass-transfer agents, mobilising and transferring carbon. The interaction of fluids and magmas with surrounding rocks results in metasomatism. The role of carbon-rich fluids in the formation of metasomatic minerals and methane reservoirs on Earth and Mars has been studied via thermodynamic modelling. Here I present the results of predictive simulations to express the evolution of metasomatic systems at different P-T-fO₂ conditions.
This study finds that the traditional distinction of diamonds through paragenetic groups cannot be used as a genetic classification because fluid-rock metasomatism can produce the compositional range of garnet and clinopyroxene found as inclusions in diamonds. The amount of carbon in the system – and its speciation – controls the geochemistry of metasomatic silicates, highlighting how carbon is even more influential than previously thought. Furthermore, fluid metasomatism can convert depleted mantle rocks into fertile websterites without championing a mechanism involving partial melting. Fluids have all the rock-forming elements to precipitate anhydrous silicates, and the presence or absence of hydrated minerals is no reliable evidence to distinguish melt and fluid metasomatism. Finally, the reduced conditions of Mars favour the formation of methane, which can be stored in geological reservoirs and then transported to the surface, sustaining the CH₄-based greenhouse required for liquid water on the surface of Early Mars.
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New investigations of monsoon depressions using observational data, theory and numerical experiments
https://hdl.handle.net/10023/28207
Monsoon depressions (MDs) are synoptic-scale storms that exist embedded within the planetary-scale summer monsoon circulation.
Their structure and propagation is distinct to other tropical and sub-tropical systems. The last five years have seen particular advances in the understanding of the atmospheric dynamics and growth mechanisms of MDs. This thesis builds upon this recent literature, and then covers the development and results of new analyses of atmospheric reanalysis data and a series of idealised modelling experiments that have been conducted to gain new understanding and insight into MDs.
This work is introduced with a discussion of the global monsoon focusing on the particular background conditions during the South Asian Summer Monsoon that support a high-frequency of MDs. A tracking algorithm for low-pressure events is developed and used to construct composite South Asian MDs in high-resolution ERA5 data. A sensitivity of faster westward MD propagation to the mid-tropospheric meridional temperature gradient is identified.
Such insights then motivate the development of a new idealised moist-thermal quasi-geostrophic (QG) model as a dynamical toolbox to understand the fundamental dynamics of MDs. Linear-modes of this QG model demonstrate a sensitivity to background temperature and precipitation gradients, but fail to organise precipitation and dynamics in a manner similar to that of observed MDs.
A variety of experiments, with large-amplitude MD-analogues, are shown to capture MD-like propagation and sensitivity to background temperature gradients by diabatic-barotropic processes and thermally-modulated beta-drift.
Finally, a set of numerical experiments are conducted in an idealised general circulation model using a series of idealised surface configurations. Results of these experiments demonstrate an idealised configuration that captures South Asian monsoon and MD-like variability, and provide insights into the relationship between MDs and meridional temperature gradients.
2023-11-28T00:00:00Z
Chaudhri, Alexander Karim
Monsoon depressions (MDs) are synoptic-scale storms that exist embedded within the planetary-scale summer monsoon circulation.
Their structure and propagation is distinct to other tropical and sub-tropical systems. The last five years have seen particular advances in the understanding of the atmospheric dynamics and growth mechanisms of MDs. This thesis builds upon this recent literature, and then covers the development and results of new analyses of atmospheric reanalysis data and a series of idealised modelling experiments that have been conducted to gain new understanding and insight into MDs.
This work is introduced with a discussion of the global monsoon focusing on the particular background conditions during the South Asian Summer Monsoon that support a high-frequency of MDs. A tracking algorithm for low-pressure events is developed and used to construct composite South Asian MDs in high-resolution ERA5 data. A sensitivity of faster westward MD propagation to the mid-tropospheric meridional temperature gradient is identified.
Such insights then motivate the development of a new idealised moist-thermal quasi-geostrophic (QG) model as a dynamical toolbox to understand the fundamental dynamics of MDs. Linear-modes of this QG model demonstrate a sensitivity to background temperature and precipitation gradients, but fail to organise precipitation and dynamics in a manner similar to that of observed MDs.
A variety of experiments, with large-amplitude MD-analogues, are shown to capture MD-like propagation and sensitivity to background temperature gradients by diabatic-barotropic processes and thermally-modulated beta-drift.
Finally, a set of numerical experiments are conducted in an idealised general circulation model using a series of idealised surface configurations. Results of these experiments demonstrate an idealised configuration that captures South Asian monsoon and MD-like variability, and provide insights into the relationship between MDs and meridional temperature gradients.
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Title redacted
https://hdl.handle.net/10023/28101
Abstract redacted
2023-11-28T00:00:00Z
Fitzpatrick, Robbie David John
Abstract redacted
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Managing urban deer in Scotland : understanding perceptions to shape policymaking
https://hdl.handle.net/10023/28100
Rising populations of deer in Scottish urban areas are creating increased potential for conflict, raising questions about whether they need to be managed. Yet, there has been little research or policy focus on urban deer in Scotland thus far. This thesis investigates perceptions of urban deer and their management in Scotland, including the role of Local Authorities, to help shape future policymaking on the topic. Four methods were used: (i) interviews with experts, (ii) a Q-methodology study with Local Authority staff, (iii) an online survey of local councillors and (iv) a postal survey of the public. Whilst urban deer are generally welcomed in Scotland, views on whether deer numbers are too high differed between stakeholders. Perceptions of the impacts of urban deer were also varied, but deer- vehicle collisions and deer welfare were the issues recognised most frequently. There was broad consensus that urban deer need to be managed. However, current practices are perceived to be insufficient, with NatureScot and Local Authorities having paid limited attention to urban deer thus far. Views differ on which management methods should be used in the Scottish urban context. Clear differences between rural and urban deer management emerged, with fragmented landholdings (such as in dense housing areas) and higher human populations adding challenges to management. There is overall support for Local Authorities taking responsibility for urban deer management on their own land and beyond their landownership. Obstacles to their engagement include concerns about public and councillor perceptions, safety, and a lack of resources, experience and support. Three factors impacting effective urban deer management in Scotland are recognised: the need for context specific understandings and responses, the need for awareness-raising amongst stakeholders to gain support and increase action, and the need to fill gaps in data and research. A policy framework for future effective urban deer management in Scotland is proposed.
2023-11-28T00:00:00Z
Whitefield, Abigail Claire Ella
Rising populations of deer in Scottish urban areas are creating increased potential for conflict, raising questions about whether they need to be managed. Yet, there has been little research or policy focus on urban deer in Scotland thus far. This thesis investigates perceptions of urban deer and their management in Scotland, including the role of Local Authorities, to help shape future policymaking on the topic. Four methods were used: (i) interviews with experts, (ii) a Q-methodology study with Local Authority staff, (iii) an online survey of local councillors and (iv) a postal survey of the public. Whilst urban deer are generally welcomed in Scotland, views on whether deer numbers are too high differed between stakeholders. Perceptions of the impacts of urban deer were also varied, but deer- vehicle collisions and deer welfare were the issues recognised most frequently. There was broad consensus that urban deer need to be managed. However, current practices are perceived to be insufficient, with NatureScot and Local Authorities having paid limited attention to urban deer thus far. Views differ on which management methods should be used in the Scottish urban context. Clear differences between rural and urban deer management emerged, with fragmented landholdings (such as in dense housing areas) and higher human populations adding challenges to management. There is overall support for Local Authorities taking responsibility for urban deer management on their own land and beyond their landownership. Obstacles to their engagement include concerns about public and councillor perceptions, safety, and a lack of resources, experience and support. Three factors impacting effective urban deer management in Scotland are recognised: the need for context specific understandings and responses, the need for awareness-raising amongst stakeholders to gain support and increase action, and the need to fill gaps in data and research. A policy framework for future effective urban deer management in Scotland is proposed.
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Seeing the wood for the trees. Rethinking 700 years of vegetation change in Iceland using meta-analysis of palaeoecological datasets and landscape scale model reconstructions
https://hdl.handle.net/10023/28083
The colonisation of Iceland around 870 A.D. saw the influx of Norse settlers to a previously uninhabited island, resulting in large-scale ecological changes. Human impacts on the landscape vary in time and are spatially complex, making it difficult to accurately assess how Iceland was affected.
To improve our knowledge about the spatial and temporal patterns of landscape changes in Iceland, this thesis uses quantitative approaches to analyse existing palaeoenvironmental data from Iceland. A meta-analysis was used to determine the spatial bias in and the temporal quality of Icelandic pollen sites. Relative pollen productivity (RPP) estimates are calculated for seven ecologically important taxa, by analysing pollen-vegetation relationships at eighteen sites. The RPPs serve as input for quantitative pollen-based reconstruction models, the Multiple Scenario Approach. Landscape reconstructions totalling 3825 km² were generated for three sites (Mývatn, Reykholtsdalur, and Skálholt) and three time slices (577-877 CE, 877-1077 CE, and 1077-1277 CE).
The analysis of spatial bias shows that pollen sites in Iceland are closer to farms and have a higher annual mean temperature and precipitation than a sample of random sites. The RPPs of Icelandic taxa are lower than RPPs in comparable areas. Different spatial patterns in vegetation cover emerge from the reconstruction model outputs, Mývatn remains wooded throughout the time slices, while Reykholtsdalur becomes mostly deforested from 1077 CE onwards.
The spatial analysis shows the need for thorough analysis of the representativeness of current palynological datasets, which helps identify where future sampling should take place to create more representative datasets. The characterisation of pollen-vegetation relationships shows that there is much more to be understood about the mechanics behind differences in RPP estimates in different
locations. Quantitative reconstruction methods provide a useful tool for gaining insight into differences in land cover changes in Iceland, and to visualise different spatial patterns in the landscape.
2023-11-28T00:00:00Z
Koster, Willem Wilmer
The colonisation of Iceland around 870 A.D. saw the influx of Norse settlers to a previously uninhabited island, resulting in large-scale ecological changes. Human impacts on the landscape vary in time and are spatially complex, making it difficult to accurately assess how Iceland was affected.
To improve our knowledge about the spatial and temporal patterns of landscape changes in Iceland, this thesis uses quantitative approaches to analyse existing palaeoenvironmental data from Iceland. A meta-analysis was used to determine the spatial bias in and the temporal quality of Icelandic pollen sites. Relative pollen productivity (RPP) estimates are calculated for seven ecologically important taxa, by analysing pollen-vegetation relationships at eighteen sites. The RPPs serve as input for quantitative pollen-based reconstruction models, the Multiple Scenario Approach. Landscape reconstructions totalling 3825 km² were generated for three sites (Mývatn, Reykholtsdalur, and Skálholt) and three time slices (577-877 CE, 877-1077 CE, and 1077-1277 CE).
The analysis of spatial bias shows that pollen sites in Iceland are closer to farms and have a higher annual mean temperature and precipitation than a sample of random sites. The RPPs of Icelandic taxa are lower than RPPs in comparable areas. Different spatial patterns in vegetation cover emerge from the reconstruction model outputs, Mývatn remains wooded throughout the time slices, while Reykholtsdalur becomes mostly deforested from 1077 CE onwards.
The spatial analysis shows the need for thorough analysis of the representativeness of current palynological datasets, which helps identify where future sampling should take place to create more representative datasets. The characterisation of pollen-vegetation relationships shows that there is much more to be understood about the mechanics behind differences in RPP estimates in different
locations. Quantitative reconstruction methods provide a useful tool for gaining insight into differences in land cover changes in Iceland, and to visualise different spatial patterns in the landscape.
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A study of the population burden of cognitive impairment in the US
https://hdl.handle.net/10023/27899
This doctoral thesis investigates novel facets of cognitive health dynamics in the older US population. Prior research on partnership status and cognitive impairment has mainly focused on their association. No study has examined the burden of cognitive impairment without a partner, with partners being an essential source of caregiving, social support, and successful aging. Cognitive impairment often coexists with disability in activities of daily living. However, their cooccurrence (termed coimpairment), a highly disadvantageous health condition, has received less attention in population health research. Furthermore, the absence of a cure for cognitive impairment underscores the importance of identifying its modifiable risk factors. Using advanced multistate models and the longitudinal Health and Retirement Study, this thesis first shows that Blacks, Latinx, and lower-educated have longer expectancies in one of the most expensive health conditions, cognitive impairment, while being unpartnered. Second, these subgroups experience greater lifetime risk of, earlier onset of, and longer expectancy in coimpairment. Counterfactual exercises reveal that educational inequalities play an important role in these disparities. Third, the study shows that loneliness is an important modifiable risk factor for cognitive function and that the association is partially mediated by depression. This PhD thesis significantly advances our understanding of the socio-demographic inequalities in the burden of cognitive impairment in the US.
2023-11-28T00:00:00Z
Sharma, Shubhankar
This doctoral thesis investigates novel facets of cognitive health dynamics in the older US population. Prior research on partnership status and cognitive impairment has mainly focused on their association. No study has examined the burden of cognitive impairment without a partner, with partners being an essential source of caregiving, social support, and successful aging. Cognitive impairment often coexists with disability in activities of daily living. However, their cooccurrence (termed coimpairment), a highly disadvantageous health condition, has received less attention in population health research. Furthermore, the absence of a cure for cognitive impairment underscores the importance of identifying its modifiable risk factors. Using advanced multistate models and the longitudinal Health and Retirement Study, this thesis first shows that Blacks, Latinx, and lower-educated have longer expectancies in one of the most expensive health conditions, cognitive impairment, while being unpartnered. Second, these subgroups experience greater lifetime risk of, earlier onset of, and longer expectancy in coimpairment. Counterfactual exercises reveal that educational inequalities play an important role in these disparities. Third, the study shows that loneliness is an important modifiable risk factor for cognitive function and that the association is partially mediated by depression. This PhD thesis significantly advances our understanding of the socio-demographic inequalities in the burden of cognitive impairment in the US.
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Ageing in an increasingly smart world : an ethnography of ageing at home with smart and assistive devices
https://hdl.handle.net/10023/27765
With increasing desires to live at home for longer and have more control of one's healthcare, coupled with rises in smart technology use and affordability, the drive for healthcare smart homes (HSH) from certain policymakers and technologists, particularly in rural communities, has heightened. These digitalised homes aim to enable older people to live independently at home for longer and potentially improve their wellbeing through the use of smart and assistive technologies. Much of the existing literature on the impacts of HSH living is from: healthcare or technocentric domains; shorter term or 'laboratory' settings with individual residents rather than more in-depth research including the wider networks. Furthermore, there is increasing development of DIY versions of HSH (i.e. portable smart and assistive devices gathered by the resident and their wider caring networks to be used in their homes, rather than a tailor-made HSH). Thus, in this thesis I use multiple ethnographic methods (visual, traditional and autoethnographic methods) to explore the longer-term experiences of five older people, and their wider caring networks, living within DIY HSH. I draw on theories and concepts relating to bricolage, dramaturgy, and simulations to explore the experiences of a sense of home, identity formation and future planning within DIY HSH living. I argue there are multiple (and potentially competing) experiences of DIY HSH living concerning sense of home, identity and envisioning the future. This range of experiences is connected to various levels and types of access to devices and technical support (what I term 'vertical noir hierarchies'), and the experiences and motivations of the wider caring networks. Ultimately, through use of multi-modal ethnographic methods and a new conceptual framework, I highlight that a singular experience of DIY HSH living is impossible. This is illustrated through understanding the (often conflicting) experiences of both older DIY HSH residents and their wider caring networks, and their types and levels of access to DIY HSH devices.
2022-06-15T00:00:00Z
Creaney, Rachel
With increasing desires to live at home for longer and have more control of one's healthcare, coupled with rises in smart technology use and affordability, the drive for healthcare smart homes (HSH) from certain policymakers and technologists, particularly in rural communities, has heightened. These digitalised homes aim to enable older people to live independently at home for longer and potentially improve their wellbeing through the use of smart and assistive technologies. Much of the existing literature on the impacts of HSH living is from: healthcare or technocentric domains; shorter term or 'laboratory' settings with individual residents rather than more in-depth research including the wider networks. Furthermore, there is increasing development of DIY versions of HSH (i.e. portable smart and assistive devices gathered by the resident and their wider caring networks to be used in their homes, rather than a tailor-made HSH). Thus, in this thesis I use multiple ethnographic methods (visual, traditional and autoethnographic methods) to explore the longer-term experiences of five older people, and their wider caring networks, living within DIY HSH. I draw on theories and concepts relating to bricolage, dramaturgy, and simulations to explore the experiences of a sense of home, identity formation and future planning within DIY HSH living. I argue there are multiple (and potentially competing) experiences of DIY HSH living concerning sense of home, identity and envisioning the future. This range of experiences is connected to various levels and types of access to devices and technical support (what I term 'vertical noir hierarchies'), and the experiences and motivations of the wider caring networks. Ultimately, through use of multi-modal ethnographic methods and a new conceptual framework, I highlight that a singular experience of DIY HSH living is impossible. This is illustrated through understanding the (often conflicting) experiences of both older DIY HSH residents and their wider caring networks, and their types and levels of access to DIY HSH devices.
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Seismic prospection for oil in Poland
https://hdl.handle.net/10023/27756
The paper consists of three parts: The first part deals in general with seismic prospection concerning refraction work in Poland, which owing to an almost lack of publications is mainly descriptive. The second and third parts deal with the reflection survey. The instruments used, and the field methods applied, the theory of the distribution of seismic energy, with its practical application and results, are discussed in the second part. The third part gives the description and analyses of the results of the prospection in the Carpathians and in the Foreland, based on the documentary data available. In some areas of the Foreland, the results of the reflection surveys appeared to be unreliable. The writer points out the possible importance of these areas from the point of view of oil accumulations, and shows the way in which the reflection method could be applied to the structural problems in zones where the reflections were unsatisfactory for correlation, and where true dips could not be determined by the dip-shooting method alone.
1945-01-01T00:00:00Z
Wyrobek, Stanislaw M.
The paper consists of three parts: The first part deals in general with seismic prospection concerning refraction work in Poland, which owing to an almost lack of publications is mainly descriptive. The second and third parts deal with the reflection survey. The instruments used, and the field methods applied, the theory of the distribution of seismic energy, with its practical application and results, are discussed in the second part. The third part gives the description and analyses of the results of the prospection in the Carpathians and in the Foreland, based on the documentary data available. In some areas of the Foreland, the results of the reflection surveys appeared to be unreliable. The writer points out the possible importance of these areas from the point of view of oil accumulations, and shows the way in which the reflection method could be applied to the structural problems in zones where the reflections were unsatisfactory for correlation, and where true dips could not be determined by the dip-shooting method alone.
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The nature of fluids associated with the subvolcanic alkaline magmas and their role in 'hi-tech' metal transport and mineralization
https://hdl.handle.net/10023/27744
Alkaline igneous rocks host many High Field Strength (HFSE) and Rare Earth Element (REE) deposits, which are key for the global low-carbon energy transition. To better target these, a better understanding of alteration associated with silicate-related ore deposits is required. Fluid-rock interaction around syenite forms altered haloes (’fenite’), normally uneconomic, but hosting many of the normally immobile HFSE expelled from the magmatic hearth. The fluid parameters which control the transport and deposition of these elements in the crust, their composition and the element speciation within need to be better constrained.
Here a field study of an exceptionally exposed fenite (Gardar Province, SW Greenland) was followed by major and trace element, and stable isotope (O-H-S) analyses of whole rocks and minerals, and the investigation of fluid inclusion assemblages. The field data show the volcano-sedimentary wall-rocks to the west of Illerfissalik centre were altered by the ejection of metasomatic fluids. Fenitized sediment comprises a skarn-like (garnet-absent) calc-silicate assemblage developed interstitially, often along relict structures, later subjected to short-lived Na– Fe(III) –Ti alteration. Using oxygen isotope equilibria, the temperature of the causal fluid was estimated at ~750°C suggesting a magmatic origin. The differences in O, H and S isotopic data also indicate the system underwent fluid-driven exchange with the country rocks, potentially mixing with externally derived meteoric water. Elements including Ti, Zr, Nb and REE are mobile during alteration, but they precipitate as silicates and phosphates mainly in the late-stage in the basement granite, while rare chevkinite and titanite host much of the early-stage HFSE in the Eriksfjord. An estimated total REE-oxide cargo mobilized from Illerfissalik (~43 Mt) rivals the tonnages of many major ore deposits (i.e. Kringlerne, Ilímaussaq) and underscores how critical fenitization is as a tipping point during evolution of fertile magmas in the upper crust.
2023-06-16T00:00:00Z
Sokol, Krzysztof
Alkaline igneous rocks host many High Field Strength (HFSE) and Rare Earth Element (REE) deposits, which are key for the global low-carbon energy transition. To better target these, a better understanding of alteration associated with silicate-related ore deposits is required. Fluid-rock interaction around syenite forms altered haloes (’fenite’), normally uneconomic, but hosting many of the normally immobile HFSE expelled from the magmatic hearth. The fluid parameters which control the transport and deposition of these elements in the crust, their composition and the element speciation within need to be better constrained.
Here a field study of an exceptionally exposed fenite (Gardar Province, SW Greenland) was followed by major and trace element, and stable isotope (O-H-S) analyses of whole rocks and minerals, and the investigation of fluid inclusion assemblages. The field data show the volcano-sedimentary wall-rocks to the west of Illerfissalik centre were altered by the ejection of metasomatic fluids. Fenitized sediment comprises a skarn-like (garnet-absent) calc-silicate assemblage developed interstitially, often along relict structures, later subjected to short-lived Na– Fe(III) –Ti alteration. Using oxygen isotope equilibria, the temperature of the causal fluid was estimated at ~750°C suggesting a magmatic origin. The differences in O, H and S isotopic data also indicate the system underwent fluid-driven exchange with the country rocks, potentially mixing with externally derived meteoric water. Elements including Ti, Zr, Nb and REE are mobile during alteration, but they precipitate as silicates and phosphates mainly in the late-stage in the basement granite, while rare chevkinite and titanite host much of the early-stage HFSE in the Eriksfjord. An estimated total REE-oxide cargo mobilized from Illerfissalik (~43 Mt) rivals the tonnages of many major ore deposits (i.e. Kringlerne, Ilímaussaq) and underscores how critical fenitization is as a tipping point during evolution of fertile magmas in the upper crust.
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Governing the High Seas : effective institutional arrangements for the conservation and sustainable use of marine biodiversity beyond national jurisdiction.
https://hdl.handle.net/10023/27658
Forming almost two-thirds of the global ocean, the High Seas and seabed areas beyond national jurisdiction (ABNJ) support some of the highest levels of biodiversity on the planet. However, these vital areas are increasingly under threat from human and climate change-induced pressures. The current governance regime related to the conservation of marine biodiversity beyond national jurisdiction (BBNJ) is fragmented (in terms of institutional mandates, powers and resources) and characterised by significant gaps (in terms of species and geographical coverage).
In response, the United Nations has negotiated an internationally legally binding instrument (ILBI) to protect the High Seas. A key aspect of the draft agreement is that that new instrument should “not undermine” existing bodies, instruments and frameworks, which raises key questions relating to interplay between the new ILBI and existing bodies.
My research seeks to understand how the agreement can be effectively operationalised by analysing two related strands:
(1) The need for the agreement to be effectively implemented by existing institutions, and
(2) Due to the migratory nature of BBNJ and governance gaps, the need for existing institutions to work together effectively.
I argue under (1) that four candidate conditions are likely to be important for implementation and deploy Qualitative Comparative Analysis (QCA) to identify one condition necessary for successful implementation (multi-party coordination) and three conditions (access to/management of data, multi-party coordination and adaptive management) which are sufficient to lead to a successful outcome.
Under (2) a case study of the Northern Atlantic institutional regime is used to characterise and help explain the forces and factors influencing institutional interplay.
Taken together, the two parts to the research generate insights into effective institutional arrangements for the future governance of BBNJ.
2023-06-14T00:00:00Z
Luger, James
Forming almost two-thirds of the global ocean, the High Seas and seabed areas beyond national jurisdiction (ABNJ) support some of the highest levels of biodiversity on the planet. However, these vital areas are increasingly under threat from human and climate change-induced pressures. The current governance regime related to the conservation of marine biodiversity beyond national jurisdiction (BBNJ) is fragmented (in terms of institutional mandates, powers and resources) and characterised by significant gaps (in terms of species and geographical coverage).
In response, the United Nations has negotiated an internationally legally binding instrument (ILBI) to protect the High Seas. A key aspect of the draft agreement is that that new instrument should “not undermine” existing bodies, instruments and frameworks, which raises key questions relating to interplay between the new ILBI and existing bodies.
My research seeks to understand how the agreement can be effectively operationalised by analysing two related strands:
(1) The need for the agreement to be effectively implemented by existing institutions, and
(2) Due to the migratory nature of BBNJ and governance gaps, the need for existing institutions to work together effectively.
I argue under (1) that four candidate conditions are likely to be important for implementation and deploy Qualitative Comparative Analysis (QCA) to identify one condition necessary for successful implementation (multi-party coordination) and three conditions (access to/management of data, multi-party coordination and adaptive management) which are sufficient to lead to a successful outcome.
Under (2) a case study of the Northern Atlantic institutional regime is used to characterise and help explain the forces and factors influencing institutional interplay.
Taken together, the two parts to the research generate insights into effective institutional arrangements for the future governance of BBNJ.
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An interdisciplinary study on Scottish saltmarsh blue carbon : data uncertainty and values in policy design
https://hdl.handle.net/10023/27576
The potential of saltmarshes to store carbon has recently been gaining increasing interest in the Scottish policy arena, particularly in the face of the recently declared climate emergency. Yet, while there are first estimates of saltmarshes’ overall carbon storage capacity, there is still significant uncertainty concerning the average soil depth of Scottish saltmarshes, and thus their total organic carbon stock. Moreover, other aspects, such as the value of the carbon storage ecosystem service and how it could be incorporated into Scottish policy, are under-researched. This thesis therefore takes a holistic and interdisciplinary approach connecting natural science, economics, and social science to investigate the potential of Scottish saltmarshes for climate change mitigation. A scenario approach is used to analyse the potential organic carbon stocks according to different average saltmarsh depths to reduce the uncertainty regarding the total Scottish saltmarsh stocks. A choice experiment was then conducted to investigate the Scottish public’s preferences and willingness to pay for the improvement of saltmarsh ecosystem services, particularly the carbon storage service. Furthermore, the experiment tests the significance of the influence of information provision on individuals’ preferences and willingness to pay. Lastly, this thesis presents an in-depth study on blue carbon policy integration based on expert-interviews to close the link between science and policy. This work suggests that even though climate change is a pressing issue, Scottish saltmarsh climate change mitigation contributions are comparatively minor and that other saltmarsh ecosystem services must not be disregarded to facilitate a prioritisation of the carbon storage service. In terms of policy integration, this means that it may be beneficial to integrate saltmarshes and their carbon storage service into the Scottish Marine Spatial Planning framework rather than climate change mitigation policy specifically.
2023-06-14T00:00:00Z
Riegel, Simone
The potential of saltmarshes to store carbon has recently been gaining increasing interest in the Scottish policy arena, particularly in the face of the recently declared climate emergency. Yet, while there are first estimates of saltmarshes’ overall carbon storage capacity, there is still significant uncertainty concerning the average soil depth of Scottish saltmarshes, and thus their total organic carbon stock. Moreover, other aspects, such as the value of the carbon storage ecosystem service and how it could be incorporated into Scottish policy, are under-researched. This thesis therefore takes a holistic and interdisciplinary approach connecting natural science, economics, and social science to investigate the potential of Scottish saltmarshes for climate change mitigation. A scenario approach is used to analyse the potential organic carbon stocks according to different average saltmarsh depths to reduce the uncertainty regarding the total Scottish saltmarsh stocks. A choice experiment was then conducted to investigate the Scottish public’s preferences and willingness to pay for the improvement of saltmarsh ecosystem services, particularly the carbon storage service. Furthermore, the experiment tests the significance of the influence of information provision on individuals’ preferences and willingness to pay. Lastly, this thesis presents an in-depth study on blue carbon policy integration based on expert-interviews to close the link between science and policy. This work suggests that even though climate change is a pressing issue, Scottish saltmarsh climate change mitigation contributions are comparatively minor and that other saltmarsh ecosystem services must not be disregarded to facilitate a prioritisation of the carbon storage service. In terms of policy integration, this means that it may be beneficial to integrate saltmarshes and their carbon storage service into the Scottish Marine Spatial Planning framework rather than climate change mitigation policy specifically.
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Fire and ice : understanding volcanic histories from sulfur isotopes in ice cores
https://hdl.handle.net/10023/27568
Reconstructing the history of explosive volcanic eruptions is important for understanding the frequency of eruptions and the climatic forcing of these events. Erupted volcanic SO₂ is oxidised to sulfate aerosols which scatter incoming solar radiation. Aerosols are then deposited at the poles resulting in a peak in sulfate above background concentrations. Therefore, polar ice cores provide an important record of volcanism. The mass-independent fractionation of sulfur isotopes (S-MIF) in ice cores is an indicator of sulfur exposure to ultraviolet radiation via eruption into and above the ozone layer in the stratosphere. Sulfate aerosols from large eruptions that reach the stratosphere have a longer residence time and greater climatic impact than tropospheric aerosols from smaller eruptions. In this thesis I measure sulfur isotopes in volcanic ice core sulfate to investigate the ~74ka Toba supereruption and six unidentified volcanic eruptions from 16ka to 32ka. I found large magnitude S-MIF signals (-4.75‰) for one of the Toba candidates, the timing of which is consistent with independent age estimates for Toba. This places the eruption on the transition into a cool stadial period in Greenland (GS-20). Toba can be excluded as a potential trigger for GS-20, although it could have contributed to the cooling. To help interpret the six eruptions from 16–32ka, I adapted a 1D-diffusion model to simulate the diffusion and thinning of sulfate isotopes in ice cores. I found that the ice core sulfate isotope signatures are consistent with modelled results of sulfate exposed to diffusion and thinning. Finally, I adapted a 1D-photochemical model (Atmos) to model the temporal evolution of sulfur isotope signatures in a volcanic plume. The model predicts S-MIF signatures consistent in timing and shape to those measured in the ice cores for stratospheric eruptions with S-MIF formation primarily via self-shielding due to high SO₂ column densities.
2023-06-16T00:00:00Z
Crick, Laura
Reconstructing the history of explosive volcanic eruptions is important for understanding the frequency of eruptions and the climatic forcing of these events. Erupted volcanic SO₂ is oxidised to sulfate aerosols which scatter incoming solar radiation. Aerosols are then deposited at the poles resulting in a peak in sulfate above background concentrations. Therefore, polar ice cores provide an important record of volcanism. The mass-independent fractionation of sulfur isotopes (S-MIF) in ice cores is an indicator of sulfur exposure to ultraviolet radiation via eruption into and above the ozone layer in the stratosphere. Sulfate aerosols from large eruptions that reach the stratosphere have a longer residence time and greater climatic impact than tropospheric aerosols from smaller eruptions. In this thesis I measure sulfur isotopes in volcanic ice core sulfate to investigate the ~74ka Toba supereruption and six unidentified volcanic eruptions from 16ka to 32ka. I found large magnitude S-MIF signals (-4.75‰) for one of the Toba candidates, the timing of which is consistent with independent age estimates for Toba. This places the eruption on the transition into a cool stadial period in Greenland (GS-20). Toba can be excluded as a potential trigger for GS-20, although it could have contributed to the cooling. To help interpret the six eruptions from 16–32ka, I adapted a 1D-diffusion model to simulate the diffusion and thinning of sulfate isotopes in ice cores. I found that the ice core sulfate isotope signatures are consistent with modelled results of sulfate exposed to diffusion and thinning. Finally, I adapted a 1D-photochemical model (Atmos) to model the temporal evolution of sulfur isotope signatures in a volcanic plume. The model predicts S-MIF signatures consistent in timing and shape to those measured in the ice cores for stratospheric eruptions with S-MIF formation primarily via self-shielding due to high SO₂ column densities.
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Public preferences for wind, fracking and nuclear energy in England and Scotland : a choice experiment approach
https://hdl.handle.net/10023/27382
This study assesses public preferences for alternative electricity generation technologies in England and Scotland, in the context of the global challenge of climate change and the current policy debate in the UK. Specifically, the study aims to provide an insight into the factors that could potentially influence the acceptability of four energy sources (onshore wind, offshore wind, fracking and nuclear energy). The preference heterogeneity is then examined with regard to observable and unobservable factors (socio-demographic and place of residence characteristics, and environmental attitudes). The choice experiment method is employed in this research to elicit preferences for future energy policy targeting environmental and climate change conditions. Through an online survey, data are collected and completed by 986 respondents residing in England and Scotland. Three choice modelling techniques are used for analysis: multinomial and mixed logit models; latent class model; and hybrid mixed model. The results show a significantly positive willingness to pay for both onshore and offshore wind energy technologies and a significantly negative willingness to pay for fracking and nuclear energy. These general results are however heterogeneous and depend to a certain extent on sociodemographic characteristics, especially age, education, income and environmental organisation membership. Furthermore, environmental attitudes (considered as three dimensions: cognitive, affective and behavioural) toward the environment and climate change emerge as significant predictors of energy sources preferences. The results also show that English and Scottish public preferences need not be considered separately, as most of the differences between them are not statistically significant. Overall, the findings of this research are useful for designing optimal future energy and climate change policies, as well as raising the public acceptability for the development of alternative energy projects in England and Scotland.
2022-11-29T00:00:00Z
Almeziad, Deema
This study assesses public preferences for alternative electricity generation technologies in England and Scotland, in the context of the global challenge of climate change and the current policy debate in the UK. Specifically, the study aims to provide an insight into the factors that could potentially influence the acceptability of four energy sources (onshore wind, offshore wind, fracking and nuclear energy). The preference heterogeneity is then examined with regard to observable and unobservable factors (socio-demographic and place of residence characteristics, and environmental attitudes). The choice experiment method is employed in this research to elicit preferences for future energy policy targeting environmental and climate change conditions. Through an online survey, data are collected and completed by 986 respondents residing in England and Scotland. Three choice modelling techniques are used for analysis: multinomial and mixed logit models; latent class model; and hybrid mixed model. The results show a significantly positive willingness to pay for both onshore and offshore wind energy technologies and a significantly negative willingness to pay for fracking and nuclear energy. These general results are however heterogeneous and depend to a certain extent on sociodemographic characteristics, especially age, education, income and environmental organisation membership. Furthermore, environmental attitudes (considered as three dimensions: cognitive, affective and behavioural) toward the environment and climate change emerge as significant predictors of energy sources preferences. The results also show that English and Scottish public preferences need not be considered separately, as most of the differences between them are not statistically significant. Overall, the findings of this research are useful for designing optimal future energy and climate change policies, as well as raising the public acceptability for the development of alternative energy projects in England and Scotland.
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Exploring the effect of location and time on human mobility flow networks
https://hdl.handle.net/10023/27259
Contemporary flow data are used to investigate a number of social science phenomena: examples include flows inferred from mobile phone data, migration flows, commuting flows, or taxi flows between pick‐up and set‐down points. This PhD thesis develops new bespoke advanced quantitative methods for flow data to better understand patterns in flows and their relationship with space and time. Flow data are mathematically represented as geographic networks and are due to their size and complicated structure a typical example of big data. In geography, there is a lack of appropriate methods for their analysis. While some disciplines, such as physics, have recently developed flow methods, these methods are not suitable for flow networks that are geographically constrained, as the methods are not scalable to large geographic networks, nor do they consider the effects of geographic location. Further, in physics, there is no consideration for temporal conditions which affect human mobility. This thesis explores different methods of flow network analysis by gradually experimenting with different approaches and network complexities. We begin the exploration by utilising community detection methods and a commuting network. Community detection allows us to find clusters within the network that have more connections between a location within them than they have to other clusters. We can consider this as a subcomponent of the network that has most of the movement happening within, and only a limited amount of movement towards other subcomponents. Then to complicate things further, we test different types of geographical weighting to the network. In that way, we confirm how to geographically weigh the distances depending on the dataset and decided purpose. Finally, we add a temporal component into the analysis and develop a bespoke method for spatio-temporal network clustering. The method allows us to look at time and space as a continuous variable and to detect patterns that span over different time periods. This would allow us to capture a pattern that only represents a few hours in a day and a pattern that captures the whole weekend behaviour without explicitly saying we are investigating a specific timespan. The results show that space and time make a significant difference in spatio-temporal analysis and the method enables us to simplify and explore huge networks in a seemingly complex way.
2022-11-29T00:00:00Z
Sekulic, Sebastijan
Contemporary flow data are used to investigate a number of social science phenomena: examples include flows inferred from mobile phone data, migration flows, commuting flows, or taxi flows between pick‐up and set‐down points. This PhD thesis develops new bespoke advanced quantitative methods for flow data to better understand patterns in flows and their relationship with space and time. Flow data are mathematically represented as geographic networks and are due to their size and complicated structure a typical example of big data. In geography, there is a lack of appropriate methods for their analysis. While some disciplines, such as physics, have recently developed flow methods, these methods are not suitable for flow networks that are geographically constrained, as the methods are not scalable to large geographic networks, nor do they consider the effects of geographic location. Further, in physics, there is no consideration for temporal conditions which affect human mobility. This thesis explores different methods of flow network analysis by gradually experimenting with different approaches and network complexities. We begin the exploration by utilising community detection methods and a commuting network. Community detection allows us to find clusters within the network that have more connections between a location within them than they have to other clusters. We can consider this as a subcomponent of the network that has most of the movement happening within, and only a limited amount of movement towards other subcomponents. Then to complicate things further, we test different types of geographical weighting to the network. In that way, we confirm how to geographically weigh the distances depending on the dataset and decided purpose. Finally, we add a temporal component into the analysis and develop a bespoke method for spatio-temporal network clustering. The method allows us to look at time and space as a continuous variable and to detect patterns that span over different time periods. This would allow us to capture a pattern that only represents a few hours in a day and a pattern that captures the whole weekend behaviour without explicitly saying we are investigating a specific timespan. The results show that space and time make a significant difference in spatio-temporal analysis and the method enables us to simplify and explore huge networks in a seemingly complex way.
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The behaviour of nitrogen during differentiation of Earths igneous continental crust
https://hdl.handle.net/10023/27219
The geological and biological nitrogen cycles are intimately linked. Nitrogen is an essential element in the structure of amino acids, proteins, nucleic acids, and other molecules vital for life, as well as 78% of the Earths atmosphere and present in significant quantities in all of Earths geological reservoirs. Planetary scale processes such as degassing, subduction and differentiation play a key role in generating and supporting a nitrogen rich surface environment suitable for supporting life. However, the fluxes and stores of nitrogen between Earths mantle, crust and atmosphere remain poorly constrained. Constraining the behaviour of nitrogen during these processes is therefore essential. This thesis targets the processing and storage of nitrogen in the Earth’s crust, with a focus on identify fundamental partitioning and isotopic fractionation during magmatic differentiation and assessing what the crustal nitrogen record can inform us about changes in the biogeochemical nitrogen cycle.
Firstly, I utilise two contrasting but well constrained magmatic systems, the aphyric lavas from Hekla volcano, Iceland, and the calc-alkaline Loch Doon zoned pluton, Scotland. These data are to the best of our knowledge the first combined abundance and isotopic ratio measurements for differentiating magmatic suites at a bulk and mineral scale. I show with the Hekla dataset that when undersaturated in a magma, nitrogen behaves more akin to lithophile rather than volatile elements and can be enriched significantly in Earths crust during differentiation. In Loch Doon, at a mineral scale, we find feldspars host 60-90% of the whole rock nitrogen contents in contrast with previous studies suggesting biotite as the main N host phase. Associated with this are significant feldspar-mica isotopic fractionation suggesting magmatic differentiation can impart significant measurable isotopic differences.
Secondly, I assess the ability of the plutonic felsic crust to record changes in the terrestrial sedimentary nitrogen cycle through analysis of a suite of well characterised strongly peraluminous granitoids (SPGs). These data show a significant change in nitrogen biomass burial coincident with sedimentological, pedogenic and biological innovations coincident with the rise of a complex terrestrial biosphere at the onset of the Phanerozoic.
Overall, this thesis improves our understanding of nitrogen in magmatic systems, shows that studying nitrogen in Earths igneous crust is essential for balancing the geobiological nitrogen cycle, and provides a strong basis for more work on igneous systems for future research.
2023-06-16T00:00:00Z
Boocock, Toby James
The geological and biological nitrogen cycles are intimately linked. Nitrogen is an essential element in the structure of amino acids, proteins, nucleic acids, and other molecules vital for life, as well as 78% of the Earths atmosphere and present in significant quantities in all of Earths geological reservoirs. Planetary scale processes such as degassing, subduction and differentiation play a key role in generating and supporting a nitrogen rich surface environment suitable for supporting life. However, the fluxes and stores of nitrogen between Earths mantle, crust and atmosphere remain poorly constrained. Constraining the behaviour of nitrogen during these processes is therefore essential. This thesis targets the processing and storage of nitrogen in the Earth’s crust, with a focus on identify fundamental partitioning and isotopic fractionation during magmatic differentiation and assessing what the crustal nitrogen record can inform us about changes in the biogeochemical nitrogen cycle.
Firstly, I utilise two contrasting but well constrained magmatic systems, the aphyric lavas from Hekla volcano, Iceland, and the calc-alkaline Loch Doon zoned pluton, Scotland. These data are to the best of our knowledge the first combined abundance and isotopic ratio measurements for differentiating magmatic suites at a bulk and mineral scale. I show with the Hekla dataset that when undersaturated in a magma, nitrogen behaves more akin to lithophile rather than volatile elements and can be enriched significantly in Earths crust during differentiation. In Loch Doon, at a mineral scale, we find feldspars host 60-90% of the whole rock nitrogen contents in contrast with previous studies suggesting biotite as the main N host phase. Associated with this are significant feldspar-mica isotopic fractionation suggesting magmatic differentiation can impart significant measurable isotopic differences.
Secondly, I assess the ability of the plutonic felsic crust to record changes in the terrestrial sedimentary nitrogen cycle through analysis of a suite of well characterised strongly peraluminous granitoids (SPGs). These data show a significant change in nitrogen biomass burial coincident with sedimentological, pedogenic and biological innovations coincident with the rise of a complex terrestrial biosphere at the onset of the Phanerozoic.
Overall, this thesis improves our understanding of nitrogen in magmatic systems, shows that studying nitrogen in Earths igneous crust is essential for balancing the geobiological nitrogen cycle, and provides a strong basis for more work on igneous systems for future research.
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Assessing the vulnerability of marine sedimentary organic carbon : the influence of anthropogenic disturbance
https://hdl.handle.net/10023/27218
As anthropogenic carbon dioxide (CO₂) concentrations rise, there is an increasing need to re-evaluate our understanding of the complex interactions involved within the global carbon (C) cycle. C stored within marine sediments have previously been largely overlooked and unaccounted for, despite their potential role in climate regulation and mitigation. Recent research over the past decade has identified inshore and coastal sediments as being significant organic carbon (OC) accumulation and burial hotspots, leading to the long-term storage of OC in these widespread depositional environments. In comparison, little is known about the potential vulnerability of sedimentary OC to anthropogenic disturbance (e.g., bottom fishing). Bottom fishing results in the resuspension of sedimentary OC, removing it from sites of burial and long-term storage. Once disturbed, sedimentary OC may be transported, consumed, and/or remineralised into CO₂. This activity may result in net changes of sedimentary OC, further altering the dynamics of the natural C cycle.
In this study, we use a combination of experimental procedures coupled with GIS mapping to develop a new methodology to estimate the potential vulnerability of sedimentary OC stores to bottom fishing pressures. In addition, we contribute knowledge about the interactions between biogeochemical cycles within post-trawl environments and examine pre-existing knowledge across various disciplines to better understand the long-term disturbance history of bottom fishing on marine sediments within UK waters.
This study indicates that sediments within the UK Exclusive Economic Zone (EEZ) have likely undergone significant physical and biogeochemical disturbance since the 1950s, particularly within fine grained sedimentary environments which have been determined to be potentially most vulnerable to fishing disturbance. The methodology developed in this study has allowed for the first complete OC vulnerability estimate of UK EEZ marine sediments and will likely play a significant role in future research and policy planning.
2023-06-14T00:00:00Z
Black, Kirsty Eleanor
As anthropogenic carbon dioxide (CO₂) concentrations rise, there is an increasing need to re-evaluate our understanding of the complex interactions involved within the global carbon (C) cycle. C stored within marine sediments have previously been largely overlooked and unaccounted for, despite their potential role in climate regulation and mitigation. Recent research over the past decade has identified inshore and coastal sediments as being significant organic carbon (OC) accumulation and burial hotspots, leading to the long-term storage of OC in these widespread depositional environments. In comparison, little is known about the potential vulnerability of sedimentary OC to anthropogenic disturbance (e.g., bottom fishing). Bottom fishing results in the resuspension of sedimentary OC, removing it from sites of burial and long-term storage. Once disturbed, sedimentary OC may be transported, consumed, and/or remineralised into CO₂. This activity may result in net changes of sedimentary OC, further altering the dynamics of the natural C cycle.
In this study, we use a combination of experimental procedures coupled with GIS mapping to develop a new methodology to estimate the potential vulnerability of sedimentary OC stores to bottom fishing pressures. In addition, we contribute knowledge about the interactions between biogeochemical cycles within post-trawl environments and examine pre-existing knowledge across various disciplines to better understand the long-term disturbance history of bottom fishing on marine sediments within UK waters.
This study indicates that sediments within the UK Exclusive Economic Zone (EEZ) have likely undergone significant physical and biogeochemical disturbance since the 1950s, particularly within fine grained sedimentary environments which have been determined to be potentially most vulnerable to fishing disturbance. The methodology developed in this study has allowed for the first complete OC vulnerability estimate of UK EEZ marine sediments and will likely play a significant role in future research and policy planning.
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Reconstructing past coastal change in southeast Scotland : evolution of the Fife coastline
https://hdl.handle.net/10023/27174
The study of past relative sea level (RSL) change is crucial to improve our understanding of how coastlines could be affected by future climate change. This thesis adopts a multidisciplinary approach to explore past coastal change in southeast Scotland, with a focus on the Fife coastline. Development of a RSL model within a geographical information system (GIS) framework allowed for the prediction of RSL over the last ~12 ka at locations around the coast of Fife. Using the created prediction surfaces, palaeo-landscapes were reconstructed for key time periods with palaeoshorelines at 3, 6, 9 and 12 ka. The RSL surfaces show a complex history of fluctuating sea level within the last 12 ka. The models were tested with sedimentological and geophysical field data at the site of Largo Bay. A chronometric framework was measured using optically stimulated luminescence (OSL) and radiocarbon (RC) dating at the site with an age range from ~29 ka to <300 years. A close correlation with the modelled RSL was obtained. Geospatial analysis at the field site of Kincraig Point, utilising LiDAR and unmanned aerial vehicle (UAV) survey, identified five prominent raised rock platforms (P1-P5) with minimum elevations of -1.1, 4.9, 12.3, 23.7 and 35.9 mOD respectively. Platforms P1 and P2 have been inundated and potentially eroded within the last 12 ka. The correlation between field data and modelled data gives a high level of confidence that this combined approach to study of coastal change could be followed in other similar field locations and further that where field evidence of past coastal change is not present the models may be relied upon to give a good indication of past sea level positions and future trends.
2022-06-15T00:00:00Z
Boyd, Sarah Louise
The study of past relative sea level (RSL) change is crucial to improve our understanding of how coastlines could be affected by future climate change. This thesis adopts a multidisciplinary approach to explore past coastal change in southeast Scotland, with a focus on the Fife coastline. Development of a RSL model within a geographical information system (GIS) framework allowed for the prediction of RSL over the last ~12 ka at locations around the coast of Fife. Using the created prediction surfaces, palaeo-landscapes were reconstructed for key time periods with palaeoshorelines at 3, 6, 9 and 12 ka. The RSL surfaces show a complex history of fluctuating sea level within the last 12 ka. The models were tested with sedimentological and geophysical field data at the site of Largo Bay. A chronometric framework was measured using optically stimulated luminescence (OSL) and radiocarbon (RC) dating at the site with an age range from ~29 ka to <300 years. A close correlation with the modelled RSL was obtained. Geospatial analysis at the field site of Kincraig Point, utilising LiDAR and unmanned aerial vehicle (UAV) survey, identified five prominent raised rock platforms (P1-P5) with minimum elevations of -1.1, 4.9, 12.3, 23.7 and 35.9 mOD respectively. Platforms P1 and P2 have been inundated and potentially eroded within the last 12 ka. The correlation between field data and modelled data gives a high level of confidence that this combined approach to study of coastal change could be followed in other similar field locations and further that where field evidence of past coastal change is not present the models may be relied upon to give a good indication of past sea level positions and future trends.
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Borderwork in times of crisis? Control, care and the resource of emotion
https://hdl.handle.net/10023/27150
This thesis explores an internal EU border in Northern Europe during a ‘crisis’ scenario. In the aftermath of the Syrian Civil War, during 2015 Sweden received 160,000 applications for asylum, the third highest total number in Europe. Consequently, Sweden introduced three forms of border controls to restrict numbers, marking a significant shift in Swedish asylum policy. This thesis engages with the notion of ‘political moments’ concerning how occasions of heightened visibilities could be appropriated and brought into the political milieu in Sweden and Denmark during 2015-2016 and subsequently used in the operations of borderwork by state and non-state actors. Borderwork is understood in this thesis in a Rumfordian manner, where state and non-state actors can contribute to actions of bordering and debordering. The thesis analyses Sweden’s border controls, grounded in particular contextualities and operating within a specific EU legal framework. This thesis draws on semi-structured interviews with 53 individuals primarily from the state and civil society in both countries. Complexities within and between civil society and the state concerning borderwork are shown as being interpenetrating, and the state’s pervasive extension is explored through ‘the Snake’ and Posthusplatsen. Emotion as a political resource (which can be appealed to, framed and (re)produced to shape discourses) is analysed and seen vis-à-vis the political left and right as a mobilising force in both bordering and debordering. Finally, and as part of this, the notion of mourning is explored concerning the evocative question: Is this Sweden?
2023-06-14T00:00:00Z
Dowle, Lewis John
This thesis explores an internal EU border in Northern Europe during a ‘crisis’ scenario. In the aftermath of the Syrian Civil War, during 2015 Sweden received 160,000 applications for asylum, the third highest total number in Europe. Consequently, Sweden introduced three forms of border controls to restrict numbers, marking a significant shift in Swedish asylum policy. This thesis engages with the notion of ‘political moments’ concerning how occasions of heightened visibilities could be appropriated and brought into the political milieu in Sweden and Denmark during 2015-2016 and subsequently used in the operations of borderwork by state and non-state actors. Borderwork is understood in this thesis in a Rumfordian manner, where state and non-state actors can contribute to actions of bordering and debordering. The thesis analyses Sweden’s border controls, grounded in particular contextualities and operating within a specific EU legal framework. This thesis draws on semi-structured interviews with 53 individuals primarily from the state and civil society in both countries. Complexities within and between civil society and the state concerning borderwork are shown as being interpenetrating, and the state’s pervasive extension is explored through ‘the Snake’ and Posthusplatsen. Emotion as a political resource (which can be appealed to, framed and (re)produced to shape discourses) is analysed and seen vis-à-vis the political left and right as a mobilising force in both bordering and debordering. Finally, and as part of this, the notion of mourning is explored concerning the evocative question: Is this Sweden?
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Boron based geochemical reconstructions of ocean pH and atmospheric CO₂ in the geological record
https://hdl.handle.net/10023/27101
The boron isotope proxy is a valuable tool for reconstructing ocean pH and atmospheric CO₂ in Earth’s history. Its use on foraminifera in deep sea sediment cores has helped shape our understanding of Cenozoic carbon cycling and climate change, yet most of the extreme examples of biotic and climatic change are in the geological record, where the proxy has seen limited use. The boron isotope proxy’s widespread usage is also hindered by the challenges involved in traditional methods for measuring it: gravity microcolumns require exacting laboratory conditions and are time intensive. Older samples may have more variable matrices which can also be a problem for a gravity column.
In order to expand the boron isotope proxy into a wider variety of matrices, Chapter 3 presents a new batch method for the purification of boron from its sample matrix. Together with methodological improvements for measurement by MC-ICPMS discussed in Chapter 2, these developments allow for measurement of a wide variety of samples with uncertainties roughly half the size, procedural blanks an order of magnitude lower, and sample throughput ~3 times faster than previous methods.
These developments are applied to the geological record in Chapters 4 and 5 for two of the most significant biotic and climatic changes in Earth’s history. Chapter 4 presents boron isotope data from the Triassic-Jurassic boundary, indicating a ≥ 0.34 unit drop in ocean pH coincident with the ‘main’ carbon isotope excursion, suggesting that the carbon isotope excursions associated with the end-Triassic mass extinction event were likely also associated with pulses of ocean acidification. Chapter 5 presents a boron isotope record through the Ordovician into the early Silurian, showing a substantial rise in ocean pH and likely fall in atmospheric CO₂ accompanying the large cooling trend and major radiation in biodiversity though the Ordovician. CO₂-driven cooling thus sets the stage for the glaciation thought to trigger the end-Ordovician extinction event, while rising CO₂ in the early Silurian would have driven climatic recovery.
Together these results highlight the success of the application of the boron isotope proxy to carbon cycle perturbations in the rock record and reveal, for the first time, the changes in the CO₂ system associated with some of the most important events in Earth’s history. In summary, this thesis allows for more accurate and precise boron isotope analysis and a deeper understanding of some of the major environmental events of the Phanerozoic.
2023-06-16T00:00:00Z
Trudgill, Molly Diana
The boron isotope proxy is a valuable tool for reconstructing ocean pH and atmospheric CO₂ in Earth’s history. Its use on foraminifera in deep sea sediment cores has helped shape our understanding of Cenozoic carbon cycling and climate change, yet most of the extreme examples of biotic and climatic change are in the geological record, where the proxy has seen limited use. The boron isotope proxy’s widespread usage is also hindered by the challenges involved in traditional methods for measuring it: gravity microcolumns require exacting laboratory conditions and are time intensive. Older samples may have more variable matrices which can also be a problem for a gravity column.
In order to expand the boron isotope proxy into a wider variety of matrices, Chapter 3 presents a new batch method for the purification of boron from its sample matrix. Together with methodological improvements for measurement by MC-ICPMS discussed in Chapter 2, these developments allow for measurement of a wide variety of samples with uncertainties roughly half the size, procedural blanks an order of magnitude lower, and sample throughput ~3 times faster than previous methods.
These developments are applied to the geological record in Chapters 4 and 5 for two of the most significant biotic and climatic changes in Earth’s history. Chapter 4 presents boron isotope data from the Triassic-Jurassic boundary, indicating a ≥ 0.34 unit drop in ocean pH coincident with the ‘main’ carbon isotope excursion, suggesting that the carbon isotope excursions associated with the end-Triassic mass extinction event were likely also associated with pulses of ocean acidification. Chapter 5 presents a boron isotope record through the Ordovician into the early Silurian, showing a substantial rise in ocean pH and likely fall in atmospheric CO₂ accompanying the large cooling trend and major radiation in biodiversity though the Ordovician. CO₂-driven cooling thus sets the stage for the glaciation thought to trigger the end-Ordovician extinction event, while rising CO₂ in the early Silurian would have driven climatic recovery.
Together these results highlight the success of the application of the boron isotope proxy to carbon cycle perturbations in the rock record and reveal, for the first time, the changes in the CO₂ system associated with some of the most important events in Earth’s history. In summary, this thesis allows for more accurate and precise boron isotope analysis and a deeper understanding of some of the major environmental events of the Phanerozoic.
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The interplay between deformation and magma transport in southeast Iceland
https://hdl.handle.net/10023/27086
Igneous intrusions are of fundamental importance to society's ability to source critical metals, predict major natural hazards and, understand how Earth’s crust evolved. However, the factors that control how magma transits through Earth’s crust and the variables that determine if magma will arrest during the process of ascent or erupt at the surface remains a challenge. This study investigates the interface between key tectonic, host rock and magma parameters to advance our understanding of how these variables influence magma transport processes in sub-volcanic plumbing systems. Specifically, this thesis assesses the interplay of magma flow dynamics and i) deformation structures associated with the ambient extensional stress regime of SE Iceland and ii) host rock deformation processes caused by the process of laccolith intrusion.
The first part of the thesis investigates how surface and overburden deformation (forced folds, faults, and fractures) correlate with the mechanism of magma emplacement. In a case study on the Sandfell Laccoith, eastern Iceland, this chapter presents new palaeomagnetic data and a modified fold test to assess the formation of a forced fold. The results show that the formation of the forced fold occurred in two distinct processes that required the temporal break between the initial injection of magma and the later inflation of the laccolith. An evolutionary model is proposed whereby the continuous forceful emplacement of magma involved initial lateral propagation of a sill-like body preferentially towards the SSW resulting in forced folding with a relatively simple geometry. Continuous addition of magma at the base of the laccolith resulted in subsequent ‘bulldozing’ of magma underlying the cooled, viscously stalled initial magma. Magma that was subsequently injected into the laccolith caused inflation facilitated by further displacement of host rock and the formation of a prominent forced fold that is today observed in outcrop. This study demonstrates the utility of a new modified fold test that provides an effective means to track the style and location of transient shallow-level magma movement associated with forced folding.
Through detailed structural mapping, ²⁰⁶Pb/²³⁸U zircon dating and, anisotropy of magnetic susceptibility (AMS) analyses, the second data chapter of this thesis investigates the relationship between pre-existing fault/fracture networks and magma flow processes in the Reyðarártindur intrusion in southeast Iceland is investigated. The intrusion is interpreted as a sub-volcanic laccolith where magma propagated laterally along a NE-SW primary axis over a timeframe of 10⁴ – 10⁵ years. Pre-existing NNE-striking, faults/fractures in the host rock accommodated intrusive sheets which themselves facilitated upward and outward evacuation of magma from the laccolith. This study elucidates on how the process of magma transport is influenced by pre-existing fault/fracture networks caused by ambient extensional tectonic regimes and shows that lateral offset of eruptive edifices can be controlled by these fracture networks.
The final data chapter uses fracture modelling to provide a revised regional tectonic framework for southeast Iceland. Fracture analysis of fault and joint populations identified within the structural aureole of the Reyðarártindur intrusion and across the southeast Iceland to identify different generations of Riedel shear structures that in turn define a sinistral Riedel shear system. The inferred Riedel shear system is interpreted to have formed within a Neogene WSW-ENE trending transfer zone that linked at least two rift segments. This investigation posits a new interpretation of the contemporaneous stress regime for southeast Iceland and discusses how the associated deformation influenced the transport and storage of magma.
The works of this thesis highlight that investigating the interplay between magma movement and host-rock properties aids in our understanding of magma transport in sub-volcanic systems.
2023-06-16T00:00:00Z
Twomey, Vincent
Igneous intrusions are of fundamental importance to society's ability to source critical metals, predict major natural hazards and, understand how Earth’s crust evolved. However, the factors that control how magma transits through Earth’s crust and the variables that determine if magma will arrest during the process of ascent or erupt at the surface remains a challenge. This study investigates the interface between key tectonic, host rock and magma parameters to advance our understanding of how these variables influence magma transport processes in sub-volcanic plumbing systems. Specifically, this thesis assesses the interplay of magma flow dynamics and i) deformation structures associated with the ambient extensional stress regime of SE Iceland and ii) host rock deformation processes caused by the process of laccolith intrusion.
The first part of the thesis investigates how surface and overburden deformation (forced folds, faults, and fractures) correlate with the mechanism of magma emplacement. In a case study on the Sandfell Laccoith, eastern Iceland, this chapter presents new palaeomagnetic data and a modified fold test to assess the formation of a forced fold. The results show that the formation of the forced fold occurred in two distinct processes that required the temporal break between the initial injection of magma and the later inflation of the laccolith. An evolutionary model is proposed whereby the continuous forceful emplacement of magma involved initial lateral propagation of a sill-like body preferentially towards the SSW resulting in forced folding with a relatively simple geometry. Continuous addition of magma at the base of the laccolith resulted in subsequent ‘bulldozing’ of magma underlying the cooled, viscously stalled initial magma. Magma that was subsequently injected into the laccolith caused inflation facilitated by further displacement of host rock and the formation of a prominent forced fold that is today observed in outcrop. This study demonstrates the utility of a new modified fold test that provides an effective means to track the style and location of transient shallow-level magma movement associated with forced folding.
Through detailed structural mapping, ²⁰⁶Pb/²³⁸U zircon dating and, anisotropy of magnetic susceptibility (AMS) analyses, the second data chapter of this thesis investigates the relationship between pre-existing fault/fracture networks and magma flow processes in the Reyðarártindur intrusion in southeast Iceland is investigated. The intrusion is interpreted as a sub-volcanic laccolith where magma propagated laterally along a NE-SW primary axis over a timeframe of 10⁴ – 10⁵ years. Pre-existing NNE-striking, faults/fractures in the host rock accommodated intrusive sheets which themselves facilitated upward and outward evacuation of magma from the laccolith. This study elucidates on how the process of magma transport is influenced by pre-existing fault/fracture networks caused by ambient extensional tectonic regimes and shows that lateral offset of eruptive edifices can be controlled by these fracture networks.
The final data chapter uses fracture modelling to provide a revised regional tectonic framework for southeast Iceland. Fracture analysis of fault and joint populations identified within the structural aureole of the Reyðarártindur intrusion and across the southeast Iceland to identify different generations of Riedel shear structures that in turn define a sinistral Riedel shear system. The inferred Riedel shear system is interpreted to have formed within a Neogene WSW-ENE trending transfer zone that linked at least two rift segments. This investigation posits a new interpretation of the contemporaneous stress regime for southeast Iceland and discusses how the associated deformation influenced the transport and storage of magma.
The works of this thesis highlight that investigating the interplay between magma movement and host-rock properties aids in our understanding of magma transport in sub-volcanic systems.
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Modelling geomagnetic bird navigation
https://hdl.handle.net/10023/27001
Geomagnetic navigation is a complex process which has been studied in experimental behaviour and observation studies. However, to date there have been relatively few modelling studies, and all have used geomagnetic data that don’t account for fine-scale dynamics of the geomagnetic field. The objective of this thesis is to study avian migratory navigation using novel data-driven approaches based on high-resolution contemporaneous and co-located geomagnetic and bird tracking data.
Two different methods (random walk models, RWM and step selection analysis, SSA) were applied to evaluate the use of geomagnetic navigational strategies by migratory birds alongside geomagnetic cues (intensity, inclination), and to study the effect of abiotic factors on navigation. Both methods incorporated navigational strategies, which were derived from literature and associated with geomagnetic values. For RWM, these were translated into novel probability surfaces (represented as spatial grids) and for SSA into strategy-based covariates. I further investigated the effect of using higher resolution satellite geomagnetic data and found that models significantly improved with their use. Future studies of geomagnetic navigation should therefore use fine-scale geomagnetic data.
My studies suggest that the most simplistic navigational compass mechanism (i.e. taxis) based on geomagnetic intensity is a preferred strategy. This is likely the most energy efficient mechanism which is the least prone to changes of the geomagnetic field. Additionally, I studied two different abiotic factors which have been proposed to influence bird navigation: the time of the day and local structure of the geomagnetic field. For both, I found the first empirical evidence for their effects on geomagnetic navigation.
My methodologies can be used for direct comparisons of different species migrating in different geographical areas and to study interaction effects with other navigational strategies and environmental factors (e.g. wind). The thesis therefore has a potential for a high impact on the study of migratory navigation.
2023-06-14T00:00:00Z
Zein, Beate
Geomagnetic navigation is a complex process which has been studied in experimental behaviour and observation studies. However, to date there have been relatively few modelling studies, and all have used geomagnetic data that don’t account for fine-scale dynamics of the geomagnetic field. The objective of this thesis is to study avian migratory navigation using novel data-driven approaches based on high-resolution contemporaneous and co-located geomagnetic and bird tracking data.
Two different methods (random walk models, RWM and step selection analysis, SSA) were applied to evaluate the use of geomagnetic navigational strategies by migratory birds alongside geomagnetic cues (intensity, inclination), and to study the effect of abiotic factors on navigation. Both methods incorporated navigational strategies, which were derived from literature and associated with geomagnetic values. For RWM, these were translated into novel probability surfaces (represented as spatial grids) and for SSA into strategy-based covariates. I further investigated the effect of using higher resolution satellite geomagnetic data and found that models significantly improved with their use. Future studies of geomagnetic navigation should therefore use fine-scale geomagnetic data.
My studies suggest that the most simplistic navigational compass mechanism (i.e. taxis) based on geomagnetic intensity is a preferred strategy. This is likely the most energy efficient mechanism which is the least prone to changes of the geomagnetic field. Additionally, I studied two different abiotic factors which have been proposed to influence bird navigation: the time of the day and local structure of the geomagnetic field. For both, I found the first empirical evidence for their effects on geomagnetic navigation.
My methodologies can be used for direct comparisons of different species migrating in different geographical areas and to study interaction effects with other navigational strategies and environmental factors (e.g. wind). The thesis therefore has a potential for a high impact on the study of migratory navigation.
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Negatively charged ions in the deep Earth : quantifying the chemical speciation of F and N in silicate melts and phases
https://hdl.handle.net/10023/26905
Nitrogen and fluorine are essential volatile elements to study in the bulk silicate Earth (BSE) due to their respective influence over the onset of habitability on Earth or over physical and chemical properties of the phases which contain them. Nitrogen is abnormally depleted in the BSE relative to CI chondrite, while fluorine is abnormally enriched, hence questions arise about their chemical speciation and storage mechanisms within planetary reservoirs.
The speciation of nitrogen in high pressure silicate melts was studied using solid-state nuclear magnetic resonance (NMR) and Raman spectroscopy and was found to be heavily influenced by oxygen fugacity. The former technique provided superior results in quantifying the abundance of individual species and higher sensitivity, however it requires ¹⁵N enrichment, low-Fe samples and performs only bulk analysis, while the latter was found to be an efficient in situ technique regardless of sample composition, but it struggled at detecting low-abundance N species.
The speciation of fluorine in silicate melts was studied via NMR spectroscopy at BSE-like concentrations, thanks to this techniques high F sensitivity. F was found to be binding solely with Mg at atmospheric pressure, and this speciation remains predominant until c.a. 8 GPa, where relevant quantities of F start binding with Ca. This is likely due to the changing coordination number of the major components of the melt, but a change in the coordination of fluorine itself might also be occurring.
The ordering of fluoride and hydroxide in the framework of humite group minerals was studied via NMR spectroscopy and computational modelling. The incorporation of one F and one OH anion in neighbouring sites was found to be favoured relative to the incorporation of two identical ions, thanks to the formation of a hydrogen bond. This likely explains the extended stability field of clinohumite when it is F rich.
2022-11-29T00:00:00Z
Formoso, Filippo
Nitrogen and fluorine are essential volatile elements to study in the bulk silicate Earth (BSE) due to their respective influence over the onset of habitability on Earth or over physical and chemical properties of the phases which contain them. Nitrogen is abnormally depleted in the BSE relative to CI chondrite, while fluorine is abnormally enriched, hence questions arise about their chemical speciation and storage mechanisms within planetary reservoirs.
The speciation of nitrogen in high pressure silicate melts was studied using solid-state nuclear magnetic resonance (NMR) and Raman spectroscopy and was found to be heavily influenced by oxygen fugacity. The former technique provided superior results in quantifying the abundance of individual species and higher sensitivity, however it requires ¹⁵N enrichment, low-Fe samples and performs only bulk analysis, while the latter was found to be an efficient in situ technique regardless of sample composition, but it struggled at detecting low-abundance N species.
The speciation of fluorine in silicate melts was studied via NMR spectroscopy at BSE-like concentrations, thanks to this techniques high F sensitivity. F was found to be binding solely with Mg at atmospheric pressure, and this speciation remains predominant until c.a. 8 GPa, where relevant quantities of F start binding with Ca. This is likely due to the changing coordination number of the major components of the melt, but a change in the coordination of fluorine itself might also be occurring.
The ordering of fluoride and hydroxide in the framework of humite group minerals was studied via NMR spectroscopy and computational modelling. The incorporation of one F and one OH anion in neighbouring sites was found to be favoured relative to the incorporation of two identical ions, thanks to the formation of a hydrogen bond. This likely explains the extended stability field of clinohumite when it is F rich.
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Carbon and sulfur isotope biosignatures in Mars-analogue hydrothermal environments
https://hdl.handle.net/10023/26844
The study of terrestrial environments that bear similarity to Mars provides valuable
information for interpreting data from missions, including how to find evidence of relict
life on the red planet. Stable isotope signatures evidencing microbial metabolic activity
are commonly used as a biosignature tool. Here, an interdisciplinary study investigating
two volcanic hydrothermal systems in Iceland is presented, with additional
contextualisation through a comparison with a non-volcanic hypersaline spring. This
thesis combines mineralogy, geochemistry, microbial community DNA, and stable
isotope systems (carbon and sulfur) to analyse: i) the preservation of isotopic
biosignatures in hydrothermal and hypersaline springs, and ii) the relationships
between the biosignatures and the geochemistry of these environments.
Firstly, a characterisation of two Mars analogue hydrothermal environments in Iceland
(Kerlingarfjöll and Kverkfjöll), reveals deep volcanic processes controlling the
geochemistry of the hydrothermal pools. The volcanic processes create two very distinct
pH environments, with Kerlingarfjöll circum-neutral and Kverkfjöll acidic, with distinct
water geochemistry and mineralogy. The water geochemistry is found to be a key
parameter controlling the microbial communities, based on pH differences and the
different electron donors and acceptors available. Secondly, carbon isotope
fractionations preserved as sedimentary organic carbon, are controlled in Kerlingarfjöll
and Kverkfjöll systems by temperature. Low temperature pools favour carbon CO₂
fixation pathways that produce larger or more variable carbon isotope fractionations.
Lastly, sulfur isotope values (δ³⁴S) recorded in the sediments are not conclusive as
geochemical biosignatures in Kerlingarfjöll and Kverkfjöll sediments. This is due to
abundant H2S with abiotic δ³⁴S values overwhelming biological δ³⁴S values. Conversely,
when combining δ³⁴S with Δ³³S and Δ³⁶S as a Quadruple Sulfur Isotope system (QSI), two
pools in Kerlingarfjöll show complex S-cycling combining biological and volcanic
processes. Importantly, the non-volcanic hypersaline spring preserves larger
fractionations in δ³⁴S and large Δ³³S values, typical of reduction and disproportionation
of sulfur by microorganisms. The main environmental variables causing larger S isotope fractionations in the hypersaline spring are the salinity stress and the limitation of
electron donors and acceptors in the environment.
Overall, this thesis improves the understanding of carbon and sulfur isotopes as
biosignature tools for investigating hydrothermal and hypersaline environments in
Mars, and opens the door for the use of QSI as a more robust biosignature for future
missions.
2022-06-21T00:00:00Z
Moreras Martí, Arola
The study of terrestrial environments that bear similarity to Mars provides valuable
information for interpreting data from missions, including how to find evidence of relict
life on the red planet. Stable isotope signatures evidencing microbial metabolic activity
are commonly used as a biosignature tool. Here, an interdisciplinary study investigating
two volcanic hydrothermal systems in Iceland is presented, with additional
contextualisation through a comparison with a non-volcanic hypersaline spring. This
thesis combines mineralogy, geochemistry, microbial community DNA, and stable
isotope systems (carbon and sulfur) to analyse: i) the preservation of isotopic
biosignatures in hydrothermal and hypersaline springs, and ii) the relationships
between the biosignatures and the geochemistry of these environments.
Firstly, a characterisation of two Mars analogue hydrothermal environments in Iceland
(Kerlingarfjöll and Kverkfjöll), reveals deep volcanic processes controlling the
geochemistry of the hydrothermal pools. The volcanic processes create two very distinct
pH environments, with Kerlingarfjöll circum-neutral and Kverkfjöll acidic, with distinct
water geochemistry and mineralogy. The water geochemistry is found to be a key
parameter controlling the microbial communities, based on pH differences and the
different electron donors and acceptors available. Secondly, carbon isotope
fractionations preserved as sedimentary organic carbon, are controlled in Kerlingarfjöll
and Kverkfjöll systems by temperature. Low temperature pools favour carbon CO₂
fixation pathways that produce larger or more variable carbon isotope fractionations.
Lastly, sulfur isotope values (δ³⁴S) recorded in the sediments are not conclusive as
geochemical biosignatures in Kerlingarfjöll and Kverkfjöll sediments. This is due to
abundant H2S with abiotic δ³⁴S values overwhelming biological δ³⁴S values. Conversely,
when combining δ³⁴S with Δ³³S and Δ³⁶S as a Quadruple Sulfur Isotope system (QSI), two
pools in Kerlingarfjöll show complex S-cycling combining biological and volcanic
processes. Importantly, the non-volcanic hypersaline spring preserves larger
fractionations in δ³⁴S and large Δ³³S values, typical of reduction and disproportionation
of sulfur by microorganisms. The main environmental variables causing larger S isotope fractionations in the hypersaline spring are the salinity stress and the limitation of
electron donors and acceptors in the environment.
Overall, this thesis improves the understanding of carbon and sulfur isotopes as
biosignature tools for investigating hydrothermal and hypersaline environments in
Mars, and opens the door for the use of QSI as a more robust biosignature for future
missions.
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Associations between exposure to air pollution and health: A longitudinal study of middle-aged and older adults in China
https://hdl.handle.net/10023/26500
The Chinese population is ageing rapidly, and older Chinese adults (aged 45 and over) have spent a
large proportion of their lives exposed to historically high levels of air pollution (AP). Previous studies
suggest that there is a strong association between AP and individual health outcomes, but most of
them have relied on cross-sectional measures of AP exposure and health, or both. These limit our
understanding of how short-term, long-term, and cumulative exposures lead to changes in health
outcomes. This PhD thesis addresses these gaps by investigating the longitudinal relationship
between long-term and short-term exposure to AP and the health of older adults in China.
The thesis uses two kinds of survey data and two kinds of AP data. The Chinese Longitudinal Healthy
Longevity Survey (CLHLS) 2011 and 2014 is linked with monitoring station AP data (used in chapter
4), and the China Health and Retirement Longitudinal Survey (CHARLS) 2011, 2013 and 2015, is linked
with PM₂.₅ data that are retrieved from satellite data via remote sensing technology (used in chapters
5 and 6).
The main finding of the
first empirical chapter using the CLHLS is that increased frailty incidence is
associated with higher long-term exposure to AP rather than short-term fluctuations. The second
empirical chapter using the CHARLS shows that exposure to PM₂.₅ over 15 years is associated with
higher multimorbidity accumulation, and higher levels of PM₂.₅ are associated with a higher likelihood
of membership to both respiratory and cardio-metabolic disease classes. The results of the third
empirical chapter indicate that long-term exposure to PM₂.₅ is associated with poorer cognitive
function, but different measures of long-term AP exposure are associated with different levels of
cognitive decline. Overall, the three chapters indicate that long-term AP exposure has a negative
association with elderly health, but that there may be some individual and contextual differences
which are being conflated with these associations, and which deserve further exploration.
This thesis, therefore, makes several substantive and methodological contributions. First, I create a
unique longitudinal dataset by linking historical AP data to representative longitudinal ageing surveys
at the city level. Second, I investigate the associations of short-term and long-term exposure with health outcomes. Third, health outcomes of older adults are measured longitudinally using three
comprehensive indicators that can reflect the complex relationship between AP and elderly health.
The findings highlight the need to further consider cumulative and life-course AP exposure on elderly
health at a smaller geographical scale.
2022-05-04T00:00:00Z
Hu, Kai
The Chinese population is ageing rapidly, and older Chinese adults (aged 45 and over) have spent a
large proportion of their lives exposed to historically high levels of air pollution (AP). Previous studies
suggest that there is a strong association between AP and individual health outcomes, but most of
them have relied on cross-sectional measures of AP exposure and health, or both. These limit our
understanding of how short-term, long-term, and cumulative exposures lead to changes in health
outcomes. This PhD thesis addresses these gaps by investigating the longitudinal relationship
between long-term and short-term exposure to AP and the health of older adults in China.
The thesis uses two kinds of survey data and two kinds of AP data. The Chinese Longitudinal Healthy
Longevity Survey (CLHLS) 2011 and 2014 is linked with monitoring station AP data (used in chapter
4), and the China Health and Retirement Longitudinal Survey (CHARLS) 2011, 2013 and 2015, is linked
with PM₂.₅ data that are retrieved from satellite data via remote sensing technology (used in chapters
5 and 6).
The main finding of the
first empirical chapter using the CLHLS is that increased frailty incidence is
associated with higher long-term exposure to AP rather than short-term fluctuations. The second
empirical chapter using the CHARLS shows that exposure to PM₂.₅ over 15 years is associated with
higher multimorbidity accumulation, and higher levels of PM₂.₅ are associated with a higher likelihood
of membership to both respiratory and cardio-metabolic disease classes. The results of the third
empirical chapter indicate that long-term exposure to PM₂.₅ is associated with poorer cognitive
function, but different measures of long-term AP exposure are associated with different levels of
cognitive decline. Overall, the three chapters indicate that long-term AP exposure has a negative
association with elderly health, but that there may be some individual and contextual differences
which are being conflated with these associations, and which deserve further exploration.
This thesis, therefore, makes several substantive and methodological contributions. First, I create a
unique longitudinal dataset by linking historical AP data to representative longitudinal ageing surveys
at the city level. Second, I investigate the associations of short-term and long-term exposure with health outcomes. Third, health outcomes of older adults are measured longitudinally using three
comprehensive indicators that can reflect the complex relationship between AP and elderly health.
The findings highlight the need to further consider cumulative and life-course AP exposure on elderly
health at a smaller geographical scale.
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Scotland's sedimentary blue carbon : new spatial tools for seabed management
https://hdl.handle.net/10023/26059
Marine sediments are significant long-term stores of carbon. Carbon burial within sediments has provided a climate regulation service over geological timescales. Despite marine sediments holding vast quantities of carbon, the spatial distribution of this carbon store is not well constrained. This information is critical to assessing and monitoring the seabed and in identifying carbon hotspots that may be vulnerable to disturbance and loss. This study focuses on marine sediments within Scotland’s seas. Scotland has a marine area six times its land area making it an exemplar nation to investigate novel methods to improve the spatial understanding of significant sedimentary carbon stores. Here, a novel methodology has been developed that uses multibeam acoustic backscatter data to map surficial sedimentary organic carbon and quantify surface stocks within a model fjordic system. In the proof-of-concept study, a strong correlation between sediment type, backscatter intensity, and organic carbon was found. The heterogeneous nature of the seabed within fjords was highlighted with implications for carbon storage, supporting the need for a greater spatial understanding of marine sediments in carbon accounting. A further study tested the opportunities and limitations of the wider application of backscatter to map sedimentary organic carbon in different coastal settings, potentially providing a cost-effective mapping tool. Results from this project also highlighted the role of estuaries on the east coast of Scotland in delivering significant amounts of terrestrial carbon to inshore sediments. Quality assessments of this organic carbon within shelf sediments indicated that remineralisation losses due to disturbance may be minimal, however anthropogenic pressures on the seabed can affect the burial potential of sediments, thereby limiting the ability of the seabed to provide climate benefits. The findings from this research can be used to provide tools to decision-makers to identify vulnerable carbon stores on the seabed, address evidence gaps relating to the transfer of carbon between ecosystems and implement targeted spatial interventions for their protection.
2022-11-29T00:00:00Z
Hunt, Corallie Anne
Marine sediments are significant long-term stores of carbon. Carbon burial within sediments has provided a climate regulation service over geological timescales. Despite marine sediments holding vast quantities of carbon, the spatial distribution of this carbon store is not well constrained. This information is critical to assessing and monitoring the seabed and in identifying carbon hotspots that may be vulnerable to disturbance and loss. This study focuses on marine sediments within Scotland’s seas. Scotland has a marine area six times its land area making it an exemplar nation to investigate novel methods to improve the spatial understanding of significant sedimentary carbon stores. Here, a novel methodology has been developed that uses multibeam acoustic backscatter data to map surficial sedimentary organic carbon and quantify surface stocks within a model fjordic system. In the proof-of-concept study, a strong correlation between sediment type, backscatter intensity, and organic carbon was found. The heterogeneous nature of the seabed within fjords was highlighted with implications for carbon storage, supporting the need for a greater spatial understanding of marine sediments in carbon accounting. A further study tested the opportunities and limitations of the wider application of backscatter to map sedimentary organic carbon in different coastal settings, potentially providing a cost-effective mapping tool. Results from this project also highlighted the role of estuaries on the east coast of Scotland in delivering significant amounts of terrestrial carbon to inshore sediments. Quality assessments of this organic carbon within shelf sediments indicated that remineralisation losses due to disturbance may be minimal, however anthropogenic pressures on the seabed can affect the burial potential of sediments, thereby limiting the ability of the seabed to provide climate benefits. The findings from this research can be used to provide tools to decision-makers to identify vulnerable carbon stores on the seabed, address evidence gaps relating to the transfer of carbon between ecosystems and implement targeted spatial interventions for their protection.
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Impacts of outdoor recreation on space-use, behaviour and interspecific interactions of red deer (Cervus elaphus) in the Scottish Highlands
https://hdl.handle.net/10023/25395
In Scotland, the geographical distribution of red deer (Cervus elaphus scoticus) overlaps with
areas used for popular outdoor activities such as hill walking. This overlap can have multiple
consequences for the animal but also for its successful management. Here, I study the impact of
hiking activity on red deer spatio-temporal distribution, behaviour, and interaction with sheep.
First, to study the impact of hiker activity on deer detection and on their behaviour, camera
traps were placed in transects at different distances (25, 75 and 150m) from the hiking path.
Hiking activity was monitored and classified as busy or quiet. Second, to study how hiking
activity influenced red deer interaction with sheep, camera traps were distributed at various
distances from the hiking path. I found that red deer spatial and temporal response occurred at
less than 150m, as more red deer were detected at 150m than at 25m. During the day, red deer
were detected at greater rates in an isolated area relative to areas close to the hiking path. This
avoidance only occurred on a short temporal scale, as deer returned to areas close to the hiking
path the following night. I did not detect an increase in vigilance or flight behaviour closer to
the hiking path or during busy hiking activity. However, the interaction between sheep and deer
changed with distance from the hiking path, with greater spatial and temporal overlap in areas
further away from the hiking path. I conclude that (i) hikers impact the spatial distribution of
red deer at distances smaller than 150m but that this impact is only of short duration temporal
scale, (ii) hiking activity does not have a significant impact on the behaviour of the animal, and
(iii) hiking activity may influence the interaction between sheep and deer.
2022-06-15T00:00:00Z
Marion, Solène
In Scotland, the geographical distribution of red deer (Cervus elaphus scoticus) overlaps with
areas used for popular outdoor activities such as hill walking. This overlap can have multiple
consequences for the animal but also for its successful management. Here, I study the impact of
hiking activity on red deer spatio-temporal distribution, behaviour, and interaction with sheep.
First, to study the impact of hiker activity on deer detection and on their behaviour, camera
traps were placed in transects at different distances (25, 75 and 150m) from the hiking path.
Hiking activity was monitored and classified as busy or quiet. Second, to study how hiking
activity influenced red deer interaction with sheep, camera traps were distributed at various
distances from the hiking path. I found that red deer spatial and temporal response occurred at
less than 150m, as more red deer were detected at 150m than at 25m. During the day, red deer
were detected at greater rates in an isolated area relative to areas close to the hiking path. This
avoidance only occurred on a short temporal scale, as deer returned to areas close to the hiking
path the following night. I did not detect an increase in vigilance or flight behaviour closer to
the hiking path or during busy hiking activity. However, the interaction between sheep and deer
changed with distance from the hiking path, with greater spatial and temporal overlap in areas
further away from the hiking path. I conclude that (i) hikers impact the spatial distribution of
red deer at distances smaller than 150m but that this impact is only of short duration temporal
scale, (ii) hiking activity does not have a significant impact on the behaviour of the animal, and
(iii) hiking activity may influence the interaction between sheep and deer.
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REE induced defects in minerals : a spectroscopic study
https://hdl.handle.net/10023/24050
This thesis examines the luminescence and mineral physics of Rare Earth Element (REE) bearing
minerals as a precursor to developing smart sorting tools for critical metals used in low-carbon
technologies. I characterise luminescence responses of complex zirconosilicates; eudialyte
(Na₁₅Ca₆(Fe²⁺,Mn²⁺)₃Zr₃[Si₂₅O₇₃](O,OH,H₂O)₃(OH,Cl)₂), wöhlerite (NaCa₂(Zr,Nb)(Si₂O₇)(O,OH,F)₂) and
catapleiite (Na₂Zr(Si₃O₉) · 2H2₂O). Fluorite was included as it is commonly associated with REE ores and
displays strong REE luminescence. Its behaviour provides key insights into REE substitution into ionic
minerals.
X-ray Excited Optical Luminescence (XEOL) and Thermoluminescence (TL) measurements were taken
from 20 to 673 K. Fluorite responses result from a balance of intrinsic luminescence and REE
substituents and evidence for REE and defect coupling. TL indicates the presence of electron traps and
the coupling of these traps to lanthanide emissions, and it shows that the defect and the lanthanide
are clustered in physical space. The absence of changes in TL for different lanthanides shows that
energy is passed efficiently between rare earths, indicating that the REE are clustered.
The zirconosilicates all show increased intensity in XEOL response below 150 K. Cryogenic emissions
are interpreted as originating from the host mineral. There are 3 shared features: UV (~280 nm)
paramagnetic oxygen or oxygen vacancy; blue (440 nm) Al-O⁻-Al /Ti centres; and REE. Wöhlerite and eudialyte show Fe³⁺ band (~708 nm) and wöhlerite displays broad emission attributed to Mn²⁺. Eudialyte shows two additional responses; UV (~320 nm) tentatively assigned to Na migration and
UV/blue (~400 nm) potentially associated with charge balances associated with the coupled
substitution of Al³⁺. Eudialyte shows little emission at room temperature, this is attributed to quenching from Fe²⁺. Emission from eudialyte above room temperature is attributed to alteration
minerals such as catapleiite and potentially to inclusions of luminescent primary mineral phases.
I demonstrate that smart sorting could be a valuable beneficiation tool for REE minerals.
2020-07-29T00:00:00Z
Horsburgh, Nicola Jane
This thesis examines the luminescence and mineral physics of Rare Earth Element (REE) bearing
minerals as a precursor to developing smart sorting tools for critical metals used in low-carbon
technologies. I characterise luminescence responses of complex zirconosilicates; eudialyte
(Na₁₅Ca₆(Fe²⁺,Mn²⁺)₃Zr₃[Si₂₅O₇₃](O,OH,H₂O)₃(OH,Cl)₂), wöhlerite (NaCa₂(Zr,Nb)(Si₂O₇)(O,OH,F)₂) and
catapleiite (Na₂Zr(Si₃O₉) · 2H2₂O). Fluorite was included as it is commonly associated with REE ores and
displays strong REE luminescence. Its behaviour provides key insights into REE substitution into ionic
minerals.
X-ray Excited Optical Luminescence (XEOL) and Thermoluminescence (TL) measurements were taken
from 20 to 673 K. Fluorite responses result from a balance of intrinsic luminescence and REE
substituents and evidence for REE and defect coupling. TL indicates the presence of electron traps and
the coupling of these traps to lanthanide emissions, and it shows that the defect and the lanthanide
are clustered in physical space. The absence of changes in TL for different lanthanides shows that
energy is passed efficiently between rare earths, indicating that the REE are clustered.
The zirconosilicates all show increased intensity in XEOL response below 150 K. Cryogenic emissions
are interpreted as originating from the host mineral. There are 3 shared features: UV (~280 nm)
paramagnetic oxygen or oxygen vacancy; blue (440 nm) Al-O⁻-Al /Ti centres; and REE. Wöhlerite and eudialyte show Fe³⁺ band (~708 nm) and wöhlerite displays broad emission attributed to Mn²⁺. Eudialyte shows two additional responses; UV (~320 nm) tentatively assigned to Na migration and
UV/blue (~400 nm) potentially associated with charge balances associated with the coupled
substitution of Al³⁺. Eudialyte shows little emission at room temperature, this is attributed to quenching from Fe²⁺. Emission from eudialyte above room temperature is attributed to alteration
minerals such as catapleiite and potentially to inclusions of luminescent primary mineral phases.
I demonstrate that smart sorting could be a valuable beneficiation tool for REE minerals.
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Alteration and fluid flow associated with sediment-hosted stratiform copper mineralisation in the 1.1 Ga Midcontinent Rift System, USA
https://hdl.handle.net/10023/23982
The White Pine Cu-Ag deposit is one of the World’s largest examples of a sediment-
hosted copper (SHC) mineral system, with a pre-mining resource of >10 Mt of Cu
metal. The deposit is located on the southern shore of Lake Superior, in Michigan’s
Upper Peninsula. Mineralisation is hosted in the late-Mesoproterozoic Keweenawan
Supergroup of the Midcontinent Rift System (MRS). This succession comprises 20 km
of flood basalts overlain by 10 km of clastic sedimentary rocks. The age, extraordinary
volume of basalt and paucity of evaporite minerals distinguishes the MRS from other
major sediment-hosted Cu basins. Basin formation commenced at c. 1111 Ma, possibly
in response to a mantle plume impacting the base of the lithosphere. The mass of
basalts loaded onto the crust initially drove rapid basin subsidence, forming sag-geometry
basalt
flows
in
the
absence
of
syn-volcanic
faults.
Volcanism
ceased
abruptly
at
c. 1090 Ma and the Oronto Group sediments were deposited at a lower rate of
subsidence. The Copper Harbor and Nonesuch Formations were deposited in a braided
fluvial-marine embayment-sabkha environment. Seawater formed the basis for the
ore-forming fluids. Metals were sourced from the breakdown of basaltic detrital grains
in the Copper Harbor Formation. A Re-Os age of chalcocite mineralisation of 1039 ± 4
Ma corresponds to the early Ottawan phase of the Grenvillian orogenesis, which
caused incipient basin inversion and deposition of the Freda Formation molasse. This
simultaneous burial and mild compression expelled fluids from the Copper Harbor
Formation aquifer. Ore precipitated via reduction of fluids by both in situ organic
matter and liquid petroleum, and thermochemical sulphate reduction, at
temperatures of c. 125˚C. Early Cu-Fe-sulphides nucleated on detrital and authigenic
chlorite. The advancement of the peneconcordant ore zones resulted in their eventual
replacement by chalcocite and native Cu, reflecting the relatively oxidised conditions
and the low sulphur content of late-Mesoproterozoic seawater.
2020-12-01T00:00:00Z
Jones, Simon Mark
The White Pine Cu-Ag deposit is one of the World’s largest examples of a sediment-
hosted copper (SHC) mineral system, with a pre-mining resource of >10 Mt of Cu
metal. The deposit is located on the southern shore of Lake Superior, in Michigan’s
Upper Peninsula. Mineralisation is hosted in the late-Mesoproterozoic Keweenawan
Supergroup of the Midcontinent Rift System (MRS). This succession comprises 20 km
of flood basalts overlain by 10 km of clastic sedimentary rocks. The age, extraordinary
volume of basalt and paucity of evaporite minerals distinguishes the MRS from other
major sediment-hosted Cu basins. Basin formation commenced at c. 1111 Ma, possibly
in response to a mantle plume impacting the base of the lithosphere. The mass of
basalts loaded onto the crust initially drove rapid basin subsidence, forming sag-geometry
basalt
flows
in
the
absence
of
syn-volcanic
faults.
Volcanism
ceased
abruptly
at
c. 1090 Ma and the Oronto Group sediments were deposited at a lower rate of
subsidence. The Copper Harbor and Nonesuch Formations were deposited in a braided
fluvial-marine embayment-sabkha environment. Seawater formed the basis for the
ore-forming fluids. Metals were sourced from the breakdown of basaltic detrital grains
in the Copper Harbor Formation. A Re-Os age of chalcocite mineralisation of 1039 ± 4
Ma corresponds to the early Ottawan phase of the Grenvillian orogenesis, which
caused incipient basin inversion and deposition of the Freda Formation molasse. This
simultaneous burial and mild compression expelled fluids from the Copper Harbor
Formation aquifer. Ore precipitated via reduction of fluids by both in situ organic
matter and liquid petroleum, and thermochemical sulphate reduction, at
temperatures of c. 125˚C. Early Cu-Fe-sulphides nucleated on detrital and authigenic
chlorite. The advancement of the peneconcordant ore zones resulted in their eventual
replacement by chalcocite and native Cu, reflecting the relatively oxidised conditions
and the low sulphur content of late-Mesoproterozoic seawater.
-
Rapid climate change in the glacial North Atlantic : new insights from geochemical records of temperature, CO₂, redox and circulation
https://hdl.handle.net/10023/23880
Rapid climate change events of the last glacial period are a prime example of the climate system’s ability to flip quickly between different states. These are associated with abrupt shifts in temperature, productivity and CO₂ and are commonly linked with major changes in circulation and sea-ice coverage in the high latitude North Atlantic Ocean. However, despite what is an increasingly well-established paradigm, major questions remain about the links between circulation, temperature, ice-sheet stability and CO₂ storage. This thesis presents a collection of new, high resolution records from Northeast Atlantic core ODP 980, which develop our understanding of the region’s role in rapid climate change.
Analysis of two robust paleo-temperature proxies (percentage abundance and Mg/Ca of Neogloboquadrina pachyderma) reveals the first marine evidence that Heinrich stadials were intervals of extreme seasonality, characterised by very cold winters and increasingly warm summers. These rising temperatures which are attributed to weak Atlantic Meridional Overturning circulation (AMOC), climbing atmospheric CO₂ and the insulating effect of sea ice, support theories for ice-sheet destabilisation in an otherwise cold climate. High resolution boron isotope data also resolve major perturbations of CO₂ in the surface ocean at climate transitions. These show that the North Atlantic CO₂ sink, which persists during stadial periods, weakened dramatically at interstadial onset, likely maintaining elevated atmospheric CO₂ and uncovering a new role for the region in rapid climate change.
Recent studies using authigenic coatings on foraminifera, have employed redox sensitive elements to reconstruct deep water oxygen concentrations. However, data from different oceanic settings, combined with a geochemical model, highlight the sensitivity of element enrichment to changes in surface productivity. The influence of sediment composition is also examined with regards to authigenic Nd/Mn ratios, which show exciting promise as a new indicator of AMOC strength. Together these authigenic data offer new opportunities for paleoclimate reconstruction.
2021-12-01T00:00:00Z
Littley, Eloise Frances Margaret
Rapid climate change events of the last glacial period are a prime example of the climate system’s ability to flip quickly between different states. These are associated with abrupt shifts in temperature, productivity and CO₂ and are commonly linked with major changes in circulation and sea-ice coverage in the high latitude North Atlantic Ocean. However, despite what is an increasingly well-established paradigm, major questions remain about the links between circulation, temperature, ice-sheet stability and CO₂ storage. This thesis presents a collection of new, high resolution records from Northeast Atlantic core ODP 980, which develop our understanding of the region’s role in rapid climate change.
Analysis of two robust paleo-temperature proxies (percentage abundance and Mg/Ca of Neogloboquadrina pachyderma) reveals the first marine evidence that Heinrich stadials were intervals of extreme seasonality, characterised by very cold winters and increasingly warm summers. These rising temperatures which are attributed to weak Atlantic Meridional Overturning circulation (AMOC), climbing atmospheric CO₂ and the insulating effect of sea ice, support theories for ice-sheet destabilisation in an otherwise cold climate. High resolution boron isotope data also resolve major perturbations of CO₂ in the surface ocean at climate transitions. These show that the North Atlantic CO₂ sink, which persists during stadial periods, weakened dramatically at interstadial onset, likely maintaining elevated atmospheric CO₂ and uncovering a new role for the region in rapid climate change.
Recent studies using authigenic coatings on foraminifera, have employed redox sensitive elements to reconstruct deep water oxygen concentrations. However, data from different oceanic settings, combined with a geochemical model, highlight the sensitivity of element enrichment to changes in surface productivity. The influence of sediment composition is also examined with regards to authigenic Nd/Mn ratios, which show exciting promise as a new indicator of AMOC strength. Together these authigenic data offer new opportunities for paleoclimate reconstruction.
-
Title redacted
https://hdl.handle.net/10023/23851
2021-12-01T00:00:00Z
Shen, Jianxun
-
Thinking energy ethics with care : citizens' perspectives on energy & the low-carbon transition
https://hdl.handle.net/10023/23505
Social science energy research is asking important questions about the social, political, and economic implications of energy transitions, and the consequent changing roles and relationships in the energy system. This has given rise to ethically and politically driven research agendas, for example around energy poverty and justice, as well as emerging conceptions of democracy and citizenship in the energy context. Within this scholarship, there is an increasing focus on the need to better understand how people relate in their daily lives, both to mundane dilemmas around energy use, and to bigger questions around energy systems and energy system change.
This thesis builds on these discussions with a particular focus on the concept of energy citizenship, an increasingly popular concept in both academic and political energy discourse. The thesis explores how a better understanding of citizens’ ethical attitudes towards energy might inform theorising of energy citizenship to better reflect everyday engagements with energy and energy transitions. To address this question, I draw on findings from Q-methodological research conducted in Denmark and the UK, and further reflect on the relevance of Q-methodology as a tool for social science energy research.
A Q-methodological study was conducted through interviews with thirty-nine residents in the UK and Denmark, in which participants were asked to consider a range of opinion statements drawn from public debates around energy transitions. Q-methodology was found to be a useful tool for opening up the complexities and ambiguities of the topic of energy transitions, in conversation with people of varying levels of energy knowledge.
The findings indicate that relational understandings of energy systems and a language of dependence, necessity and mutual responsibility are important elements in how people make sense of the energy transition and their place in it. This speaks strongly to recent advances of relational theories of energy systems and transitions, but calls for a recognition not only of inter-connections and relations, but of their ethical significance. To this end, I discuss the relevance of a care ethical framework for enriching our thinking around energy citizenship, and energy ethics more broadly.
2021-06-30T00:00:00Z
Damgaard, Caroline Sejer
Social science energy research is asking important questions about the social, political, and economic implications of energy transitions, and the consequent changing roles and relationships in the energy system. This has given rise to ethically and politically driven research agendas, for example around energy poverty and justice, as well as emerging conceptions of democracy and citizenship in the energy context. Within this scholarship, there is an increasing focus on the need to better understand how people relate in their daily lives, both to mundane dilemmas around energy use, and to bigger questions around energy systems and energy system change.
This thesis builds on these discussions with a particular focus on the concept of energy citizenship, an increasingly popular concept in both academic and political energy discourse. The thesis explores how a better understanding of citizens’ ethical attitudes towards energy might inform theorising of energy citizenship to better reflect everyday engagements with energy and energy transitions. To address this question, I draw on findings from Q-methodological research conducted in Denmark and the UK, and further reflect on the relevance of Q-methodology as a tool for social science energy research.
A Q-methodological study was conducted through interviews with thirty-nine residents in the UK and Denmark, in which participants were asked to consider a range of opinion statements drawn from public debates around energy transitions. Q-methodology was found to be a useful tool for opening up the complexities and ambiguities of the topic of energy transitions, in conversation with people of varying levels of energy knowledge.
The findings indicate that relational understandings of energy systems and a language of dependence, necessity and mutual responsibility are important elements in how people make sense of the energy transition and their place in it. This speaks strongly to recent advances of relational theories of energy systems and transitions, but calls for a recognition not only of inter-connections and relations, but of their ethical significance. To this end, I discuss the relevance of a care ethical framework for enriching our thinking around energy citizenship, and energy ethics more broadly.
-
Alteration of Ballantrae lavas, Ayrshire
https://hdl.handle.net/10023/21867
The Pinbain Block of the Ballantrae Complex has suffered a very low grade metamorphism, with the formation of albite-chlorite-sphene mineral assemblages. The base of the succession also has prehnite and pumpellyite, indicating the prehnite-pumpellyite fades, while the top is in the zeolite fades, and contains analcime. The temperature of the transition, based on mineral stabilities, is <190°C. The metamorphism affected the sedimentary cover of the Ballantrae Complex, and it occurred without penetrative deformation, therefore it was a burial metamorphism.
Stable isotope studies show that the rocks were altered by large quantities of sea water, at a temperature of 150-170°C. This alteration resulted in the mobilisation of many of the chemical elements in the Pinbain Rocks, in a manner similar to that seen in experiments in which basalts are altered by sea water. Titanium, zirconium and yttrium remained immobile, and these elements can be used to identify the rocks as within-plate basalts.
Fluid inclusion studies show that some of the veins in the Pinbain Block were formed by a high-temperature hydrothermal fluid, which probably formed the ascending leg of a hydrothermal cell, which was replenished by downwards percolation of sea water. The metamorphism probably occurred at the time of deepest burial, at the end of the Silurian, when Caledonian orogenesis may have raised the geothermal gradient and triggered the hydrothermal circulation.
1990-01-01T00:00:00Z
Marshall, Andrew David
The Pinbain Block of the Ballantrae Complex has suffered a very low grade metamorphism, with the formation of albite-chlorite-sphene mineral assemblages. The base of the succession also has prehnite and pumpellyite, indicating the prehnite-pumpellyite fades, while the top is in the zeolite fades, and contains analcime. The temperature of the transition, based on mineral stabilities, is <190°C. The metamorphism affected the sedimentary cover of the Ballantrae Complex, and it occurred without penetrative deformation, therefore it was a burial metamorphism.
Stable isotope studies show that the rocks were altered by large quantities of sea water, at a temperature of 150-170°C. This alteration resulted in the mobilisation of many of the chemical elements in the Pinbain Rocks, in a manner similar to that seen in experiments in which basalts are altered by sea water. Titanium, zirconium and yttrium remained immobile, and these elements can be used to identify the rocks as within-plate basalts.
Fluid inclusion studies show that some of the veins in the Pinbain Block were formed by a high-temperature hydrothermal fluid, which probably formed the ascending leg of a hydrothermal cell, which was replenished by downwards percolation of sea water. The metamorphism probably occurred at the time of deepest burial, at the end of the Silurian, when Caledonian orogenesis may have raised the geothermal gradient and triggered the hydrothermal circulation.
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Investigations into a macrosegregated, differentiated dolerite dyke, northern Skye, Scotland
https://hdl.handle.net/10023/21844
The Mystery Dyke is a differentiated dolerite sheet intruded along hexagonal joints of the Bornaskitaig leaf of the Little Minch Sill Complex (L.M.S.C.)/ northern Skye. Near-vertical banding parallel to the margins and approximately symmetrical about the median plane is displayed along the exposed 65m length of the dyke. A complete half-transect across the northern part of the dyke, comprising 11 bands distinguished on the basis of modal and textural differences has been obtained. The bands however may change progressively laterally along strike with certain amygdaloidal bands bifurcating both vertically and along strike. Bands of particular interest contain comb-layered olivine- and plagioclase or pyroxene. In the northern part, olivine- and plagioclase are the common comb-layered minerals, while to the south comb-layered pyroxene is more abundant. Petrographically, the normally porphyritic dyke is diverse, with comb-layering, ophitic, poikiliophitic and trachytic textures and chills developed. Whole-rock analyses of the bands indicate that the dyke consists of three distinct chemical groupings which have a general affinity with the L.M.S.C. picrodolerite analyses of Gibson (1988).
Variation in whole-rock and mineral analyses across the banding may be progressive or abrupt. Comb-layered olivine- and plagioclase have restricted compositions with forsterite content increasing into the bands, towards the centre of the dyke. This suggest that supercooling of magma declined through the growth of these bands (or the melt became magnesium-rich). The dyke is multiple in type, although the compositional variations are not so great as to merit the term composite. A provisional model of oogenetic pulses of melt plus crystal-mush over a short time period, from a vertically layered, shallow-level chamber similar to that proposed by Gibson and Jones (1991) as the source for the Little Minch Sill Complex is proposed.
1993-01-01T00:00:00Z
Kyle, Alison H.
The Mystery Dyke is a differentiated dolerite sheet intruded along hexagonal joints of the Bornaskitaig leaf of the Little Minch Sill Complex (L.M.S.C.)/ northern Skye. Near-vertical banding parallel to the margins and approximately symmetrical about the median plane is displayed along the exposed 65m length of the dyke. A complete half-transect across the northern part of the dyke, comprising 11 bands distinguished on the basis of modal and textural differences has been obtained. The bands however may change progressively laterally along strike with certain amygdaloidal bands bifurcating both vertically and along strike. Bands of particular interest contain comb-layered olivine- and plagioclase or pyroxene. In the northern part, olivine- and plagioclase are the common comb-layered minerals, while to the south comb-layered pyroxene is more abundant. Petrographically, the normally porphyritic dyke is diverse, with comb-layering, ophitic, poikiliophitic and trachytic textures and chills developed. Whole-rock analyses of the bands indicate that the dyke consists of three distinct chemical groupings which have a general affinity with the L.M.S.C. picrodolerite analyses of Gibson (1988).
Variation in whole-rock and mineral analyses across the banding may be progressive or abrupt. Comb-layered olivine- and plagioclase have restricted compositions with forsterite content increasing into the bands, towards the centre of the dyke. This suggest that supercooling of magma declined through the growth of these bands (or the melt became magnesium-rich). The dyke is multiple in type, although the compositional variations are not so great as to merit the term composite. A provisional model of oogenetic pulses of melt plus crystal-mush over a short time period, from a vertically layered, shallow-level chamber similar to that proposed by Gibson and Jones (1991) as the source for the Little Minch Sill Complex is proposed.
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Heavy mineral analyses and facies interpretations of part of the calciferous sandstone measures, Pittenweem, E. Fife, Scotland
https://hdl.handle.net/10023/21825
A vertical section of fluvio - deltaic sediments of Dinantian age is exposed along the coast in Fife. These sediments form a series of cycles and cycle types evolving by progradation into a shallow bay area at the eastern end of the Midland Valley. Analysis of the heavy fraction indicates provenance from a variety of rock types comprising the Caledonian Massif. Although certain suites can be identified it is impossible to determine absolutely the origin of the sediment due to transport and deposition effects. The analysis of the delta cycle patterns shows an increased importance of marine influences towards the top of the section resulting in limestone formation. The measured section shows five distinctive environments of deposition - swamp, splay, channel, overbank interdistributary and lagoon each with their own distinctive types of sediment, structure and sedimentation pattern. The overlying form is of a birdfoot lobate type delta similar to that of the Guadalupe Delta of Texas.
1990-01-01T00:00:00Z
Robertson, Alasdair E.
A vertical section of fluvio - deltaic sediments of Dinantian age is exposed along the coast in Fife. These sediments form a series of cycles and cycle types evolving by progradation into a shallow bay area at the eastern end of the Midland Valley. Analysis of the heavy fraction indicates provenance from a variety of rock types comprising the Caledonian Massif. Although certain suites can be identified it is impossible to determine absolutely the origin of the sediment due to transport and deposition effects. The analysis of the delta cycle patterns shows an increased importance of marine influences towards the top of the section resulting in limestone formation. The measured section shows five distinctive environments of deposition - swamp, splay, channel, overbank interdistributary and lagoon each with their own distinctive types of sediment, structure and sedimentation pattern. The overlying form is of a birdfoot lobate type delta similar to that of the Guadalupe Delta of Texas.
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An exploration of the implementation of global REDD+ policy in Nigeria's neo-patrimonial context : implications for sustainable development
https://hdl.handle.net/10023/21588
REDD+ is a global programme for disbursing funds, primarily to pay national governments in
developing countries to reduce forest carbon emission. REDD+ is presently translated from
global discourse into national arena amidst on-the-ground realities of weak governance,
corruption, and power struggles. This thesis responds to these concerns towards
implementing REDD+ policy sustainably. In the last 5 years, Nigeria REDD+ went through a
national readiness phase and is piloted at sub-national scale. However, its governance is
essentially a political process likely to face strong opposition from those benefiting from the
status quo.
This thesis conducts an exploratory analysis to investigate how global REDD+ policy discourse
transforms in a local political setting, to have in-depth understanding of how different forms
of governance influence forest policy outcomes. I draw on political ecology in an investigation
of the politics over forest management and builds on a modified ‘4Is’ analytical framework –
Institutions, Interests, Ideas and Information – to explore actors’ perceptions to analyse
REDD+. The study was qualitative in design and employed the triangulation approach,
participant observation, document analysis, FGDs and interview methods to establish the
problem. Unpacking REDD+ design and implementation interaction could holistically identify
intrinsic institutional impediments in the context of sustainable development.
An analysis brings up a number of key issues. Actor constellations understand, interpret and
implement REDD+ through a ‘complex’ governance setting, deeply entrenched political
system. This limit the potential for transforming a business-as-usual to achieve emissions
reductions. I question the naïve assumption that Nigeria REDD+ is a “win-win” strategy under
the ‘rules of the game’, as against the performed ‘tricks of the game’ embedded in the political
context.
Throughout this thesis I argue that Nigeria REDD+ is seized upon as an opportunity to promote
neo-patrimonial governance system. Findings suggest therefore, the potential for its long-term
sustainability will be a challenge.
2020-12-01T00:00:00Z
Adogame, Aneshimode
REDD+ is a global programme for disbursing funds, primarily to pay national governments in
developing countries to reduce forest carbon emission. REDD+ is presently translated from
global discourse into national arena amidst on-the-ground realities of weak governance,
corruption, and power struggles. This thesis responds to these concerns towards
implementing REDD+ policy sustainably. In the last 5 years, Nigeria REDD+ went through a
national readiness phase and is piloted at sub-national scale. However, its governance is
essentially a political process likely to face strong opposition from those benefiting from the
status quo.
This thesis conducts an exploratory analysis to investigate how global REDD+ policy discourse
transforms in a local political setting, to have in-depth understanding of how different forms
of governance influence forest policy outcomes. I draw on political ecology in an investigation
of the politics over forest management and builds on a modified ‘4Is’ analytical framework –
Institutions, Interests, Ideas and Information – to explore actors’ perceptions to analyse
REDD+. The study was qualitative in design and employed the triangulation approach,
participant observation, document analysis, FGDs and interview methods to establish the
problem. Unpacking REDD+ design and implementation interaction could holistically identify
intrinsic institutional impediments in the context of sustainable development.
An analysis brings up a number of key issues. Actor constellations understand, interpret and
implement REDD+ through a ‘complex’ governance setting, deeply entrenched political
system. This limit the potential for transforming a business-as-usual to achieve emissions
reductions. I question the naïve assumption that Nigeria REDD+ is a “win-win” strategy under
the ‘rules of the game’, as against the performed ‘tricks of the game’ embedded in the political
context.
Throughout this thesis I argue that Nigeria REDD+ is seized upon as an opportunity to promote
neo-patrimonial governance system. Findings suggest therefore, the potential for its long-term
sustainability will be a challenge.
-
Theoretical and practical geological remote sensing in an arid environment : Landsat MSS imagery of the Central Zone of the Damara Orogen, Namibia
https://hdl.handle.net/10023/21229
Two adjacent Landsat Multispectral Scanner (MSS) scenes have been digitally processed and
enhanced to maximise the display of geological information contained within imagery covering
the western portion of the Central Zone of the Damara Orogen, Namibia.
Structural information has been obtained from the spatial component of image information
through the compilation of lineament maps. Linear features have been objectively enhanced
through the generation of the first principal component image and by convolution filtering. By
means of visual interpretation, linear features have then been mapped, then digitised and
subjected to computer analysis to establish any orientation trends. Positive topographic
lineaments, which represent the Etendeka regional dolerite dyke swarm (130-120 Ma), show a
strong north-northeast trend and are closely associated with the splitting of Gondwana and the
formation of the Southern Atlantic Ocean. Negative topographic lineaments are believed to
represent sinistral strike-slip faults and show a strong northwest trend. They are believed to
have formed under brittle conditions at the end of the Damaran Orogen. Tonal lineaments,
caused by linear lithological horizons, either side of parallel fold axes, show a dominant
northeast trend, and are believed to have formed during either compressional or extensional
conditions during the main Damaran deformation event. A number of regional photolineaments
are also recognisable from the Landsat imagery.
A remotely-sensed geology map has also been produced using both the spatial and spectral
components of image information. Mappable lithological units have been established in a
previously mapped test area, and these units have been extrapolated further afield to produce a
regional geology map of the western portion of the Central Zone of the Damara Orogen.
Comparison with published geology maps of the same area shows that the procedure proves
generally effective and new outcrops of basement rocks have been recognised in the area to the
west of the Namibfontein Dome. However, the limited spectral resolution of the imagery is
high-lighted by the inability to resolve between the Rossing, Chuos and Karibib Formations.
The study area proves to be well-suited to geological remote sensing using Landsat MSS imagery
because of the excellent rock exposure in the region, the lack of vegetation, and the wide variety
of lithologies which appear spectrally distinct from one another on digitally-enhanced imagery. The procedure provides a low-cost, effective means of geological reconnaissance which is well-suited to remote and inaccessible areas.
1995-07-07T00:00:00Z
Lord, Jeffrey
Two adjacent Landsat Multispectral Scanner (MSS) scenes have been digitally processed and
enhanced to maximise the display of geological information contained within imagery covering
the western portion of the Central Zone of the Damara Orogen, Namibia.
Structural information has been obtained from the spatial component of image information
through the compilation of lineament maps. Linear features have been objectively enhanced
through the generation of the first principal component image and by convolution filtering. By
means of visual interpretation, linear features have then been mapped, then digitised and
subjected to computer analysis to establish any orientation trends. Positive topographic
lineaments, which represent the Etendeka regional dolerite dyke swarm (130-120 Ma), show a
strong north-northeast trend and are closely associated with the splitting of Gondwana and the
formation of the Southern Atlantic Ocean. Negative topographic lineaments are believed to
represent sinistral strike-slip faults and show a strong northwest trend. They are believed to
have formed under brittle conditions at the end of the Damaran Orogen. Tonal lineaments,
caused by linear lithological horizons, either side of parallel fold axes, show a dominant
northeast trend, and are believed to have formed during either compressional or extensional
conditions during the main Damaran deformation event. A number of regional photolineaments
are also recognisable from the Landsat imagery.
A remotely-sensed geology map has also been produced using both the spatial and spectral
components of image information. Mappable lithological units have been established in a
previously mapped test area, and these units have been extrapolated further afield to produce a
regional geology map of the western portion of the Central Zone of the Damara Orogen.
Comparison with published geology maps of the same area shows that the procedure proves
generally effective and new outcrops of basement rocks have been recognised in the area to the
west of the Namibfontein Dome. However, the limited spectral resolution of the imagery is
high-lighted by the inability to resolve between the Rossing, Chuos and Karibib Formations.
The study area proves to be well-suited to geological remote sensing using Landsat MSS imagery
because of the excellent rock exposure in the region, the lack of vegetation, and the wide variety
of lithologies which appear spectrally distinct from one another on digitally-enhanced imagery. The procedure provides a low-cost, effective means of geological reconnaissance which is well-suited to remote and inaccessible areas.
-
Government resettlement as participatory adaptation to climate change : exploring the role of knowledge in the Lower Shire region of Malawi
https://hdl.handle.net/10023/20615
There has been debate over how environmental change will influence migration. This
PhD explores one aspect of this: the impact of flooding on migration patterns and the
subsequent move by government actors to govern these migration patterns through
resettlement in Malawi. This research suggests that this move to govern migration reflects a
broader shift in the discourse of seeing migration as a positive opportunity and as adaptation
to environmental change. It focuses on the Lower Shire region of Malawi, an area particularly
impacted by flooding, and especially reflects on the participatory nature of the resettlement
process, as this is highlighted by influential international guidelines as being necessary for the
resettlement to be adaptive rather than mal-adaptive. To this end the research focuses on
the knowledges involved and the varying power dynamics. Fieldwork occurred between
August and November 2017 and consisted of 48 Interviews and six focus group discussions
with three communities in the Lower Shire that had three different attitudes (unwilling,
undecided, and resettled) towards resettlement. As well as 21 interviews with stakeholders
in government and NGOs involved in these communities and in the resettlement process at a
national and district level. The data showed that flooding related movements already occur
in the communities but, due to the increasing severity of flooding, there is a growing desire
by those in government and NGOs to initiate their own resettlement. However, official
resettlement due to flooding is novel in Malawi, and there is confusion over what it entails
and who is involved. This appears to lead to a disconnect between Resettlement, established
by the government and resettlement, movements initiated by those in vulnerable
communities. The data suggests that a key reason this disconnect develops is due to the
different perceptions of knowledge. It appears that there is a subtly pervasive disregard of
community knowledge and this can reduce the community agency within the resettlement
process and prevent it from being participatory. However, the data also highlighted the
intriguing ways the communities themselves can re-appropriate resettlement to indicate
their needs in the process, illustrating the fluidity of knowledge and power within the
resettlement process in Malawi.
2020-12-01T00:00:00Z
Nicholson, Hebe
There has been debate over how environmental change will influence migration. This
PhD explores one aspect of this: the impact of flooding on migration patterns and the
subsequent move by government actors to govern these migration patterns through
resettlement in Malawi. This research suggests that this move to govern migration reflects a
broader shift in the discourse of seeing migration as a positive opportunity and as adaptation
to environmental change. It focuses on the Lower Shire region of Malawi, an area particularly
impacted by flooding, and especially reflects on the participatory nature of the resettlement
process, as this is highlighted by influential international guidelines as being necessary for the
resettlement to be adaptive rather than mal-adaptive. To this end the research focuses on
the knowledges involved and the varying power dynamics. Fieldwork occurred between
August and November 2017 and consisted of 48 Interviews and six focus group discussions
with three communities in the Lower Shire that had three different attitudes (unwilling,
undecided, and resettled) towards resettlement. As well as 21 interviews with stakeholders
in government and NGOs involved in these communities and in the resettlement process at a
national and district level. The data showed that flooding related movements already occur
in the communities but, due to the increasing severity of flooding, there is a growing desire
by those in government and NGOs to initiate their own resettlement. However, official
resettlement due to flooding is novel in Malawi, and there is confusion over what it entails
and who is involved. This appears to lead to a disconnect between Resettlement, established
by the government and resettlement, movements initiated by those in vulnerable
communities. The data suggests that a key reason this disconnect develops is due to the
different perceptions of knowledge. It appears that there is a subtly pervasive disregard of
community knowledge and this can reduce the community agency within the resettlement
process and prevent it from being participatory. However, the data also highlighted the
intriguing ways the communities themselves can re-appropriate resettlement to indicate
their needs in the process, illustrating the fluidity of knowledge and power within the
resettlement process in Malawi.
-
Geochemical reconstructions of Southern Ocean pH and temperature over the last glacial cycle
https://hdl.handle.net/10023/20385
The Southern Ocean is widely thought to play an important role in atmospheric CO₂ change over glacial-interglacial cycles. It has been suggested that as the region that ventilates the majority of the world’s carbon-rich deep waters today, reduced exchange between deep waters and the atmosphere in the Southern Ocean acted to draw down CO₂ over glacial timescales. However, direct evidence of the Southern Ocean’s role in glacial CO₂ drawdown has been lacking thus far.
Here I apply the boron-isotope pH-proxy to foraminifera from the Antarctic Zone sediment core PS1506 over the last glacial cycle. The low boron concentrations in these polar foraminifera makes these samples particularly sensitive to boron blank and so a close examination of the sources of blank, and an assessment of the precision of blank measurements, has been made.
The ratios of trace elements to calcium in foraminiferal shells are widely applied as proxies for palaeoenvironmental parameters such as temperature. As Southern Ocean carbonate sediments are particularly prone to dissolution, which can affect trace element concentrations, an assessment of dissolution has been made. Firstly, dissolution experiments were conducted to constrain the impact of dissolution in a controlled setting, and secondly, shell mass and trace elements were evaluated for the downcore record. Imaging reveals similar etching textures in both experimentally dissolved samples and deglacial intervals, when shell mass is also low and several trace elements exhibit an excursion to lower values.
Boron isotope data for PS1506 show that during the penultimate interglacial, surface water pH was low. At the onset of atmospheric CO₂ drawdown, pH increased, indicating low CO₂ surface waters. This is consistent with the signature predicted for a more stratified Southern Ocean, and is evidence that stratification in the Antarctic Zone acted to contribute to CO₂ drawdown early in the transition to a glacial state.
2020-12-01T00:00:00Z
Crumpton-Banks, Jessica Georgina Magdalen
The Southern Ocean is widely thought to play an important role in atmospheric CO₂ change over glacial-interglacial cycles. It has been suggested that as the region that ventilates the majority of the world’s carbon-rich deep waters today, reduced exchange between deep waters and the atmosphere in the Southern Ocean acted to draw down CO₂ over glacial timescales. However, direct evidence of the Southern Ocean’s role in glacial CO₂ drawdown has been lacking thus far.
Here I apply the boron-isotope pH-proxy to foraminifera from the Antarctic Zone sediment core PS1506 over the last glacial cycle. The low boron concentrations in these polar foraminifera makes these samples particularly sensitive to boron blank and so a close examination of the sources of blank, and an assessment of the precision of blank measurements, has been made.
The ratios of trace elements to calcium in foraminiferal shells are widely applied as proxies for palaeoenvironmental parameters such as temperature. As Southern Ocean carbonate sediments are particularly prone to dissolution, which can affect trace element concentrations, an assessment of dissolution has been made. Firstly, dissolution experiments were conducted to constrain the impact of dissolution in a controlled setting, and secondly, shell mass and trace elements were evaluated for the downcore record. Imaging reveals similar etching textures in both experimentally dissolved samples and deglacial intervals, when shell mass is also low and several trace elements exhibit an excursion to lower values.
Boron isotope data for PS1506 show that during the penultimate interglacial, surface water pH was low. At the onset of atmospheric CO₂ drawdown, pH increased, indicating low CO₂ surface waters. This is consistent with the signature predicted for a more stratified Southern Ocean, and is evidence that stratification in the Antarctic Zone acted to contribute to CO₂ drawdown early in the transition to a glacial state.
-
Title redacted
https://hdl.handle.net/10023/20220
2020-07-29T00:00:00Z
Hiles, William
-
North Atlantic marine tephrochronology : a tool for reconstructing events and processes during the penultimate glacial-interglacial cycle
https://hdl.handle.net/10023/19595
The focus of this thesis is the analyses of tephra deposits found in the penultimate glacial–interglacial interval of the marine sediments from Integrated Ocean Drilling Project (IODP) Site U1304, southern Gardar Drift, North Atlantic. The location and the high-resolution of U1304 are ideal to investigate changes in deep-ocean ventilation, sea-surface circulation pattern well as ice-sheet dynamics. Especially, the climate conditions during the Last Interglacial (LIG) with warmer annual temperature and higher global sea-level are of particular interest because this period is often seen as an analogue to predicted future climate scenarios.
By means of geochemical and shard size analyses the transport mechanism of the tephra deposits were determined. The tephra deposits found during the penultimate glacial (Marine Isotope Stage 6 (MIS 6)) were transported by iceberg–rafting. Comparison of individual shard geochemistry with the geochemistry of Holocene volcanic systems from Iceland showed that the shards originated from different volcanic systems on Iceland. Combining source evidence with Icelandic Ice Sheet (IIS) flow models for the Last Glacial Maximum (LGM) suggests that the IIS had marine calving margins to both the north and south of Iceland during the late MIS 6 and that icebergs could have been transported to the U1304 core site by following surface ocean circulation patterns similar to those that prevailed during the LGM.
In contrast, one of the analysed tephra horizons deposited during MIS 5e at the U1304 core site can be correlated with the known 5e-Eem/RHY-I isochron in the tephrostratigraphical framework of the North Atlantic. The 5e-Eem/RHY-I tephra is also found in the nearby marine sediment core MD99-2253. In both cores, U1304 and MD99-2253, the 5e-Eem/RHY-I tephra occurs just above the onset of fully-interglacial deep-ocean ventilation, indicated by an abrupt shift in foraminiferal benthic δ¹³C. Aligning both cores on a common timescale with the 5e-Eem/RHY-I age of 121.99 ± 1 ka as an additional tie-point, suggests that the onset to full-interglacial conditions occurred synchronously at both core sites. This finding provides the opportunity to develop a new event-based stratigraphy, reliably sub-dividing MIS 5e into an early and later phase.
Electronic version excludes material for which permission has not been granted by the rights holder
2016-11-30T00:00:00Z
Kuhs, Marion
The focus of this thesis is the analyses of tephra deposits found in the penultimate glacial–interglacial interval of the marine sediments from Integrated Ocean Drilling Project (IODP) Site U1304, southern Gardar Drift, North Atlantic. The location and the high-resolution of U1304 are ideal to investigate changes in deep-ocean ventilation, sea-surface circulation pattern well as ice-sheet dynamics. Especially, the climate conditions during the Last Interglacial (LIG) with warmer annual temperature and higher global sea-level are of particular interest because this period is often seen as an analogue to predicted future climate scenarios.
By means of geochemical and shard size analyses the transport mechanism of the tephra deposits were determined. The tephra deposits found during the penultimate glacial (Marine Isotope Stage 6 (MIS 6)) were transported by iceberg–rafting. Comparison of individual shard geochemistry with the geochemistry of Holocene volcanic systems from Iceland showed that the shards originated from different volcanic systems on Iceland. Combining source evidence with Icelandic Ice Sheet (IIS) flow models for the Last Glacial Maximum (LGM) suggests that the IIS had marine calving margins to both the north and south of Iceland during the late MIS 6 and that icebergs could have been transported to the U1304 core site by following surface ocean circulation patterns similar to those that prevailed during the LGM.
In contrast, one of the analysed tephra horizons deposited during MIS 5e at the U1304 core site can be correlated with the known 5e-Eem/RHY-I isochron in the tephrostratigraphical framework of the North Atlantic. The 5e-Eem/RHY-I tephra is also found in the nearby marine sediment core MD99-2253. In both cores, U1304 and MD99-2253, the 5e-Eem/RHY-I tephra occurs just above the onset of fully-interglacial deep-ocean ventilation, indicated by an abrupt shift in foraminiferal benthic δ¹³C. Aligning both cores on a common timescale with the 5e-Eem/RHY-I age of 121.99 ± 1 ka as an additional tie-point, suggests that the onset to full-interglacial conditions occurred synchronously at both core sites. This finding provides the opportunity to develop a new event-based stratigraphy, reliably sub-dividing MIS 5e into an early and later phase.
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Ethnic differences in health in Scotland : the contrast between morbidity and mortality
https://hdl.handle.net/10023/19578
In Scotland, most minority ethnic groups live longer than the White Scottish population but whether they report better health is unclear. Similarly, the international literature on ethnicity and health is divided between a strand that highlights the overall morbidity disadvantage in ethnic minorities and another strand that is puzzled by their mortality advantage. This thesis brings the two strands together by investigating whether ethnic patterns in morbidity and mortality align, based on a unique population source. The Scottish Health and Ethnicity Linkage Study links the Scottish Census 2001 to 12 years of hospitalisation and death records and provides a considerable sample size (4.6 million people) for this research. Therefore, this thesis makes a number of methodological contributions in addition to providing key empirical evidence of an ethnic morbidity-mortality paradox in Scotland. In particular, healthy life expectancy by sex and ethnicity is calculated for the first time in the UK using a direct method. Findings highlight the shortest healthy life expectancies in the Pakistani population contrasting with their mortality advantage. Hence, the Pakistani population experiences the highest number of years in poor health in Scotland. Indeed, the Pakistani population reports poorer health than the majority population which contrasts with their mortality advantage. This contrast persists beyond socio-economic circumstances and across migrant generations. Furthermore, using interaction analyses, this research demonstrates that reporting poorer health strongly predicts higher risks of mortality in minority ethnic groups but with greater strength for particular groups. Finally, findings show higher risks of (hospitalisation-based) multimorbidity in the Pakistani population which supports their morbidity disadvantage in Scotland. Diseases underlying this disadvantage include those related to the metabolic syndrome and respiratory disease. Policy makers should aim to improve the quality of life of the Pakistani population of Scotland while future research pinpoints the root causes of this morbidity-mortality paradox.
2020-06-24T00:00:00Z
Cezard, Genevieve
In Scotland, most minority ethnic groups live longer than the White Scottish population but whether they report better health is unclear. Similarly, the international literature on ethnicity and health is divided between a strand that highlights the overall morbidity disadvantage in ethnic minorities and another strand that is puzzled by their mortality advantage. This thesis brings the two strands together by investigating whether ethnic patterns in morbidity and mortality align, based on a unique population source. The Scottish Health and Ethnicity Linkage Study links the Scottish Census 2001 to 12 years of hospitalisation and death records and provides a considerable sample size (4.6 million people) for this research. Therefore, this thesis makes a number of methodological contributions in addition to providing key empirical evidence of an ethnic morbidity-mortality paradox in Scotland. In particular, healthy life expectancy by sex and ethnicity is calculated for the first time in the UK using a direct method. Findings highlight the shortest healthy life expectancies in the Pakistani population contrasting with their mortality advantage. Hence, the Pakistani population experiences the highest number of years in poor health in Scotland. Indeed, the Pakistani population reports poorer health than the majority population which contrasts with their mortality advantage. This contrast persists beyond socio-economic circumstances and across migrant generations. Furthermore, using interaction analyses, this research demonstrates that reporting poorer health strongly predicts higher risks of mortality in minority ethnic groups but with greater strength for particular groups. Finally, findings show higher risks of (hospitalisation-based) multimorbidity in the Pakistani population which supports their morbidity disadvantage in Scotland. Diseases underlying this disadvantage include those related to the metabolic syndrome and respiratory disease. Policy makers should aim to improve the quality of life of the Pakistani population of Scotland while future research pinpoints the root causes of this morbidity-mortality paradox.
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Benthic foraminifera as a novel bio-monitoring tool in the assessment of environmental impacts linked to marine aquaculture
https://hdl.handle.net/10023/18964
The present thesis describes the behaviour of benthic foraminiferal
species in response to various levels of natural and/or anthropogenic
organic matter enrichment in the benthic environment. Loch Creran, on
the west coast of Scotland, was chosen as representative of such
environments, with both organic matter accumulation from natural
sources and an active marine aquaculture industry. An improved,
quantitative understanding of foraminiferal response to the variation in
benthic environmental gradients associated with fish is established.
Furthermore, the performance of these foraminiferal species as a novel
bio-monitoring tool to assess the impact of marine aquaculture is
evaluated. In order to address how aquaculture has influenced the benthic
environment at Loch Creran, foraminifera, sediment grain-size, organic
matter (OM) content and abundances were analysed in surface samples
collected from beneath and around floating fish cage complexes. In this
study, we followed the Foraminiferal Bio-Monitoring (FOBIMO)
protocol (Schönfeld. et al., 2012), which proposed a standardised
methodology of using foraminifera as a bio-monitoring tool to assess the
quality of the marine ecosystem and applied these protocols to the rapidly
expanding marine aquaculture sector in Scotland.
The thesis quantified the potential of benthic foraminifera for use
in reconstructing paleoenvironments from areas the pre-impacted
environmental status in areas exposed to environmental stress (e.g.
accumulation of organic matter) following the onset of marine
aquaculture. Twenty stations were sampled within Loch Creran to
describe the spatial and down-core (temporal) distribution pattern of
benthic foraminiferal assemblages. For the spatial distribution study, triplicate, Rose-Bengal stained samples from an interval of (0_1cm) below
the sediment surface were studied at each station from below the fish cages
(impacted stations) to a distance of over 1 km from the farming sites and
from the upper basin, where fish caged are absent and a natural source of
organic matter exists from the River Creran. Morphospecies counts were
conducted, and the organic carbon and the grain size distributions
determined. For the down-core study, two short sediment cores, SC-02-A
and SC-04-B were examined to present the fish farming site and a more
distant, non-fish farming site. The two cores were analysed to assess the
temporal (down-core) changes in benthic foraminiferal distribution. The
total organic matter (TOM) content was determined and indicates
temporal changes in OM accumulation rate and associated benthic
foraminiferal responses.
The results indicated 4 foraminiferal assemblage groups within the
surface sediments: (i) A1 (the reference site), (ii) A2-1 (non-fish farming
sites), (iii) A2-2 (fish farming sites) and (iv) the upper basin assemblage
group (River Creran). The assemblages were found to be well adapted to
a high input of OM contents and a minimum dissolved oxygen (DO2)
penetration depth into the sediment. The majority of foraminiferal species
at the impacted sites were agglutinated species (e.g. Eggerella scabra),
likely related to the presence high sediment (OM) contents and low
dissolved oxygen concentrations. Down-core distribution data indicated
that a faunal shift has taken place, correlating with changes in OM
enrichment in the sediment. The species diversity of foraminifera
decreases above this OM enrichment horizon in the fish farming core.
Specimens of Ammonia beccarii were dominant in the lowermost
sediment core (i.e. the pre-impacted sediment). Above 7 cm, the
assemblages change and become dominated by Eggerella scabra,
coinciding with a marked change in sediment colour. The results of this
study highlight the potential of using benthic foraminifera as reliable
indicators of pre-impacted marine habitats, with great potential to
understand environmental history around the globe.
2019-06-26T00:00:00Z
Alammar, Montaha
The present thesis describes the behaviour of benthic foraminiferal
species in response to various levels of natural and/or anthropogenic
organic matter enrichment in the benthic environment. Loch Creran, on
the west coast of Scotland, was chosen as representative of such
environments, with both organic matter accumulation from natural
sources and an active marine aquaculture industry. An improved,
quantitative understanding of foraminiferal response to the variation in
benthic environmental gradients associated with fish is established.
Furthermore, the performance of these foraminiferal species as a novel
bio-monitoring tool to assess the impact of marine aquaculture is
evaluated. In order to address how aquaculture has influenced the benthic
environment at Loch Creran, foraminifera, sediment grain-size, organic
matter (OM) content and abundances were analysed in surface samples
collected from beneath and around floating fish cage complexes. In this
study, we followed the Foraminiferal Bio-Monitoring (FOBIMO)
protocol (Schönfeld. et al., 2012), which proposed a standardised
methodology of using foraminifera as a bio-monitoring tool to assess the
quality of the marine ecosystem and applied these protocols to the rapidly
expanding marine aquaculture sector in Scotland.
The thesis quantified the potential of benthic foraminifera for use
in reconstructing paleoenvironments from areas the pre-impacted
environmental status in areas exposed to environmental stress (e.g.
accumulation of organic matter) following the onset of marine
aquaculture. Twenty stations were sampled within Loch Creran to
describe the spatial and down-core (temporal) distribution pattern of
benthic foraminiferal assemblages. For the spatial distribution study, triplicate, Rose-Bengal stained samples from an interval of (0_1cm) below
the sediment surface were studied at each station from below the fish cages
(impacted stations) to a distance of over 1 km from the farming sites and
from the upper basin, where fish caged are absent and a natural source of
organic matter exists from the River Creran. Morphospecies counts were
conducted, and the organic carbon and the grain size distributions
determined. For the down-core study, two short sediment cores, SC-02-A
and SC-04-B were examined to present the fish farming site and a more
distant, non-fish farming site. The two cores were analysed to assess the
temporal (down-core) changes in benthic foraminiferal distribution. The
total organic matter (TOM) content was determined and indicates
temporal changes in OM accumulation rate and associated benthic
foraminiferal responses.
The results indicated 4 foraminiferal assemblage groups within the
surface sediments: (i) A1 (the reference site), (ii) A2-1 (non-fish farming
sites), (iii) A2-2 (fish farming sites) and (iv) the upper basin assemblage
group (River Creran). The assemblages were found to be well adapted to
a high input of OM contents and a minimum dissolved oxygen (DO2)
penetration depth into the sediment. The majority of foraminiferal species
at the impacted sites were agglutinated species (e.g. Eggerella scabra),
likely related to the presence high sediment (OM) contents and low
dissolved oxygen concentrations. Down-core distribution data indicated
that a faunal shift has taken place, correlating with changes in OM
enrichment in the sediment. The species diversity of foraminifera
decreases above this OM enrichment horizon in the fish farming core.
Specimens of Ammonia beccarii were dominant in the lowermost
sediment core (i.e. the pre-impacted sediment). Above 7 cm, the
assemblages change and become dominated by Eggerella scabra,
coinciding with a marked change in sediment colour. The results of this
study highlight the potential of using benthic foraminifera as reliable
indicators of pre-impacted marine habitats, with great potential to
understand environmental history around the globe.
-
The effect of forest-to-bog restoration on net ecosystem exchange in Flow Country peatlands
https://hdl.handle.net/10023/18563
Northern peatlands play a critical role in the regulation of atmospheric carbon (C) and are
estimated to store approximately 550 Gt C, which is around a quarter of the world soil C pool.
Saturated conditions means aboveground net primary productivity is low, but also results in low
decomposition and subsequently low respiratory losses. The Flow Country of Caithness and
Sutherland, Northern Scotland is the one of the largest areas of contiguous blanket bog in
Europe encompassing an area in excess of 4000 km². However, these peatlands were badly
degraded in the 1970s and 1980s by large-scale forestry plantations with around 17% of the
Flow Country drained and planted with Sitka spruce and Lodgepole pine altering net ecosystem
C functioning. Restoration efforts have been on going since the 1990s to restore these sites to
blanket bog and return them to net C sinks. Using eddy covariance techniques this research
sought to understand C dynamics over two sites restored at different times, assess their C
sink/source status and the key environmental factors driving changes in C dynamics.
Results showed the youngest restoration site (Lonielist; restored in 2003/04) to be a net source
of C to the atmosphere of 80 g C m⁻² yr⁻¹, while the older restoration site (Talaheel; restored in
1997/98) was a net C sink of -71 g C m⁻² yr⁻¹. Partitioning of the net exchange into its
constituent parts of respiration (R[sub](eco)) and photosynthesis (GPP) found significant differences in R[sub](eco) between the two sites, whilst no significant differences were observed in GPP. Soil
temperature and soil moisture were found to be the greatest controls on R[sub](eco), with higher R[sub](eco) associated with drier, warmer conditions. Incident solar radiation controlled GPP, however dry
periods coupled with high vapour pressure deficit resulted in a limitation of photosynthesis.
These results highlight that peatland restoration is successful at returning sites to net C sinks
over multi-decadal timescales.
2016-11-30T00:00:00Z
Hambley, Graham
Northern peatlands play a critical role in the regulation of atmospheric carbon (C) and are
estimated to store approximately 550 Gt C, which is around a quarter of the world soil C pool.
Saturated conditions means aboveground net primary productivity is low, but also results in low
decomposition and subsequently low respiratory losses. The Flow Country of Caithness and
Sutherland, Northern Scotland is the one of the largest areas of contiguous blanket bog in
Europe encompassing an area in excess of 4000 km². However, these peatlands were badly
degraded in the 1970s and 1980s by large-scale forestry plantations with around 17% of the
Flow Country drained and planted with Sitka spruce and Lodgepole pine altering net ecosystem
C functioning. Restoration efforts have been on going since the 1990s to restore these sites to
blanket bog and return them to net C sinks. Using eddy covariance techniques this research
sought to understand C dynamics over two sites restored at different times, assess their C
sink/source status and the key environmental factors driving changes in C dynamics.
Results showed the youngest restoration site (Lonielist; restored in 2003/04) to be a net source
of C to the atmosphere of 80 g C m⁻² yr⁻¹, while the older restoration site (Talaheel; restored in
1997/98) was a net C sink of -71 g C m⁻² yr⁻¹. Partitioning of the net exchange into its
constituent parts of respiration (R[sub](eco)) and photosynthesis (GPP) found significant differences in R[sub](eco) between the two sites, whilst no significant differences were observed in GPP. Soil
temperature and soil moisture were found to be the greatest controls on R[sub](eco), with higher R[sub](eco) associated with drier, warmer conditions. Incident solar radiation controlled GPP, however dry
periods coupled with high vapour pressure deficit resulted in a limitation of photosynthesis.
These results highlight that peatland restoration is successful at returning sites to net C sinks
over multi-decadal timescales.
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Understanding socio-demographic change and sustainability in Scotland’s coastal communities
https://hdl.handle.net/10023/18517
The original contribution that this work offers is the understandings of demographic (un)sustainability of places and communities, and in particular, coastal communities with ties to marine related economies. This research considers population and social change in Scottish coastal communities using a relational approach and contributes to a growing field of coastal social research that seeks to inform marine planning policy. A relational approach was implemented by deploying a mixed-method research design in two phases. Phase one, applies a traditional population geography approach to develop a geodemographic profile, in order to characterise 149 coastal localities in Scotland. It builds on existing approaches by formulating a multi-level, dynamic typology. Phase two, focuses on coastal localities with economic ties to the marine industries. It employs a case study research design of three coastal localities (Banff, Cruden Bay and Peterhead) located on Scotland’s North East coast. The case study design focussed around the qualitative methods of in-depth interviews and ethnography, in order to explore the mobility practices influencing demographic change in the Scottish coastal context. The findings demonstrate the significance of local context, economy, opportunity and coastal identity to the socio-demographic sustainability of Scottish coastal populations, as shaped through the processes of mobility and immobility.
The approach has created a working definition of the social coast that is applicable across localities in Scotland, and can be deployed to provide a taxonomic analysis for use in policy and planning more widely. The research also addresses a gap in the coastal geography literature, which has previously focussed on economic or cultural identity of coastal places, by considering the implications of population change to the construction of coastal places. Finally, the thesis was responsive to the ways of knowing traditionally mobilised in population geography and was able to critically reflect on the limitations that underpin them within the research process. The relational, mixed methods approach taken enabled a greater understanding of the importance of context, and the internal relationship between the characteristics of place and a population’s capacity to ‘answer back’.
2019-12-03T00:00:00Z
Duffy, Paula
The original contribution that this work offers is the understandings of demographic (un)sustainability of places and communities, and in particular, coastal communities with ties to marine related economies. This research considers population and social change in Scottish coastal communities using a relational approach and contributes to a growing field of coastal social research that seeks to inform marine planning policy. A relational approach was implemented by deploying a mixed-method research design in two phases. Phase one, applies a traditional population geography approach to develop a geodemographic profile, in order to characterise 149 coastal localities in Scotland. It builds on existing approaches by formulating a multi-level, dynamic typology. Phase two, focuses on coastal localities with economic ties to the marine industries. It employs a case study research design of three coastal localities (Banff, Cruden Bay and Peterhead) located on Scotland’s North East coast. The case study design focussed around the qualitative methods of in-depth interviews and ethnography, in order to explore the mobility practices influencing demographic change in the Scottish coastal context. The findings demonstrate the significance of local context, economy, opportunity and coastal identity to the socio-demographic sustainability of Scottish coastal populations, as shaped through the processes of mobility and immobility.
The approach has created a working definition of the social coast that is applicable across localities in Scotland, and can be deployed to provide a taxonomic analysis for use in policy and planning more widely. The research also addresses a gap in the coastal geography literature, which has previously focussed on economic or cultural identity of coastal places, by considering the implications of population change to the construction of coastal places. Finally, the thesis was responsive to the ways of knowing traditionally mobilised in population geography and was able to critically reflect on the limitations that underpin them within the research process. The relational, mixed methods approach taken enabled a greater understanding of the importance of context, and the internal relationship between the characteristics of place and a population’s capacity to ‘answer back’.
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Geophysical, geochemical and isotope analysis of the Figueira Branca Suite, Mato Grosso, Brazil
https://hdl.handle.net/10023/18191
The Figueira Branca Suite is a layered mafic-ultramafic complex in the Jauru Terrane,
southwest Amazon Craton. New lithological, geochemical, gamma-ray and potential field data,
integrated with geological, isotope and paleomagnetic data are used to characterize this pulse
of Mesoproterozoic extension-related magmatism. The Figueira Branca Suite formed through
juvenile magma emplacement into the crust at 1425 Ma, coeval with the later stages of the
Santa Helena Orogen. In three papers, this suite was studied from microscopic to continental
scales. First, the Figueira Branca suite was analysed through thin sections to determine the
influence of inaccurate constraints in magnetic and gravity field modelling. Then, the extent of
magmatism within the suite was delimited to four bodies to the north of Indiavaí city, MT -
Brazil, with potential fields and gamma-ray data. Modelling gravity and magnetic field data
indicated that the anomalous sources are close to the surface or outcropping. These intrusions
trend northwest over 8 km, with significant remanent magnetization that is consistent with
published direction obtained through paleomagnetic data. The increasing enrichment of LREE
in the gabbroic bodies of the suite was interpreted as evidence of progressive fractionation of
the magma. The emplacement, mineralogy and geochemical signature point towards a backarc extension tectonic framework in the later stages of the Santa Helena Orogen. The third part of the work consisted on evaluating reconstructions of the Paleo-Mesoproterozoic supercontinent Nuna with magnetic field data. The global magnetic anomaly map, EMAG2, allowed to observe continuity of magnetic lineaments and regimes in domains of similar ages in different cratons (Amazon, Baltica, West Africa and North China). These magnetic features indicated the theory which the magnetic field best supported, and suggested the regional environment where the Jauru Terrane was inserted by the time of the intrusion of the Figueira Branca Suite.
2017-06-21T00:00:00Z
Louro, Vinicius Hector Abud
The Figueira Branca Suite is a layered mafic-ultramafic complex in the Jauru Terrane,
southwest Amazon Craton. New lithological, geochemical, gamma-ray and potential field data,
integrated with geological, isotope and paleomagnetic data are used to characterize this pulse
of Mesoproterozoic extension-related magmatism. The Figueira Branca Suite formed through
juvenile magma emplacement into the crust at 1425 Ma, coeval with the later stages of the
Santa Helena Orogen. In three papers, this suite was studied from microscopic to continental
scales. First, the Figueira Branca suite was analysed through thin sections to determine the
influence of inaccurate constraints in magnetic and gravity field modelling. Then, the extent of
magmatism within the suite was delimited to four bodies to the north of Indiavaí city, MT -
Brazil, with potential fields and gamma-ray data. Modelling gravity and magnetic field data
indicated that the anomalous sources are close to the surface or outcropping. These intrusions
trend northwest over 8 km, with significant remanent magnetization that is consistent with
published direction obtained through paleomagnetic data. The increasing enrichment of LREE
in the gabbroic bodies of the suite was interpreted as evidence of progressive fractionation of
the magma. The emplacement, mineralogy and geochemical signature point towards a backarc extension tectonic framework in the later stages of the Santa Helena Orogen. The third part of the work consisted on evaluating reconstructions of the Paleo-Mesoproterozoic supercontinent Nuna with magnetic field data. The global magnetic anomaly map, EMAG2, allowed to observe continuity of magnetic lineaments and regimes in domains of similar ages in different cratons (Amazon, Baltica, West Africa and North China). These magnetic features indicated the theory which the magnetic field best supported, and suggested the regional environment where the Jauru Terrane was inserted by the time of the intrusion of the Figueira Branca Suite.
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The construction of success and negotiation of minority identities : a mixed methods study of the experiences and outcomes of school leavers in Scotland
https://hdl.handle.net/10023/17985
Each year in Scotland, around 50,000 young people complete their secondary
education and leave school. This period of educational transition is laden with risks
and opportunities; significant decisions are made and life chances established.
This thesis explores the divergent educational experiences and outcomes of
school leavers in Scotland using mixed methods and is situated within debates
about structural inequalities in the UK.
Inequalities in educational achievement appear to be associated with three key
drivers, socio-economic status, ethnicity and gender. Most recent research has
looked at these factors separately. This study examines ethnic and migrant
background alongside other axes of difference in order to gain a more accurate
picture of the educational transitions of school leavers in Scotland.
The findings draw on repeat interviews with school leavers (n=34) in two
contrasting secondary schools over a period of two years. In addition, a novel
linkage of two administrative datasets gives a large sample allowing the analysis
of national trends in the educational outcomes of school leavers between 2006-2016 (n=471,317) with detailed ethnic and social stratification. Together, these
data provide a powerful analytical tool to interrogate post-school destinations in
Scotland.
The analysis of quantitative and qualitative data reveal new insights on the
significant differences in post-school destinations and aspirations depending on
ethnic and socio-economic background. For example, White Polish and White
Other pupils are less likely to go to University than any other minority ethnic group,
even once socio-economic differences are taken into account. Yet the qualitative
fieldwork reveals high aspirations and attainment within these groups.
This research raises questions about the persistence of educational inequalities
and illustrates how this is underpinned by the ways in which educational success
is constructed and measured within neoliberal educational environments and how
minority identities are negotiated in the transition to adulthood.
2019-06-26T00:00:00Z
Packwood, Helen
Each year in Scotland, around 50,000 young people complete their secondary
education and leave school. This period of educational transition is laden with risks
and opportunities; significant decisions are made and life chances established.
This thesis explores the divergent educational experiences and outcomes of
school leavers in Scotland using mixed methods and is situated within debates
about structural inequalities in the UK.
Inequalities in educational achievement appear to be associated with three key
drivers, socio-economic status, ethnicity and gender. Most recent research has
looked at these factors separately. This study examines ethnic and migrant
background alongside other axes of difference in order to gain a more accurate
picture of the educational transitions of school leavers in Scotland.
The findings draw on repeat interviews with school leavers (n=34) in two
contrasting secondary schools over a period of two years. In addition, a novel
linkage of two administrative datasets gives a large sample allowing the analysis
of national trends in the educational outcomes of school leavers between 2006-2016 (n=471,317) with detailed ethnic and social stratification. Together, these
data provide a powerful analytical tool to interrogate post-school destinations in
Scotland.
The analysis of quantitative and qualitative data reveal new insights on the
significant differences in post-school destinations and aspirations depending on
ethnic and socio-economic background. For example, White Polish and White
Other pupils are less likely to go to University than any other minority ethnic group,
even once socio-economic differences are taken into account. Yet the qualitative
fieldwork reveals high aspirations and attainment within these groups.
This research raises questions about the persistence of educational inequalities
and illustrates how this is underpinned by the ways in which educational success
is constructed and measured within neoliberal educational environments and how
minority identities are negotiated in the transition to adulthood.
-
Adaptation to the impacts of climate change in small island communities : an analysis of Scottish case studies
https://hdl.handle.net/10023/17898
The IPCC have identified small islands as high-risk settings facing adverse impacts
of climate change, particularly flooding and storm surge, with potentially
detrimental consequences for human wellbeing and livelihoods. The Scottish
Islands are peripheral locations that are physically exposed to storms and coastal
flooding; the frequency and magnitude of which are likely to be exacerbated under
changing climatic conditions. Key questions remain about the issues, capacity and
priorities of small island communities for adapting to climate change impacts. The
research seeks to review and develop theory on the scale of adaptation measures
and considers: the appropriateness of top-down versus bottom-up approaches
within small island contexts; the role of participatory processes and utility of
scenario-based tools in island adaptation; and the effectiveness of ‘one-size-fits-all’
adaptation planning where local priorities differ significantly. Communities in
South Uist (Outer Hebrides), Westray (Orkney) and Unst (Shetland) formed a
multiple case study approach. Policy mapping, documentary analysis and
deliberative workshops were employed to develop initial background
understandings of each case study. Empirical evidence was drawn from focus
groups (N=9) which explored local perspectives on issues and priorities for
adaptation in the case study communities. The findings highlight that place-based
issues and priorities exist within the case studies, with significant variation across
all cases despite the communities being of similar population, demographic profile
and island context. The research contributes to debate on one-size-fits-all
adaptation planning and supports the argument that national adaptation strategies
can only be effective in small islands if local issues are understood. The findings
support the integration of top-down-and-bottom-up approaches as a pathway for
effective adaptation in small island settings. Deeper knowledge of the interface
between community-based action and strategic policy in cross-scale climate
change governance processes is developed and there is scope to apply a similar
approach to understand adaptation planning priorities in other small island
locations.
2019-06-26T00:00:00Z
Cunningham, Fiona
The IPCC have identified small islands as high-risk settings facing adverse impacts
of climate change, particularly flooding and storm surge, with potentially
detrimental consequences for human wellbeing and livelihoods. The Scottish
Islands are peripheral locations that are physically exposed to storms and coastal
flooding; the frequency and magnitude of which are likely to be exacerbated under
changing climatic conditions. Key questions remain about the issues, capacity and
priorities of small island communities for adapting to climate change impacts. The
research seeks to review and develop theory on the scale of adaptation measures
and considers: the appropriateness of top-down versus bottom-up approaches
within small island contexts; the role of participatory processes and utility of
scenario-based tools in island adaptation; and the effectiveness of ‘one-size-fits-all’
adaptation planning where local priorities differ significantly. Communities in
South Uist (Outer Hebrides), Westray (Orkney) and Unst (Shetland) formed a
multiple case study approach. Policy mapping, documentary analysis and
deliberative workshops were employed to develop initial background
understandings of each case study. Empirical evidence was drawn from focus
groups (N=9) which explored local perspectives on issues and priorities for
adaptation in the case study communities. The findings highlight that place-based
issues and priorities exist within the case studies, with significant variation across
all cases despite the communities being of similar population, demographic profile
and island context. The research contributes to debate on one-size-fits-all
adaptation planning and supports the argument that national adaptation strategies
can only be effective in small islands if local issues are understood. The findings
support the integration of top-down-and-bottom-up approaches as a pathway for
effective adaptation in small island settings. Deeper knowledge of the interface
between community-based action and strategic policy in cross-scale climate
change governance processes is developed and there is scope to apply a similar
approach to understand adaptation planning priorities in other small island
locations.
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The archaeological potential of windblown sand and its impacts on prehistoric settlements and landscapes in the Orkney Islands, Scotland
https://hdl.handle.net/10023/17889
This thesis comprises an investigation into the nature, chronology, and significance of prehistoric windblown sand deposition on archaeological sites in the Orkney Islands, Scotland. One of the most visible and frequently-encountered forms of evidence for dynamic coastal processes which took place over the last four millennia are horizons of calcareous (shell) and mineral (quartz and feldspar) sands, which were deposited in coastal landscapes and settlements by wind and wave dynamics. Around 20% of the Scottish coastline is made up of sand-based features, with the dune area comprising some 48,000ha (Dargie and Duncan 1999, 143).
Such coastal zones were densely settled in the prehistoric period. As monitoring of the modern coastline for changes affecting known archaeological sites continues, deposits of windblown sand - often interleaved with material evidence for human occupation – are becoming frequently recognised in the archaeological record. One coastal region which has felt the impacts of this coastal process (and continues to do so), is the Orkney archipelago, located off the northern coast of Mainland Scotland. It is this group of islands which form the geographical focus of this thesis. Previous archaeological interpretations of this important coastal process have been concerned with the development of chronologies of deposition in an attempt to tie the deposition of windblown sand to narratives of climatic deterioration. Such approaches fail to recognise the broader social significance of these windblown sand deposits, and how they were encountered by prehistorical inhabitants of the coastline. This thesis synthesises all known occurrences of windblown sand on archaeological sites in Orkney, and suggests additional ways in which their socio-economic significance can be realised.
2019-06-26T00:00:00Z
Gal, Emily Louise
This thesis comprises an investigation into the nature, chronology, and significance of prehistoric windblown sand deposition on archaeological sites in the Orkney Islands, Scotland. One of the most visible and frequently-encountered forms of evidence for dynamic coastal processes which took place over the last four millennia are horizons of calcareous (shell) and mineral (quartz and feldspar) sands, which were deposited in coastal landscapes and settlements by wind and wave dynamics. Around 20% of the Scottish coastline is made up of sand-based features, with the dune area comprising some 48,000ha (Dargie and Duncan 1999, 143).
Such coastal zones were densely settled in the prehistoric period. As monitoring of the modern coastline for changes affecting known archaeological sites continues, deposits of windblown sand - often interleaved with material evidence for human occupation – are becoming frequently recognised in the archaeological record. One coastal region which has felt the impacts of this coastal process (and continues to do so), is the Orkney archipelago, located off the northern coast of Mainland Scotland. It is this group of islands which form the geographical focus of this thesis. Previous archaeological interpretations of this important coastal process have been concerned with the development of chronologies of deposition in an attempt to tie the deposition of windblown sand to narratives of climatic deterioration. Such approaches fail to recognise the broader social significance of these windblown sand deposits, and how they were encountered by prehistorical inhabitants of the coastline. This thesis synthesises all known occurrences of windblown sand on archaeological sites in Orkney, and suggests additional ways in which their socio-economic significance can be realised.
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Reconciling molecules and morphology in benthic foraminifera : a morphometric study of Ammonia and Elphidiidae in the NE Atlantic
https://hdl.handle.net/10023/17878
A robust and consistent taxonomy underpins the use of fossil material in palaeoenvironmental research and long-term assessments of biodiversity. However, the successful identification of benthic foraminiferal species is often challenged by enigmatic morphological species boundaries, nomenclatural uncertainty and the recent advent of molecular techniques and the identification of cryptic species. This thesis sought to reconcile molecules and morphology in two scientifically important yet taxonomically challenging groups of benthic foraminifera, the genus Ammonia and the family Elphidiidae, in samples obtained widely across the NE Atlantic shelf seas. Through the production of detailed quantitative morphometric analysis of over 750 genetically sequenced specimens, coupled with assessments of their biogeographical distributions, this thesis provides the most comprehensive re-evaluation of these taxa conducted to date. The integration of these new lines of taxonomic evidence has refined interspecific boundaries, clarified key diagnostic morphological features and has unveiled the presence of a number of enigmatic species boundaries (particularly within the genus Ammonia). The results highlight that classical morphospecies concepts may not always accurately reflect the genetic diversity currently found within this region, which could have important repercussions for applied taxonomic investigations. The extensive sampling across the NE Atlantic has also enabled one of the first re-evaluations of intraspecific morphological variability, revealing that many specimens taken from distinct sampling localities can be morphologically delineated. In a first step to addressing temporal dynamics of previously unrecognised cryptic species, a time series study was conducted in the NW Scottish shelf seas, which unveiled subtle seasonal partitioning between two sympatric species of Ammonia. Finally, a new taxonomic framework was developed which bridges the current discontinuity between molecular and morphological lines of evidence. This new framework, applied to Elphidium williamsoni (Haynes, 1973), provides the first clear link between morphologically characterised type material and a unique genotype.
Electronic version excludes material for which permission has not been granted by the rights holder
2016-06-22T00:00:00Z
Roberts, Angela
A robust and consistent taxonomy underpins the use of fossil material in palaeoenvironmental research and long-term assessments of biodiversity. However, the successful identification of benthic foraminiferal species is often challenged by enigmatic morphological species boundaries, nomenclatural uncertainty and the recent advent of molecular techniques and the identification of cryptic species. This thesis sought to reconcile molecules and morphology in two scientifically important yet taxonomically challenging groups of benthic foraminifera, the genus Ammonia and the family Elphidiidae, in samples obtained widely across the NE Atlantic shelf seas. Through the production of detailed quantitative morphometric analysis of over 750 genetically sequenced specimens, coupled with assessments of their biogeographical distributions, this thesis provides the most comprehensive re-evaluation of these taxa conducted to date. The integration of these new lines of taxonomic evidence has refined interspecific boundaries, clarified key diagnostic morphological features and has unveiled the presence of a number of enigmatic species boundaries (particularly within the genus Ammonia). The results highlight that classical morphospecies concepts may not always accurately reflect the genetic diversity currently found within this region, which could have important repercussions for applied taxonomic investigations. The extensive sampling across the NE Atlantic has also enabled one of the first re-evaluations of intraspecific morphological variability, revealing that many specimens taken from distinct sampling localities can be morphologically delineated. In a first step to addressing temporal dynamics of previously unrecognised cryptic species, a time series study was conducted in the NW Scottish shelf seas, which unveiled subtle seasonal partitioning between two sympatric species of Ammonia. Finally, a new taxonomic framework was developed which bridges the current discontinuity between molecular and morphological lines of evidence. This new framework, applied to Elphidium williamsoni (Haynes, 1973), provides the first clear link between morphologically characterised type material and a unique genotype.
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Foreign direct investment and South-South cooperation : negotiating space, place and power within Chinese FDI in South Africa
https://hdl.handle.net/10023/17854
Chinese Foreign Direct Investment (FDI) in South Africa is indicative of a two-fold transformation in the contemporary development landscape: the rise of South-South Cooperation (SSC) and a re-centering of economic growth as a driver of development. However, to attract investment, and accrue developmental opportunities, hosts must first offer an enabling environment. Where an enabling environment does not presently exist, it must be actively produced. This is undertaken by a range of actors and against multiple and contested priorities. FDI, therefore, cannot be understood without an appreciation of the intimate, yet understudied, negotiations over space and place.
Through the use of semi-structured interviews, field observations, and documentary analysis at the location of three differing Chinese investments in South Africa – including a Chinese SOE within an economic zone, a mining partnership with a traditional rural community, and a ‘new city’ development led by a private Chinese investor – the thesis asks how space and place is produced to support investment, the location of agency, and the limits realities place upon the role of FDI in SSC.
Findings show that, whilst space and place were often co-produced and actively negotiated between host and investors, motivations and priorities were aligned to a need to provide spaces of comparative and competitive difference within wider international political economy. The structural production of space and place in this way created new dependencies and further uneven development. This had implications for a host ability to develop in accordance with their own values and objectives. Conclusions suggest FDI in the development landscape limits the radical potential of SSC.
The thesis applies geographic theory in a context not yet seen and, through bringing together Chinese and South African voices in a single study, contributes original empirical data from underrepresented voices in scholarship on China-Africa relations.
2019-06-26T00:00:00Z
O'Brien, Liam M
Chinese Foreign Direct Investment (FDI) in South Africa is indicative of a two-fold transformation in the contemporary development landscape: the rise of South-South Cooperation (SSC) and a re-centering of economic growth as a driver of development. However, to attract investment, and accrue developmental opportunities, hosts must first offer an enabling environment. Where an enabling environment does not presently exist, it must be actively produced. This is undertaken by a range of actors and against multiple and contested priorities. FDI, therefore, cannot be understood without an appreciation of the intimate, yet understudied, negotiations over space and place.
Through the use of semi-structured interviews, field observations, and documentary analysis at the location of three differing Chinese investments in South Africa – including a Chinese SOE within an economic zone, a mining partnership with a traditional rural community, and a ‘new city’ development led by a private Chinese investor – the thesis asks how space and place is produced to support investment, the location of agency, and the limits realities place upon the role of FDI in SSC.
Findings show that, whilst space and place were often co-produced and actively negotiated between host and investors, motivations and priorities were aligned to a need to provide spaces of comparative and competitive difference within wider international political economy. The structural production of space and place in this way created new dependencies and further uneven development. This had implications for a host ability to develop in accordance with their own values and objectives. Conclusions suggest FDI in the development landscape limits the radical potential of SSC.
The thesis applies geographic theory in a context not yet seen and, through bringing together Chinese and South African voices in a single study, contributes original empirical data from underrepresented voices in scholarship on China-Africa relations.
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'Tiny house, big impact?' : an investigation into the 'rise' of the Tiny Home Lifestyle (THL) in the United States
https://hdl.handle.net/10023/17821
The burst of the housing bubble in the United States ignited political and economic shockwaves, bringing global financial markets to the brink of collapse and kick-starting the Great Recession. This devastating crisis was the result of irresponsible housing practices and policy interventions rooted in the contemporary neoliberal mentality of rule that encouraged homeownership and failed to regulate high-risk lending (Aalbers, 2015). The Tiny Home Lifestyle (THL) has gained popularity amidst this contemporary era of housing instability, and offers a small, more affordable, and often aesthetically appealing version of a traditional American home. Despite growing awareness around the THL, it has been neglected as the subject of rigorous academic study. Therefore, the primary aim of this thesis was to explore and explain the Tiny Home Lifestyle (THL) in the United States. This alternative, small-living housing option was positioned amidst the traditional housing market, debt encumbrance, and contemporary consumer culture, relying on the American dream ethos as a lens to explore aspirations of homeownership.
The conceptual basis for the interrogation of the THL was rooted in the Foucauldian (1988) notion of ‘technologies of the self’. This was applied to investigate the promotion of a self-governing individual in pursuit of being a responsible and ethical citizen. The methodological approach of this research was reliant on the recent turn in governmentalities studies that employ non-archival methods to explore the nuances of governing practices and actualities of subject identity formation. One key finding of this thesis was that almost all participants expressed financial freedom as the primary motivation for adoption. Arguably, these dwellers have been governed into taking responsibility over their housing and understanding the provisions of the THL as ‘more free’ than what is provided by traditional housing, rather than the result of a constraining neoliberal mentality of rule. However, data suggested that dwellers were active in this process and appropriated normalisation and differentiation tactics to responsibilise and moralise their decision to adopt this lifestyle and become ‘tiny housers’. This thesis demonstrates how an unaffordable housing market ignited new housing ‘choices’ and how dwellers shifted identities in this process, potentially altering housing trajectories in the future. This contributes to post-recession understandings of housing amidst the contemporary neoliberal regime.
2019-06-26T00:00:00Z
Carras, Megan
The burst of the housing bubble in the United States ignited political and economic shockwaves, bringing global financial markets to the brink of collapse and kick-starting the Great Recession. This devastating crisis was the result of irresponsible housing practices and policy interventions rooted in the contemporary neoliberal mentality of rule that encouraged homeownership and failed to regulate high-risk lending (Aalbers, 2015). The Tiny Home Lifestyle (THL) has gained popularity amidst this contemporary era of housing instability, and offers a small, more affordable, and often aesthetically appealing version of a traditional American home. Despite growing awareness around the THL, it has been neglected as the subject of rigorous academic study. Therefore, the primary aim of this thesis was to explore and explain the Tiny Home Lifestyle (THL) in the United States. This alternative, small-living housing option was positioned amidst the traditional housing market, debt encumbrance, and contemporary consumer culture, relying on the American dream ethos as a lens to explore aspirations of homeownership.
The conceptual basis for the interrogation of the THL was rooted in the Foucauldian (1988) notion of ‘technologies of the self’. This was applied to investigate the promotion of a self-governing individual in pursuit of being a responsible and ethical citizen. The methodological approach of this research was reliant on the recent turn in governmentalities studies that employ non-archival methods to explore the nuances of governing practices and actualities of subject identity formation. One key finding of this thesis was that almost all participants expressed financial freedom as the primary motivation for adoption. Arguably, these dwellers have been governed into taking responsibility over their housing and understanding the provisions of the THL as ‘more free’ than what is provided by traditional housing, rather than the result of a constraining neoliberal mentality of rule. However, data suggested that dwellers were active in this process and appropriated normalisation and differentiation tactics to responsibilise and moralise their decision to adopt this lifestyle and become ‘tiny housers’. This thesis demonstrates how an unaffordable housing market ignited new housing ‘choices’ and how dwellers shifted identities in this process, potentially altering housing trajectories in the future. This contributes to post-recession understandings of housing amidst the contemporary neoliberal regime.
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Quantification of the effects of ocean acidification on benthic foraminifera
https://hdl.handle.net/10023/17792
The global ocean has experienced an alteration of its seawater chemistry due to the continuing uptake of anthropogenic carbon dioxide (CO₂) from the atmosphere. This ongoing process called Ocean acidification (OA) has reduced seawater pH levels, carbonate ion concentrations (CO₃⁻²) and carbonate saturation state (Ω) with implications for the diversity and functioning of marine life, particularly for marine calcifiers such as foraminifera.
The vulnerability of this ubiquitous calcifying group to future high 𝘱CO₂ /low pH scenarios has been assessed naturally and experimentally in the last decades. However, little is known about how benthic foraminifera from coastal environments such as intertidal environments will respond to the effects of OA projected by the end of the century.
This research aimed to quantify the effects of OA on a series of biological parameters measured on the benthic foraminifera 𝘌𝘭𝘱𝘩𝘪𝘥𝘪𝘶𝘮 𝘸𝘪𝘭𝘭𝘪𝘢𝘮𝘴𝘰𝘯𝘪 and 𝘏𝘢𝘺𝘯𝘦𝘴𝘪𝘯𝘢 𝘨𝘦𝘳𝘮𝘢𝘯𝘪𝘤𝘢 through a laboratory-based experimental approach where future scenarios of a high CO₂ atmosphere and low seawater pH were explored.
Experimental evidence revealed that survival rates, test weight and size-normalized weight (SNW) of 𝘌. 𝘸𝘪𝘭𝘭𝘪𝘢𝘮𝘴𝘰𝘯𝘪 were negatively affected by OA. Whereas 𝘏. 𝘨𝘦𝘳𝘮𝘢𝘯𝘪𝘤𝘢 was positively affected (i.e. enhanced growth rates) showing a species-specific response to OA at 13°C. However, the combined effect of OA and temperature (15°C) reduced survival and growth rates for 𝘌𝘭𝘱𝘩𝘪𝘥𝘪𝘶𝘮 𝘸𝘪𝘭𝘭𝘪𝘢𝘮𝘴𝘰𝘯𝘪 and 𝘏𝘢𝘺𝘯𝘦𝘴𝘪𝘯𝘢 𝘨𝘦𝘳𝘮𝘢𝘯𝘪𝘤𝘢.
Test morphology (i.e. test surface and feeding ornamentation) of live 𝘌. 𝘸𝘪𝘭𝘭𝘪𝘢𝘮𝘴𝘰𝘯𝘪 and 𝘏. 𝘨𝘦𝘳𝘮𝘢𝘯𝘪𝘤𝘢 were severely affected after 6 weeks by OA, negatively influencing the uptake of 13C-labelled diatoms of 𝘕𝘢𝘷𝘪𝘤𝘶𝘭𝘢 𝘴𝘱., notably for 𝘌. 𝘸𝘪𝘭𝘭𝘪𝘢𝘮𝘴𝘰𝘯𝘪.
Test dissolution rates were enhanced by OA and negatively affected foraminiferal morphology of recently dead assemblages with implications for net accumulation and preservation. These results imply that the long-term storage of inorganic carbon and cycling of carbon in coastal benthic ecosystems will be considerably altered by future OA.
2019-06-26T00:00:00Z
Guamán Guevara, Luis Fabricio
The global ocean has experienced an alteration of its seawater chemistry due to the continuing uptake of anthropogenic carbon dioxide (CO₂) from the atmosphere. This ongoing process called Ocean acidification (OA) has reduced seawater pH levels, carbonate ion concentrations (CO₃⁻²) and carbonate saturation state (Ω) with implications for the diversity and functioning of marine life, particularly for marine calcifiers such as foraminifera.
The vulnerability of this ubiquitous calcifying group to future high 𝘱CO₂ /low pH scenarios has been assessed naturally and experimentally in the last decades. However, little is known about how benthic foraminifera from coastal environments such as intertidal environments will respond to the effects of OA projected by the end of the century.
This research aimed to quantify the effects of OA on a series of biological parameters measured on the benthic foraminifera 𝘌𝘭𝘱𝘩𝘪𝘥𝘪𝘶𝘮 𝘸𝘪𝘭𝘭𝘪𝘢𝘮𝘴𝘰𝘯𝘪 and 𝘏𝘢𝘺𝘯𝘦𝘴𝘪𝘯𝘢 𝘨𝘦𝘳𝘮𝘢𝘯𝘪𝘤𝘢 through a laboratory-based experimental approach where future scenarios of a high CO₂ atmosphere and low seawater pH were explored.
Experimental evidence revealed that survival rates, test weight and size-normalized weight (SNW) of 𝘌. 𝘸𝘪𝘭𝘭𝘪𝘢𝘮𝘴𝘰𝘯𝘪 were negatively affected by OA. Whereas 𝘏. 𝘨𝘦𝘳𝘮𝘢𝘯𝘪𝘤𝘢 was positively affected (i.e. enhanced growth rates) showing a species-specific response to OA at 13°C. However, the combined effect of OA and temperature (15°C) reduced survival and growth rates for 𝘌𝘭𝘱𝘩𝘪𝘥𝘪𝘶𝘮 𝘸𝘪𝘭𝘭𝘪𝘢𝘮𝘴𝘰𝘯𝘪 and 𝘏𝘢𝘺𝘯𝘦𝘴𝘪𝘯𝘢 𝘨𝘦𝘳𝘮𝘢𝘯𝘪𝘤𝘢.
Test morphology (i.e. test surface and feeding ornamentation) of live 𝘌. 𝘸𝘪𝘭𝘭𝘪𝘢𝘮𝘴𝘰𝘯𝘪 and 𝘏. 𝘨𝘦𝘳𝘮𝘢𝘯𝘪𝘤𝘢 were severely affected after 6 weeks by OA, negatively influencing the uptake of 13C-labelled diatoms of 𝘕𝘢𝘷𝘪𝘤𝘶𝘭𝘢 𝘴𝘱., notably for 𝘌. 𝘸𝘪𝘭𝘭𝘪𝘢𝘮𝘴𝘰𝘯𝘪.
Test dissolution rates were enhanced by OA and negatively affected foraminiferal morphology of recently dead assemblages with implications for net accumulation and preservation. These results imply that the long-term storage of inorganic carbon and cycling of carbon in coastal benthic ecosystems will be considerably altered by future OA.
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Volunteer tourism : a path to buen vivir?
https://hdl.handle.net/10023/17542
The popularity of volunteer tourism stems from its discursive positioning as fostering
mutually beneficial relations between volunteer tourists and the host destination.
Despite extensive scholarly work, the outcomes of this activity for host communities
and volunteer tourists are still unclear. This study examines how volunteer tourism is
interpreted across a range of stakeholders in two indigenous communities in Ecuador
- one Kichwa community in the town of Chilcapamba and one Tsa'chila community
near the town of Santa Domingo. Employing qualitative research methods of
interviews, focus groups, participant observation, document analysis and diary
analysis, this study makes multiple contributions to existing literatures. Through the
inclusion of host community members, it provides new insights into a tourist practice,
predominantly understood from the perspective of volunteer tourists from the Global
North. Moreover, it provides an alternative reading of volunteer tourism by framing
this activity through a worldview and political discourse originating from the Global
South - Buen Vivir or 'good living'.
The study argues that volunteer tourism functions through and reinforces the
structures and imaginaries of an unequal and uneven global economic system.
Chapter Four contextualises the study, deducing that despite using the discourses of
Buen Vivir the Ecuadorian state employs practices typical of the neoliberal agenda.
Chapter Five illustrates how host community members adopt and negotiate
knowledge and practices from the Global North, to satisfy the demands of the
volunteer tourism industry. Following this, Chapter Six argues that marginalised
community members mobilise the discourses of Buen Vivir, to challenge neoliberal
practices, which perpetuate existing inequalities in the communities. Finally, Chapter
Seven proposes that volunteer tourists demonstrate a neoliberal subjectivity in how
they manage and narrate their experience in the host communities. The study
concludes that volunteer tourism embodies the spirit of neoliberal development
models, whilst Buen Vivir provides a critical avenue for unsettling this agenda, by
providing a framework through which alternative possibilities can be imagined.
2019-06-26T00:00:00Z
Owen, Steven
The popularity of volunteer tourism stems from its discursive positioning as fostering
mutually beneficial relations between volunteer tourists and the host destination.
Despite extensive scholarly work, the outcomes of this activity for host communities
and volunteer tourists are still unclear. This study examines how volunteer tourism is
interpreted across a range of stakeholders in two indigenous communities in Ecuador
- one Kichwa community in the town of Chilcapamba and one Tsa'chila community
near the town of Santa Domingo. Employing qualitative research methods of
interviews, focus groups, participant observation, document analysis and diary
analysis, this study makes multiple contributions to existing literatures. Through the
inclusion of host community members, it provides new insights into a tourist practice,
predominantly understood from the perspective of volunteer tourists from the Global
North. Moreover, it provides an alternative reading of volunteer tourism by framing
this activity through a worldview and political discourse originating from the Global
South - Buen Vivir or 'good living'.
The study argues that volunteer tourism functions through and reinforces the
structures and imaginaries of an unequal and uneven global economic system.
Chapter Four contextualises the study, deducing that despite using the discourses of
Buen Vivir the Ecuadorian state employs practices typical of the neoliberal agenda.
Chapter Five illustrates how host community members adopt and negotiate
knowledge and practices from the Global North, to satisfy the demands of the
volunteer tourism industry. Following this, Chapter Six argues that marginalised
community members mobilise the discourses of Buen Vivir, to challenge neoliberal
practices, which perpetuate existing inequalities in the communities. Finally, Chapter
Seven proposes that volunteer tourists demonstrate a neoliberal subjectivity in how
they manage and narrate their experience in the host communities. The study
concludes that volunteer tourism embodies the spirit of neoliberal development
models, whilst Buen Vivir provides a critical avenue for unsettling this agenda, by
providing a framework through which alternative possibilities can be imagined.
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Sources, sinks and subsidies : carbon in Scotland's coastal environments
https://hdl.handle.net/10023/17397
The rise of anthropogenic carbon dioxide concentrations in the atmosphere has forced a revaluation of our current understanding of the magnitude and mechanisms which govern natural carbon pools around the world. A largely overlooked carbon pool is held within the sediments of the world’s oceans with the coastal oceans potentially playing a globally significant role in climate regulation. These marine sedimentary environments and fjords in particular are recognised as hotspots for the burial of carbon, yet little is known about the quantity of carbon held within such environments. In this study, we use the mid-latitude fjords of Scotland as a natural laboratory to develop new methodologies to quantify marine sedimentary C stores and better understand how these stores develop through time with a specific focus on the long-term linkages with the terrestrial environment.
The newly developed methodology has allowed for the first time the quantification of a national marine sedimentary carbon stock. The sediments within these mid-latitude fjords hold a quantity of carbon comparable in magnitude to most terrestrial environments in Scotland. However, when area-normalised comparisons are made, these mid-latitude fjords are significantly more effective as C stores than their terrestrial counterparts, including Scottish peatlands. Additionally; our understanding of the long-term role of the terrestrial environment in the development of these systems has been significantly improved with it being estimate that approximately half the carbon held within Scottish fjords is terrestrial in origin. Through the Holocene fjordic sediments have been shown too adapted to increased carbon input through increasing the rate at which carbon in buried, going forward this will be highly significant in mitigating the impact of predicated climatic and human induced environmental change.
This project has highlighted the importance of understanding carbon held within marine and coastal sediments. By increasing our understanding of such coastal sedimentary carbon stores we will be better able to estimate the global carbon burial rates and storage further constraining the their role in the global carbon cycle.
2018-01-01T00:00:00Z
Smeaton, Craig
The rise of anthropogenic carbon dioxide concentrations in the atmosphere has forced a revaluation of our current understanding of the magnitude and mechanisms which govern natural carbon pools around the world. A largely overlooked carbon pool is held within the sediments of the world’s oceans with the coastal oceans potentially playing a globally significant role in climate regulation. These marine sedimentary environments and fjords in particular are recognised as hotspots for the burial of carbon, yet little is known about the quantity of carbon held within such environments. In this study, we use the mid-latitude fjords of Scotland as a natural laboratory to develop new methodologies to quantify marine sedimentary C stores and better understand how these stores develop through time with a specific focus on the long-term linkages with the terrestrial environment.
The newly developed methodology has allowed for the first time the quantification of a national marine sedimentary carbon stock. The sediments within these mid-latitude fjords hold a quantity of carbon comparable in magnitude to most terrestrial environments in Scotland. However, when area-normalised comparisons are made, these mid-latitude fjords are significantly more effective as C stores than their terrestrial counterparts, including Scottish peatlands. Additionally; our understanding of the long-term role of the terrestrial environment in the development of these systems has been significantly improved with it being estimate that approximately half the carbon held within Scottish fjords is terrestrial in origin. Through the Holocene fjordic sediments have been shown too adapted to increased carbon input through increasing the rate at which carbon in buried, going forward this will be highly significant in mitigating the impact of predicated climatic and human induced environmental change.
This project has highlighted the importance of understanding carbon held within marine and coastal sediments. By increasing our understanding of such coastal sedimentary carbon stores we will be better able to estimate the global carbon burial rates and storage further constraining the their role in the global carbon cycle.
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Investigating preference heterogeneity for restoring estuarine ecosystem services
https://hdl.handle.net/10023/17208
Given the general decline of estuarine ecosystem services (ES), policy makers require to understand further the drivers and barriers to increase society’s support for policies restoring them. The objective of this study is to identify significant sources of preference heterogeneity for improvements in flood control, recreation and biodiversity levels, resulting from tax-funded restoration projects that would be developed in the Clyde, Forth, and Tay catchment.
We used data from a discrete choice experiment conducted in Scotland and applied several choice modelling techniques (e.g. MNL, RPL, HMXL, posterior analysis) to explore the effect of respondents socioeconomic characteristics, their latent attitudes and the local geographical context on their preferences towards policies managing estuarine ES.
We found a positive and significant willingness to pay (WTP) for improving all ES, although differences in WTP estimates exist for all estuarine ES, across catchments and between user types. Recreation values were found to be lower on average than either flood control or biodiversity conservation, while preference differences emerge due to whether people live within a catchment and whether they visit it for recreational purposes or not. People visiting the areas for doing outdoor activities presented a higher latent environmental consciousness attitude. Moreover, environmentally conscious individuals showed stronger preferences for management alternatives delivering estuarine ES improvements. Finally, the presence of significant local clusters of WTP estimates suggests that respondents’ preferences interact with their immediate spatial context. Nonetheless, the local clusters of WTP for estuarine ES improvements are distributed similarly in space regardless of the ES in question, or the estuary under consideration.
The research findings can be informative for designing more efficient and contextualised policies. Moreover, they can be helpful in raising the social acceptability of the policies aiming to manage estuarine ES in Scotland.
2019-06-26T00:00:00Z
Toledo Gallegos, Valeria Maria
Given the general decline of estuarine ecosystem services (ES), policy makers require to understand further the drivers and barriers to increase society’s support for policies restoring them. The objective of this study is to identify significant sources of preference heterogeneity for improvements in flood control, recreation and biodiversity levels, resulting from tax-funded restoration projects that would be developed in the Clyde, Forth, and Tay catchment.
We used data from a discrete choice experiment conducted in Scotland and applied several choice modelling techniques (e.g. MNL, RPL, HMXL, posterior analysis) to explore the effect of respondents socioeconomic characteristics, their latent attitudes and the local geographical context on their preferences towards policies managing estuarine ES.
We found a positive and significant willingness to pay (WTP) for improving all ES, although differences in WTP estimates exist for all estuarine ES, across catchments and between user types. Recreation values were found to be lower on average than either flood control or biodiversity conservation, while preference differences emerge due to whether people live within a catchment and whether they visit it for recreational purposes or not. People visiting the areas for doing outdoor activities presented a higher latent environmental consciousness attitude. Moreover, environmentally conscious individuals showed stronger preferences for management alternatives delivering estuarine ES improvements. Finally, the presence of significant local clusters of WTP estimates suggests that respondents’ preferences interact with their immediate spatial context. Nonetheless, the local clusters of WTP for estuarine ES improvements are distributed similarly in space regardless of the ES in question, or the estuary under consideration.
The research findings can be informative for designing more efficient and contextualised policies. Moreover, they can be helpful in raising the social acceptability of the policies aiming to manage estuarine ES in Scotland.
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The North Pacific from glacial to modern : assemblages, isotopes and CO₂
https://hdl.handle.net/10023/17140
Investigating past changes in Earth’s climate can provide useful information for assessing future climate change scenarios. Planktic foraminifera preserved in marine sediment are commonly used as a tool to reconstruct past environmental change. Here I present a combination of modern census and multinet data from the North Pacific, a new compilation of global census data, a new global calibration for Mg/Ca ratios in Neogloboquadrina pachyderma, and foraminifera assemblage, trace element, and boron isotope data from the North Pacific spanning the last deglaciation.
New modern census data from the North Pacific shows that two key sub-polar proxy carrying species, N. pachyderma and Globigerina bulloides, predominantly live between 0-50 m in the water column. Global planktic foraminifera diversity is observed to be driven primarily by sea surface temperature, with upwelling and ocean productivity providing key secondary roles. In the North Pacific, a preservation bias of N. pachyderma over G. bulloides is observed when comparing multinet and core-top samples, highlighting the importance of tracking dissolution during downcore studies. To improve the use of Mg/Ca ratios in N. pachyderma downcore, I produced a new global calibration with a temperature sensitivity of 6 % per °C. This calibration was combined with boron isotope and Mg/Ca data from sediment core MD02-2489 to investigate changes in North Pacific circulation, productivity, and CO₂ during the last deglaciation. Two intervals of high surface CO₂ were observed, the first during Heinrich Stadial 1, where deep ventilation mixed CO₂ and nutrients throughout the water column. The second occurred during the Bølling-Allerød, where stratification pooled nutrients and CO₂ in surface waters, leading to enhanced productivity and CO₂ outgassing. Overall, this thesis improves the use of planktic foraminifera as tools for investigating past climate change and highlights the role of the North Pacific in deglacial CO₂ release.
2019-06-26T00:00:00Z
Taylor, Ben Justin
Investigating past changes in Earth’s climate can provide useful information for assessing future climate change scenarios. Planktic foraminifera preserved in marine sediment are commonly used as a tool to reconstruct past environmental change. Here I present a combination of modern census and multinet data from the North Pacific, a new compilation of global census data, a new global calibration for Mg/Ca ratios in Neogloboquadrina pachyderma, and foraminifera assemblage, trace element, and boron isotope data from the North Pacific spanning the last deglaciation.
New modern census data from the North Pacific shows that two key sub-polar proxy carrying species, N. pachyderma and Globigerina bulloides, predominantly live between 0-50 m in the water column. Global planktic foraminifera diversity is observed to be driven primarily by sea surface temperature, with upwelling and ocean productivity providing key secondary roles. In the North Pacific, a preservation bias of N. pachyderma over G. bulloides is observed when comparing multinet and core-top samples, highlighting the importance of tracking dissolution during downcore studies. To improve the use of Mg/Ca ratios in N. pachyderma downcore, I produced a new global calibration with a temperature sensitivity of 6 % per °C. This calibration was combined with boron isotope and Mg/Ca data from sediment core MD02-2489 to investigate changes in North Pacific circulation, productivity, and CO₂ during the last deglaciation. Two intervals of high surface CO₂ were observed, the first during Heinrich Stadial 1, where deep ventilation mixed CO₂ and nutrients throughout the water column. The second occurred during the Bølling-Allerød, where stratification pooled nutrients and CO₂ in surface waters, leading to enhanced productivity and CO₂ outgassing. Overall, this thesis improves the use of planktic foraminifera as tools for investigating past climate change and highlights the role of the North Pacific in deglacial CO₂ release.
-
Title redacted
https://hdl.handle.net/10023/16840
2016-11-30T00:00:00Z
Sila-Nowicka, Katarzyna
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New methods and applications for context aware movement analysis (CAMA)
https://hdl.handle.net/10023/16812
Recent years have seen a rapid growth in movement research owing to new technologies contributing to the miniaturization and reduced costs of tracking devices. Similar trends have occurred in how environmental data are being collected (e.g., through satellites, unmanned aerial vehicles, and sensor networks). However, the development of analytical techniques for movement research has failed to keep pace with the data collection advances. There is a need for new methods capable of integrating increasingly detailed movement data with a myriad of contextual data - termed context aware movement analysis (CAMA). CAMA investigates more than movement geometry, by including biological and environmental conditions that may influence movement. However, there is a shortage of methods relating movement patterns to contextual factors, which is still limiting our ability to extract meaningful information from movement data. This thesis contributes to this methodological research gap by assessing the state-of-the art for CAMA within movement ecology and human mobility research, developing innovative methods to consider the spatio-temporal differences between movement data and contextual data and exploring computational methods that allow identification of patterns in contextualized movement data. We developed new methods and demonstrated how they facilitated and improved the integration between high frequency tracking data and temporally dynamic environmental variables. One of the methods, multi-channel sequence analysis, is then used to discover varying human behaviour relative to weather conditions in a large human GPS tracking dataset from Scotland. The second method is developed for combing multi-sensor satellite imagery (i.e., image fusion) of differing spatial and temporal resolutions. This method is applied to a GPS tracking data on maned wolves in Brazil to understand fine-scale movement behaviours related to vegetation changes across seasons. In summary, this thesis provides a significant development in terms of new ideas and techniques for performing CAMA for human and wildlife movement studies.
2019-06-26T00:00:00Z
da Silva Brum Bastos, Vanessa
Recent years have seen a rapid growth in movement research owing to new technologies contributing to the miniaturization and reduced costs of tracking devices. Similar trends have occurred in how environmental data are being collected (e.g., through satellites, unmanned aerial vehicles, and sensor networks). However, the development of analytical techniques for movement research has failed to keep pace with the data collection advances. There is a need for new methods capable of integrating increasingly detailed movement data with a myriad of contextual data - termed context aware movement analysis (CAMA). CAMA investigates more than movement geometry, by including biological and environmental conditions that may influence movement. However, there is a shortage of methods relating movement patterns to contextual factors, which is still limiting our ability to extract meaningful information from movement data. This thesis contributes to this methodological research gap by assessing the state-of-the art for CAMA within movement ecology and human mobility research, developing innovative methods to consider the spatio-temporal differences between movement data and contextual data and exploring computational methods that allow identification of patterns in contextualized movement data. We developed new methods and demonstrated how they facilitated and improved the integration between high frequency tracking data and temporally dynamic environmental variables. One of the methods, multi-channel sequence analysis, is then used to discover varying human behaviour relative to weather conditions in a large human GPS tracking dataset from Scotland. The second method is developed for combing multi-sensor satellite imagery (i.e., image fusion) of differing spatial and temporal resolutions. This method is applied to a GPS tracking data on maned wolves in Brazil to understand fine-scale movement behaviours related to vegetation changes across seasons. In summary, this thesis provides a significant development in terms of new ideas and techniques for performing CAMA for human and wildlife movement studies.
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Family formation in Scotland : the role of social norms, housing and partnership
https://hdl.handle.net/10023/16741
This thesis examines family formation in Scotland, with a focus on having a first birth. I argue that fertility behaviour must be researched as part of a process of family formation across the life course and informed by the conceptual framework of the Theory of Planned Behaviour.
Starting from geographical patterns in fertility rates, housing and partnership, I establish relationships between shared social attitudes, partnership, housing, and family formation behaviour. I use cross-sectional and panel data from the Scottish Social Attitude Survey, the Scottish Census, the Scottish Longitudinal Study and the British Household Panel Study. The methodological contribution lies in the use of a Latent Class Analysis to identify shared social attitudes groups, which are then incorporated in more generic models predicting fertility intentions and first birth outcomes.
The findings indicate that social attitudes and norms are important for family formation. While the Second Demographic Transition Theory argued that social norms are being replaced by more independent choices, more recent fertility literature has called for more attention to social norms. The current thesis thus supports these recent calls by showing how social norms might be (indirectly) measured in quantitative research.
A key focus is on relationships between housing and family formation, especially normative ideas of ‘proper’ family housing. I demonstrate that family housing is a significant predictor of first births, at least for women. The gendered nature of family formation is also demonstrated by the different indicators found to predict men’s and women’s fertility intentions and realisations.
I conclude that improved understanding of fertility behaviour requires longitudinal research that goes beyond the usual fertility indicators such as partnership and recognises the importance of gender differences, housing, shared social attitudes, and, above all, the continuing relevance of social norms in the family formation process.
2016-11-30T00:00:00Z
Ernsten, Annemarie
This thesis examines family formation in Scotland, with a focus on having a first birth. I argue that fertility behaviour must be researched as part of a process of family formation across the life course and informed by the conceptual framework of the Theory of Planned Behaviour.
Starting from geographical patterns in fertility rates, housing and partnership, I establish relationships between shared social attitudes, partnership, housing, and family formation behaviour. I use cross-sectional and panel data from the Scottish Social Attitude Survey, the Scottish Census, the Scottish Longitudinal Study and the British Household Panel Study. The methodological contribution lies in the use of a Latent Class Analysis to identify shared social attitudes groups, which are then incorporated in more generic models predicting fertility intentions and first birth outcomes.
The findings indicate that social attitudes and norms are important for family formation. While the Second Demographic Transition Theory argued that social norms are being replaced by more independent choices, more recent fertility literature has called for more attention to social norms. The current thesis thus supports these recent calls by showing how social norms might be (indirectly) measured in quantitative research.
A key focus is on relationships between housing and family formation, especially normative ideas of ‘proper’ family housing. I demonstrate that family housing is a significant predictor of first births, at least for women. The gendered nature of family formation is also demonstrated by the different indicators found to predict men’s and women’s fertility intentions and realisations.
I conclude that improved understanding of fertility behaviour requires longitudinal research that goes beyond the usual fertility indicators such as partnership and recognises the importance of gender differences, housing, shared social attitudes, and, above all, the continuing relevance of social norms in the family formation process.
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The application of highly resolved tree-ring isotopes for reconstructing the ecohydrological interactions within riparian forests
https://hdl.handle.net/10023/16672
The research conducted within this thesis aims to advance our understanding of plant-water
interactions, specifically the identification of the source(s) of water available for tree growth
within riparian zones. Through highly resolved tree ring isotopic analyses, it is possible to deconvolve the δ¹⁸O signature of water utilised by a tree during the growing season and relate
this to dynamic hydroclimatic processes. In doing so, this methodology allows for the
reconstruction of the seasonal evolution of tree source water availability for the historical
period. The utility of this method is initially demonstrated for the determination of the isotopic
signature of water utilised by individuals of co-occuring riparian tree species over ten consecutive years. It is found that species-specific seasonal source water variability is indicative of tree rooting depth and the hydroclimatic partitioning of water to each of the floodplain hydrological reservoirs. The technique is then developed in to a methodological ‘toolkit’, comprised of tool groups representing differing levels of data availability. The aim is to enable continued progress in this research area, even under conditions of sub-optimal data availability, whilst also making the suite of methods accessible to other researchers and resource managers. Finally, the hydroclimatic expression of seasonal tree source water avaialbility is characterised across a climate gradient utilising over 800 δ¹⁸O cellulose measurements. The results show that the seasonal progression of tree water availability responds to near- and far-field hydroclimatic processes, but this is mediated by species’ functional type and site lithology. Where near-field processes dominate water availability, there is a potential for increased vulnerability to localised drought conditions and species-specific competition for water resources. Retrodictions of seasonal water source use may prove useful in forest restoration and rehabilitation efforts, assessment of forest vulnerability to future hydroclimatic regimes and for improving agroforestry and sustainable water management practices.
2018-01-15T00:00:00Z
Sargeant, Christopher
The research conducted within this thesis aims to advance our understanding of plant-water
interactions, specifically the identification of the source(s) of water available for tree growth
within riparian zones. Through highly resolved tree ring isotopic analyses, it is possible to deconvolve the δ¹⁸O signature of water utilised by a tree during the growing season and relate
this to dynamic hydroclimatic processes. In doing so, this methodology allows for the
reconstruction of the seasonal evolution of tree source water availability for the historical
period. The utility of this method is initially demonstrated for the determination of the isotopic
signature of water utilised by individuals of co-occuring riparian tree species over ten consecutive years. It is found that species-specific seasonal source water variability is indicative of tree rooting depth and the hydroclimatic partitioning of water to each of the floodplain hydrological reservoirs. The technique is then developed in to a methodological ‘toolkit’, comprised of tool groups representing differing levels of data availability. The aim is to enable continued progress in this research area, even under conditions of sub-optimal data availability, whilst also making the suite of methods accessible to other researchers and resource managers. Finally, the hydroclimatic expression of seasonal tree source water avaialbility is characterised across a climate gradient utilising over 800 δ¹⁸O cellulose measurements. The results show that the seasonal progression of tree water availability responds to near- and far-field hydroclimatic processes, but this is mediated by species’ functional type and site lithology. Where near-field processes dominate water availability, there is a potential for increased vulnerability to localised drought conditions and species-specific competition for water resources. Retrodictions of seasonal water source use may prove useful in forest restoration and rehabilitation efforts, assessment of forest vulnerability to future hydroclimatic regimes and for improving agroforestry and sustainable water management practices.
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The petrology and mineral chemistry of the Shira ring complex, Northern Nigeria
https://hdl.handle.net/10023/16437
The Shira complex belongs to the anorogenic
province of Niger and Nigeria. It is dominated by
peralkaline syenites and granites and has an estimated area
of 152 sq.km. Apart from a related intrusion of granite
porphyry at Zigau to the southwest, the Shira complex can be
divided into three centres. Centre 1 is dominated by the
Shira quartz syenite and this has been intruded by a large
cone sheet of Birji granite and by microgranite dykes. These
peralkaline syenites and granites are believed to represent
successive intrusions from a progressively differentiating
magma chamber. The Birji granite has two facies
distinguished by the habit of the arfvedsonite and both facies exhibit layering. Centre 2 is composed of the Andaburi granite and a small intrusion of Amdulayi syenite. Centre 3 consists of the very poorly exposed Eldewo aluminous biotite granite.
The Zigau granite porphyry contains phenocrysts of
alkali feldspar, quartz, fayalite and ferrohedenbergite in a
quartzofeldspathic groundmass. The Shira quartz syenite
consists of microperthite, quartz, ferrorichterite-arfvedsonite and aenigmatite. The Birji granite contains
microperthite, quartz, arfvedsonite and a little aegirine,
and the dykes related to it have a similar mineralogy but
are more mafic-rich. The Andaburi granite consists of
microperthite, quartz, ferrorichterite-arfvedsonite and
aegirine. The Amdulayi syenite has three facies which
collectively contain microperthite, quartz, ferrowinchite-
arfvedsonite, aenigmatite and aegirine . The Eldewo granite
contains microperthite, quartz and biotite.
Several minerals have been discovered which are either
new to the province or are recorded for the first time in
Nigeria, namely, aegirine-hedenbergite, chevkinite and
narsarsukite.
In the Zigau granite porphyry, fayalite has a
composition of Fa93-100 and the pyroxene is
ferrohedenbergite with sodic margins. Amphiboles from the
Shira complex exhibit a compositional trend from
ferrorichterite or ferrowinchite to arfvedsonite. In the
syenitic rocks there are two periods of alkali pyroxene growth – early aegirine-hedenbergite and later aegirine,
separated by a period of anphibole and aenigmatite crystallisation. Aenigmatite occurs in the syenitic rocks,
which have the highest Ti contents, but it shows limited
compositional range. Biotite composition in the aluminous
granite is close to the theoretical annite end-member.
Whole rock geochemical data suggest that there is a
progression from the syenites to the highly fractionated
granites. With regard to the occurrence and characteristics
of the peralkaline and aluminous granites in particular, it
is concluded that the peralkaline syenites and granites from
Shira are the result of fractional crystallisation from a
basaltic parent, whereas the aluminous rocks are the result
of partial melting in the continental crust.
1980-01-01T00:00:00Z
Bennett, John N.
The Shira complex belongs to the anorogenic
province of Niger and Nigeria. It is dominated by
peralkaline syenites and granites and has an estimated area
of 152 sq.km. Apart from a related intrusion of granite
porphyry at Zigau to the southwest, the Shira complex can be
divided into three centres. Centre 1 is dominated by the
Shira quartz syenite and this has been intruded by a large
cone sheet of Birji granite and by microgranite dykes. These
peralkaline syenites and granites are believed to represent
successive intrusions from a progressively differentiating
magma chamber. The Birji granite has two facies
distinguished by the habit of the arfvedsonite and both facies exhibit layering. Centre 2 is composed of the Andaburi granite and a small intrusion of Amdulayi syenite. Centre 3 consists of the very poorly exposed Eldewo aluminous biotite granite.
The Zigau granite porphyry contains phenocrysts of
alkali feldspar, quartz, fayalite and ferrohedenbergite in a
quartzofeldspathic groundmass. The Shira quartz syenite
consists of microperthite, quartz, ferrorichterite-arfvedsonite and aenigmatite. The Birji granite contains
microperthite, quartz, arfvedsonite and a little aegirine,
and the dykes related to it have a similar mineralogy but
are more mafic-rich. The Andaburi granite consists of
microperthite, quartz, ferrorichterite-arfvedsonite and
aegirine. The Amdulayi syenite has three facies which
collectively contain microperthite, quartz, ferrowinchite-
arfvedsonite, aenigmatite and aegirine . The Eldewo granite
contains microperthite, quartz and biotite.
Several minerals have been discovered which are either
new to the province or are recorded for the first time in
Nigeria, namely, aegirine-hedenbergite, chevkinite and
narsarsukite.
In the Zigau granite porphyry, fayalite has a
composition of Fa93-100 and the pyroxene is
ferrohedenbergite with sodic margins. Amphiboles from the
Shira complex exhibit a compositional trend from
ferrorichterite or ferrowinchite to arfvedsonite. In the
syenitic rocks there are two periods of alkali pyroxene growth – early aegirine-hedenbergite and later aegirine,
separated by a period of anphibole and aenigmatite crystallisation. Aenigmatite occurs in the syenitic rocks,
which have the highest Ti contents, but it shows limited
compositional range. Biotite composition in the aluminous
granite is close to the theoretical annite end-member.
Whole rock geochemical data suggest that there is a
progression from the syenites to the highly fractionated
granites. With regard to the occurrence and characteristics
of the peralkaline and aluminous granites in particular, it
is concluded that the peralkaline syenites and granites from
Shira are the result of fractional crystallisation from a
basaltic parent, whereas the aluminous rocks are the result
of partial melting in the continental crust.
-
Modelling subsurface hydrological processes in riparian zones
https://hdl.handle.net/10023/16337
Soil moisture is a crucial but unseen component of the hydrologic cycle. It provides a hydrologic link
and storage between surface waters and groundwater. This unexposed water sanctuary could be the key to
sustain life during ever-prevalent climatic extremes. To quantify and understand the role of soil moisture in
catchment hydrology, the HaughFlow model has been developed as a new tool to simulate subsurface
hydrology and water flow in floodplain soils. The model is constructed to be flexible, adaptable and
logically composed in order to encourage interaction from the wider scientific community. Model transparency
and parsimony are key; with assumptions clearly explained and only the dominant processes simulated
to limit the number of inputs required and retain efficiency. The dominant processes for hydraulically
connected floodplains comprise lateral saturated flow, driven by river-stage fluctuations, and vertical unsaturated
flow, driven by precipitation and evapotranspiration.
HaughFlow is applied to study sites in Australia and Germany with distinct climate conditions to
exhibit the model’s range of applicability. The lateral and vertical components of the model are calibrated
and evaluated in detail to determine the accuracy of model outputs. Evaluation methods (i.e. graphical
comparison, standard regression, Nash-Sutcliffe efficiency and percentage bias) are used to suggest best
practice for model calibration and the best outputs are then used to establish dominant trends in subsurface
hydrology at each site; including climatic changes and the long-term effects of drought periods.
Oxygen and hydrogen isotope tracers are also incorporated into the model, allowing the user to decouple
the intermixed contributions from lateral and vertical processes in the soil. Observed precipitation and river
isotope inputs can be used to predict actual isotope fractionation and mixing patterns in the soil. Using
artificial isotope inputs, however, can be used to clearly delineate the capillary fringe and water plumes
from individual rainfall events, within the soil. Hence, HaughFlow is a powerful numerical tool that can be
used to establish hydrologic trends and their drivers in the soil, to understand the role of soil moisture in
the hydrologic cycle. Ultimately these outputs can be used to investigate key questions in vegetative water
sourcing and how plants adapt to changes in water availability.
2018-05-30T00:00:00Z
Evans, Cristina M.
Soil moisture is a crucial but unseen component of the hydrologic cycle. It provides a hydrologic link
and storage between surface waters and groundwater. This unexposed water sanctuary could be the key to
sustain life during ever-prevalent climatic extremes. To quantify and understand the role of soil moisture in
catchment hydrology, the HaughFlow model has been developed as a new tool to simulate subsurface
hydrology and water flow in floodplain soils. The model is constructed to be flexible, adaptable and
logically composed in order to encourage interaction from the wider scientific community. Model transparency
and parsimony are key; with assumptions clearly explained and only the dominant processes simulated
to limit the number of inputs required and retain efficiency. The dominant processes for hydraulically
connected floodplains comprise lateral saturated flow, driven by river-stage fluctuations, and vertical unsaturated
flow, driven by precipitation and evapotranspiration.
HaughFlow is applied to study sites in Australia and Germany with distinct climate conditions to
exhibit the model’s range of applicability. The lateral and vertical components of the model are calibrated
and evaluated in detail to determine the accuracy of model outputs. Evaluation methods (i.e. graphical
comparison, standard regression, Nash-Sutcliffe efficiency and percentage bias) are used to suggest best
practice for model calibration and the best outputs are then used to establish dominant trends in subsurface
hydrology at each site; including climatic changes and the long-term effects of drought periods.
Oxygen and hydrogen isotope tracers are also incorporated into the model, allowing the user to decouple
the intermixed contributions from lateral and vertical processes in the soil. Observed precipitation and river
isotope inputs can be used to predict actual isotope fractionation and mixing patterns in the soil. Using
artificial isotope inputs, however, can be used to clearly delineate the capillary fringe and water plumes
from individual rainfall events, within the soil. Hence, HaughFlow is a powerful numerical tool that can be
used to establish hydrologic trends and their drivers in the soil, to understand the role of soil moisture in
the hydrologic cycle. Ultimately these outputs can be used to investigate key questions in vegetative water
sourcing and how plants adapt to changes in water availability.
-
Nutrient cycling and oxygen availability in ancient oceans : extinction events and evolutionary opportunities
https://hdl.handle.net/10023/16334
2018-05-30T00:00:00Z
Mettam, Colin
-
Behaviour of zircon and its isotopic systems during intracrustal differentiation
https://hdl.handle.net/10023/16331
2018-06-27T00:00:00Z
Fischer, Sebastian
-
The modern and late Holocene marine environments of Loch Sunart, N.W. Scotland
https://hdl.handle.net/10023/15910
The first study to exploit the sedimentary archives of Loch Sunart, a relatively well-flushed fjord on the NW coast of Scotland, for palaeoenvironmental reconstruction is presented. In order to understand environmental influences on past environments, the
modern physical, chemical and biological conditions of the loch and surrounding
catchment were studied. Both observational and computer modelled annual inner basin
salinity show a clear response to climatic forcing, modulated by NAO behaviour. Main
basin salinity appears to remain very stable and a well-defined salinity: δ¹⁸O relationship
suggests excellent potential for palaeotemperature reconstructions based on foraminiferal δ¹⁸O
.
Multi-variate statistical analyses identified 4 benthic foraminiferal assemblage groups in
the surface sediments of the loch: A) restricted basin (E. scaber); B) very high current
activity (C. lobatulus-A. mammilla -A. beccarii); C) calm environment undera stratified
water column (B. marginata-N. turgida-S. fusiformis) and D) coastal water influence and
mild/episodic current activity (A. beccarii-C. lobatulus-S. wrightii-E. excavatum). Using
assemblage data, an existing benthic foraminiferal transfer function was modified in
order to reconstruct Loch Sunart bottom water temperature (BWS); these reconstructions
agree well with Scottish coastal temperature series (Millport).
C. lobatulus appears to calcify close to theoretical equilibrium δ¹⁸O calcite (Δδ¹⁸O = -0.11 ± 0.17 %), probably during the warm bottom water temperatures (BWT) of late
autumn, and predominantly reflects changes in BWT rather than BWS in the main basin
of Loch Sunart.
The first late Holocene high resolution palaeoenvironmental reconstruction from the deep
(121 m) main basin of Loch Sunart is presented; gravity core (GC023) is 3 m long and
spans the last 2,000 years. Despite difficulties with geochronology, palaeoenvironmental
reconstructions from Loch Sunart suggest that these high resolution sedimentary archives
have the potential to resolve inter-annual marine climate variability of the order of 1-2°C
and capture an integrated record of changes in the catchment and marine environment.
2006-06-22T00:00:00Z
Cage, Alix Gayle
The first study to exploit the sedimentary archives of Loch Sunart, a relatively well-flushed fjord on the NW coast of Scotland, for palaeoenvironmental reconstruction is presented. In order to understand environmental influences on past environments, the
modern physical, chemical and biological conditions of the loch and surrounding
catchment were studied. Both observational and computer modelled annual inner basin
salinity show a clear response to climatic forcing, modulated by NAO behaviour. Main
basin salinity appears to remain very stable and a well-defined salinity: δ¹⁸O relationship
suggests excellent potential for palaeotemperature reconstructions based on foraminiferal δ¹⁸O
.
Multi-variate statistical analyses identified 4 benthic foraminiferal assemblage groups in
the surface sediments of the loch: A) restricted basin (E. scaber); B) very high current
activity (C. lobatulus-A. mammilla -A. beccarii); C) calm environment undera stratified
water column (B. marginata-N. turgida-S. fusiformis) and D) coastal water influence and
mild/episodic current activity (A. beccarii-C. lobatulus-S. wrightii-E. excavatum). Using
assemblage data, an existing benthic foraminiferal transfer function was modified in
order to reconstruct Loch Sunart bottom water temperature (BWS); these reconstructions
agree well with Scottish coastal temperature series (Millport).
C. lobatulus appears to calcify close to theoretical equilibrium δ¹⁸O calcite (Δδ¹⁸O = -0.11 ± 0.17 %), probably during the warm bottom water temperatures (BWT) of late
autumn, and predominantly reflects changes in BWT rather than BWS in the main basin
of Loch Sunart.
The first late Holocene high resolution palaeoenvironmental reconstruction from the deep
(121 m) main basin of Loch Sunart is presented; gravity core (GC023) is 3 m long and
spans the last 2,000 years. Despite difficulties with geochronology, palaeoenvironmental
reconstructions from Loch Sunart suggest that these high resolution sedimentary archives
have the potential to resolve inter-annual marine climate variability of the order of 1-2°C
and capture an integrated record of changes in the catchment and marine environment.
-
Concepts of place in non-metropolitan USA :
evidence from selected discourses on proposed passenger high-speed rail
https://hdl.handle.net/10023/15700
This research deepens the understanding of “sense of place” in
nonmetropolitan areas in the context of the possible development of high-speed
passenger-rail services in relation to three geographical dimensions: economic space,
environmental concerns, and human mobility. Specifically, this qualitative research
project examines how proposed passenger high-speed rail to nonmetropolitan
geographies in the Midwest region of the United States affects conceptions of sense
of place and space and how changes to nonmetropolitan dimensions of economics,
environment, and mobility affect the sense of place and space.
The United States has renewed interest in advancing passenger high-speed
rail. Most research about proposed passenger high-speed rail networks in the United
States have centered on the impact on major metropolitan areas of the country, but
little is known about what the impact might be on smaller, nonurban and rural places
along the proposed lines, much less on what they might think of it. This dissertation is
intended to remedy this lack of understanding about rural place and space and how
they are affected by planning for a new transportation mode such as high-speed
passenger rail. The results show that a high-speed-rail network does not have to be
constructed but only planned to drive changes in the conceptions of nonmetropolitan
place and space.
The implications affect local understandings of distribution of economic
resources, social and political power, and the environment. Despite optimism about
improved opportunities for accessibility and what Knowles et al. called “shrinkage of
space,” concerns also include ways in which segments of the nonurban population
may be further distanced and isolated. This research shows that people living in small towns and cities outside of the large metropolitan area have a continually evolving
sense of themselves and their sense of place and space.
Keywords: high-speed rail, planning, population geography, nonmetropolitan, rural,
micropolitan, space, sense of place, social segmentation.
2017-01-01T00:00:00Z
Boyle, Mark Patrick
This research deepens the understanding of “sense of place” in
nonmetropolitan areas in the context of the possible development of high-speed
passenger-rail services in relation to three geographical dimensions: economic space,
environmental concerns, and human mobility. Specifically, this qualitative research
project examines how proposed passenger high-speed rail to nonmetropolitan
geographies in the Midwest region of the United States affects conceptions of sense
of place and space and how changes to nonmetropolitan dimensions of economics,
environment, and mobility affect the sense of place and space.
The United States has renewed interest in advancing passenger high-speed
rail. Most research about proposed passenger high-speed rail networks in the United
States have centered on the impact on major metropolitan areas of the country, but
little is known about what the impact might be on smaller, nonurban and rural places
along the proposed lines, much less on what they might think of it. This dissertation is
intended to remedy this lack of understanding about rural place and space and how
they are affected by planning for a new transportation mode such as high-speed
passenger rail. The results show that a high-speed-rail network does not have to be
constructed but only planned to drive changes in the conceptions of nonmetropolitan
place and space.
The implications affect local understandings of distribution of economic
resources, social and political power, and the environment. Despite optimism about
improved opportunities for accessibility and what Knowles et al. called “shrinkage of
space,” concerns also include ways in which segments of the nonurban population
may be further distanced and isolated. This research shows that people living in small towns and cities outside of the large metropolitan area have a continually evolving
sense of themselves and their sense of place and space.
Keywords: high-speed rail, planning, population geography, nonmetropolitan, rural,
micropolitan, space, sense of place, social segmentation.
-
Evaluation of visualisations of geographically weighted regression, with perceptual stability
https://hdl.handle.net/10023/15680
Given the large volume of data that is regularly accumulated, the need to properly manage,
efficiently display and correctly interpret, becomes more important. Complex analysis of data
is best performed using statistical models and in particular those with a geographical element
are best analysed using Spatial Statistical Methods, including local regression. Spatial Statistical
Methods are employed in a wide range of disciplines to analyse and interpret data where it is
necessary to detect significant spatial patterns or relationships. The topic of the research
presented in this thesis is an exploration of the most effective methods of visualising results.
A human being is capable of processing a vast amount of data as long as it is effectively
displayed. However, the perceptual load will at some point exceed the cognitive processing
ability and therefore the ability to comprehend data. Although increases in data scale did
increase the cognitive load and reduce processing, prior knowledge of geographical information
systems did not result in an overall processing advantage.
The empirical work in the thesis is divided into two parts. The first part aims to gain insight into
visualisations which would be effective for interpretation and analysis of Geographically
Weighted Regression (GWR), a popular Spatial Statistical Method. Three different visualisation
techniques; two dimensional, three dimensional and interactive, are evaluated through an
experiment comprising two data set sizes. Interactive visualisations perform best overall,
despite the apparent lack of researcher familiarity.
The increase in data volume can present additional complexity for researchers. Although the
evaluation of the first experiment augments understanding of effective visualisation display,
the scale at which data can be adequately presented within these visualisations is unclear.
Therefore, the second empirical investigation seeks to provide insight into data scalability, and
human cognitive limitations associated with data comprehension.
The general discussion concludes that there is a need to better inform researchers of the
potential of interactive visualisations. People do need to be properly trained to use these
systems, but the limits of human perceptual processing also need to be considered in order to
permit more efficient and insightful analysis.
2016-01-01T00:00:00Z
Burke, Tommy
Given the large volume of data that is regularly accumulated, the need to properly manage,
efficiently display and correctly interpret, becomes more important. Complex analysis of data
is best performed using statistical models and in particular those with a geographical element
are best analysed using Spatial Statistical Methods, including local regression. Spatial Statistical
Methods are employed in a wide range of disciplines to analyse and interpret data where it is
necessary to detect significant spatial patterns or relationships. The topic of the research
presented in this thesis is an exploration of the most effective methods of visualising results.
A human being is capable of processing a vast amount of data as long as it is effectively
displayed. However, the perceptual load will at some point exceed the cognitive processing
ability and therefore the ability to comprehend data. Although increases in data scale did
increase the cognitive load and reduce processing, prior knowledge of geographical information
systems did not result in an overall processing advantage.
The empirical work in the thesis is divided into two parts. The first part aims to gain insight into
visualisations which would be effective for interpretation and analysis of Geographically
Weighted Regression (GWR), a popular Spatial Statistical Method. Three different visualisation
techniques; two dimensional, three dimensional and interactive, are evaluated through an
experiment comprising two data set sizes. Interactive visualisations perform best overall,
despite the apparent lack of researcher familiarity.
The increase in data volume can present additional complexity for researchers. Although the
evaluation of the first experiment augments understanding of effective visualisation display,
the scale at which data can be adequately presented within these visualisations is unclear.
Therefore, the second empirical investigation seeks to provide insight into data scalability, and
human cognitive limitations associated with data comprehension.
The general discussion concludes that there is a need to better inform researchers of the
potential of interactive visualisations. People do need to be properly trained to use these
systems, but the limits of human perceptual processing also need to be considered in order to
permit more efficient and insightful analysis.
-
Monitoring environmental change and ecosystem health using seabird guano chemistry
https://hdl.handle.net/10023/15602
One of the first studies to investigate the use of stable isotopes from seabird guano
and extracted uric acid for monitoring environmental changes in diet and trophic
relationships of seabirds and anthropogenic pollutant levels, this study supported the
hypothesis that guano and uric acid offer an alternative non-invasive sampling
technique.
The study found strong evidence of inter- and intra-specific differences in δ¹³ C and
δ¹⁵ N signatures across species and breeding locations, which were primarily
attributed to the feeding ecology of each species. Patterns of intra-and inter-specific
variation were also seen in kittiwakes from the east coast of Scotland where samples
were collected within and between years, with considerable isotopic overlap
observed in the results suggesting that individuals from these colonies were
consuming isotopically similar prey, taken largely from similar regions.
For most species the δ¹³ C and δ¹⁵ N signatures of uric acid were not significantly
different from that of guano (<1‰ for δ¹³ C and 1.2‰ for δ¹⁵ N) with a highly linear
relationship, suggesting that either tissue could be used when studying the short-
term (in the order of days) foraging behaviour of seabirds.
When considering the heavy metal burden of seabirds, the present study showed
that there are both similarities and differences in trace element concentrations both
within and between species that can largely be attributed to dietary variation,
although other factors including anthropogenic activities can potentially contribute to
this variability in specific locations. With knowledge of the sources and controls on
metal variability in diets and bodily accumulation such data derived from seabird
guano can provide a potentially useful bio-monitor of trace element concentrations in
the wider marine environment.
Stable isotope analysis of seabird guano and uric acid can be used to document
changes in diet and trophic relationships that may be associated with environmental
change. Using multiple species and sampling locations, such studies can provide an
alternative monitoring tool at a range of temporal and spatial scales.
2017-01-01T00:00:00Z
Tait, Elaine M.
One of the first studies to investigate the use of stable isotopes from seabird guano
and extracted uric acid for monitoring environmental changes in diet and trophic
relationships of seabirds and anthropogenic pollutant levels, this study supported the
hypothesis that guano and uric acid offer an alternative non-invasive sampling
technique.
The study found strong evidence of inter- and intra-specific differences in δ¹³ C and
δ¹⁵ N signatures across species and breeding locations, which were primarily
attributed to the feeding ecology of each species. Patterns of intra-and inter-specific
variation were also seen in kittiwakes from the east coast of Scotland where samples
were collected within and between years, with considerable isotopic overlap
observed in the results suggesting that individuals from these colonies were
consuming isotopically similar prey, taken largely from similar regions.
For most species the δ¹³ C and δ¹⁵ N signatures of uric acid were not significantly
different from that of guano (<1‰ for δ¹³ C and 1.2‰ for δ¹⁵ N) with a highly linear
relationship, suggesting that either tissue could be used when studying the short-
term (in the order of days) foraging behaviour of seabirds.
When considering the heavy metal burden of seabirds, the present study showed
that there are both similarities and differences in trace element concentrations both
within and between species that can largely be attributed to dietary variation,
although other factors including anthropogenic activities can potentially contribute to
this variability in specific locations. With knowledge of the sources and controls on
metal variability in diets and bodily accumulation such data derived from seabird
guano can provide a potentially useful bio-monitor of trace element concentrations in
the wider marine environment.
Stable isotope analysis of seabird guano and uric acid can be used to document
changes in diet and trophic relationships that may be associated with environmental
change. Using multiple species and sampling locations, such studies can provide an
alternative monitoring tool at a range of temporal and spatial scales.
-
Geodynamic evolution of the southern chewore inliers, Zimbabwe: evidence for 1.4 Ga marginal basin crust
https://hdl.handle.net/10023/15585
This thesis reports the detailed study of 150 km2 of a newly discovered ophiolite terrane in the Chewore Inliers of northern Zimbabwe. It is apparently the oldest dated ophiolite (senso stricto) in Africa. Field and laboratory investigation of the Ophiolite Terrane (OT) shows that it comprises three distinct lithological groups. The Maunde Ophiolite Group is comprised of back - arc ophiolite - type assemblages, namely:-meta - mafic volcanics, sheeted meta - mafic dykes, meta - gabbro, meta - mafic cumulates and serpentinites. The Kaourera Island - Arc Group is comprised of a silica and potassium variable suite of extrusive volcanic lithologies which represent a tectonically excised island - arc complex. The Kadunguri Whiteschists are comprised of chemically restricted whiteschists which are characterised by the equilibrium assemblage of talc and kyanite and unusual yoderite + kyanite + chlorite + talc + dravite + hematite assemblages. The Ophiolite Terrane has had a single period of crustal thickening with a NNE - SSW shortening direction. This event is characterised by high shear strains with the development of non - coaxial intrafolial shear folds, an axial planar cleavage and an extension lineation which is parallel to the intrafolial fold hinges. Tectonic transport was directed obliquely toward the NNE. Associated clockwise metamorphism peaked within the upper amphibolite facies at 700°C and 10 kbar. The high pressure, moderate temperature Kadunguri Group whiteschists record peak metamorphic PT's of between 13 and 21 kbar and 550 - 650°C with the production of the second natural occurrence of the mineral yoderite. A plagiogranite sheet within the ophiolite has been SHRIMP dated at 1393 ± 22 Ma (Oliver et al., 1998) and is interpreted to be the age of the ophiolite. Investigation of the terranes to the north of the OT by Goscombe et al., (1998) reveal a previous, high T, low P, anti - clockwise, local granulite facies tectono - metamorphic cycle (M1) which is not recognised within the OT. All terranes are variably overprinted by the main clockwise PTt path, amphibolite facies, crustal thickening event (M2). The M1 cycle has been U / Pb SHRIMP dated from zircons within the Granulite Terrane at 943 ± 34 Ma (Goscombe et al., 1998) and interpreted to represent crustal extension associated with continental break up of Rodinia. Zircon overgrowths within the Granulite Terrane date the M2 cycle at 524 ± 16 Ma. The lack of M1 metamorphism and associated fabrics within the OT and the similarity in early M2 structures between all terranes indicate that juxtaposition of the Chewore terranes occurred during the earliest part of the M2 cycle i.e., at 524 ± 16 Ma. The plethora of Pan - African radiometric ages (c. 520 - 530 Ma) throughout the Zambezi Belt suggests that the belt containing the OT represents a complex east to west trending suture zone which divides West Gondwana into a 'northern' (Congo Craton) and 'southern' (Zimbabwe Craton) component. The Zimbabwe and Congo Cratons were therefore ultimately juxtaposed during the Pan - African Orogeny.
1999-01-01T00:00:00Z
Johnson, Simon Paul
This thesis reports the detailed study of 150 km2 of a newly discovered ophiolite terrane in the Chewore Inliers of northern Zimbabwe. It is apparently the oldest dated ophiolite (senso stricto) in Africa. Field and laboratory investigation of the Ophiolite Terrane (OT) shows that it comprises three distinct lithological groups. The Maunde Ophiolite Group is comprised of back - arc ophiolite - type assemblages, namely:-meta - mafic volcanics, sheeted meta - mafic dykes, meta - gabbro, meta - mafic cumulates and serpentinites. The Kaourera Island - Arc Group is comprised of a silica and potassium variable suite of extrusive volcanic lithologies which represent a tectonically excised island - arc complex. The Kadunguri Whiteschists are comprised of chemically restricted whiteschists which are characterised by the equilibrium assemblage of talc and kyanite and unusual yoderite + kyanite + chlorite + talc + dravite + hematite assemblages. The Ophiolite Terrane has had a single period of crustal thickening with a NNE - SSW shortening direction. This event is characterised by high shear strains with the development of non - coaxial intrafolial shear folds, an axial planar cleavage and an extension lineation which is parallel to the intrafolial fold hinges. Tectonic transport was directed obliquely toward the NNE. Associated clockwise metamorphism peaked within the upper amphibolite facies at 700°C and 10 kbar. The high pressure, moderate temperature Kadunguri Group whiteschists record peak metamorphic PT's of between 13 and 21 kbar and 550 - 650°C with the production of the second natural occurrence of the mineral yoderite. A plagiogranite sheet within the ophiolite has been SHRIMP dated at 1393 ± 22 Ma (Oliver et al., 1998) and is interpreted to be the age of the ophiolite. Investigation of the terranes to the north of the OT by Goscombe et al., (1998) reveal a previous, high T, low P, anti - clockwise, local granulite facies tectono - metamorphic cycle (M1) which is not recognised within the OT. All terranes are variably overprinted by the main clockwise PTt path, amphibolite facies, crustal thickening event (M2). The M1 cycle has been U / Pb SHRIMP dated from zircons within the Granulite Terrane at 943 ± 34 Ma (Goscombe et al., 1998) and interpreted to represent crustal extension associated with continental break up of Rodinia. Zircon overgrowths within the Granulite Terrane date the M2 cycle at 524 ± 16 Ma. The lack of M1 metamorphism and associated fabrics within the OT and the similarity in early M2 structures between all terranes indicate that juxtaposition of the Chewore terranes occurred during the earliest part of the M2 cycle i.e., at 524 ± 16 Ma. The plethora of Pan - African radiometric ages (c. 520 - 530 Ma) throughout the Zambezi Belt suggests that the belt containing the OT represents a complex east to west trending suture zone which divides West Gondwana into a 'northern' (Congo Craton) and 'southern' (Zimbabwe Craton) component. The Zimbabwe and Congo Cratons were therefore ultimately juxtaposed during the Pan - African Orogeny.
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The structure, petrology and geochemistry of the Tibchi younger granite ring-complex, Nigeria
https://hdl.handle.net/10023/15584
The 1:50,000 geological map of the Tibchi Complex presented is characterised by a closed elliptical ring-dyke framework hitherto unpredicted by pioneer workers. Major rock units comprise a basalt - potassic granite suite. The structural history of the Complex involved a central shield volcano, succeeded by a caldera and fluidised intra-caldera volcanism. The model proposed is on the principle of positive magma pressure during both caldera formation and ring-dyke intrusion. With ash-fall tuff and rhyolite lavas resting directly on the subsided basement block within the ring-fracture, the Tibchi Complex shows the first clear exposure of the Jurassic landscape to be recorded in Nigeria. An olivine tholeiite - tholeiite - andesine basalt - trachyte sequence, and a microferrodiorite - microsyenite - granitic porphyries sequence are separately established but together appear to form a unified petrogenetic succession. The scarcity of modal plagioclase, and the low levels of calcium and magnesium, together with the extreme iron-enrichment, in the rocks, are accounted for. The petrology is complicated by various post- magmatic hydrothermal and metasomatic processes from which certain distinctive rock-types formed. These processes are described in full and explanations offered. Contact metamorphism previously unassociated with the Nigerian Younger Granites is recorded in a bifacial metamorphic aureole related to the biotite granite intrusion. Joint-controlled greisen vein development and primary mineralisation are among the most extensive in the Nigerian Younger Granites. Chemical analyses of fayalites, Ca-rich pyroxenes, amphiboles and a selection of biotites and chlorites show that these minerals approach very closely the iron end-members of their solid solution series. Two distinct but related pyroxene crystallisation trends are found in the porphyries. The 'granite porphyry pyroxene trend' involved a significant role of the acmite component in a way that suggests a modification of the 'quartz porphyry pyroxene trend' by increased oxygen fugacity. The presence of sufficient volatiles in the quartz porphyry magma was probably enough to account for the observed difference between the two trends. Pyroxene data on the whole indicate the Tibchi Complex to be of tholeiitic affinity, but with a mild alkalinity. Amphiboles are mostly postmagmatic in origin and define two divergent reaction series: a ferro- actinolite - ferroedenite series, and a ferroactinolite - ferrorichterite - alkali amphibole series. The compositions of the amphiboles are predestined by the compositions of the pyroxenes from which they formed. Despite the origin of the Tibchi, rocks from basaltic liquids, the presence of large volumes of granitic rocks suggests .extensive crustal anatexis as possible source of additional acid magma.
1979-01-01T00:00:00Z
Ike, Echefu Cyriacus
The 1:50,000 geological map of the Tibchi Complex presented is characterised by a closed elliptical ring-dyke framework hitherto unpredicted by pioneer workers. Major rock units comprise a basalt - potassic granite suite. The structural history of the Complex involved a central shield volcano, succeeded by a caldera and fluidised intra-caldera volcanism. The model proposed is on the principle of positive magma pressure during both caldera formation and ring-dyke intrusion. With ash-fall tuff and rhyolite lavas resting directly on the subsided basement block within the ring-fracture, the Tibchi Complex shows the first clear exposure of the Jurassic landscape to be recorded in Nigeria. An olivine tholeiite - tholeiite - andesine basalt - trachyte sequence, and a microferrodiorite - microsyenite - granitic porphyries sequence are separately established but together appear to form a unified petrogenetic succession. The scarcity of modal plagioclase, and the low levels of calcium and magnesium, together with the extreme iron-enrichment, in the rocks, are accounted for. The petrology is complicated by various post- magmatic hydrothermal and metasomatic processes from which certain distinctive rock-types formed. These processes are described in full and explanations offered. Contact metamorphism previously unassociated with the Nigerian Younger Granites is recorded in a bifacial metamorphic aureole related to the biotite granite intrusion. Joint-controlled greisen vein development and primary mineralisation are among the most extensive in the Nigerian Younger Granites. Chemical analyses of fayalites, Ca-rich pyroxenes, amphiboles and a selection of biotites and chlorites show that these minerals approach very closely the iron end-members of their solid solution series. Two distinct but related pyroxene crystallisation trends are found in the porphyries. The 'granite porphyry pyroxene trend' involved a significant role of the acmite component in a way that suggests a modification of the 'quartz porphyry pyroxene trend' by increased oxygen fugacity. The presence of sufficient volatiles in the quartz porphyry magma was probably enough to account for the observed difference between the two trends. Pyroxene data on the whole indicate the Tibchi Complex to be of tholeiitic affinity, but with a mild alkalinity. Amphiboles are mostly postmagmatic in origin and define two divergent reaction series: a ferro- actinolite - ferroedenite series, and a ferroactinolite - ferrorichterite - alkali amphibole series. The compositions of the amphiboles are predestined by the compositions of the pyroxenes from which they formed. Despite the origin of the Tibchi, rocks from basaltic liquids, the presence of large volumes of granitic rocks suggests .extensive crustal anatexis as possible source of additional acid magma.
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The basic intrusives and associated rocks of the Shoshong-Makhware area Bechuanaland protectorate
https://hdl.handle.net/10023/15582
The Shoshong-Makhware area, which covers approximately 1200 square miles west of the Mahalapye-Palapye rail track in Latitude 23°s, and longitude 26.5°w, contains several tholeiitic intrusions. These are probably differentiates of subterraneous magma body, which was roughly contemporary with the Bushveld Igneous Complex in the Union. The present author first visited the area in July 1957 and subsequently spent four months remapping and collecting the necessary material for a more detailed laboratory study. Mapping was done with the aid of aerial photographs, and where those were not available, resort was made to triangulation survey methods, using a prismatic compass. Inclinations of joints, faults and bedding planed were determined with the aid of a Brunton Compass. The laboratory work was carried out in both Department of Geology in the University of St Andrews, and also at the University of Cape Town. Particular attention was paid to the petrology, mineralogy and chemistry of the intrusive. A description of the techniques applied is given.
1960-01-01T00:00:00Z
Grubb, Patrick Louis Cedric
The Shoshong-Makhware area, which covers approximately 1200 square miles west of the Mahalapye-Palapye rail track in Latitude 23°s, and longitude 26.5°w, contains several tholeiitic intrusions. These are probably differentiates of subterraneous magma body, which was roughly contemporary with the Bushveld Igneous Complex in the Union. The present author first visited the area in July 1957 and subsequently spent four months remapping and collecting the necessary material for a more detailed laboratory study. Mapping was done with the aid of aerial photographs, and where those were not available, resort was made to triangulation survey methods, using a prismatic compass. Inclinations of joints, faults and bedding planed were determined with the aid of a Brunton Compass. The laboratory work was carried out in both Department of Geology in the University of St Andrews, and also at the University of Cape Town. Particular attention was paid to the petrology, mineralogy and chemistry of the intrusive. A description of the techniques applied is given.
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The alluvial minerals of the River Indus, West Pakistan
https://hdl.handle.net/10023/15578
The river Indus originates at an elevation of 17,000 feet on the northern flank of Kailash Mountain in Tibet, and before it joins the Indian Ocean near Karaohi in West Pakistan, it flows for about 2000 miles, partly in the mountainous terrain of the Himalaya and partly over the plains of Sind and the Punjab. The investigations reported upon in this thesis relate to a study of the alluvial deposits in the upper reaches of the river, along a stretch of about 500 miles between Skardu in the Great Himalayas and Kalabagh in the Outer Himalayas. The thesis includes a description of the bed-rock geology of the area, and reports studies on the degree of sorting and the mineralogy of the gravels. Only the economic aspects of this work are reported in this abstract. Because of accessibility, the alluvials between Attock and Amb were chosen for economic study. Hero a primitive gold-washing industry exists and around 20 or 25 families are seasonably engaged in gold production. At a very rough estimate, the overall production is only 14 troy ounces per year, worth say £175. The method of mining, using a primitive sluice known as a nava, is described; and a report is given on detailed sampling tests employing a skilled gold-washer. The average yield is 1.05 grains per cubic yard of specially selected alluvium. The valuable mineral species present in the alluvium are gold, uraninite, tinstone and scheelite. The value of the average yield of gold from selected "high-grade" alluvium is about 60 per cubic yard. From the radiometric and mineralogical assays the tenor of uraninite in the natural sands in estimated to be around. 0,0002%, equivalent at full recovery to about Id per cubic yard. The tenor of tinstone and scheelite have been estimated visually to be about 1 oz. and 0.02 oz per cubic yard; but this estimate based on grain counts is almost certainly much too high for tinstone, since "tinning" tests using zinc and hydrochloric acid show that cassiterite is much rarer than the visual, optical, assessment. Considered overall, therefore, even the small patches of heavy mineral concentrate on which the indigenous gold industry is based have a value of contained minerals of well under one shilling per cubic yard. Since the grade of material which would have to be worked in a large-scale mechanized operation would be much lower than that of selected patches operated on manually, it is plain that there are no commercial prospects for any large-scale dredging. Radiometric studies have been conducted on the bed-rocks traversed by the river, and also on the alluvium. The highest values encountered are, firstly, in veins of aplite, pegmatite and younger granite giving 0.03- 0.55 mr/hr; secondly, graphitic schists usually giving 0.03 - 0.04 mr/hr, but rising in pockets to 0.08 mr/hr; and thirdly, some acid gneissose bands in the metamorphic formation giving as high as 0.15 mr/hr. Considered overall, no significant change in the radioactivity profile has been found along the course of the river; but the greatest proportion of high values is to be found where the country rocks are the metamorphosed gneisses bearing bands of high radioactivity. This suggests that the main source of the uraninite is local, predominately in the metamorphic rocks between Amb and Pattan, the mineral most probably occurring as disseminations of dispersed grains in these formations. In the terrace gravel deposits uraninite is less frequent at depth than it is near the surface; and in hand-panned concentrates from the Siwalik sandstones, which represent the alluvials derived from the Himalayan crystalline rocks by the Indus-Brahma river system of Neogene times, uraninite could not be found at all. These facts suggest that detrital uraninite does not survive lithification but is removed from sandstones by intra-stratal waters permeating the rooks during the period of early to late diagenesis.
1963-01-01T00:00:00Z
Tahirkheli, Rashid Ahmad Khan
The river Indus originates at an elevation of 17,000 feet on the northern flank of Kailash Mountain in Tibet, and before it joins the Indian Ocean near Karaohi in West Pakistan, it flows for about 2000 miles, partly in the mountainous terrain of the Himalaya and partly over the plains of Sind and the Punjab. The investigations reported upon in this thesis relate to a study of the alluvial deposits in the upper reaches of the river, along a stretch of about 500 miles between Skardu in the Great Himalayas and Kalabagh in the Outer Himalayas. The thesis includes a description of the bed-rock geology of the area, and reports studies on the degree of sorting and the mineralogy of the gravels. Only the economic aspects of this work are reported in this abstract. Because of accessibility, the alluvials between Attock and Amb were chosen for economic study. Hero a primitive gold-washing industry exists and around 20 or 25 families are seasonably engaged in gold production. At a very rough estimate, the overall production is only 14 troy ounces per year, worth say £175. The method of mining, using a primitive sluice known as a nava, is described; and a report is given on detailed sampling tests employing a skilled gold-washer. The average yield is 1.05 grains per cubic yard of specially selected alluvium. The valuable mineral species present in the alluvium are gold, uraninite, tinstone and scheelite. The value of the average yield of gold from selected "high-grade" alluvium is about 60 per cubic yard. From the radiometric and mineralogical assays the tenor of uraninite in the natural sands in estimated to be around. 0,0002%, equivalent at full recovery to about Id per cubic yard. The tenor of tinstone and scheelite have been estimated visually to be about 1 oz. and 0.02 oz per cubic yard; but this estimate based on grain counts is almost certainly much too high for tinstone, since "tinning" tests using zinc and hydrochloric acid show that cassiterite is much rarer than the visual, optical, assessment. Considered overall, therefore, even the small patches of heavy mineral concentrate on which the indigenous gold industry is based have a value of contained minerals of well under one shilling per cubic yard. Since the grade of material which would have to be worked in a large-scale mechanized operation would be much lower than that of selected patches operated on manually, it is plain that there are no commercial prospects for any large-scale dredging. Radiometric studies have been conducted on the bed-rocks traversed by the river, and also on the alluvium. The highest values encountered are, firstly, in veins of aplite, pegmatite and younger granite giving 0.03- 0.55 mr/hr; secondly, graphitic schists usually giving 0.03 - 0.04 mr/hr, but rising in pockets to 0.08 mr/hr; and thirdly, some acid gneissose bands in the metamorphic formation giving as high as 0.15 mr/hr. Considered overall, no significant change in the radioactivity profile has been found along the course of the river; but the greatest proportion of high values is to be found where the country rocks are the metamorphosed gneisses bearing bands of high radioactivity. This suggests that the main source of the uraninite is local, predominately in the metamorphic rocks between Amb and Pattan, the mineral most probably occurring as disseminations of dispersed grains in these formations. In the terrace gravel deposits uraninite is less frequent at depth than it is near the surface; and in hand-panned concentrates from the Siwalik sandstones, which represent the alluvials derived from the Himalayan crystalline rocks by the Indus-Brahma river system of Neogene times, uraninite could not be found at all. These facts suggest that detrital uraninite does not survive lithification but is removed from sandstones by intra-stratal waters permeating the rooks during the period of early to late diagenesis.
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The geology of the lower paleozoic rocks in the southern Rhinns of Galloway, S. W. Scotland: studies in an imbricate thrust terrane
https://hdl.handle.net/10023/15575
This thesis is the first detailed, modem account of the geology of the southern Rhinns of Galloway, SW Scotland subsequent to work by the Geological Survey last century. It integrates the geology described with the rest of the Southern Uplands-Down-Longford terrane and offers a plate-tectonic synthesis for its development. The southern Rhinns consists of eleven NE-SW trending, sub-vertical tectonic blocks resulting from the thrust imbrication of a c. 35 million year Caradoc to Llandovery age sequence of chert, bentonite, shale, mudstone, greywacke and conglomerate. The pelagic/hemipelagic Moffat Shale Group acted as a locus for thrust development. The greywackes have a siliceous petrography with sporadic input of volcaniclastic material and a major influx of detrital carbonate in the youngest formation. A recycled orogen provenance is indicated. Facies analysis indicates the catastrophic progradation of clastic, inboard deposits southeastwards over contemporaneous pelagic/hemipelagic, outboard deposits. Most of the formations were deposited in a highly confined basin, whereas the Port Logan Formation and Mull of Galloway Formation were deposited in large, unconfined submarine fans. Palaeocurrent flow was dominantly from the NE or NW, though the two youngest formations provide the first unequivocal evidence of major southeasterly derivation in the Southern Uplands. The style and vergence of D1 deformation changes across the Port Logan Bay Fault, the area to the SE constituting a 12 km zone of opposing fold and thrust geometry to that dominant in the terrane. A model of sequential Silurian simple shear and pure shear deformation in a steady-state trench environment above a NW-dipping subduction zone is proposed. A set of post-D₂ NW-vergent recumbent folds and thrusts related to end-Caledonian terminal collision of Cadomia and Laurentia provide evidence of major sinistral strike-slip along the Cairngarroch Fault prior to collision.
1989-01-01T00:00:00Z
McCurry, John A.
This thesis is the first detailed, modem account of the geology of the southern Rhinns of Galloway, SW Scotland subsequent to work by the Geological Survey last century. It integrates the geology described with the rest of the Southern Uplands-Down-Longford terrane and offers a plate-tectonic synthesis for its development. The southern Rhinns consists of eleven NE-SW trending, sub-vertical tectonic blocks resulting from the thrust imbrication of a c. 35 million year Caradoc to Llandovery age sequence of chert, bentonite, shale, mudstone, greywacke and conglomerate. The pelagic/hemipelagic Moffat Shale Group acted as a locus for thrust development. The greywackes have a siliceous petrography with sporadic input of volcaniclastic material and a major influx of detrital carbonate in the youngest formation. A recycled orogen provenance is indicated. Facies analysis indicates the catastrophic progradation of clastic, inboard deposits southeastwards over contemporaneous pelagic/hemipelagic, outboard deposits. Most of the formations were deposited in a highly confined basin, whereas the Port Logan Formation and Mull of Galloway Formation were deposited in large, unconfined submarine fans. Palaeocurrent flow was dominantly from the NE or NW, though the two youngest formations provide the first unequivocal evidence of major southeasterly derivation in the Southern Uplands. The style and vergence of D1 deformation changes across the Port Logan Bay Fault, the area to the SE constituting a 12 km zone of opposing fold and thrust geometry to that dominant in the terrane. A model of sequential Silurian simple shear and pure shear deformation in a steady-state trench environment above a NW-dipping subduction zone is proposed. A set of post-D₂ NW-vergent recumbent folds and thrusts related to end-Caledonian terminal collision of Cadomia and Laurentia provide evidence of major sinistral strike-slip along the Cairngarroch Fault prior to collision.
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Palaeo-geothermal activity in basaltic lavas of Lower Carboniferous age in the Midland Valley of Scotland
https://hdl.handle.net/10023/15574
Post-extrusive hydrothermal alteration within basaltic lavas has been examined with special reference to the Lower Carboniferous Clyde Plateau Basalts of the Midland Valley of Scotland. Within this province several steep-sided, narrowly constrained zones of intense water-rock interaction have been located and examined. It is thought that these zones, or metadomains, developed where hydrothermal fluids exploited permeability contrasts within the volcanic pile and as such they represent foci for geothermal fluids which advected through the lavas. In the field metadomains are often manifest as areas of intense alteration and hydrofracting of the host basalts. Characteristic alteration mineralogies are often hydrous and typically include evolved phyllosilicate assemblages, prehnite, analcime and calcite. Petrography reveals that prehnite and analcime are always paragentetically earlier than calcite across the whole of the lavas. Also, metadomain development was accompanied by significant elemental mobility within the host basalts; Si, Ti, Fe, Mn, Mg, Ca, Na and K all exhibit varying degrees of mobility, whilst Sr, Rb, Cu and Zn display extreme mobility. Furthermore, metadomain basalts have higher volatile contents than there unaltered counterparts. Fluids present during metadomain development typically were Ca2+, Na+, Cl- dominated brines which exhibited both a wide range in salinity (approximately 0 to 25 equiv. wt. % NaCI) and temperatures (approximately 50°C to 300°C). As the development of metadomains proceeded it appears that the fluid present was a hybrid formed from the interaction and mixing of a low temperature, low salinity fluid which was ultimately of surface origin and a higher temperature brine derived from the underlying sediments. The presence of minor amounts of hydrocarbon material within the fluids testified to the involvement of organic rich sequences within the underlying Inverclyde Group sediments. These fluids also record a number of physical processes which are observed within currently active geothermal systems such as mixing and boiling indicative of near surface conditions. Such processes appeared to be largely responsible for controlling the gas content of the fluids. Combined fluid inclusion and stable isotopic analysis of alteration phases (specifically analcime and calcite) has been used to determine fluid origins and evolution during metadomain development. Fluids present during the precipitation of analcime appears to have originated as a surface derived fluid which interacted (isotopically and chemically) with reactive, carbonate rich sediments, possibly the underlying Inverclyde Group. Fluids present during calcite precipitation can be separated into two distinct groups; a low to intermediate (c. 90 to 200°C) surface derived fluid and a higher temperature fluid which also appears to have interacted with reactive sediments. Carbon isotopic results confirm that organic derived material interacted with these fluids. Uniformity in carbon isotopic compositions suggests that the carbon reservoir was active prior to calcite precipitation. As geothermal activity waned calcite precipitation still continued whilst fluid temperatures decreased due to convective cooling of the lava pile. During this stage it appears that fluids were dominantly of surficial origin.
1992-07-01T00:00:00Z
McDonald, Michael
Post-extrusive hydrothermal alteration within basaltic lavas has been examined with special reference to the Lower Carboniferous Clyde Plateau Basalts of the Midland Valley of Scotland. Within this province several steep-sided, narrowly constrained zones of intense water-rock interaction have been located and examined. It is thought that these zones, or metadomains, developed where hydrothermal fluids exploited permeability contrasts within the volcanic pile and as such they represent foci for geothermal fluids which advected through the lavas. In the field metadomains are often manifest as areas of intense alteration and hydrofracting of the host basalts. Characteristic alteration mineralogies are often hydrous and typically include evolved phyllosilicate assemblages, prehnite, analcime and calcite. Petrography reveals that prehnite and analcime are always paragentetically earlier than calcite across the whole of the lavas. Also, metadomain development was accompanied by significant elemental mobility within the host basalts; Si, Ti, Fe, Mn, Mg, Ca, Na and K all exhibit varying degrees of mobility, whilst Sr, Rb, Cu and Zn display extreme mobility. Furthermore, metadomain basalts have higher volatile contents than there unaltered counterparts. Fluids present during metadomain development typically were Ca2+, Na+, Cl- dominated brines which exhibited both a wide range in salinity (approximately 0 to 25 equiv. wt. % NaCI) and temperatures (approximately 50°C to 300°C). As the development of metadomains proceeded it appears that the fluid present was a hybrid formed from the interaction and mixing of a low temperature, low salinity fluid which was ultimately of surface origin and a higher temperature brine derived from the underlying sediments. The presence of minor amounts of hydrocarbon material within the fluids testified to the involvement of organic rich sequences within the underlying Inverclyde Group sediments. These fluids also record a number of physical processes which are observed within currently active geothermal systems such as mixing and boiling indicative of near surface conditions. Such processes appeared to be largely responsible for controlling the gas content of the fluids. Combined fluid inclusion and stable isotopic analysis of alteration phases (specifically analcime and calcite) has been used to determine fluid origins and evolution during metadomain development. Fluids present during the precipitation of analcime appears to have originated as a surface derived fluid which interacted (isotopically and chemically) with reactive, carbonate rich sediments, possibly the underlying Inverclyde Group. Fluids present during calcite precipitation can be separated into two distinct groups; a low to intermediate (c. 90 to 200°C) surface derived fluid and a higher temperature fluid which also appears to have interacted with reactive sediments. Carbon isotopic results confirm that organic derived material interacted with these fluids. Uniformity in carbon isotopic compositions suggests that the carbon reservoir was active prior to calcite precipitation. As geothermal activity waned calcite precipitation still continued whilst fluid temperatures decreased due to convective cooling of the lava pile. During this stage it appears that fluids were dominantly of surficial origin.
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Mid-crustal geodynamics of the southern central zone, Damara Orogen, Namibia
https://hdl.handle.net/10023/15573
Two areas of well exposed mid-crustal structures in the axial zone of the Pan-African Damaran orogenic belt show that basement has formed domes which have amoeboid forms on the scale of tens of km with steep sided overturned non-planar, non- cylindrical geometry. These are surrounded by open to tight synclinal cover envelopes that converge at depressions between the domes. The domes are found in association with a strong regional WSW moderately plunging lineation. Strain analysis demonstrates that domes have formed in a moderately plunging constrictional field. Structural features which normally indicate polyphase evolution such as mesoscale fold interference patterns are rare and inconsistent. Regional structural form, described morphogically by cylindrical domains, is defined by one fabric S0/S1. Secondary fabric trajectories and mesoscale fold oreintations are controlled by domain scale structure and not regional deformation trends. Dome formation is thus interpreted as being the result of a simultaneous flow and buckling episode within the middle crust. Deformation was extremely ductile. P-T estimates from thermobarometry with Grt-Bt, Grt-Crd-Bt-Sil assemblages indicate that peak metamorphic conditions during deformation were approximately 3.5kbar and 650°C in the cover envelopes and 7kbar 791°C in the basement domes, approaching the amphibolite-granulite transition. Interactive transpressional collision between three cratons during the latest Neoproterozoic-early Paleozoic: namely the Kalahari, Congo and Rio de la Plata caused constriction and extrusion in the Central Zone. The metamorphic gap between basement and cover occurred when the distance between regional isotherms was reduced by thinning at the basement-cover interface. Higher temperatures where preserved at dome cores. At the cooler margins of the Damara Belt thrust tectonics occurred, albeit obliquely with sinistral transpression. After dome formation granite intruded many domal structures.
1997-12-01T00:00:00Z
Poli, Lucio Colin
Two areas of well exposed mid-crustal structures in the axial zone of the Pan-African Damaran orogenic belt show that basement has formed domes which have amoeboid forms on the scale of tens of km with steep sided overturned non-planar, non- cylindrical geometry. These are surrounded by open to tight synclinal cover envelopes that converge at depressions between the domes. The domes are found in association with a strong regional WSW moderately plunging lineation. Strain analysis demonstrates that domes have formed in a moderately plunging constrictional field. Structural features which normally indicate polyphase evolution such as mesoscale fold interference patterns are rare and inconsistent. Regional structural form, described morphogically by cylindrical domains, is defined by one fabric S0/S1. Secondary fabric trajectories and mesoscale fold oreintations are controlled by domain scale structure and not regional deformation trends. Dome formation is thus interpreted as being the result of a simultaneous flow and buckling episode within the middle crust. Deformation was extremely ductile. P-T estimates from thermobarometry with Grt-Bt, Grt-Crd-Bt-Sil assemblages indicate that peak metamorphic conditions during deformation were approximately 3.5kbar and 650°C in the cover envelopes and 7kbar 791°C in the basement domes, approaching the amphibolite-granulite transition. Interactive transpressional collision between three cratons during the latest Neoproterozoic-early Paleozoic: namely the Kalahari, Congo and Rio de la Plata caused constriction and extrusion in the Central Zone. The metamorphic gap between basement and cover occurred when the distance between regional isotherms was reduced by thinning at the basement-cover interface. Higher temperatures where preserved at dome cores. At the cooler margins of the Damara Belt thrust tectonics occurred, albeit obliquely with sinistral transpression. After dome formation granite intruded many domal structures.
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A petrogenetic study of harrisite in the Isle of Rhum Pluton, Scotland
https://hdl.handle.net/10023/15572
There is textural evidence in the Rhum pluton for crystallization of layered ultrabasic rocks ('harrisite') under conditions of massive olivine supersaturation. Some of these rocks are comb layered. This field, petrographic and experimental investigation of harrisite is aimed at determining (1) the degree of supercooling at which different shapes of olivine crystallized in harrisite, (2) how magma in a plutonic environment became massively supersaturated in olivine and (3) whether the parent magma of harrisite was basaltic or ultrabasic. The results have particular relevance to the conditions under which magmas crystallize close to, or on, their margins and enclosures, sometimes to produce comb layers. Harrisite is here defined as "an ultrabasic, plutonic, igneous rock in layered intrusions which contains >25 vol. percent of olivine. The olivine crystals are characterized by skeletal or dendritic shapes and have larger size than olivines in contiguous layers. Hydrous minerals are essential phases in the rock," Harrisite is a varietal type of peridotite, allivalite or olivine eucirite. Harrisite layers are mainly confined to the Western Layered Series of the Rhum pluton. They range in thickness from 7 cm to 10 m and have a preferred thickness of about 1 m. Individual layers vary laterally in thickness and olivine crystal shape. A few harrisite layers are intrusive into the Layered Series, but the majority crystallized in conformable sequence with cumulate layers. Five percent of the ultrabasic rock of the island is harrisite; sixty percent of the Transition Series is harrisite. The shapes of olivines in igneous rocks are classified into thirteen categories (those found in harrisite are underlined): polyhedral, porphyritic, granular, chain-like, parallel-growth, plate, branching (non-crystallographic, crystallographic, linked parallel-unit), randomly oriented, radiate, dendritic, lattice-work, swallow-tail and irregular olivines. Elongate olivines in harrisite can grow preferentially upwards, downwards, horizontally or in random orientation. There is a gradual, systematic upward change in layers from granular or polyhedral cumulus olivines to skeletal porphyritic olivines, to branching olivines (present only in some layers). This change is accompanied by up to a 10 vol. percent decrease in olivine content and by increases in contents of both chrome magnetite and hydrous minerals; also, olivine crystals increase up to 1000 times in size and plagioclase crystals increase in size up to 10 times. Olivine crystals in harrisite grew as fast as 10-4 cm/s. Olivine in harrisite has a composition range of Fo84- 73. Some crystals are reverse zoned (2 - 2.5 mol. percent Fo). Olivines in cumulate layers are up to 2 mol. percent poorer in Fo than those in contiguous harrisite layers. Augite (e.g., Wo46En46FS9) and rare orthopyroxene crystals (e.g., Wo1.3En79.4 Fs 19.3) indicate crystallization from a transitional magma. Plagioclases range from An87 in the generally broad, unzoned cores of crystals, to approximately An60 at in the extremity of the normally-zoned mantles. Cr-rich kaersutite and phlogopite crystallized by reaction of magma with pyroxene, whereas Cr-deficient varieties of the same minerals crystallized directly from the magma. Chrome magnetite composition is dependent on the enclosing silicate mineral- crystals enclosed in olivine are generally richer in Fe and poorer in Al, Cr and Mg than those enclosed by plagioclase and pyroxene. Variations in olivine, plagioclase and chrome magnetite compositions in one comb layer of harrisite are consistent with upward crystallization of the layer along a thermal gradient in the magma of increasing temperature with height. (Abstract shortened by Proquest)
1975-03-01T00:00:00Z
Donaldson, Colin H.
There is textural evidence in the Rhum pluton for crystallization of layered ultrabasic rocks ('harrisite') under conditions of massive olivine supersaturation. Some of these rocks are comb layered. This field, petrographic and experimental investigation of harrisite is aimed at determining (1) the degree of supercooling at which different shapes of olivine crystallized in harrisite, (2) how magma in a plutonic environment became massively supersaturated in olivine and (3) whether the parent magma of harrisite was basaltic or ultrabasic. The results have particular relevance to the conditions under which magmas crystallize close to, or on, their margins and enclosures, sometimes to produce comb layers. Harrisite is here defined as "an ultrabasic, plutonic, igneous rock in layered intrusions which contains >25 vol. percent of olivine. The olivine crystals are characterized by skeletal or dendritic shapes and have larger size than olivines in contiguous layers. Hydrous minerals are essential phases in the rock," Harrisite is a varietal type of peridotite, allivalite or olivine eucirite. Harrisite layers are mainly confined to the Western Layered Series of the Rhum pluton. They range in thickness from 7 cm to 10 m and have a preferred thickness of about 1 m. Individual layers vary laterally in thickness and olivine crystal shape. A few harrisite layers are intrusive into the Layered Series, but the majority crystallized in conformable sequence with cumulate layers. Five percent of the ultrabasic rock of the island is harrisite; sixty percent of the Transition Series is harrisite. The shapes of olivines in igneous rocks are classified into thirteen categories (those found in harrisite are underlined): polyhedral, porphyritic, granular, chain-like, parallel-growth, plate, branching (non-crystallographic, crystallographic, linked parallel-unit), randomly oriented, radiate, dendritic, lattice-work, swallow-tail and irregular olivines. Elongate olivines in harrisite can grow preferentially upwards, downwards, horizontally or in random orientation. There is a gradual, systematic upward change in layers from granular or polyhedral cumulus olivines to skeletal porphyritic olivines, to branching olivines (present only in some layers). This change is accompanied by up to a 10 vol. percent decrease in olivine content and by increases in contents of both chrome magnetite and hydrous minerals; also, olivine crystals increase up to 1000 times in size and plagioclase crystals increase in size up to 10 times. Olivine crystals in harrisite grew as fast as 10-4 cm/s. Olivine in harrisite has a composition range of Fo84- 73. Some crystals are reverse zoned (2 - 2.5 mol. percent Fo). Olivines in cumulate layers are up to 2 mol. percent poorer in Fo than those in contiguous harrisite layers. Augite (e.g., Wo46En46FS9) and rare orthopyroxene crystals (e.g., Wo1.3En79.4 Fs 19.3) indicate crystallization from a transitional magma. Plagioclases range from An87 in the generally broad, unzoned cores of crystals, to approximately An60 at in the extremity of the normally-zoned mantles. Cr-rich kaersutite and phlogopite crystallized by reaction of magma with pyroxene, whereas Cr-deficient varieties of the same minerals crystallized directly from the magma. Chrome magnetite composition is dependent on the enclosing silicate mineral- crystals enclosed in olivine are generally richer in Fe and poorer in Al, Cr and Mg than those enclosed by plagioclase and pyroxene. Variations in olivine, plagioclase and chrome magnetite compositions in one comb layer of harrisite are consistent with upward crystallization of the layer along a thermal gradient in the magma of increasing temperature with height. (Abstract shortened by Proquest)
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Petrological studies of Devonian rocks in Scotland and cretaceous rocks in Canada
https://hdl.handle.net/10023/15571
Sedimentological, petrological and geochemical studies have been carried out to analyse the process of calcretization and to understand the influence of environment of deposition on sandstone diagenesis. The sediments examined come from Lower Old Red Sandstones (Lr. Devonian) of eastern Scotland and hydrocarbon bearing Viking, Cardium and Belly River Formations (Cretaceous) of southcentral Canada. Some scepticism has been expressed regarding the occurrence of displacive calcite but this type of growth has been found in the calcrete profiles in Lower Old Red Sandstones of Carnoustie, east Scotland. This thesis presents fresh petrographic evidence of expansion and isolation of clastic grains by growing calcite crystals. The morphology of calcite crystals observed under cathodoluminescence provide compelling evidence that they are not a passive pore filling cement but have grown in confined spaces from supersaturated solutions by displacing the constraining medium. Field relationships suggest that the calcite was generated within the vadose zone where crystallization was promoted by rapid surface evaporation leading to supersaturation. A two-water model based on petrological and geochemical criteria has been suggested to explain the mechanism of growth of displacive calcite crystals (Chapter - IV). The recognition of displacive calcite is highly significant as it offers insight into paleoclimatic conditions and diagenetic history. Crystal morphologies observed under cathodoluminescence and microprobe data suggests that the displacive calcite was originally low Mg-calcite and grew from rapidly evaporating fresh pore waters with extremely low Mg/Ca ratios. The growth of originally low Mg-calcite and absence of palygorskite, sepiolite and dolomite in the Carnoustie calcretes is considered significant and it has been emphasized that no one process applies to all calcretes and the chemistry of pore waters and micro-environmental conditions within the pores are major significant factors controlling process of calcretization. The comparisons drawn between the diagenetic products observed in the Lower Old Red Sandstone and the Viking, Cardium and Belly River Formations suggest that the detrital mineralogy and aqueous solutions migrating through the pore system of sandstones are the two major factors that accomplish all the complex chemical reactions during diagenesis. In general, the Viking, Cardium and Belly River sediments show large variations in their pre-burial early diagenetic histories within small areas (even between adjoining wells) while the Lr. Old Red Sandstone show a monotonous paragenetic sequence over the entire area. This is compatible with the expected variations in the pore-fluid chemistry and micro-environmental conditions within the pores deduced from the depositional environments of these sediments. Hence it has been concluded that the pre-burial early diagenetic processes and products in clastic sediments are controlled by their environment of deposition which subsequently could influence the course of late stage diagenesis as well.
1985-07-01T00:00:00Z
Saigal, Girish C.
Sedimentological, petrological and geochemical studies have been carried out to analyse the process of calcretization and to understand the influence of environment of deposition on sandstone diagenesis. The sediments examined come from Lower Old Red Sandstones (Lr. Devonian) of eastern Scotland and hydrocarbon bearing Viking, Cardium and Belly River Formations (Cretaceous) of southcentral Canada. Some scepticism has been expressed regarding the occurrence of displacive calcite but this type of growth has been found in the calcrete profiles in Lower Old Red Sandstones of Carnoustie, east Scotland. This thesis presents fresh petrographic evidence of expansion and isolation of clastic grains by growing calcite crystals. The morphology of calcite crystals observed under cathodoluminescence provide compelling evidence that they are not a passive pore filling cement but have grown in confined spaces from supersaturated solutions by displacing the constraining medium. Field relationships suggest that the calcite was generated within the vadose zone where crystallization was promoted by rapid surface evaporation leading to supersaturation. A two-water model based on petrological and geochemical criteria has been suggested to explain the mechanism of growth of displacive calcite crystals (Chapter - IV). The recognition of displacive calcite is highly significant as it offers insight into paleoclimatic conditions and diagenetic history. Crystal morphologies observed under cathodoluminescence and microprobe data suggests that the displacive calcite was originally low Mg-calcite and grew from rapidly evaporating fresh pore waters with extremely low Mg/Ca ratios. The growth of originally low Mg-calcite and absence of palygorskite, sepiolite and dolomite in the Carnoustie calcretes is considered significant and it has been emphasized that no one process applies to all calcretes and the chemistry of pore waters and micro-environmental conditions within the pores are major significant factors controlling process of calcretization. The comparisons drawn between the diagenetic products observed in the Lower Old Red Sandstone and the Viking, Cardium and Belly River Formations suggest that the detrital mineralogy and aqueous solutions migrating through the pore system of sandstones are the two major factors that accomplish all the complex chemical reactions during diagenesis. In general, the Viking, Cardium and Belly River sediments show large variations in their pre-burial early diagenetic histories within small areas (even between adjoining wells) while the Lr. Old Red Sandstone show a monotonous paragenetic sequence over the entire area. This is compatible with the expected variations in the pore-fluid chemistry and micro-environmental conditions within the pores deduced from the depositional environments of these sediments. Hence it has been concluded that the pre-burial early diagenetic processes and products in clastic sediments are controlled by their environment of deposition which subsequently could influence the course of late stage diagenesis as well.
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Testing for compositional convection in silicate melts : crystal growth experiments and a petrographic study of a differentiated ring dyke
https://hdl.handle.net/10023/15570
Convection in magma chambers, driven by compositional density differences, is thought to be a major process in fractionation of liquid from crystals in the differentiation of magmas. Compositional convection has been tested for by undertaking two sets of experiments in silicate melts, and by re-examining the vertically differentiated gabbro-granophyre Glen More ring dyke on the Isle of Mull. Crystal growth quenching experiments have been carried out in a synthetic basalt in which iron is replaced by cobalt. Co-Mg olivine was overgrown on olivine seeds cemented in alumina crucibles and the glasses produced on quenching were analysed by EPMA for compositional variation at and above the overgrowth-glass interface. Boundary layers up to 50?m wide, and depleted in Co and Mg by upto 25 %, have been found at crystal-glass interfaces, and plumes of the same melt have been detected above the apexes of growing olivine crystals. The computed density difference which causes the convection of this boundary layer, melt is in the region of 1 %. This phenomenon, known as compositional convection, has been seen associated with dissolving crystals in silicate melts, and around growing crystals in aqueous salt solutions, but this is the first time it has been reported accompanying crystal growth in silicate melts. Other experiments in which hematite underwent dissolution in a natural basalt melt show that dense, Fe-enriched melt can be lifted above its origin by the buoyant rise of bubbles. In both sets of experiments a zone of buoyant boundary layer melt has been produced by side-wall crystallization of hercynite. This zone of melt has convected up and has ponded beneath the meniscus by a process that can be likened to side-wall crystallization in magma chambers. Petrological, mineralogical, textural, and new geochemical evidence from the re-examination of the Glen More ring dyke strongly suggests that the petrological variation is the result of a magma mixing mechanism. It is proposed that this was produced by the injection of a basic magma which underwent partial consolidation. This was then followed by a second injection of a silicic magma which underwent partial mixing with the dioritic residual magma remaining after crystallization of gabbros from the initial magma.
1994-07-01T00:00:00Z
Seedhouse, Jonathan K.
Convection in magma chambers, driven by compositional density differences, is thought to be a major process in fractionation of liquid from crystals in the differentiation of magmas. Compositional convection has been tested for by undertaking two sets of experiments in silicate melts, and by re-examining the vertically differentiated gabbro-granophyre Glen More ring dyke on the Isle of Mull. Crystal growth quenching experiments have been carried out in a synthetic basalt in which iron is replaced by cobalt. Co-Mg olivine was overgrown on olivine seeds cemented in alumina crucibles and the glasses produced on quenching were analysed by EPMA for compositional variation at and above the overgrowth-glass interface. Boundary layers up to 50?m wide, and depleted in Co and Mg by upto 25 %, have been found at crystal-glass interfaces, and plumes of the same melt have been detected above the apexes of growing olivine crystals. The computed density difference which causes the convection of this boundary layer, melt is in the region of 1 %. This phenomenon, known as compositional convection, has been seen associated with dissolving crystals in silicate melts, and around growing crystals in aqueous salt solutions, but this is the first time it has been reported accompanying crystal growth in silicate melts. Other experiments in which hematite underwent dissolution in a natural basalt melt show that dense, Fe-enriched melt can be lifted above its origin by the buoyant rise of bubbles. In both sets of experiments a zone of buoyant boundary layer melt has been produced by side-wall crystallization of hercynite. This zone of melt has convected up and has ponded beneath the meniscus by a process that can be likened to side-wall crystallization in magma chambers. Petrological, mineralogical, textural, and new geochemical evidence from the re-examination of the Glen More ring dyke strongly suggests that the petrological variation is the result of a magma mixing mechanism. It is proposed that this was produced by the injection of a basic magma which underwent partial consolidation. This was then followed by a second injection of a silicic magma which underwent partial mixing with the dioritic residual magma remaining after crystallization of gabbros from the initial magma.
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A petrological investigation of the xenolithic ultrabasic dykes of the Cuillins and the Strathaird Peninsula, Isle of Skye
https://hdl.handle.net/10023/15569
The Tertiary ultrabasic dykes of the Cuillins and the Strathaird peninsula are studied and classified on the bases of their content of cognate xenoliths and textures. Two principal types are, recognised, the Coire Lagan type (similar to those studied by Drever and Johnston, 1958) and the xenolithic Ben Cleat type. The dykes of the Ben Cleat type are investigated in detail. The Ben Cleat dykes are composed principally of olivine (Fa11), plagioclase (Ang4 with normally zoned margins) and clinopyroxene (Ca43 Mg46 Fe11) with accessory chrome spinel: the compositions of these minerals are constant throughout the dykes. The transverse variations in modal amount and crystal size of the three principal minerals within selected representative dykes have been determined and it is established beyond doubt that the dykes are differentiated. The petrogenetic hypothesis of composite intrusion previously proposed for these dykes by Bowen (l928) is examined in the light of this evidence and found to be inadequate. It is suggested that the dykes were intruded as suspensions of olivine crystals and rock fragments in an ultrabasic liquid from which plagioclase, pyroxene and a small amount of olivine subsequently crystallised. It is demonstrated that the dykes are unlikely to have been differentiated in their present positions and the possibility that the differentiation occurred during their emplacement is examined. The processes by which, crystals might migrate in flowing magma are considered, and it is shown that the mineral distributions and crystal size variations occurring in the dykes are analogous to those expected, from the results of theoretical and experimental investigations, to arise during laminar flow of suspensions of solid particles in a viscous fluid in vertical conduits. Several of the apparently anomalous differentiation phenomena are also interpreted in the light of theoretical fluid mechanics as the results of flow in near-vertical fissures. It is concluded that (i) the dykes were each intruded as a single pulse of ultrabasic liquid containing large amounts of olivine phenocsrysts,?(ii) the distinctive type of differentiation which is characteristic of these dykes occurred during their intrusion and (iii) the mechanism involved was flowage differentiation. The petrographiea of the cognate xenoliths are studied and their distribution and orientation explained on the basis of laminar flow of the dyke magma. The age of the xenolithic ultrabasic dykes in relation to the other intrusions of the Cuillin Tertiary igneous complex is reconsidered and it is suggested that the dykes were emplaced contemporaneously with the Sgurr Dubh ultrabasic intrusion. Petrogenetic hypotheses are advanced for both the dykes; and the cognate xenoliths and it is tentatively proposed that both were derived by partial fusion of a deep-seated peridotitic rook.
1966-01-01T00:00:00Z
Gibb, Fergus George Ferguson
The Tertiary ultrabasic dykes of the Cuillins and the Strathaird peninsula are studied and classified on the bases of their content of cognate xenoliths and textures. Two principal types are, recognised, the Coire Lagan type (similar to those studied by Drever and Johnston, 1958) and the xenolithic Ben Cleat type. The dykes of the Ben Cleat type are investigated in detail. The Ben Cleat dykes are composed principally of olivine (Fa11), plagioclase (Ang4 with normally zoned margins) and clinopyroxene (Ca43 Mg46 Fe11) with accessory chrome spinel: the compositions of these minerals are constant throughout the dykes. The transverse variations in modal amount and crystal size of the three principal minerals within selected representative dykes have been determined and it is established beyond doubt that the dykes are differentiated. The petrogenetic hypothesis of composite intrusion previously proposed for these dykes by Bowen (l928) is examined in the light of this evidence and found to be inadequate. It is suggested that the dykes were intruded as suspensions of olivine crystals and rock fragments in an ultrabasic liquid from which plagioclase, pyroxene and a small amount of olivine subsequently crystallised. It is demonstrated that the dykes are unlikely to have been differentiated in their present positions and the possibility that the differentiation occurred during their emplacement is examined. The processes by which, crystals might migrate in flowing magma are considered, and it is shown that the mineral distributions and crystal size variations occurring in the dykes are analogous to those expected, from the results of theoretical and experimental investigations, to arise during laminar flow of suspensions of solid particles in a viscous fluid in vertical conduits. Several of the apparently anomalous differentiation phenomena are also interpreted in the light of theoretical fluid mechanics as the results of flow in near-vertical fissures. It is concluded that (i) the dykes were each intruded as a single pulse of ultrabasic liquid containing large amounts of olivine phenocsrysts,?(ii) the distinctive type of differentiation which is characteristic of these dykes occurred during their intrusion and (iii) the mechanism involved was flowage differentiation. The petrographiea of the cognate xenoliths are studied and their distribution and orientation explained on the basis of laminar flow of the dyke magma. The age of the xenolithic ultrabasic dykes in relation to the other intrusions of the Cuillin Tertiary igneous complex is reconsidered and it is suggested that the dykes were emplaced contemporaneously with the Sgurr Dubh ultrabasic intrusion. Petrogenetic hypotheses are advanced for both the dykes; and the cognate xenoliths and it is tentatively proposed that both were derived by partial fusion of a deep-seated peridotitic rook.
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Experimental and petrological investigations of some magmatic phenomena
https://hdl.handle.net/10023/15568
This thesis is devoted to a detailed investigation of a piorite sill of Tertiary age intruded into Torridonian strata on the island of Soay, south Skye. It is devided into four parts (1) studies on the petrography of the picrate, (2) the thermal metamorphism of the enclosing Torridonian strata, (3) and (4) a consideration of the genetic problems of the piorite and the metamorphosed and partially fused Torridonian especially in the light of experimental data on silicate systems related in composition thereto. The first section gives in detail the mineralogy and petrography of one of the piorite sills of Harker's "later peridotite" group of intrusions and particular attention is devoted to the question of the habit of the olivine phase in its textural setting through the sill in the light of Bowen's reinterpretation of the condition of intrusion of the Skye later peridotites. Part 2 of the thesis deals with the metamorphism induced in the associated Torridonian sediments. This metamorphism culminated in partial fusion of the sediments. The account of these phenomena, including the hybridism with the picrate is well set out and an analysis provided of a fused xenolith within the sill. In Part 3 an attempt is made in the light of experimental studies on a related silicate system to evaluate the liquidus of a piorite of the composition analysed. The discussion concerns the studies of Ricker on the Ca2Sio4-Mg2Sio4-Fe2Sio4 plane in the quatemary system and the application of the results, with, it must be admitted, considerable extrapolation to the related piorite. It is concluded that these studies indicate that the liquidus of the piorite would be at considerably lower temperatures than suggested by earlier phase equilibrium work. A beginning with some experimental work by the candidate in the picrate itself in the presence of water vapour is reported but no liquidus determinations were recorded. The temperature deduced for the liquidus is roughly placed around 1500oc. With still lower values, if volatiles are allowed for. This temperatures is still very high, at least 300oc. higher than that known for the liquidus of a calcalkali type of basalt. The discussion of the fusion of the Torridonian assemblage in relation to the experimental data on the granite system (Ab-Or-SiO2-H2O) is well presented and probably provided a real picture of the processes involved. The final part of the thesis is devoted to the petrogenesis. Included here are discussions on the significance of the variations in the shape and size of olivine crystals, on the interpretation of porphyritic texture in relation to the olivine phase and the bearing of these phenomena on the question of in situ crystallization of olivine. The evidence considered unfavourable to the hypothesis of intrusion of a basaltic liquid containing a high proportion of olivine crystals is marshalled but not all of the argument can be regarded as cogent evidence. The candidate has however brought forward good evidence from his own detailed studies that there are good grounds for extending the composition of true magmatic liquids beyond the limits given by Bowen. (Abstract shortened by ProQuest.)
1958-03-01T00:00:00Z
Wyllie, Peter John
This thesis is devoted to a detailed investigation of a piorite sill of Tertiary age intruded into Torridonian strata on the island of Soay, south Skye. It is devided into four parts (1) studies on the petrography of the picrate, (2) the thermal metamorphism of the enclosing Torridonian strata, (3) and (4) a consideration of the genetic problems of the piorite and the metamorphosed and partially fused Torridonian especially in the light of experimental data on silicate systems related in composition thereto. The first section gives in detail the mineralogy and petrography of one of the piorite sills of Harker's "later peridotite" group of intrusions and particular attention is devoted to the question of the habit of the olivine phase in its textural setting through the sill in the light of Bowen's reinterpretation of the condition of intrusion of the Skye later peridotites. Part 2 of the thesis deals with the metamorphism induced in the associated Torridonian sediments. This metamorphism culminated in partial fusion of the sediments. The account of these phenomena, including the hybridism with the picrate is well set out and an analysis provided of a fused xenolith within the sill. In Part 3 an attempt is made in the light of experimental studies on a related silicate system to evaluate the liquidus of a piorite of the composition analysed. The discussion concerns the studies of Ricker on the Ca2Sio4-Mg2Sio4-Fe2Sio4 plane in the quatemary system and the application of the results, with, it must be admitted, considerable extrapolation to the related piorite. It is concluded that these studies indicate that the liquidus of the piorite would be at considerably lower temperatures than suggested by earlier phase equilibrium work. A beginning with some experimental work by the candidate in the picrate itself in the presence of water vapour is reported but no liquidus determinations were recorded. The temperature deduced for the liquidus is roughly placed around 1500oc. With still lower values, if volatiles are allowed for. This temperatures is still very high, at least 300oc. higher than that known for the liquidus of a calcalkali type of basalt. The discussion of the fusion of the Torridonian assemblage in relation to the experimental data on the granite system (Ab-Or-SiO2-H2O) is well presented and probably provided a real picture of the processes involved. The final part of the thesis is devoted to the petrogenesis. Included here are discussions on the significance of the variations in the shape and size of olivine crystals, on the interpretation of porphyritic texture in relation to the olivine phase and the bearing of these phenomena on the question of in situ crystallization of olivine. The evidence considered unfavourable to the hypothesis of intrusion of a basaltic liquid containing a high proportion of olivine crystals is marshalled but not all of the argument can be regarded as cogent evidence. The candidate has however brought forward good evidence from his own detailed studies that there are good grounds for extending the composition of true magmatic liquids beyond the limits given by Bowen. (Abstract shortened by ProQuest.)
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A detailed structural study of the northern portion of the Strontian Granitic Complex
https://hdl.handle.net/10023/15567
Previous work on the Strontian complex has been substantiated by the present investigation, and the knowledge of the structures in the rocks of the complex, and in the adjoining Moine schists end gneisses has been considerably augmented. It has been shown that a planar structure occurs throughout two of the three main unite of the complex - the tonalite and the porphyritic granodiorite. A linear structure also occurs in these rocks in a restricted area it the north. These structures largely conform to a simple pattern common to both tonalite and granodiorite. In the northern part of the complex, the granitic veins end the joints both appear to possess distinctive patterns of orientation, which prevail throughout this northern region. These patterns show little similarity to each other, and appear to be largely unrelated to the orientation of the foliation and lineation in the tonalite and granodiorite in this area. The formation of the complex appears to have been attended by considerable shearing and folding in the Moine country rocks which lie within half a mile of the complex. The overall pattern of the structures within the complex and the adjoining areas of country rock, appears to be distinctive, and does not closely resemble the structural pattern within and around other granitic complexes. It is suggested that the two main units of the complex with a common internal structural pattern have been formed by the more or less simultaneous intrusion of two magmas, and that these magmas were probably emplaced by a process which involved forcible intrusion, and may have under the control of forces associated with the Caledonian orogeny.
1955-01-01T00:00:00Z
Munro, Martin
Previous work on the Strontian complex has been substantiated by the present investigation, and the knowledge of the structures in the rocks of the complex, and in the adjoining Moine schists end gneisses has been considerably augmented. It has been shown that a planar structure occurs throughout two of the three main unite of the complex - the tonalite and the porphyritic granodiorite. A linear structure also occurs in these rocks in a restricted area it the north. These structures largely conform to a simple pattern common to both tonalite and granodiorite. In the northern part of the complex, the granitic veins end the joints both appear to possess distinctive patterns of orientation, which prevail throughout this northern region. These patterns show little similarity to each other, and appear to be largely unrelated to the orientation of the foliation and lineation in the tonalite and granodiorite in this area. The formation of the complex appears to have been attended by considerable shearing and folding in the Moine country rocks which lie within half a mile of the complex. The overall pattern of the structures within the complex and the adjoining areas of country rock, appears to be distinctive, and does not closely resemble the structural pattern within and around other granitic complexes. It is suggested that the two main units of the complex with a common internal structural pattern have been formed by the more or less simultaneous intrusion of two magmas, and that these magmas were probably emplaced by a process which involved forcible intrusion, and may have under the control of forces associated with the Caledonian orogeny.
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Mineralogy, petrology and geochemistry of Caradocian phosphorites, N. Wales, U.K.
https://hdl.handle.net/10023/15566
Caradocian phosphorite nodules sampled from the Powys county of N. Wales, U.K. have been investigated in order to characterize the deposit geochemically, mineralogically and petrographically and to evaluate their mode of formation. Nodules are the main form of phosphorite although phosphatized organic fragments and oolitic grains are also present. On the basis of petrographio characteristics, nodules are grouped into two types; Type I nodules (with abundant organic material) and Type II nodules (with abundant clay minerals). Mineralogical compositions of the phosphorite nodules reflect varying degrees of dilution of the phosphate material, francolite, by authigenic and detrital minerals. Examination with the scanning electron microscope of freshly fractured surfaces of nodules suggests that the apatite formed authigenically as a direct chemical precipitate. Surfaces of abundant siliceous spicules and other organic fragments as well as some minerals appear to be favoured sites for apatite nucleation. Geochemical studies showed significant impoverishment of lattice elements and enrichment of non-lattice elements in both types of nodules. Chemically the phosphorite nodules may be described in terms of four major components: SiO2, CaO, P2O5 and F. The average concentrations of trace elements present in these nodular phosphorites were compared with an average concentration in marine shales. The enrichment and/or depletion largely suggested precipitation from sea water. The proposed model of phosphorite formation involves inorganic (or biochemical) precipitation of apatite within pore waters of anoxic sediments and subsequent concentration of the apatite by physical processes. Oxidation of organic material during sulphate reduction is the main source of phosphate. This is supported by the very light delta13c isotopic composition of structural carbonate present in the francolites. These studies have also shown that these phosphorites have undergone differential leaching during weathering processes with the development of secondary phosphate: minerals, decarbonation of francolite and removal of many major and minor elements.
1985-07-01T00:00:00Z
Saigal, Neeta
Caradocian phosphorite nodules sampled from the Powys county of N. Wales, U.K. have been investigated in order to characterize the deposit geochemically, mineralogically and petrographically and to evaluate their mode of formation. Nodules are the main form of phosphorite although phosphatized organic fragments and oolitic grains are also present. On the basis of petrographio characteristics, nodules are grouped into two types; Type I nodules (with abundant organic material) and Type II nodules (with abundant clay minerals). Mineralogical compositions of the phosphorite nodules reflect varying degrees of dilution of the phosphate material, francolite, by authigenic and detrital minerals. Examination with the scanning electron microscope of freshly fractured surfaces of nodules suggests that the apatite formed authigenically as a direct chemical precipitate. Surfaces of abundant siliceous spicules and other organic fragments as well as some minerals appear to be favoured sites for apatite nucleation. Geochemical studies showed significant impoverishment of lattice elements and enrichment of non-lattice elements in both types of nodules. Chemically the phosphorite nodules may be described in terms of four major components: SiO2, CaO, P2O5 and F. The average concentrations of trace elements present in these nodular phosphorites were compared with an average concentration in marine shales. The enrichment and/or depletion largely suggested precipitation from sea water. The proposed model of phosphorite formation involves inorganic (or biochemical) precipitation of apatite within pore waters of anoxic sediments and subsequent concentration of the apatite by physical processes. Oxidation of organic material during sulphate reduction is the main source of phosphate. This is supported by the very light delta13c isotopic composition of structural carbonate present in the francolites. These studies have also shown that these phosphorites have undergone differential leaching during weathering processes with the development of secondary phosphate: minerals, decarbonation of francolite and removal of many major and minor elements.
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A petrological study of the appenite suite associated with the Ardara pluton, Co. Donegal, Ireland
https://hdl.handle.net/10023/15565
Appinites are enigmatic rocks commonly associated with major I-type plutons in the Caledonian orogen, a number of different models have been proposed for the origin of their parental magmas and unusual textural characteristics. The appinite cluster associated with the Ardara pluton has been studied using petrological techniques with the aim of understanding these features as well as their relationships to the main pluton. The approach of this study has been to select a few appinite bodies considered to be representative of the whole Ardara appinite suite, and to study each in detail in parallel with a limited study of the main pluton. The techniques adopted include field mapping, petrography, mineral chemistry, whole rock major and trace element geochemistry. The detailed aims were to constrain the origin of the magma, its emplacement history and differentiation, for each selected body. In one case (Portnoo) the role of fluids was investigated in detail using stable isotope geochemistry. The Ardara appinite suite comprises a wide variety of generally amphibole-rich rocks typically including hornblendite, meladiorite, diorite, granodiorite and granite. There is one case of cortlandtite. Most have evidence of a significant volatile phase at crystallisation. The intrusions display a wide range in form and emplacement mechanism and most were emplaced prior to, or coeval with, the diapiric granite pluton of Ardara. They have a history of tectonic control on emplacement and are associated with major shear zones acting as potential magma pathways. Mineral geobarometry and geothermometry indicate that the appinites crystallised at 5-8 kb, and selected mineral pairs equilibrated between 800 and 976°C. G1 and G2 of the Ardara pluton crystallised at 5 kb and amphibole-plagioclase equilibrated at around 800°C. These pressures are high if the appinites are high-level diatremes, and this apparent inconsistency is discussed. Variations in bulk geochemistry are considerable and attempts are made to model these as the products of crystal-liquid processes using mass balance major oxide and Rayleigh trace element techniques. The results tend to be dominated by solutions involving amphibole, other mafic minerals and plagioclase, although in many cases no satisfactory result was obtained which suggests that crystal fractionation is not always the sole cause of differentiation. Stable isotope studies of delta18O, delta13C and 5D from the appinites and country rocks at Portnoo indicate that the dominant fluid in this appinite was magmatic in origin, although crustal contamination had occurred, while 6D data also indicate role for meteoric fluids. The data show that fluids from the appinite penetrated the limestone aureole to about 40m. The compositional characteristics of the Ardara appinite suite support a model of derivation of a hydrous basic magma from a mantle source. These magmas undergo differentiation by multiple processes, including crystal-liquid fractionation, as well as contamination by crustal assimilation and possibly by other magmas. The source of G1 & G2 of the main pluton is relatively primitive and could be immature lower crust. It is possible to derive G1 from G2 by crystal fractionation, but probably not in situ. The central G3 granite was almost certainly derived from a distinct, rather more mature crustal source.
1992-07-01T00:00:00Z
Yarr, Timothy Roderick
Appinites are enigmatic rocks commonly associated with major I-type plutons in the Caledonian orogen, a number of different models have been proposed for the origin of their parental magmas and unusual textural characteristics. The appinite cluster associated with the Ardara pluton has been studied using petrological techniques with the aim of understanding these features as well as their relationships to the main pluton. The approach of this study has been to select a few appinite bodies considered to be representative of the whole Ardara appinite suite, and to study each in detail in parallel with a limited study of the main pluton. The techniques adopted include field mapping, petrography, mineral chemistry, whole rock major and trace element geochemistry. The detailed aims were to constrain the origin of the magma, its emplacement history and differentiation, for each selected body. In one case (Portnoo) the role of fluids was investigated in detail using stable isotope geochemistry. The Ardara appinite suite comprises a wide variety of generally amphibole-rich rocks typically including hornblendite, meladiorite, diorite, granodiorite and granite. There is one case of cortlandtite. Most have evidence of a significant volatile phase at crystallisation. The intrusions display a wide range in form and emplacement mechanism and most were emplaced prior to, or coeval with, the diapiric granite pluton of Ardara. They have a history of tectonic control on emplacement and are associated with major shear zones acting as potential magma pathways. Mineral geobarometry and geothermometry indicate that the appinites crystallised at 5-8 kb, and selected mineral pairs equilibrated between 800 and 976°C. G1 and G2 of the Ardara pluton crystallised at 5 kb and amphibole-plagioclase equilibrated at around 800°C. These pressures are high if the appinites are high-level diatremes, and this apparent inconsistency is discussed. Variations in bulk geochemistry are considerable and attempts are made to model these as the products of crystal-liquid processes using mass balance major oxide and Rayleigh trace element techniques. The results tend to be dominated by solutions involving amphibole, other mafic minerals and plagioclase, although in many cases no satisfactory result was obtained which suggests that crystal fractionation is not always the sole cause of differentiation. Stable isotope studies of delta18O, delta13C and 5D from the appinites and country rocks at Portnoo indicate that the dominant fluid in this appinite was magmatic in origin, although crustal contamination had occurred, while 6D data also indicate role for meteoric fluids. The data show that fluids from the appinite penetrated the limestone aureole to about 40m. The compositional characteristics of the Ardara appinite suite support a model of derivation of a hydrous basic magma from a mantle source. These magmas undergo differentiation by multiple processes, including crystal-liquid fractionation, as well as contamination by crustal assimilation and possibly by other magmas. The source of G1 & G2 of the main pluton is relatively primitive and could be immature lower crust. It is possible to derive G1 from G2 by crystal fractionation, but probably not in situ. The central G3 granite was almost certainly derived from a distinct, rather more mature crustal source.
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Weathering and landform evolution in North-East Scotland
https://hdl.handle.net/10023/15562
Weathered rock has been located at over 450 sites in northeast Scotland. Depths of weathering locally exceed 30m but the weathering front is often highly irregular. The incidence of weathering is spatially variable and weathering zones are identified which reflect the influence of geology, fracturing, slopes and patterns of glacial erosion. Two weathering types, grusses and clayey grusses, are recognised after examination of granulometry, geochemistry and clay mineralogy. The grusses have low clay contents, high proportions of little-altered felspar and biotite, modest soluble base losses and heterogeneous clay mineral assemblages. The grusses are equivalent to the 'sandy weathering type' of Bakker (1967) and were formed mainly under the temperate environments of the late Pliocene and the early Pleistocene. The clayey grusses have elevated clay contents, high proportions of detrital quartz, high soluble base losses, kaolinite-illite bi-mineralic assemblages and may be rubefied. The clayey grusses formed under warmer environments than at present, probably in the Miocene. The Buchan Gravels consist of two formations of separate age. The Windyhills Formation comprises fluvial gravels of Middle to Late Pliocene age. The Buchan Ridge Formation includes glacially- disturbed masses of fluviatile deposits of Late Miocene to Early Pliocene age. The denudational history of the region is reconstructed using evidence from morphology, weathering types, and onshore and offshore geology. In the Late Cretaceous, transgression into the Buchan area left a cover of Greensand and Chalk. In the Palaeocene, the eastern Grampians were uplifted and tilted but the eastern lowlands were simultaneously downwarped towards the outer Moray Firth. Western areas subsided after the Early Eocene, the Chalk was exposed and the Mid-Palaeogene etchplain developed under tropical environments. Differential movements recurred at the Oligo-Miocene boundary, with uplift and tilting west of the Bennachie-Fare Fracture and initiation of basin development. Further etching in the warm and stable Middle Miocene period led to the establishment of the main erosion surfaces. The Eastern Grampian Surface (450 - 750m) is an etchsurface produced by lowering of the Mid-Palaeogene etchplain. The Marginal Surface (280 - 370m) is derived from a Miocene etchplain that was raised and tilted gently eastwards in the late Neogene. Fragments of this surface are associated with clayey grusses and the Buchan Ridge gravels in central Buchan and the Buchan Surface (60 - 140m) has developed by lowering of this relief in the Pliocene. Drainage incision in the early Pleistocene led to development of younger forms along valleys. Repeated glaciation failed to greatly modify pre-existing relief.
1983-01-01T00:00:00Z
Hall, A. M.
Weathered rock has been located at over 450 sites in northeast Scotland. Depths of weathering locally exceed 30m but the weathering front is often highly irregular. The incidence of weathering is spatially variable and weathering zones are identified which reflect the influence of geology, fracturing, slopes and patterns of glacial erosion. Two weathering types, grusses and clayey grusses, are recognised after examination of granulometry, geochemistry and clay mineralogy. The grusses have low clay contents, high proportions of little-altered felspar and biotite, modest soluble base losses and heterogeneous clay mineral assemblages. The grusses are equivalent to the 'sandy weathering type' of Bakker (1967) and were formed mainly under the temperate environments of the late Pliocene and the early Pleistocene. The clayey grusses have elevated clay contents, high proportions of detrital quartz, high soluble base losses, kaolinite-illite bi-mineralic assemblages and may be rubefied. The clayey grusses formed under warmer environments than at present, probably in the Miocene. The Buchan Gravels consist of two formations of separate age. The Windyhills Formation comprises fluvial gravels of Middle to Late Pliocene age. The Buchan Ridge Formation includes glacially- disturbed masses of fluviatile deposits of Late Miocene to Early Pliocene age. The denudational history of the region is reconstructed using evidence from morphology, weathering types, and onshore and offshore geology. In the Late Cretaceous, transgression into the Buchan area left a cover of Greensand and Chalk. In the Palaeocene, the eastern Grampians were uplifted and tilted but the eastern lowlands were simultaneously downwarped towards the outer Moray Firth. Western areas subsided after the Early Eocene, the Chalk was exposed and the Mid-Palaeogene etchplain developed under tropical environments. Differential movements recurred at the Oligo-Miocene boundary, with uplift and tilting west of the Bennachie-Fare Fracture and initiation of basin development. Further etching in the warm and stable Middle Miocene period led to the establishment of the main erosion surfaces. The Eastern Grampian Surface (450 - 750m) is an etchsurface produced by lowering of the Mid-Palaeogene etchplain. The Marginal Surface (280 - 370m) is derived from a Miocene etchplain that was raised and tilted gently eastwards in the late Neogene. Fragments of this surface are associated with clayey grusses and the Buchan Ridge gravels in central Buchan and the Buchan Surface (60 - 140m) has developed by lowering of this relief in the Pliocene. Drainage incision in the early Pleistocene led to development of younger forms along valleys. Repeated glaciation failed to greatly modify pre-existing relief.
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Lower palaeozoic geology of the Gala area borders region, Scotland
https://hdl.handle.net/10023/15559
The Lower Palaeozoic succession of the Gala area, Southern Uplands, comprises two contrasting facies, a pelagic/hemipelagic sequence, the Moffat Shales, and overlying turbidite sandstone (greywacke) successions variously of Ordovician and Silurian age. The area is divided into fault blocks bounded by a series of major strike faults, leading to contrasting sequences variously successive fault blocks; pelagic/hemipelagic facies are replaced by turbidites progressively later south-eastwards. Turbidites in the two northernmost blocks are of Ordovician age, and include two formations. Blocks to the south are formed of three successively younger formations of the Gala Group (Upper Llandovery), with Moffat Shales spanning the Upper Llandeilo - Upper Llandovery interval, whilst the southernmost block includes one formation representing the Hawick Group (Wenlock). Two formations within the Gala Group have been further subdivided into members. In most instances, formations crop out within discrete fault blocks, though in one instance successively higher levels within a single formation form three separate blocks, whilst another block includes an interdigitating intraformational contact, attributed to the overlapping of two turbidite fans of contrasting source areas. Whereas blocks display successively younger flysch sequences to the SE, strata within each block young dominantly to MW. The structural style is comparable to areas elsewhere in the Southern Uplands; showing evidence of prolonged and continuous deformation. Though these observations would support formation of an accretionary prism on an active continental-oceanic margin in response to a north-westward subduction of an oceanic plate, lack of consistent variation in dip attitudes and axial overturning may dispute this proposition. Palaeocurrents suggest a combination of axial and lateral derivation of rudites and associated fine-grained lithologies with contrasting zones of facies associations, representing environments ranging from inner- to outer-fan (fringe) and basin plain, and suggesting at least three cycles of progression and regression of turbidite fans. Greywacke petrography suggests mainly a magmatic-arc and ophiolitic derivation for 'basic-clast' greywackes and a dominantly Highland type derivation for 'silicic' greywackes, with recycling becoming increasingly significant in the higher levels, and indicating elevations of parts of the succession already accreted. Mineral assemblages, illite crystallinity and values of illites establishes the anchizone of metamorphism without a significant areal variation increase in grade.
1985-01-01T00:00:00Z
Kassi, Akhtar Mohammad
The Lower Palaeozoic succession of the Gala area, Southern Uplands, comprises two contrasting facies, a pelagic/hemipelagic sequence, the Moffat Shales, and overlying turbidite sandstone (greywacke) successions variously of Ordovician and Silurian age. The area is divided into fault blocks bounded by a series of major strike faults, leading to contrasting sequences variously successive fault blocks; pelagic/hemipelagic facies are replaced by turbidites progressively later south-eastwards. Turbidites in the two northernmost blocks are of Ordovician age, and include two formations. Blocks to the south are formed of three successively younger formations of the Gala Group (Upper Llandovery), with Moffat Shales spanning the Upper Llandeilo - Upper Llandovery interval, whilst the southernmost block includes one formation representing the Hawick Group (Wenlock). Two formations within the Gala Group have been further subdivided into members. In most instances, formations crop out within discrete fault blocks, though in one instance successively higher levels within a single formation form three separate blocks, whilst another block includes an interdigitating intraformational contact, attributed to the overlapping of two turbidite fans of contrasting source areas. Whereas blocks display successively younger flysch sequences to the SE, strata within each block young dominantly to MW. The structural style is comparable to areas elsewhere in the Southern Uplands; showing evidence of prolonged and continuous deformation. Though these observations would support formation of an accretionary prism on an active continental-oceanic margin in response to a north-westward subduction of an oceanic plate, lack of consistent variation in dip attitudes and axial overturning may dispute this proposition. Palaeocurrents suggest a combination of axial and lateral derivation of rudites and associated fine-grained lithologies with contrasting zones of facies associations, representing environments ranging from inner- to outer-fan (fringe) and basin plain, and suggesting at least three cycles of progression and regression of turbidite fans. Greywacke petrography suggests mainly a magmatic-arc and ophiolitic derivation for 'basic-clast' greywackes and a dominantly Highland type derivation for 'silicic' greywackes, with recycling becoming increasingly significant in the higher levels, and indicating elevations of parts of the succession already accreted. Mineral assemblages, illite crystallinity and values of illites establishes the anchizone of metamorphism without a significant areal variation increase in grade.
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St Andrews Bay: A sedimentological, geophysical and morphological investigation
https://hdl.handle.net/10023/15558
This thesis examines past and present day processes responsible for the morphological development of St Andrews Bay in eastern Scotland. Quaternary glacial events have contributed large volumes of sediment from the Scottish Mainland to the North Sea Basin over the last 3 million years. Since the most recent glacial event, the Late Devensian, which terminated some 14,000 years ago in Scotland, the sediments of the coastal areas have been redistributed by wave and tidal activity. Thus the bathymetry and platform of St Andrews Bay has evolved since that time, although some elements of the morphology appear to predate the last glaciation. The grain size distributions of the bed sediments of the bay show a narrow range of mean sizes between fine and very fine sand. These are indicative of a low energy tidal environment although Quartile Deviation - Median Diameter plots suggest the importance of wave activity in determining their distribution. Current measurements in the bay confirm that the hydrodynamic environment is of low energy with average current speeds rarely exceeding 15 cm s ⁻¹ one metre above the bed. Progressive vector plots show closed ellipses during calm weather but meteorological forcing and wave activity generate residual currents predominantly in the direction of wave propagation or down wind. Application of a transfer function to the current data predicts low rates of bedload transport, the residual of which generally accords with the recent pattern of sedimentation at the head of the bay. The rocky platforms of the southern margins of the bay cannot easily be sub-divided into features at different elevations. No firm evidence is presented for a pre-Late Devensian origin of the platform but it is argued that such a chronology explains the morphology of the platform. Offshore sedimentary sequences, up to 30 metres in thickness, are reported from geophysical surveys which have been laid down since the last glaciation. The units identified reflect changing environments of deposition associated with climatic and sea level changes over the last 14,000 years.
1996-01-01T00:00:00Z
Al-Washmi, Hamad Abdullah
This thesis examines past and present day processes responsible for the morphological development of St Andrews Bay in eastern Scotland. Quaternary glacial events have contributed large volumes of sediment from the Scottish Mainland to the North Sea Basin over the last 3 million years. Since the most recent glacial event, the Late Devensian, which terminated some 14,000 years ago in Scotland, the sediments of the coastal areas have been redistributed by wave and tidal activity. Thus the bathymetry and platform of St Andrews Bay has evolved since that time, although some elements of the morphology appear to predate the last glaciation. The grain size distributions of the bed sediments of the bay show a narrow range of mean sizes between fine and very fine sand. These are indicative of a low energy tidal environment although Quartile Deviation - Median Diameter plots suggest the importance of wave activity in determining their distribution. Current measurements in the bay confirm that the hydrodynamic environment is of low energy with average current speeds rarely exceeding 15 cm s ⁻¹ one metre above the bed. Progressive vector plots show closed ellipses during calm weather but meteorological forcing and wave activity generate residual currents predominantly in the direction of wave propagation or down wind. Application of a transfer function to the current data predicts low rates of bedload transport, the residual of which generally accords with the recent pattern of sedimentation at the head of the bay. The rocky platforms of the southern margins of the bay cannot easily be sub-divided into features at different elevations. No firm evidence is presented for a pre-Late Devensian origin of the platform but it is argued that such a chronology explains the morphology of the platform. Offshore sedimentary sequences, up to 30 metres in thickness, are reported from geophysical surveys which have been laid down since the last glaciation. The units identified reflect changing environments of deposition associated with climatic and sea level changes over the last 14,000 years.
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An evaluation of the use of Fe-Ti oxide geochemistry and environmental magentism as sedimentary provenance indicators in the River Eden catchment Scotland
https://hdl.handle.net/10023/15551
The potential of geochemical and magnetic measurements in sedimentary provenance studies is evaluated in the River Eden catchment (Scotland), where three principal rock types (basalts, andesites and sedimentary rocks) are petrogenetically, temporally and spatially distinct. The northern part of the catchment, occupied by Lower Devonian andesitic rocks, is separated from the southern part of the catchment, occupied by Upper Carboniferous basaltic rocks, by a valley underlain by more erodable Upper Devonian sandstones. All rock types are partially covered by Quaternary glacial till. These four well distinguished potential sediment sources were expected to robustly fingerprint the source components of the stream sediment transported by the fluvial system defining the River Eden catchment. Mineral composition analysis together with magnetic measurements have enabled the characterisation, differentiation and, therefore, the classification of different groups within all potential sources (rocks and till) in terms of concentration, composition and grain size of Fe-Ti oxides. Stream sediment samples were also characterised using the same approaches. Raw data are analysed and interpreted graphically by scattergrams, and statistically by correlation coefficients, analysis of variance and simultaneous R- and Q-mode factor analysis. A comparison of both source and sediment characteristics is assisted principally by discriminant function analysis which leads to a qualitative estimation of each source contribution to the sediment. Linear programming is then applied in order to model quantitatively the provenance of stream sediment samples. Magnetite is found to be the best provenance indicator in the study area. Basalts have higher concentrations, Ti-content and grain size of magnetite than andesites. Till shows a wide variability in magnetite composition, its concentration being close to that of the andesites, whereas the sedimentary rocks are characterised by the scarcity or absence of magnetite. Oxidation of magnetite, eventually to hematite, is found to occur during rock crystallisation, and alteration under aerial conditions. However, during fluvial transport magnetite transforms to sphene. Despite the chemical alteration of magnetite, an environmentally-consistent qualitative provenance model is derived in this study. The sediment transported by each Eden tributary is found to be mineralogically unique as a result not only of mineralogical differences but also of the mixing proportions of the constituting sources. Although, tributary inputs are recognised downstream the River Eden course, sediment characteristics in the main course tend to be homogenised during transport. Even when magnetic parameters are more discriminating than magnetite composition, the intra-source magnetic variability and principally the magnetic interdependence of the sediment sources significantly hinder successful modelling of mixtures using linear programming methodology. More complex statistical methods and/or more discriminating and independent variables are required to achieve a complete quantitative model of the stream sediment provenance over the whole River Eden catchment.
1998-01-01T00:00:00Z
Martinez, Edurne
The potential of geochemical and magnetic measurements in sedimentary provenance studies is evaluated in the River Eden catchment (Scotland), where three principal rock types (basalts, andesites and sedimentary rocks) are petrogenetically, temporally and spatially distinct. The northern part of the catchment, occupied by Lower Devonian andesitic rocks, is separated from the southern part of the catchment, occupied by Upper Carboniferous basaltic rocks, by a valley underlain by more erodable Upper Devonian sandstones. All rock types are partially covered by Quaternary glacial till. These four well distinguished potential sediment sources were expected to robustly fingerprint the source components of the stream sediment transported by the fluvial system defining the River Eden catchment. Mineral composition analysis together with magnetic measurements have enabled the characterisation, differentiation and, therefore, the classification of different groups within all potential sources (rocks and till) in terms of concentration, composition and grain size of Fe-Ti oxides. Stream sediment samples were also characterised using the same approaches. Raw data are analysed and interpreted graphically by scattergrams, and statistically by correlation coefficients, analysis of variance and simultaneous R- and Q-mode factor analysis. A comparison of both source and sediment characteristics is assisted principally by discriminant function analysis which leads to a qualitative estimation of each source contribution to the sediment. Linear programming is then applied in order to model quantitatively the provenance of stream sediment samples. Magnetite is found to be the best provenance indicator in the study area. Basalts have higher concentrations, Ti-content and grain size of magnetite than andesites. Till shows a wide variability in magnetite composition, its concentration being close to that of the andesites, whereas the sedimentary rocks are characterised by the scarcity or absence of magnetite. Oxidation of magnetite, eventually to hematite, is found to occur during rock crystallisation, and alteration under aerial conditions. However, during fluvial transport magnetite transforms to sphene. Despite the chemical alteration of magnetite, an environmentally-consistent qualitative provenance model is derived in this study. The sediment transported by each Eden tributary is found to be mineralogically unique as a result not only of mineralogical differences but also of the mixing proportions of the constituting sources. Although, tributary inputs are recognised downstream the River Eden course, sediment characteristics in the main course tend to be homogenised during transport. Even when magnetic parameters are more discriminating than magnetite composition, the intra-source magnetic variability and principally the magnetic interdependence of the sediment sources significantly hinder successful modelling of mixtures using linear programming methodology. More complex statistical methods and/or more discriminating and independent variables are required to achieve a complete quantitative model of the stream sediment provenance over the whole River Eden catchment.
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Structure and tectonic history of Lewisian gneiss, Isle of Barra
https://hdl.handle.net/10023/15547
The Lewisian of Barra has been found to comprise foliated orthogeneisses ranging; in composition from basic amphibolites, pyroxene and hornblende granulites and intermediate amphibole-bearing quartzo-feldspathic rooks to more acid gneisses of dioritic and granitic composition. It includes some inter-foliated acid rocks which may be paragneisses. The whole complex is cut by the Hebridean Thrust and the petrography of some strongly magnetic gneisses associated with the Thrust belt has also been described. The gneisses were intruded at an early stage by basic dykes, represented by rooks ranging from amphibolites to pyroxene granulite in composition. Cross-cutting relationships between Lewisian dykes and rectilinear quartzo-feldspathic pegmatite veins consider to have been injected along axial planes of folds are used to relate the phases of dyke instrusion and migmatization to the overall tootonic sequence. Structural analysis has been carried out on planner and linear fabric date recorded on a base map on the scale of 1:0, 560, from thin section and also from the attitudes of structural elements recorded from selected localities in which the structure is particularly well exposed. Data recorded on the map have been considered separately from the following areas; the total area mapped; areas on each side of the main Thrust outcrop; areas exposing large scale structures; several small areas defined by an arbitrarily located grid to the west of the main thrust outcrop. Form the results of the structural analysis and from consideration of structural relationship in the field a tectonic sequence has been determined. The first recognizable event after the formation of the original banding was the development of isoclinal folding, followed by regional metamorphism in the amphibolites facies and succeeded in turn by the emplacement of basic to intermediate intrusions. Three successive phases of intrusion hive been recognized here. Next, folding took place on axes now trending at 30°followed by boudinage and agmatite formation and three further phases of basic intrusions. Part of the overthrust sheet exposed on the east coast was then subjected to regional metamorphism up to pyroxene granulite grade. Movement on the Hebridean thrust probably began soon after this, end asymmetrical folding about axes now plunging to 350 °established the present general orientation of the foliation and produced axial planar traces which trend south-east. The gneisses were then folded about sub-horizontal axes trending at to 150°, prior to strong folding about sub-horizontal axes trending at 100 °which resulted in the present dominant fold pattern. Finally, very open folding took place about 60 °trending axes. Except during the last fold period, migmatization was associated with all the folding and followed by pegmatite injection parallel to fold axial planes. Style has not been found to be a reliable guide to the chronological classification of folds. Open signoidal tension gashes related to the thrusting indicate that this movement continued after the final folding, and show the trusting to have beta directed to the west at an angle of elevation of between 5°and 10°, A comparison on has been wade between the structure of this area and that discussed in some published work on the Lewisian elsewhere in the Outer Isles and the Scottish Mainland. The petrogrphy and metamorphism of six phases of Lewisian dyke intrusives have been studied, and various possible mechanisms to account for dyke reorientation by sheer have boon examined in conjunction with the field relationships of these bodies. It is concluded that the intrusives have not been substantially reorientated with respect to the foliation since their emplacement a discussion is presented on the effects of ana texis on basic, intermediate and acid, gneisses, on the employment of quartzo-feldspathic pegmatite veins, and on the formation of boudinage and agmatite. Three relative ages of pegmatites have been distinguished early coarse quartzo-feldspathic pegmatites with dark feldspars, later pink quartzo-feldspathic pegmatites and late white quartzosc pegmatites.
1964-01-01T00:00:00Z
Hopgood, Alaric M.
The Lewisian of Barra has been found to comprise foliated orthogeneisses ranging; in composition from basic amphibolites, pyroxene and hornblende granulites and intermediate amphibole-bearing quartzo-feldspathic rooks to more acid gneisses of dioritic and granitic composition. It includes some inter-foliated acid rocks which may be paragneisses. The whole complex is cut by the Hebridean Thrust and the petrography of some strongly magnetic gneisses associated with the Thrust belt has also been described. The gneisses were intruded at an early stage by basic dykes, represented by rooks ranging from amphibolites to pyroxene granulite in composition. Cross-cutting relationships between Lewisian dykes and rectilinear quartzo-feldspathic pegmatite veins consider to have been injected along axial planes of folds are used to relate the phases of dyke instrusion and migmatization to the overall tootonic sequence. Structural analysis has been carried out on planner and linear fabric date recorded on a base map on the scale of 1:0, 560, from thin section and also from the attitudes of structural elements recorded from selected localities in which the structure is particularly well exposed. Data recorded on the map have been considered separately from the following areas; the total area mapped; areas on each side of the main Thrust outcrop; areas exposing large scale structures; several small areas defined by an arbitrarily located grid to the west of the main thrust outcrop. Form the results of the structural analysis and from consideration of structural relationship in the field a tectonic sequence has been determined. The first recognizable event after the formation of the original banding was the development of isoclinal folding, followed by regional metamorphism in the amphibolites facies and succeeded in turn by the emplacement of basic to intermediate intrusions. Three successive phases of intrusion hive been recognized here. Next, folding took place on axes now trending at 30°followed by boudinage and agmatite formation and three further phases of basic intrusions. Part of the overthrust sheet exposed on the east coast was then subjected to regional metamorphism up to pyroxene granulite grade. Movement on the Hebridean thrust probably began soon after this, end asymmetrical folding about axes now plunging to 350 °established the present general orientation of the foliation and produced axial planar traces which trend south-east. The gneisses were then folded about sub-horizontal axes trending at to 150°, prior to strong folding about sub-horizontal axes trending at 100 °which resulted in the present dominant fold pattern. Finally, very open folding took place about 60 °trending axes. Except during the last fold period, migmatization was associated with all the folding and followed by pegmatite injection parallel to fold axial planes. Style has not been found to be a reliable guide to the chronological classification of folds. Open signoidal tension gashes related to the thrusting indicate that this movement continued after the final folding, and show the trusting to have beta directed to the west at an angle of elevation of between 5°and 10°, A comparison on has been wade between the structure of this area and that discussed in some published work on the Lewisian elsewhere in the Outer Isles and the Scottish Mainland. The petrogrphy and metamorphism of six phases of Lewisian dyke intrusives have been studied, and various possible mechanisms to account for dyke reorientation by sheer have boon examined in conjunction with the field relationships of these bodies. It is concluded that the intrusives have not been substantially reorientated with respect to the foliation since their emplacement a discussion is presented on the effects of ana texis on basic, intermediate and acid, gneisses, on the employment of quartzo-feldspathic pegmatite veins, and on the formation of boudinage and agmatite. Three relative ages of pegmatites have been distinguished early coarse quartzo-feldspathic pegmatites with dark feldspars, later pink quartzo-feldspathic pegmatites and late white quartzosc pegmatites.
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The Lewisian rocks of the Island of Tiree, Inner Hebrides
https://hdl.handle.net/10023/15544
The research work presented in this thesis was undertaken to determine the nature and the relationships of the rocks which make up the Lewisian Complex on the Island of Tiree, and to attempt to interpret their metamorphic history. The rocks have been mapped and some 250 thin-sections examined in the laboratory, Twenty-one chemical analyses have been executed using rapid techniques. The complex has been found to consist predominantly of migmatites but there also occur some bodies of fairly homogeneous intermediate, basic and ultrabasic gneiss. The general outlines of these bodies are generally more or less conformable with the trend of the banding in the enclosing migmatite. The commonest type of migmatite is a light to medium grey, generally well banded rook, the principal mafia components of which are hornblende and biotite. It is designated the Banded Migmatite. Two other varieties, the Massive Migmatite and the Contorted Migmatite, occur in lesser amount, The Massive Migmatite contains varying amounts of clinopyroxene and ortho-pyroxene in addition to some hornblende and minor biotite; banding within it is generally weakly developed and sometimes completely absent. The Contorted Migatite has a streaky rather than banded appearance and irregular contortions and crenulations s are common within it. The principal mafic component of this phase of the migmatite is biotite and, at one locality, it also contains varying amounts of orthopyroxone and garnet. The mineral assemblage in the Banded Migmatite is indicative of crystallization in the upper amphibolites facies end that in the Massive Migmatite suggests lower granulate facies. The presence of both orthopyroxene and biotite in the Contorted Migmatite indicates that the assemblage in that phase is one transitional between the amphibolite and the granulite facies and that equilibrium was probably not attained within it during metamorphism. Throughout the migmatite mass there occur 'resister' (Road, 1957) bands and lenses of basic, ultrabasic and met sedimentary rock. These bodies of 'resister' rook are in almost all cases extended parallel to the banding of the enclosing sigcatite. Concordant and transgressive veins and hands of acid pegmatite are common and 'resister' bands are often penetrated and disrupted by pegmatitie materiel. The 'resister' bands appear, therefore, to have been in a much more brittle condition during migmatitization than was the enclosing rock. The mineral assemblages within the broader 'resister' bands are often suggestive of crystallization under lower granulite facies conditions but in the narrower bands and lenses and in the marginal, zones of the broad hands, amphibolite facies assemblages occur; chemical analyses suggest that the mineralogical transformations in the 'resister' bands were essentially isochemical. A series of analyses between the centre and the margin of a large ultrabasic lens reveal that its marginal zone is richer n silica, lime, cinema and awnina and alkalies poorer in magnesia and iron oxides, compared with its interior. The contamination of the marginal, zone is considered to have taken place during the migmatitization of the enclosing rocks when fluids worn available to facilitate diffusion. Isoclinal folds with axial planes parallel to the banding of the migmatite occur in occasional, basic lenses, Their presence demonstrates that the palacosome had been folded prior to migmatitization and that the same stress system probably prevailed during both these processes, Textural evidence, although not conclusive, suggests that in the broad btzsia 'resistor' bands the pyroxene has, at least in part, formed at the expense of pre-existent hornblende, Furthermore, there is no textural evidence, such as the rimuning of pyroxene grains by amphibole, to suggest that the amphibole assemblages in the marginal zones of these bends have formed by diaphthoresis of a granulite facies assemblage.
1963-01-01T00:00:00Z
Sinclair, Iain Glen Lamond
The research work presented in this thesis was undertaken to determine the nature and the relationships of the rocks which make up the Lewisian Complex on the Island of Tiree, and to attempt to interpret their metamorphic history. The rocks have been mapped and some 250 thin-sections examined in the laboratory, Twenty-one chemical analyses have been executed using rapid techniques. The complex has been found to consist predominantly of migmatites but there also occur some bodies of fairly homogeneous intermediate, basic and ultrabasic gneiss. The general outlines of these bodies are generally more or less conformable with the trend of the banding in the enclosing migmatite. The commonest type of migmatite is a light to medium grey, generally well banded rook, the principal mafia components of which are hornblende and biotite. It is designated the Banded Migmatite. Two other varieties, the Massive Migmatite and the Contorted Migmatite, occur in lesser amount, The Massive Migmatite contains varying amounts of clinopyroxene and ortho-pyroxene in addition to some hornblende and minor biotite; banding within it is generally weakly developed and sometimes completely absent. The Contorted Migatite has a streaky rather than banded appearance and irregular contortions and crenulations s are common within it. The principal mafic component of this phase of the migmatite is biotite and, at one locality, it also contains varying amounts of orthopyroxone and garnet. The mineral assemblage in the Banded Migmatite is indicative of crystallization in the upper amphibolites facies end that in the Massive Migmatite suggests lower granulate facies. The presence of both orthopyroxene and biotite in the Contorted Migmatite indicates that the assemblage in that phase is one transitional between the amphibolite and the granulite facies and that equilibrium was probably not attained within it during metamorphism. Throughout the migmatite mass there occur 'resister' (Road, 1957) bands and lenses of basic, ultrabasic and met sedimentary rock. These bodies of 'resister' rook are in almost all cases extended parallel to the banding of the enclosing sigcatite. Concordant and transgressive veins and hands of acid pegmatite are common and 'resister' bands are often penetrated and disrupted by pegmatitie materiel. The 'resister' bands appear, therefore, to have been in a much more brittle condition during migmatitization than was the enclosing rock. The mineral assemblages within the broader 'resister' bands are often suggestive of crystallization under lower granulite facies conditions but in the narrower bands and lenses and in the marginal, zones of the broad hands, amphibolite facies assemblages occur; chemical analyses suggest that the mineralogical transformations in the 'resister' bands were essentially isochemical. A series of analyses between the centre and the margin of a large ultrabasic lens reveal that its marginal zone is richer n silica, lime, cinema and awnina and alkalies poorer in magnesia and iron oxides, compared with its interior. The contamination of the marginal, zone is considered to have taken place during the migmatitization of the enclosing rocks when fluids worn available to facilitate diffusion. Isoclinal folds with axial planes parallel to the banding of the migmatite occur in occasional, basic lenses, Their presence demonstrates that the palacosome had been folded prior to migmatitization and that the same stress system probably prevailed during both these processes, Textural evidence, although not conclusive, suggests that in the broad btzsia 'resistor' bands the pyroxene has, at least in part, formed at the expense of pre-existent hornblende, Furthermore, there is no textural evidence, such as the rimuning of pyroxene grains by amphibole, to suggest that the amphibole assemblages in the marginal zones of these bends have formed by diaphthoresis of a granulite facies assemblage.
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Sedimentology, stratigraphy and diagenetic history of the taglu member and equivalents, MacKenzie delta area, Canada
https://hdl.handle.net/10023/15541
The Taglu is introduced as a new member of the Reindeer Formation. Its type section is in the Taglu G-33 well and its age is Eocene. This member conformably overlies the Aklak Member and underlies the "Un-named shale" or the "Kugmallit" member. The thickness of the Taglu varies from well to well but in the type section it is 800 ft. (268 m). Correlation of the Taglu Member is difficult due to facies changes, similarity in composition of successive facies, faulting, and the absence of marker beds or diagnostic fauna. Correlation, however, was accomplished through seismic interpretation, sedimentary megacycles, trace elements, biology, gamma-ray logs and logic. The Taglu Member was deposited under cool but occasionally warm temperate climatic conditions and is composed of two main deltaic sequences, each represented by a regressive phase overlain by a transgressive phase. Each sequence includes environments such as prodelta, delta front, distributary mouth bars, marshes and swamps, and finally distributary channels on top. The depositional basin during accumulation was undergoing moderate subsidence and receiving a high influx of sediments. Both the Richardson Mountains and the Eskimo Lakes Arch supplied, at least in part, the Taglu sediments. Occasional presence of volcanic rock fragments may indicate a third source, possibly well to the south. Based on its composition, the Taglu sandstone can be classified as quartz arenite and sublitharenite. It consists of quartz, chert, feldspar, mica, rock fragments, woody herbaceous matter, and cementing material. The cementing material includes non-ferroan calcite, ferroan and non-ferroan dolomite, siderite, silica and authigenic clay minerals. The cement, which is mainly controlled by the environment of deposition, is eodiagenetic and in places mesodiagenetic.
1978-01-01T00:00:00Z
Shawa, Monzer S.
The Taglu is introduced as a new member of the Reindeer Formation. Its type section is in the Taglu G-33 well and its age is Eocene. This member conformably overlies the Aklak Member and underlies the "Un-named shale" or the "Kugmallit" member. The thickness of the Taglu varies from well to well but in the type section it is 800 ft. (268 m). Correlation of the Taglu Member is difficult due to facies changes, similarity in composition of successive facies, faulting, and the absence of marker beds or diagnostic fauna. Correlation, however, was accomplished through seismic interpretation, sedimentary megacycles, trace elements, biology, gamma-ray logs and logic. The Taglu Member was deposited under cool but occasionally warm temperate climatic conditions and is composed of two main deltaic sequences, each represented by a regressive phase overlain by a transgressive phase. Each sequence includes environments such as prodelta, delta front, distributary mouth bars, marshes and swamps, and finally distributary channels on top. The depositional basin during accumulation was undergoing moderate subsidence and receiving a high influx of sediments. Both the Richardson Mountains and the Eskimo Lakes Arch supplied, at least in part, the Taglu sediments. Occasional presence of volcanic rock fragments may indicate a third source, possibly well to the south. Based on its composition, the Taglu sandstone can be classified as quartz arenite and sublitharenite. It consists of quartz, chert, feldspar, mica, rock fragments, woody herbaceous matter, and cementing material. The cementing material includes non-ferroan calcite, ferroan and non-ferroan dolomite, siderite, silica and authigenic clay minerals. The cement, which is mainly controlled by the environment of deposition, is eodiagenetic and in places mesodiagenetic.
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Mineralogy, petrology and geochemistry of some zoned diorite complexes in Scotland
https://hdl.handle.net/10023/15475
This study is an investigation into the nature and causes of petrological zonation in calc-alkaline diorite-granite plutons from the Newer granites of the Caledonian orogeny in Scotland. Six plutons were used for the study, namely Garabal Hill-Glen Fyne in the western Highlands, Glen Tilt and Glen Doll in the eastern Highlands, Comrie in the southern Highlands, and Carsphairn and Loch Doon in the Southern Uplands. The petrological zoning is concentric in the Southern Uplands and Comrie and irregular in the other three. The approach has been to acquire data on the petrography, mineral chemistry, and whole rock major and trace element chemistry for representative rock types of the petrological range within each pluton. Variations in mineral compositions are related to equilibrium crystallisation processes and indicate falling crystallisation temperatures with evolving magma composition. Mineral compositions have also been used in chemical models used to explain the observed wide variations in whole rock major oxide compositions. These models are then independently tested using models of trace element behaviour. The principal conclusions are that the main variations within the gabbro-diorite series (including cumulate peridotites and pyroxenites) are best explained by processes of fractional crystallisation from a parental gabbro or diorite magma, but in some cases the more evolved rocks (granites and granodiorites) have a more complex origin including possibly contamination of the parental magma or a distinctive magma source. The assemblage of fractionating minerals in the Garabal Hill, Comrie and Loch Doon plutons is dominated by the relatively anhydrous assemblage of orthopyroxene, clinopyroxene, plagioclase, and biotite whereas in Glen Doll it is a more hydrous assemblage dominated by amphibole. Processes of magma mixing and multi-source pulses are considered appropriate in a few cases. Regional comparisons of the within-pluton compositional variations reveal significant differences. The dominantly calc-alkaline trend shows marked differences in Fe/Mg between plutons as do trace element abundances, reflecting both differences in source region compositions and the influence of fractionating mineral phases. All plutons are I-type and high-K calc-alkaline. Parental magmas for the gabbro-diorite series have features of mantle-derived magmas though the more evolved rock types including granodiorites and granites indicate a significant contribution by crustal anatexis to the magmas.
1986-07-01T00:00:00Z
Mahmood, Layla A.
This study is an investigation into the nature and causes of petrological zonation in calc-alkaline diorite-granite plutons from the Newer granites of the Caledonian orogeny in Scotland. Six plutons were used for the study, namely Garabal Hill-Glen Fyne in the western Highlands, Glen Tilt and Glen Doll in the eastern Highlands, Comrie in the southern Highlands, and Carsphairn and Loch Doon in the Southern Uplands. The petrological zoning is concentric in the Southern Uplands and Comrie and irregular in the other three. The approach has been to acquire data on the petrography, mineral chemistry, and whole rock major and trace element chemistry for representative rock types of the petrological range within each pluton. Variations in mineral compositions are related to equilibrium crystallisation processes and indicate falling crystallisation temperatures with evolving magma composition. Mineral compositions have also been used in chemical models used to explain the observed wide variations in whole rock major oxide compositions. These models are then independently tested using models of trace element behaviour. The principal conclusions are that the main variations within the gabbro-diorite series (including cumulate peridotites and pyroxenites) are best explained by processes of fractional crystallisation from a parental gabbro or diorite magma, but in some cases the more evolved rocks (granites and granodiorites) have a more complex origin including possibly contamination of the parental magma or a distinctive magma source. The assemblage of fractionating minerals in the Garabal Hill, Comrie and Loch Doon plutons is dominated by the relatively anhydrous assemblage of orthopyroxene, clinopyroxene, plagioclase, and biotite whereas in Glen Doll it is a more hydrous assemblage dominated by amphibole. Processes of magma mixing and multi-source pulses are considered appropriate in a few cases. Regional comparisons of the within-pluton compositional variations reveal significant differences. The dominantly calc-alkaline trend shows marked differences in Fe/Mg between plutons as do trace element abundances, reflecting both differences in source region compositions and the influence of fractionating mineral phases. All plutons are I-type and high-K calc-alkaline. Parental magmas for the gabbro-diorite series have features of mantle-derived magmas though the more evolved rock types including granodiorites and granites indicate a significant contribution by crustal anatexis to the magmas.
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Source and equilibration studies of xenoliths from the Caledonian granites of Scotland
https://hdl.handle.net/10023/15474
The origin of the dark microdioritic inclusions within I-type granitoids has been the subject of much debate and speculation. These 'xenoliths' have been variously ascribed to restite or cognate crystallisation (autoliths), wall rocks (accidental xenoliths), exotic (mantle) magmas and immiscible liquids. The object of this study was to test between these potential sources of inclusions and processes and to investigate whether such inclusions can be used to provide information on the petrogenesis of the host pluton and the nature of the source region(s) as well as processes of compositional zoning. The approach used was to study inclusions and their host rocks from three zoned plutons in the Caledonian of Scotland, namely Strontian, Ballachulish and Criffell. These were investigated petrographically, by whole rock major and trace element analysis and by Sr and Nd isotopes. Interpretation of the equilibration between inclusion and host benefitted from theoretical considerations of diffusion. It was found that for most 'igneous' inclusions Sr isotopes had thoroughly equilibrated, hosts and inclusions normally having identical Sr initial ratios. However the microdioritic inclusions normally retain a more primitive signature in their Nd isotopes (normally up to +2 Nd units greater than the host) precluding cognate, restite or immiscibility origins and are quite different from local country rocks. Most 'igneous' inclusions thus appear to have an exotic source of more primitive composition, presumably the upper mantle. The appinites of the Strontian pluton were also investigated as part of a study of coexisting acid-basic melts in granitoid plutons. It is shown that these appinites have quenched liquid contacts with the granitoid hosts and some degree of mixing between appinitic magma and host granitoid has given rise to a reverse zonation pattern in composition and texture. The isotopic data for the appinites of Strontian and for inclusions and their host granitoids in the Strontian and Criffell plutons point to a model for the initiation of granitoid magma genesis in the crust by advection of heat through transfer of basaltic magma from the upper mantle. Some of this magma is incorporated in the granitoid magma as basaltic inclusions which gradually become modified towards dioritic compositions. The characteristics of this mantle derived magma and the granitoid crustal source do not vary significantly between Strontian and Criffell in terms of Nd isotope model ages. This is a remarkable finding considering the very different tectonic settings and suggests greater similarities at deeper lithospheric levels. The study of Nd isotopes in xenolithic inclusions in granitoids has been shown to provide at least as much additional information on the petrogenesis of granitoid plutons as the conventional study of their host rocks, but a complementary study of Sr isotopes is not particularly useful. This investigation provides some of the theoretical basis for this and presents a methodology for carrying out such investigations.
1987-07-01T00:00:00Z
Holden, Peter
The origin of the dark microdioritic inclusions within I-type granitoids has been the subject of much debate and speculation. These 'xenoliths' have been variously ascribed to restite or cognate crystallisation (autoliths), wall rocks (accidental xenoliths), exotic (mantle) magmas and immiscible liquids. The object of this study was to test between these potential sources of inclusions and processes and to investigate whether such inclusions can be used to provide information on the petrogenesis of the host pluton and the nature of the source region(s) as well as processes of compositional zoning. The approach used was to study inclusions and their host rocks from three zoned plutons in the Caledonian of Scotland, namely Strontian, Ballachulish and Criffell. These were investigated petrographically, by whole rock major and trace element analysis and by Sr and Nd isotopes. Interpretation of the equilibration between inclusion and host benefitted from theoretical considerations of diffusion. It was found that for most 'igneous' inclusions Sr isotopes had thoroughly equilibrated, hosts and inclusions normally having identical Sr initial ratios. However the microdioritic inclusions normally retain a more primitive signature in their Nd isotopes (normally up to +2 Nd units greater than the host) precluding cognate, restite or immiscibility origins and are quite different from local country rocks. Most 'igneous' inclusions thus appear to have an exotic source of more primitive composition, presumably the upper mantle. The appinites of the Strontian pluton were also investigated as part of a study of coexisting acid-basic melts in granitoid plutons. It is shown that these appinites have quenched liquid contacts with the granitoid hosts and some degree of mixing between appinitic magma and host granitoid has given rise to a reverse zonation pattern in composition and texture. The isotopic data for the appinites of Strontian and for inclusions and their host granitoids in the Strontian and Criffell plutons point to a model for the initiation of granitoid magma genesis in the crust by advection of heat through transfer of basaltic magma from the upper mantle. Some of this magma is incorporated in the granitoid magma as basaltic inclusions which gradually become modified towards dioritic compositions. The characteristics of this mantle derived magma and the granitoid crustal source do not vary significantly between Strontian and Criffell in terms of Nd isotope model ages. This is a remarkable finding considering the very different tectonic settings and suggests greater similarities at deeper lithospheric levels. The study of Nd isotopes in xenolithic inclusions in granitoids has been shown to provide at least as much additional information on the petrogenesis of granitoid plutons as the conventional study of their host rocks, but a complementary study of Sr isotopes is not particularly useful. This investigation provides some of the theoretical basis for this and presents a methodology for carrying out such investigations.
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A study of the anchizone-epizone metamorphic transition
https://hdl.handle.net/10023/15473
The offshore Karoo Supergroup (+2 km thick) of the Seychelles has been divided into five members based mainly on sandstone/mudstone development as revealed by wireline logs and lithological samples. The four lower members are characterized by thick sandstones with minor mudstones and the lowest member distinguished by the presence of occasional bands of lignite; the topmost member has thick mudstones as well as thick sandstones. Members 2 and 3, and 4 and 5 form two upward-fining megacycles in which members 2 and 4 have coarser-grained pebbly, sandstones while the sandstones of 3 and 5 are medium and fine-grained. The sediments are fluvial in origin, possibly braid plain except for the uppermost member which may have formed under a meandering system. Paleogeographic reconstruction invokes a source area in north-east Madagascar shedding debris eastwards towards the Seychelles which at that time (pre-mid-Jurassic) lay between Madagascar to the west, and India to the east. Burial curves are presented from considerations of sediment thickness and texture, structure, including the positions of unconformities and diagenesis as an aid in assessing oil potential. With possible source rocks in overlying marine sediments, hydrocarbon generation may have occurred in late Mesozoic and early Tertiary. Migration could possibly have taken place into fault-juxtaposed Karoo sandstones. For comparative purposes petrographic features of samples from the Elk Point Group Alberta, Canada were studied. This Devonian sequence comprises marginal and marine sediments including carbonates and evaporites, but the sandstones studied come from marginal deltaic deposits. Sandstones studied are remarkably similar in both original composition and diagenetic history. Primary mineralogy was determined by similar source areas - predominantly granitic with minor metamorphic and volcanic components. Despite being deposited in different sedimentary environments both groups show extensive diagenesis involving dissolution of feldspars and lithoclasts, precipitation of quartz, and a second phase of dissolution of feldspar, lithoclasts and quartz. Kaolinite is the dominating clay in the sandstones of Karoo Supergroup up to depths of 10,000 ft, while illite prevails over other clays in the sequence between 10,000-12,500 ft. Illite and chlorite are present in the Elk Point Group: kaolinite is absent. The last stage of cementation in Elk Point sandstones was anhydrite precipitation during Cretaceous times. Precipitation of authigenic cements ended with the formation of carbonates in Karoo sandstones. Cementation, especially by quartz appears to have considerably reduced porosity in many places in both the successions. In both the study areas early diagenesis was controlled by meteoric waters while burial and marine influence are responsible for later diagenetic episodes. The presence of illite and chlorite against kaolinite in the Elk Point Group is due to greater depths of burial than Karoo sandstones. Presence of evaporitic environments lead to the formation of anhydrite in the sandstones of Elk Point Group, while feldspar overgrowths are formed as a result of retention of pore-fluids due to the formation of a closed system controlled by marine flooding surfaces.
1990-07-01T00:00:00Z
Morrison, Charles William Ker
The offshore Karoo Supergroup (+2 km thick) of the Seychelles has been divided into five members based mainly on sandstone/mudstone development as revealed by wireline logs and lithological samples. The four lower members are characterized by thick sandstones with minor mudstones and the lowest member distinguished by the presence of occasional bands of lignite; the topmost member has thick mudstones as well as thick sandstones. Members 2 and 3, and 4 and 5 form two upward-fining megacycles in which members 2 and 4 have coarser-grained pebbly, sandstones while the sandstones of 3 and 5 are medium and fine-grained. The sediments are fluvial in origin, possibly braid plain except for the uppermost member which may have formed under a meandering system. Paleogeographic reconstruction invokes a source area in north-east Madagascar shedding debris eastwards towards the Seychelles which at that time (pre-mid-Jurassic) lay between Madagascar to the west, and India to the east. Burial curves are presented from considerations of sediment thickness and texture, structure, including the positions of unconformities and diagenesis as an aid in assessing oil potential. With possible source rocks in overlying marine sediments, hydrocarbon generation may have occurred in late Mesozoic and early Tertiary. Migration could possibly have taken place into fault-juxtaposed Karoo sandstones. For comparative purposes petrographic features of samples from the Elk Point Group Alberta, Canada were studied. This Devonian sequence comprises marginal and marine sediments including carbonates and evaporites, but the sandstones studied come from marginal deltaic deposits. Sandstones studied are remarkably similar in both original composition and diagenetic history. Primary mineralogy was determined by similar source areas - predominantly granitic with minor metamorphic and volcanic components. Despite being deposited in different sedimentary environments both groups show extensive diagenesis involving dissolution of feldspars and lithoclasts, precipitation of quartz, and a second phase of dissolution of feldspar, lithoclasts and quartz. Kaolinite is the dominating clay in the sandstones of Karoo Supergroup up to depths of 10,000 ft, while illite prevails over other clays in the sequence between 10,000-12,500 ft. Illite and chlorite are present in the Elk Point Group: kaolinite is absent. The last stage of cementation in Elk Point sandstones was anhydrite precipitation during Cretaceous times. Precipitation of authigenic cements ended with the formation of carbonates in Karoo sandstones. Cementation, especially by quartz appears to have considerably reduced porosity in many places in both the successions. In both the study areas early diagenesis was controlled by meteoric waters while burial and marine influence are responsible for later diagenetic episodes. The presence of illite and chlorite against kaolinite in the Elk Point Group is due to greater depths of burial than Karoo sandstones. Presence of evaporitic environments lead to the formation of anhydrite in the sandstones of Elk Point Group, while feldspar overgrowths are formed as a result of retention of pore-fluids due to the formation of a closed system controlled by marine flooding surfaces.
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The Karoo Supergroup (Triassic-Jurassic), Seychelles : sedimentology, provenance and diagenesis of a terrestrial succession and comparisons with marginal sediments from Elk Point group (Devonian), Alberta, Canada
https://hdl.handle.net/10023/15472
The offshore Karoo Supergroup (+2 km thick) of the Seychelles has been divided into five members based mainly on sandstone/mudstone development as revealed by wireline logs and lithological samples. The four lower members are characterized by thick sandstones with minor mudstones and the lowest member distinguished by the presence of occasional bands of lignite; the topmost member has thick mudstones as well as thick sandstones. Members 2 and 3, and 4 and 5 form two upward-fining megacycles in which members 2 and 4 have coarser-grained pebbly, sandstones while the sandstones of 3 and 5 are medium and fine-grained. The sediments are fluvial in origin, possibly braid plain except for the uppermost member which may have formed under a meandering system. Paleogeographic reconstruction invokes a source area in north-east Madagascar shedding debris eastwards towards the Seychelles which at that time (pre-mid-Jurassic) lay between Madagascar to the west, and India to the east. Burial curves are presented from considerations of sediment thickness and texture, structure, including the positions of unconformities and diagenesis as an aid in assessing oil potential. With possible source rocks in overlying marine sediments, hydrocarbon generation may have occurred in late Mesozoic and early Tertiary. Migration could possibly have taken place into fault-juxtaposed Karoo sandstones. For comparative purposes petrographic features of samples from the Elk Point Group Alberta, Canada were studied. This Devonian sequence comprises marginal and marine sediments including carbonates and evaporites, but the sandstones studied come from marginal deltaic deposits. Sandstones studied are remarkably similar in both original composition and diagenetic history. Primary mineralogy was determined by similar source areas - predominantly granitic with minor metamorphic and volcanic components. Despite being deposited in different sedimentary environments both groups show extensive diagenesis involving dissolution of feldspars and lithoclasts, precipitation of quartz, and a second phase of dissolution of feldspar, lithoclasts and quartz. Kaolinite is the dominating clay in the sandstones of Karoo Supergroup up to depths of 10,000 ft, while illite prevails over other clays in the sequence between 10,000-12,500 ft. Illite and chlorite are present in the Elk Point Group: kaolinite is absent. The last stage of cementation in Elk Point sandstones was anhydrite precipitation during Cretaceous times. Precipitation of authigenic cements ended with the formation of carbonates in Karoo sandstones. Cementation, especially by quartz appears to have considerably reduced porosity in many places in both the successions. In both the study areas early diagenesis was controlled by meteoric waters while burial and marine influence are responsible for later diagenetic episodes. The presence of illite and chlorite against kaolinite in the Elk Point Group is due to greater depths of burial than Karoo sandstones. Presence of evaporitic environments lead to the formation of anhydrite in the sandstones of Elk Point Group, while feldspar overgrowths are formed as a result of retention of pore-fluids due to the formation of a closed system controlled by marine flooding surfaces.
1992-07-01T00:00:00Z
Khanna, Mohit
The offshore Karoo Supergroup (+2 km thick) of the Seychelles has been divided into five members based mainly on sandstone/mudstone development as revealed by wireline logs and lithological samples. The four lower members are characterized by thick sandstones with minor mudstones and the lowest member distinguished by the presence of occasional bands of lignite; the topmost member has thick mudstones as well as thick sandstones. Members 2 and 3, and 4 and 5 form two upward-fining megacycles in which members 2 and 4 have coarser-grained pebbly, sandstones while the sandstones of 3 and 5 are medium and fine-grained. The sediments are fluvial in origin, possibly braid plain except for the uppermost member which may have formed under a meandering system. Paleogeographic reconstruction invokes a source area in north-east Madagascar shedding debris eastwards towards the Seychelles which at that time (pre-mid-Jurassic) lay between Madagascar to the west, and India to the east. Burial curves are presented from considerations of sediment thickness and texture, structure, including the positions of unconformities and diagenesis as an aid in assessing oil potential. With possible source rocks in overlying marine sediments, hydrocarbon generation may have occurred in late Mesozoic and early Tertiary. Migration could possibly have taken place into fault-juxtaposed Karoo sandstones. For comparative purposes petrographic features of samples from the Elk Point Group Alberta, Canada were studied. This Devonian sequence comprises marginal and marine sediments including carbonates and evaporites, but the sandstones studied come from marginal deltaic deposits. Sandstones studied are remarkably similar in both original composition and diagenetic history. Primary mineralogy was determined by similar source areas - predominantly granitic with minor metamorphic and volcanic components. Despite being deposited in different sedimentary environments both groups show extensive diagenesis involving dissolution of feldspars and lithoclasts, precipitation of quartz, and a second phase of dissolution of feldspar, lithoclasts and quartz. Kaolinite is the dominating clay in the sandstones of Karoo Supergroup up to depths of 10,000 ft, while illite prevails over other clays in the sequence between 10,000-12,500 ft. Illite and chlorite are present in the Elk Point Group: kaolinite is absent. The last stage of cementation in Elk Point sandstones was anhydrite precipitation during Cretaceous times. Precipitation of authigenic cements ended with the formation of carbonates in Karoo sandstones. Cementation, especially by quartz appears to have considerably reduced porosity in many places in both the successions. In both the study areas early diagenesis was controlled by meteoric waters while burial and marine influence are responsible for later diagenetic episodes. The presence of illite and chlorite against kaolinite in the Elk Point Group is due to greater depths of burial than Karoo sandstones. Presence of evaporitic environments lead to the formation of anhydrite in the sandstones of Elk Point Group, while feldspar overgrowths are formed as a result of retention of pore-fluids due to the formation of a closed system controlled by marine flooding surfaces.
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The sedimentary geochemistry of the Moffat Shales : a carbonaceous sequence in the Southern Uplands of Scotland
https://hdl.handle.net/10023/15471
The Moffat Shales form a 100-metre condensed politic succession of middle Ordovician to Silurian age. 210 samples were collected from several inliers and were dated by contained graptolites. Mineralogy indicates low greenschist facies regional metamorphism. Correlation and multivariate statistical techniques assess the interdependence of the range of major and trace elements analysed, and demonstrate progressive change related to an increasing input of clay. Physiography is deduced as the main factor controlling sedimentation with physico-chemical conditions and the decay of organic matter having important influences. Amino acids were not detected. Minor amounts of alkanes occur, with the highest average yield extracted from sediments at the locality of Hartfell, and lesser amounts from Dobb's Linn and Clanyard Bay. Their abundance and distribution is related to thermal effects of metamorphism and to biodegradation. Metamorphism of kerogen has produced a graphite-d1a structure. Structural ordering is highest in Hartfell kerogens and can be related to the proximity of reverse faults. Optical properties and textural relationships of carbonized graptolite fragments are related to distance from a porphyrite dyke. Samples show increasing reflectivity, refractive and absorptive indices approaching the intrusion from the south. To the north, three discontinuities in the reflectivity trend are attributed to reactivation of reverse faults following intrusion. Dispersion of reflectivity with wavelength shows a rise from blue to red corresponding to that of anthracitic vitrinites. The relationship between optical parameters and temperature indicates that carbonization has occurred at lower temperatures than for the coal-carbon transformation. Contrasts are attributed to initial chemistry, and rank, also to the unknown effects of time and tectonically induced pressure and temperature. Reflectivity of dispersed graptolite fragments is used as a rank index for Moffat Shales cropping out in Luce Bay and near Moffat. At Luce Bay values correspond to those of coals in the low volatile bituminous to anthracitic range with high values occurring near faults. Coalification is related mainly to regional metamorphism; secondary processes, e.g. migration of hot fluids along fractures, may also have operated. At Moffat, comparable rank ranges are distributed along the southeast flank of a Caledonoid trending dome, low values occurring adjacent to the Ettrick Valley Thrust, high at Hartfell. Secondary thermal effects from an unexposed pluton are deduced. Further evidence of enhanced thermal activity in the Hartfell sediments is presented from a study of the electrical conduction of powdered samples. The low resistance of Hartfell samples is attributed to the graphitic nature of the relatively abundant carbonaceous material.
1976-01-01T00:00:00Z
Watson, Stewart W.
The Moffat Shales form a 100-metre condensed politic succession of middle Ordovician to Silurian age. 210 samples were collected from several inliers and were dated by contained graptolites. Mineralogy indicates low greenschist facies regional metamorphism. Correlation and multivariate statistical techniques assess the interdependence of the range of major and trace elements analysed, and demonstrate progressive change related to an increasing input of clay. Physiography is deduced as the main factor controlling sedimentation with physico-chemical conditions and the decay of organic matter having important influences. Amino acids were not detected. Minor amounts of alkanes occur, with the highest average yield extracted from sediments at the locality of Hartfell, and lesser amounts from Dobb's Linn and Clanyard Bay. Their abundance and distribution is related to thermal effects of metamorphism and to biodegradation. Metamorphism of kerogen has produced a graphite-d1a structure. Structural ordering is highest in Hartfell kerogens and can be related to the proximity of reverse faults. Optical properties and textural relationships of carbonized graptolite fragments are related to distance from a porphyrite dyke. Samples show increasing reflectivity, refractive and absorptive indices approaching the intrusion from the south. To the north, three discontinuities in the reflectivity trend are attributed to reactivation of reverse faults following intrusion. Dispersion of reflectivity with wavelength shows a rise from blue to red corresponding to that of anthracitic vitrinites. The relationship between optical parameters and temperature indicates that carbonization has occurred at lower temperatures than for the coal-carbon transformation. Contrasts are attributed to initial chemistry, and rank, also to the unknown effects of time and tectonically induced pressure and temperature. Reflectivity of dispersed graptolite fragments is used as a rank index for Moffat Shales cropping out in Luce Bay and near Moffat. At Luce Bay values correspond to those of coals in the low volatile bituminous to anthracitic range with high values occurring near faults. Coalification is related mainly to regional metamorphism; secondary processes, e.g. migration of hot fluids along fractures, may also have operated. At Moffat, comparable rank ranges are distributed along the southeast flank of a Caledonoid trending dome, low values occurring adjacent to the Ettrick Valley Thrust, high at Hartfell. Secondary thermal effects from an unexposed pluton are deduced. Further evidence of enhanced thermal activity in the Hartfell sediments is presented from a study of the electrical conduction of powdered samples. The low resistance of Hartfell samples is attributed to the graphitic nature of the relatively abundant carbonaceous material.
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Geochemistry and mineralization of Buru and Kuge volcanic carbonatite centres, Western Kenya
https://hdl.handle.net/10023/15470
Western Kenya hosts a number of Tertiary and Quaternary alkaline volcanic carbonatite centres, such as Rangwa, the North and South Ruri centres, Kuge, Homa Mountain and Legetet which are located along an old Precambrian major shear zone lying within the Nyanza rift, off the main Kenyan (Gregory) rift. The centres consist of agglomerates and breccias with mixed clasts of silicate rocks and carbonatites, interbedded with carbonatitic and nephelinitic tuffs. The volcanic assemblage is transected by high level sheets and dykes of calcite carbonatite and ferrocarbonatite which were probably later feeders for the volcanic eruptions. Carbon, oxygen, and sulphur isotopic compositions were determined for calcite, siderite and barite from the Buru and Kuge carbonatite centres. Wide ranges in the isotopic compositions of the minerals were observed with values for delta13C and delta18O for the Buru calcites ranging from +1.27 to -3.23‰ (PDB) and +11.25 to +26.21‰ (SMOW). The delta13 C and delta18O for the Kuge calcites are -3.11 to -8.44‰ (PDB) and +18.09 to +25.73‰ (SMOW). The Buru siderites plot in a narrow and restricted range at -3.07 to -4.39‰ (PDB) and +12.61 to +16.10‰ (SMOW). Data on the sulphur isotopic composition from the Buru hill carbonatite show a fairly widespread variation in delta34S ranging from +4.50 to +12.40‰ (CDT), whereas Kuge hill displays a slightly more homogenous isotopic composition with values ranging from +1.10 to +5.10‰ (CDT). The carbon and oxygen isotopic compositions from the Buru and Kuge carbonatite centres do not retain the primary isotopic signatures expected for magmatic primary carbonatites. Most of the variations in isotopic composition have been attributed to secondary processes involving low temperature (60° to 144°C) hydrothemal alteration and isotopic exchange between the carbonatites and fluids (meteoric water). Higher delta18O values (+21.91 to +26.21‰) with a significant increase in delta13Cvalues (-1.48 to +1.27‰) shown by the most oxidized samples from the Buru carbonatite may indicate the involvement of supergene exchange with atmospheric CO2 at relatively lower temperatures (<50°C). The variations in 34S shown by the two centres compared to mantle sulphur could be due to either redox processes and/or isotopic fractionations due to loss of volatiles. The Buru and Kuge carbonatite centres are characterized by enriched rare earth element (REE) values dominated by higher abundances of LREEs with steep chondrite-normalized distribution patterns. The lateritic zone at Buru hill, however, contains the greatest concentrations of REEs, barium, iron and manganese compared to the fresh carbonatite in which calcite and particularly siderite increase in abundance as the influence of supergene processes decrease with depth. The most common rare earth minerals encountered in the Buru and Kuge carbonatite centres are the fluorocarbonates (bastnaesite, synchysite and parisite), and monazite. The lanthanide fluorocarbonate and monazite control the concentration and bulk distribution of the REEs. The replacement textures of the lanthanide fluorocarbonates and monazite indicate that they are secondary in origin and appear to have been introduced by late stage, low temperature hydrothermal processes. The rare earth minerals are commonly accompanied by fluorite, and barite. Stable isotope studies suggest that the low temperature mineralogical changes and REE mineralization observed in western Kenyan carbonatites were controlled initially by hydrothermal activity and later by supergene processes. Higher delta18O and values, especially in the oxidized zones, correspond to higher REE abundances.
1997-06-01T00:00:00Z
Onuonga, Isaac Oriechi
Western Kenya hosts a number of Tertiary and Quaternary alkaline volcanic carbonatite centres, such as Rangwa, the North and South Ruri centres, Kuge, Homa Mountain and Legetet which are located along an old Precambrian major shear zone lying within the Nyanza rift, off the main Kenyan (Gregory) rift. The centres consist of agglomerates and breccias with mixed clasts of silicate rocks and carbonatites, interbedded with carbonatitic and nephelinitic tuffs. The volcanic assemblage is transected by high level sheets and dykes of calcite carbonatite and ferrocarbonatite which were probably later feeders for the volcanic eruptions. Carbon, oxygen, and sulphur isotopic compositions were determined for calcite, siderite and barite from the Buru and Kuge carbonatite centres. Wide ranges in the isotopic compositions of the minerals were observed with values for delta13C and delta18O for the Buru calcites ranging from +1.27 to -3.23‰ (PDB) and +11.25 to +26.21‰ (SMOW). The delta13 C and delta18O for the Kuge calcites are -3.11 to -8.44‰ (PDB) and +18.09 to +25.73‰ (SMOW). The Buru siderites plot in a narrow and restricted range at -3.07 to -4.39‰ (PDB) and +12.61 to +16.10‰ (SMOW). Data on the sulphur isotopic composition from the Buru hill carbonatite show a fairly widespread variation in delta34S ranging from +4.50 to +12.40‰ (CDT), whereas Kuge hill displays a slightly more homogenous isotopic composition with values ranging from +1.10 to +5.10‰ (CDT). The carbon and oxygen isotopic compositions from the Buru and Kuge carbonatite centres do not retain the primary isotopic signatures expected for magmatic primary carbonatites. Most of the variations in isotopic composition have been attributed to secondary processes involving low temperature (60° to 144°C) hydrothemal alteration and isotopic exchange between the carbonatites and fluids (meteoric water). Higher delta18O values (+21.91 to +26.21‰) with a significant increase in delta13Cvalues (-1.48 to +1.27‰) shown by the most oxidized samples from the Buru carbonatite may indicate the involvement of supergene exchange with atmospheric CO2 at relatively lower temperatures (<50°C). The variations in 34S shown by the two centres compared to mantle sulphur could be due to either redox processes and/or isotopic fractionations due to loss of volatiles. The Buru and Kuge carbonatite centres are characterized by enriched rare earth element (REE) values dominated by higher abundances of LREEs with steep chondrite-normalized distribution patterns. The lateritic zone at Buru hill, however, contains the greatest concentrations of REEs, barium, iron and manganese compared to the fresh carbonatite in which calcite and particularly siderite increase in abundance as the influence of supergene processes decrease with depth. The most common rare earth minerals encountered in the Buru and Kuge carbonatite centres are the fluorocarbonates (bastnaesite, synchysite and parisite), and monazite. The lanthanide fluorocarbonate and monazite control the concentration and bulk distribution of the REEs. The replacement textures of the lanthanide fluorocarbonates and monazite indicate that they are secondary in origin and appear to have been introduced by late stage, low temperature hydrothermal processes. The rare earth minerals are commonly accompanied by fluorite, and barite. Stable isotope studies suggest that the low temperature mineralogical changes and REE mineralization observed in western Kenyan carbonatites were controlled initially by hydrothermal activity and later by supergene processes. Higher delta18O and values, especially in the oxidized zones, correspond to higher REE abundances.
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Sedimentology and petrology of the carboniferous rocks of St Monance, Fife, Scotland
https://hdl.handle.net/10023/15469
1. The rooks of the study area belong to the upper part of the Carboniferous Sandstone Series, and the Lower Limestone Group of the St Monance syncline. The succession consists of alternating limestones, shales, siltstones, and sandstones with occasional coals. Six sedimentary cycles were examined, and the boundaries to cycles were taken at those points where a carbonate lithology occurs. 2 Sedimentary structures include rib-and-furrow structures, large-scale, mainly through cross-lamination, hummocky cross-stratification, and deformation structures including pseudonodules. Lenticular, wavy and flaser bedding are common. The main palaeocurrent directions are towards the south-west. 3 Sediment distribution, structures, and grain size studies lead to the depositional model of deltaic sediments prograding from NE to SW. 4 Petrological studies by optical microscope, SEM, and X-ray diffraction have been carried out especially on the sandstones. The rocks classify as orthoquartzites. The provenance suggested is principally one of low-grade metamorphic rocks. 5 Studies of diagenesis show cements of carbonates, quartz and Iron-oxides. Authigenic clay minerals are mainly kaolinite with smaller amounts of illlte, chlorite and smectite. 6 The amount of original pore space has been reduced by precipitation of cement and clays. Before the reduction the porosity value may have reached 40%. Two methods were used to get the actual amount of porosity, core sample and thin-section, and they gave values of 30-60% and 25% respectively. The sandstones are mostly permeable, and the pore types associated are intergranular, either formed through dissolution of carbonate cement or other unstable materials. If there has been little or no dissolution, and/or if a high amount of clay is present, microporosity is developed and thirteen types have been recognized. Microporosity may reach up to 89/t of the total porosity as determined by mercury Injection.
1986-07-01T00:00:00Z
Al-Rubaii, Mohammed A.
1. The rooks of the study area belong to the upper part of the Carboniferous Sandstone Series, and the Lower Limestone Group of the St Monance syncline. The succession consists of alternating limestones, shales, siltstones, and sandstones with occasional coals. Six sedimentary cycles were examined, and the boundaries to cycles were taken at those points where a carbonate lithology occurs. 2 Sedimentary structures include rib-and-furrow structures, large-scale, mainly through cross-lamination, hummocky cross-stratification, and deformation structures including pseudonodules. Lenticular, wavy and flaser bedding are common. The main palaeocurrent directions are towards the south-west. 3 Sediment distribution, structures, and grain size studies lead to the depositional model of deltaic sediments prograding from NE to SW. 4 Petrological studies by optical microscope, SEM, and X-ray diffraction have been carried out especially on the sandstones. The rocks classify as orthoquartzites. The provenance suggested is principally one of low-grade metamorphic rocks. 5 Studies of diagenesis show cements of carbonates, quartz and Iron-oxides. Authigenic clay minerals are mainly kaolinite with smaller amounts of illlte, chlorite and smectite. 6 The amount of original pore space has been reduced by precipitation of cement and clays. Before the reduction the porosity value may have reached 40%. Two methods were used to get the actual amount of porosity, core sample and thin-section, and they gave values of 30-60% and 25% respectively. The sandstones are mostly permeable, and the pore types associated are intergranular, either formed through dissolution of carbonate cement or other unstable materials. If there has been little or no dissolution, and/or if a high amount of clay is present, microporosity is developed and thirteen types have been recognized. Microporosity may reach up to 89/t of the total porosity as determined by mercury Injection.
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Lithium and tantalum mineralization in rare-element pegmatites from southern Africa
https://hdl.handle.net/10023/15468
Lithium and tantalum mineralization in rare-element pegmatites has been studied in 4 field areas. Three field areas are within a pegmatite belt which stretches for 450 km from Steinkopf, Namaqualand in the west, to Kenhardt in the east along the Orange River in South Africa, incorporating Tantalite Valley, Namibia in the central area. This Belt is considered to be of 1200 my age. The 4th field area is in central Namibia in the Karibib-Usakos region of 500 my age. Lithium mineralization involves primary minerals, petalite and spodumene (crystallizing< 650° C) and amblygonite which crystallize from a magma +/- an aqueous fluid, and lithian mica which along with cleavelandite is one of the last mineral assemblages to form, probably these last two assemblages are replacement in origin. Petalite is dominant in the Karibib area and spodumene in Steinkopf, Namaqualand and Tantalite Valley. The Kenhardt area is poor in lithium in comparison with the western and central portions of the Pegmatite Belt. Amblygonite-montebrasite is present in Karibib and Tantalite Valley usually in association with cleavelandite and lithian mica. Hydrothermal low temperature replacements, < 400°C occur in spodumene in the Steinkopf and Tantalite Valley pegmatites, being pseudomorphed by albite and mica +/- sericite. Amblygonite-montebrasite in Karibib displays replacements of natromontebrasite (the first occurrence in Karibib, Namibia), crandallite, brazilianite and possibly cookeite. Apatite is always prominent at the contact. An unusual occurrence of Mn-tantalite lamellae, primarily parallel, lying in microlite, is intergrown with montebrasite at the Rubicon pegmatite, Karibib, suggesting simultaneous crystallization of these three minerals, i.e. Ta-dominated tantalite and microlite and LiAl(F/P04) involving late fluids rich in F, P and Ta. Mn-tantalite and Ta-rich microlite are the dominant Ta-minerals in the rare-element Li-rich pegmatites of Namaqualand, Tantalite Valley and Karibib. In contrast, columbite (Nb-rich) is prevalent in the Li-poor, less differentiated pegmatites in the eastern Pegmatite Belt near Kenhardt. Microlite replaces Mn-tantalite in Li-rich rare-element pegmatites in all three field areas. A uranmicrolite from Karibib, Namibia contains 14.35% UO2, 1.03% PbO, 56.12% Ta205, 13.18% Nb205, 0.58% Fe203, 6.87% CaO, 0.54% SrO, 0.59% MnO, 0.86% Na2O and 0.47% F. U-plumbomicrolite or Pb-uranmicrolite is intergrown with manganotantalite from the same pegmatite. Throughout one aggregate of microlite PbO varied from 21.98 to 1.57% and UO2 from 12.89 to 16.20%. Pb appears to be concentrated around the periphery of the crystal. Backscattered electron images reveal metamict textures in radioactive microlites and distinctive subspheroidal features. A uranoan microlite from Tantalite Valley, Namibia, revealed two essentially different compositions; a more hydrated rim area of 200 mum radius containing 7% higher Ta2O5, 10% lower CaO and 1.3% lower F than a main central area of slightly variable composition. Crystals of uranoan microlite from Steinkopf, Namaqualand contain remnants of a bismuth phase. Bismuth intergrowths with quartz reveal the presence of two rare-minerals, pyromorphite [Pb5(PO4) 3 C1] and m0ttramite[PbCu(VO4)OH], new data is given for these minerals. Ferro tantalite occurs at Rubicon mine. A schematic diagram is produced for the paragenetic sequence of mineral assemblage in each of the pegmatite areas in Karibib, Tantalite Valley, and Steinkopf, Namaqualand in relation to T and P of formation, and the magma and fluids effecting the crystallization sequence. Finally different fractionation trends of Ta-Nb, Mn-Fe, Rb-K and Cs-K in columbite-tantalites and lithian mica have highlighted variable paths of differentiation in contrasting rare-element pegmatites which may reflect different sources of original parental magma.
1994-07-01T00:00:00Z
Baldwin, Joy Rosina
Lithium and tantalum mineralization in rare-element pegmatites has been studied in 4 field areas. Three field areas are within a pegmatite belt which stretches for 450 km from Steinkopf, Namaqualand in the west, to Kenhardt in the east along the Orange River in South Africa, incorporating Tantalite Valley, Namibia in the central area. This Belt is considered to be of 1200 my age. The 4th field area is in central Namibia in the Karibib-Usakos region of 500 my age. Lithium mineralization involves primary minerals, petalite and spodumene (crystallizing< 650° C) and amblygonite which crystallize from a magma +/- an aqueous fluid, and lithian mica which along with cleavelandite is one of the last mineral assemblages to form, probably these last two assemblages are replacement in origin. Petalite is dominant in the Karibib area and spodumene in Steinkopf, Namaqualand and Tantalite Valley. The Kenhardt area is poor in lithium in comparison with the western and central portions of the Pegmatite Belt. Amblygonite-montebrasite is present in Karibib and Tantalite Valley usually in association with cleavelandite and lithian mica. Hydrothermal low temperature replacements, < 400°C occur in spodumene in the Steinkopf and Tantalite Valley pegmatites, being pseudomorphed by albite and mica +/- sericite. Amblygonite-montebrasite in Karibib displays replacements of natromontebrasite (the first occurrence in Karibib, Namibia), crandallite, brazilianite and possibly cookeite. Apatite is always prominent at the contact. An unusual occurrence of Mn-tantalite lamellae, primarily parallel, lying in microlite, is intergrown with montebrasite at the Rubicon pegmatite, Karibib, suggesting simultaneous crystallization of these three minerals, i.e. Ta-dominated tantalite and microlite and LiAl(F/P04) involving late fluids rich in F, P and Ta. Mn-tantalite and Ta-rich microlite are the dominant Ta-minerals in the rare-element Li-rich pegmatites of Namaqualand, Tantalite Valley and Karibib. In contrast, columbite (Nb-rich) is prevalent in the Li-poor, less differentiated pegmatites in the eastern Pegmatite Belt near Kenhardt. Microlite replaces Mn-tantalite in Li-rich rare-element pegmatites in all three field areas. A uranmicrolite from Karibib, Namibia contains 14.35% UO2, 1.03% PbO, 56.12% Ta205, 13.18% Nb205, 0.58% Fe203, 6.87% CaO, 0.54% SrO, 0.59% MnO, 0.86% Na2O and 0.47% F. U-plumbomicrolite or Pb-uranmicrolite is intergrown with manganotantalite from the same pegmatite. Throughout one aggregate of microlite PbO varied from 21.98 to 1.57% and UO2 from 12.89 to 16.20%. Pb appears to be concentrated around the periphery of the crystal. Backscattered electron images reveal metamict textures in radioactive microlites and distinctive subspheroidal features. A uranoan microlite from Tantalite Valley, Namibia, revealed two essentially different compositions; a more hydrated rim area of 200 mum radius containing 7% higher Ta2O5, 10% lower CaO and 1.3% lower F than a main central area of slightly variable composition. Crystals of uranoan microlite from Steinkopf, Namaqualand contain remnants of a bismuth phase. Bismuth intergrowths with quartz reveal the presence of two rare-minerals, pyromorphite [Pb5(PO4) 3 C1] and m0ttramite[PbCu(VO4)OH], new data is given for these minerals. Ferro tantalite occurs at Rubicon mine. A schematic diagram is produced for the paragenetic sequence of mineral assemblage in each of the pegmatite areas in Karibib, Tantalite Valley, and Steinkopf, Namaqualand in relation to T and P of formation, and the magma and fluids effecting the crystallization sequence. Finally different fractionation trends of Ta-Nb, Mn-Fe, Rb-K and Cs-K in columbite-tantalites and lithian mica have highlighted variable paths of differentiation in contrasting rare-element pegmatites which may reflect different sources of original parental magma.
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Low-grade regional metamorphism of paleozoic rocks in the Midland valley of Scotland
https://hdl.handle.net/10023/15467
Low-grade burial metamorphism in the Midland Valley of Scotland, has been investigated with reference to the Silurian sediments and to the Carboniferous volcanics. In the Silurian sediments, facies definitive phyllosilicates are absent. Thin-section examination indicates that cementation was early and despite strong deformation, the lack of cleavage is related to the isotropic dispersal of domains during burial. Scanning electron microscopy and X-ray diffraction define clay mineral assemblages which characterize the transformation of montmorillonite to illite during burial. Illite crystallinity, bo and conodont alteration, show values consistent with this transformation and are indicative of diagenetic/anchizone conditions. Metamorphism is related to Siluro-Devonian syn-sedimentary burial. Despite tentative links between the Midland Valley and the Southern Uplands during the Llandovery, the relative simplicity of the burial metamorphic sequence in the former region suggests that the Silurian trough became palaeo-geographically distinct. The Carboniferous volcanics have undergone burial metamorphism in the zeolite facies, which occurred once the bulk of the lavas had been extruded, and following burial beneath the Central and Ayrshire Basins. Alteration was dominated by hydrothermal processes and has resulted in the production of early greenstones, later burial metamorphic zones and palaeo-geothermal plumes. Seven zones have been defined upon the distribution of amygdale minerals. Thin-section examination however divides the zeolite facies in the Midland Valley into an upper analcime and a lower laumontite zone. Mineralogical assemblages are conducive with metamorphism at a) Pfluid = 2-4 kb at 200 °C and b) Pfluid = 2 kb at 350-420 °C, for the zeolite zones and the palaeo-geothermal plumes respectively. These values are compatible with burial depth estimates, with homogenization temperatures in fluid inclusions and with calcite-water fractionation temperatures. Water/rock ratios indicate that metamorphism was related to the flow of seawater and meteoric water through the volcanic sequences. Evidence for episodic boiling in fluid inclusions indicates fluid convection occurred, and was related to fracturing associated with a change from a lithostatic to a hydrostatic pressure regime. Seismic pumping was related to fracturing and to renewed magmatic activity in shallow chambers beneath the Midland Valley.
1988-07-01T00:00:00Z
Evans, Lesley Jayne
Low-grade burial metamorphism in the Midland Valley of Scotland, has been investigated with reference to the Silurian sediments and to the Carboniferous volcanics. In the Silurian sediments, facies definitive phyllosilicates are absent. Thin-section examination indicates that cementation was early and despite strong deformation, the lack of cleavage is related to the isotropic dispersal of domains during burial. Scanning electron microscopy and X-ray diffraction define clay mineral assemblages which characterize the transformation of montmorillonite to illite during burial. Illite crystallinity, bo and conodont alteration, show values consistent with this transformation and are indicative of diagenetic/anchizone conditions. Metamorphism is related to Siluro-Devonian syn-sedimentary burial. Despite tentative links between the Midland Valley and the Southern Uplands during the Llandovery, the relative simplicity of the burial metamorphic sequence in the former region suggests that the Silurian trough became palaeo-geographically distinct. The Carboniferous volcanics have undergone burial metamorphism in the zeolite facies, which occurred once the bulk of the lavas had been extruded, and following burial beneath the Central and Ayrshire Basins. Alteration was dominated by hydrothermal processes and has resulted in the production of early greenstones, later burial metamorphic zones and palaeo-geothermal plumes. Seven zones have been defined upon the distribution of amygdale minerals. Thin-section examination however divides the zeolite facies in the Midland Valley into an upper analcime and a lower laumontite zone. Mineralogical assemblages are conducive with metamorphism at a) Pfluid = 2-4 kb at 200 °C and b) Pfluid = 2 kb at 350-420 °C, for the zeolite zones and the palaeo-geothermal plumes respectively. These values are compatible with burial depth estimates, with homogenization temperatures in fluid inclusions and with calcite-water fractionation temperatures. Water/rock ratios indicate that metamorphism was related to the flow of seawater and meteoric water through the volcanic sequences. Evidence for episodic boiling in fluid inclusions indicates fluid convection occurred, and was related to fracturing associated with a change from a lithostatic to a hydrostatic pressure regime. Seismic pumping was related to fracturing and to renewed magmatic activity in shallow chambers beneath the Midland Valley.
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The geography of petro-chemical industry in Turkey
https://hdl.handle.net/10023/15391
The subject of the thesis is the geography of the petro-chemical industry in Turkey. The geography of the industry is divided into three sections and seven chapters. The first section, which covers the first two chapters, is an introduction to the industry in Turkey. The geographical and the industrial background of Turkey is described together with the major theories of industrial location and the history of industrial location in Turkey, from the foundation of the Republic to the present day. The function and creation of the petro-chemical industry in the world in general and in Turkey are described. The second section, which contains five chapters, studies the location factors of the first Turkish petro-chemical complex, its products, the domestic and external market for petro-chemical products, the socioeconomic problems which have been created in the areas surrounding the complex, and a suggestion as to where the planned second petro-chemical complex of Turkey should be located. The third section summarises the findings of the study.
1974-01-01T00:00:00Z
Engin, Naci
The subject of the thesis is the geography of the petro-chemical industry in Turkey. The geography of the industry is divided into three sections and seven chapters. The first section, which covers the first two chapters, is an introduction to the industry in Turkey. The geographical and the industrial background of Turkey is described together with the major theories of industrial location and the history of industrial location in Turkey, from the foundation of the Republic to the present day. The function and creation of the petro-chemical industry in the world in general and in Turkey are described. The second section, which contains five chapters, studies the location factors of the first Turkish petro-chemical complex, its products, the domestic and external market for petro-chemical products, the socioeconomic problems which have been created in the areas surrounding the complex, and a suggestion as to where the planned second petro-chemical complex of Turkey should be located. The third section summarises the findings of the study.
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The effect of the national institutional environment on business recipes: comparative case studies of ESSO in Britain and Germany
https://hdl.handle.net/10023/15294
The increasing globalisation of business activities since the Second World War might seem to indicate the end of economic diversity within and among nations, and to point towards the standardisation of business recipes across the industrialised world. However, various cross-cultural studies have revealed considerable differences among organisations even within the fairly narrow context of Europe (for example. Lane, 1989; 1992), which are attributed to differences in the institutional environments in which the organisations are embedded. Institutional theorists argue that contingency theorists' emphasis on the influence of the task environment of an organisation, and cultural theorists' focus on the influence of ideational factors, are not sufficient to explain the continuing diversity of organisations across nations. This research analyses the influence of the institutional environment on the business recipe of private sector organisations. It thus combines institutional theories of organisations and the concept of business recipes. The companies analysed are Esso in Britain and Germany. Given that Esso in both countries is part of the Exxon Corporation, the research not only considers the influence of the national institutional environment, but also offers insights into the workings of a multinational organisation. In-depth case studies of both companies were undertaken by way of interviews and documentary research. These case studies were contextualised by research into areas such as the nature of the petroleum industry, the economic context of the companies, and the history and policy of Exxon Corporation. The case studies reveal that despite each company's common dependence on Exxon and a fair degree of similarity in the technical factors of their environments, they have distinctive features in their business recipes, and these can be attributed to the configurations of the respective institutional environments. The study illustrates the need for the managers to cope with conflicting institutional pressures, especially from their parent company and the national institutional context. Overall, the findings support the view of institutional theorists (for example Lane, 1989; Whitley, 1992a) that economic diversity among countries will persist as long as the configurations of key national institutions differ.
1997-01-01T00:00:00Z
Hanemann, Sibylle
The increasing globalisation of business activities since the Second World War might seem to indicate the end of economic diversity within and among nations, and to point towards the standardisation of business recipes across the industrialised world. However, various cross-cultural studies have revealed considerable differences among organisations even within the fairly narrow context of Europe (for example. Lane, 1989; 1992), which are attributed to differences in the institutional environments in which the organisations are embedded. Institutional theorists argue that contingency theorists' emphasis on the influence of the task environment of an organisation, and cultural theorists' focus on the influence of ideational factors, are not sufficient to explain the continuing diversity of organisations across nations. This research analyses the influence of the institutional environment on the business recipe of private sector organisations. It thus combines institutional theories of organisations and the concept of business recipes. The companies analysed are Esso in Britain and Germany. Given that Esso in both countries is part of the Exxon Corporation, the research not only considers the influence of the national institutional environment, but also offers insights into the workings of a multinational organisation. In-depth case studies of both companies were undertaken by way of interviews and documentary research. These case studies were contextualised by research into areas such as the nature of the petroleum industry, the economic context of the companies, and the history and policy of Exxon Corporation. The case studies reveal that despite each company's common dependence on Exxon and a fair degree of similarity in the technical factors of their environments, they have distinctive features in their business recipes, and these can be attributed to the configurations of the respective institutional environments. The study illustrates the need for the managers to cope with conflicting institutional pressures, especially from their parent company and the national institutional context. Overall, the findings support the view of institutional theorists (for example Lane, 1989; Whitley, 1992a) that economic diversity among countries will persist as long as the configurations of key national institutions differ.
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Some studies on the stratigraphy and sedimentation of the Trias of the Western Highlands and Hebrides, Scotland
https://hdl.handle.net/10023/15279
Sediments referred to the Trias outcrop at intervals over a distance of 105 miles (157 km) along the northwestern seaboard of Scotland. A detailed description is given of the field occurrences and successions, and the stratigraphy revised. Important rod sediments in Westor Ross, previously mapped as Trias, are shown to be Torridonian and their significance is discussed. The Trias is very variable in thickness ranging from negligible to over 300 m (1000 ft). Lithological units show rapid lateral variation, and it is impossible to draw detailed comparisons between successions in different areas. The sediments mainly consist of conglomerates and sandstones which are compared of materials derived from formations, known in the area at the present time. The study of textures and sedimentary structures shows that the sediments are fluviatile. Piedmont deposits and sediments which accumulated in an environment intermediate between piedmont and valley-flat are common true valley-flat deposits also occur, represented by thin fine-grained said-stones and siltstones, Concretionary limestones occur throughout the area, except in one locality, find are interpreted as pedocals. The sediments probably, accumulated in a series of partially isolated basins. Sedimentation was influenced early on by a chain of upland area consisting of n sequence, of Torridonian and Cambro-Ordovician sediments which extended from Loch Broom to Iona, west of the present outcrop of the Hoine Thrust. Source areas to the east became dominant later. The climate was probably hot and semi-arid, with seasonal rainfall.
1965-01-01T00:00:00Z
Lowe, Martin John Brodie
Sediments referred to the Trias outcrop at intervals over a distance of 105 miles (157 km) along the northwestern seaboard of Scotland. A detailed description is given of the field occurrences and successions, and the stratigraphy revised. Important rod sediments in Westor Ross, previously mapped as Trias, are shown to be Torridonian and their significance is discussed. The Trias is very variable in thickness ranging from negligible to over 300 m (1000 ft). Lithological units show rapid lateral variation, and it is impossible to draw detailed comparisons between successions in different areas. The sediments mainly consist of conglomerates and sandstones which are compared of materials derived from formations, known in the area at the present time. The study of textures and sedimentary structures shows that the sediments are fluviatile. Piedmont deposits and sediments which accumulated in an environment intermediate between piedmont and valley-flat are common true valley-flat deposits also occur, represented by thin fine-grained said-stones and siltstones, Concretionary limestones occur throughout the area, except in one locality, find are interpreted as pedocals. The sediments probably, accumulated in a series of partially isolated basins. Sedimentation was influenced early on by a chain of upland area consisting of n sequence, of Torridonian and Cambro-Ordovician sediments which extended from Loch Broom to Iona, west of the present outcrop of the Hoine Thrust. Source areas to the east became dominant later. The climate was probably hot and semi-arid, with seasonal rainfall.
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The last glaciation of Shetland
https://hdl.handle.net/10023/15278
Evidence of the last glaciation of the Shetland Islands, UK, is re-examined and combined with new data on terrestrial glacigenic deposits and recent offshore data from the continental shelf to produce a dynamic, integrated model of the history of the whole ice cap. It is shown that evidence which has previously been attributed to last glacial, or earlier, Scandinavian ice incursion, might be explained by the eastwards migration of local ice sheds. At its maximum, the ice sheet reached the continental shelf edge to the west of the islands, at least 75 km east, at least 50 km north and might be seen as a peninsular extension of the Scottish ice sheet to the south. The changing patterns of ice flow during deglaciation are reconstructed, implying an early phase of deglaciation at the west and northwest margins (possibly accounting for the suggested eastern migration of the ice shed), followed by retreat at more northern, then eastern, then southern margins. It is suggested that the above pattern reflects tidewater calving controlled by bathymmetric variation around the ice sheet. During a later phase of deglaciation, the margin of the ice cap may have grounded at around the current -100m bathymmetric contour and from there retreated terrestrially. The importance of topographic control on patterns of deglaciation as ice retreated towards the island group is clearly established. Some minor moraines in parts of Shetland are due to active ice margins but their age is unknown. Radiocarbon dates reported here show that the last glaciation was Late Weichselian and that the maximum northern extent was at least 50 km north of the islands. The concepts of an eastwards migrating ice shed and an early, extensive ice cap retreating to a grounding point, could have parallels elsewhere in Scotland during the last glaciation. The methodology applied in this study of Shetland - integrating onshore and offshore data, and developing a dynamic picture of the whole ice cap - needs to be applied to the last Scottish ice sheet also.
1997-06-01T00:00:00Z
Ross, Hamish
Evidence of the last glaciation of the Shetland Islands, UK, is re-examined and combined with new data on terrestrial glacigenic deposits and recent offshore data from the continental shelf to produce a dynamic, integrated model of the history of the whole ice cap. It is shown that evidence which has previously been attributed to last glacial, or earlier, Scandinavian ice incursion, might be explained by the eastwards migration of local ice sheds. At its maximum, the ice sheet reached the continental shelf edge to the west of the islands, at least 75 km east, at least 50 km north and might be seen as a peninsular extension of the Scottish ice sheet to the south. The changing patterns of ice flow during deglaciation are reconstructed, implying an early phase of deglaciation at the west and northwest margins (possibly accounting for the suggested eastern migration of the ice shed), followed by retreat at more northern, then eastern, then southern margins. It is suggested that the above pattern reflects tidewater calving controlled by bathymmetric variation around the ice sheet. During a later phase of deglaciation, the margin of the ice cap may have grounded at around the current -100m bathymmetric contour and from there retreated terrestrially. The importance of topographic control on patterns of deglaciation as ice retreated towards the island group is clearly established. Some minor moraines in parts of Shetland are due to active ice margins but their age is unknown. Radiocarbon dates reported here show that the last glaciation was Late Weichselian and that the maximum northern extent was at least 50 km north of the islands. The concepts of an eastwards migrating ice shed and an early, extensive ice cap retreating to a grounding point, could have parallels elsewhere in Scotland during the last glaciation. The methodology applied in this study of Shetland - integrating onshore and offshore data, and developing a dynamic picture of the whole ice cap - needs to be applied to the last Scottish ice sheet also.
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Computer simulation of sedimentation in meandering streams
https://hdl.handle.net/10023/15277
A dynamic mathematical model has been constructed for the computer simulation of sedimentation in free meandering streams. The system is defined in terms of form and process, and component mathematical models (with mainly deterministic, but also probabilistic, characteristics) are formulated for the prediction of the following aspects of the system for a given physical situation and a single time increment; (l) The characteristics of the plan form of free meanders; (2) The movement of meanders in plan, and definition of cross sections across the meander in which erosion and deposition are considered in detail; (3) The hydraulic properties of the channel and the erosional and depositional activity within the channel as defined in specific cross sections; (4) Whether neck or chute cut off will occur; (5) A relative measure of the discharge during seasonal high water periods, which s is used in (3) and (4); (5) Aggradation. The limitations, qualifications and validity of the component mathematical models are discussed during their development, as is the input required. The overall model has been translated into a FORTRAN IV computer program and a set of experiments with selected input parameters has been performed. The results and their implications are fully documented and compared qualitatively with recent and ancient fluviatile sedimentation. The shape of simulated pointbar sediments, as controlled by channel migration over floodplains of variable sediment type, agrees broadly with the natural situation. Sheet deposits cannot be simulated because large-scale meander-belt movements are not accounted for; this also inhibits generation of thick sequences of alluvial sediments. When channel, migration is combined with a constant aggradation rate the model predicts a general slope (relative to the land surface) of facies boundaries and scoured basal surfaces upward in the direction of channel movement. If aggradation sufficiently increases the thickness of fine grained overbank material, there is a channel stabilisation effect. Epsilon cross-stratification, which represents the shape of a pointbar surface before falling-stage deposition (lateral and vertical), may be picked out in the simulated sediments. The epsilon unit thickness is that measured from bankfull stage down to the lowest channel position existing prior to deposition. The model records the characteristic fining upwards of grain sizes in the pointbar, and the systematic distribution of sedimentary structures. Channel migration combined with seasonal scouring and filling across the channel produces a characteristic relief in the basal scoured surfaces and the grain size and sedimentary structure boundaries. A related lensing and inter- fingering of grain size and sedimentary structure facies may also be present. The model also records large-scale lateral changes in grain size and sedimentary structure associated with changes in the shape of developing meanders. It is shown that a complete sequence of pointbar sediments capped by overbank sediments would rarely be preserved in the moving-phase situation. Such preservation only becomes likely when an aggrading section lies out of range of an eroding channel for a considerably longer time span than it takes a meander to move one half-wavelength downvalley. Deep channel-scours have a higher preservation potential than contemporary shallower ones. Where appropriate field data exist the model can be used in the more accurate recognition of ancient fluviatile sediments. Inferences may be made about the erosion-deposition processes operating in the ancient channel system, and the geometry and hydraulics of the system can be alluded to. A representative application of the model to the quantitative interpretation of an ancient pointbar deposit is illustrated. There is reasonable agreement between the natural and the simulated deposits, and a broad quantitative picture of the palace environment of sedimentation is obtained.
1973-06-01T00:00:00Z
Bridge, John S.
A dynamic mathematical model has been constructed for the computer simulation of sedimentation in free meandering streams. The system is defined in terms of form and process, and component mathematical models (with mainly deterministic, but also probabilistic, characteristics) are formulated for the prediction of the following aspects of the system for a given physical situation and a single time increment; (l) The characteristics of the plan form of free meanders; (2) The movement of meanders in plan, and definition of cross sections across the meander in which erosion and deposition are considered in detail; (3) The hydraulic properties of the channel and the erosional and depositional activity within the channel as defined in specific cross sections; (4) Whether neck or chute cut off will occur; (5) A relative measure of the discharge during seasonal high water periods, which s is used in (3) and (4); (5) Aggradation. The limitations, qualifications and validity of the component mathematical models are discussed during their development, as is the input required. The overall model has been translated into a FORTRAN IV computer program and a set of experiments with selected input parameters has been performed. The results and their implications are fully documented and compared qualitatively with recent and ancient fluviatile sedimentation. The shape of simulated pointbar sediments, as controlled by channel migration over floodplains of variable sediment type, agrees broadly with the natural situation. Sheet deposits cannot be simulated because large-scale meander-belt movements are not accounted for; this also inhibits generation of thick sequences of alluvial sediments. When channel, migration is combined with a constant aggradation rate the model predicts a general slope (relative to the land surface) of facies boundaries and scoured basal surfaces upward in the direction of channel movement. If aggradation sufficiently increases the thickness of fine grained overbank material, there is a channel stabilisation effect. Epsilon cross-stratification, which represents the shape of a pointbar surface before falling-stage deposition (lateral and vertical), may be picked out in the simulated sediments. The epsilon unit thickness is that measured from bankfull stage down to the lowest channel position existing prior to deposition. The model records the characteristic fining upwards of grain sizes in the pointbar, and the systematic distribution of sedimentary structures. Channel migration combined with seasonal scouring and filling across the channel produces a characteristic relief in the basal scoured surfaces and the grain size and sedimentary structure boundaries. A related lensing and inter- fingering of grain size and sedimentary structure facies may also be present. The model also records large-scale lateral changes in grain size and sedimentary structure associated with changes in the shape of developing meanders. It is shown that a complete sequence of pointbar sediments capped by overbank sediments would rarely be preserved in the moving-phase situation. Such preservation only becomes likely when an aggrading section lies out of range of an eroding channel for a considerably longer time span than it takes a meander to move one half-wavelength downvalley. Deep channel-scours have a higher preservation potential than contemporary shallower ones. Where appropriate field data exist the model can be used in the more accurate recognition of ancient fluviatile sediments. Inferences may be made about the erosion-deposition processes operating in the ancient channel system, and the geometry and hydraulics of the system can be alluded to. A representative application of the model to the quantitative interpretation of an ancient pointbar deposit is illustrated. There is reasonable agreement between the natural and the simulated deposits, and a broad quantitative picture of the palace environment of sedimentation is obtained.
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The ordovician rocks of the Bail Hill area, Sanquhar, South Scotland : volcanism and sedimentation in the Iapetus Ocean
https://hdl.handle.net/10023/15275
The Ordovician rocks of the Bail Hill area, Sanquhar, South Scotland : volcanism and sedimentation in the lapetus Ocean. by M. J .McMurtry. The Bail Hill area lies in the "Northern Belt" of the Southern Uplands and contains sedimentary and volcanic rocks of Llandeilo/Caradoc age. The sedimentary succession has been divided into four formations - the Glenflosh, Kiln, Spothfore and Guffock Formations. The Glenflosh and Guffock Formations are mainly arenaceous and were largely deposited by turbidity currents flowing to the southwest. They typically consist of Tae units. The fine-grained sandstones and siltstones of the Kiln Formation were also deposited by turbidity currents. Parallel-laminated units in the lower part of the formation represent "overbank" deposits, whilst lenticular- bedded units in the upper part are interpreted as channel- mouth deposits. Bouma sequences are not common in these lithologies. The Spothfore Formation consists of rudites deposited by a variety of sediment and fluid gravity flows close to a feeder system. The petrography of greywackes within the formations shows no significant variation across strike, in contrast to successions studied to the southwest. The provenance of detritus in the sediments is believed to be the north-westerly Laurentian continent with a significant but variable intrabasinal contribution of sedimentary and volcanic debris. A stratigraphic succession for the area is proposed, although graptolite evidence for the relative ages of the formations is equivocal. A new stratigraphic unit, the Bail Hill Volcanic Group, is proposed and the petrography and field relations of the subdivisions within this group are discussed. Field relations suggest that the Bail Hill volcano was a composite, central-type structure. Early basaltic lavas were succeeded by more differentiated lithologies and pyroclastic activity increased with time. The mineral and whole-rock chemistry indicates the Bail Hill Volcanic Group has differentiated along the sodic alkaline series (alkali basalt - hawaiite - mugearite - trachyte). Gabbroic and dioritic xenoliths in the extrusive rocks are believed to be fragments of a large sub-volcanic intrusive mass that underlay the Bail Hill volcano in Ordovician times. The volcanic pile as a whole has undergone metamorphism to zeolite facies grade. Higher grade assemblages in the xenoliths suggest that they were hydrothermally altered prior to incorporation in the extrusive rocks. It is concluded that the Bail Hill Volcanic Group represents the remnants of a seamount within the Iapetus Ocean, whilst the sedimentary rocks record the transition from the abyssal plain into a Lower Palaeozoic trench. Northwesterly subduction of the lapetus Ocean crust resulted in the accretion of the Bail Hill area on to the facing edge of the northwesterly Laurentian continent.
1979-11-01T00:00:00Z
McMurtry, M. J.
The Ordovician rocks of the Bail Hill area, Sanquhar, South Scotland : volcanism and sedimentation in the lapetus Ocean. by M. J .McMurtry. The Bail Hill area lies in the "Northern Belt" of the Southern Uplands and contains sedimentary and volcanic rocks of Llandeilo/Caradoc age. The sedimentary succession has been divided into four formations - the Glenflosh, Kiln, Spothfore and Guffock Formations. The Glenflosh and Guffock Formations are mainly arenaceous and were largely deposited by turbidity currents flowing to the southwest. They typically consist of Tae units. The fine-grained sandstones and siltstones of the Kiln Formation were also deposited by turbidity currents. Parallel-laminated units in the lower part of the formation represent "overbank" deposits, whilst lenticular- bedded units in the upper part are interpreted as channel- mouth deposits. Bouma sequences are not common in these lithologies. The Spothfore Formation consists of rudites deposited by a variety of sediment and fluid gravity flows close to a feeder system. The petrography of greywackes within the formations shows no significant variation across strike, in contrast to successions studied to the southwest. The provenance of detritus in the sediments is believed to be the north-westerly Laurentian continent with a significant but variable intrabasinal contribution of sedimentary and volcanic debris. A stratigraphic succession for the area is proposed, although graptolite evidence for the relative ages of the formations is equivocal. A new stratigraphic unit, the Bail Hill Volcanic Group, is proposed and the petrography and field relations of the subdivisions within this group are discussed. Field relations suggest that the Bail Hill volcano was a composite, central-type structure. Early basaltic lavas were succeeded by more differentiated lithologies and pyroclastic activity increased with time. The mineral and whole-rock chemistry indicates the Bail Hill Volcanic Group has differentiated along the sodic alkaline series (alkali basalt - hawaiite - mugearite - trachyte). Gabbroic and dioritic xenoliths in the extrusive rocks are believed to be fragments of a large sub-volcanic intrusive mass that underlay the Bail Hill volcano in Ordovician times. The volcanic pile as a whole has undergone metamorphism to zeolite facies grade. Higher grade assemblages in the xenoliths suggest that they were hydrothermally altered prior to incorporation in the extrusive rocks. It is concluded that the Bail Hill Volcanic Group represents the remnants of a seamount within the Iapetus Ocean, whilst the sedimentary rocks record the transition from the abyssal plain into a Lower Palaeozoic trench. Northwesterly subduction of the lapetus Ocean crust resulted in the accretion of the Bail Hill area on to the facing edge of the northwesterly Laurentian continent.
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The evolution of layered, basic plutons - evidence from small-scale structures
https://hdl.handle.net/10023/15274
Many basic and ultrabasic plutons are commonly lithologically, texturally and compositionally layered on several scales. Associated with and defined by, the layering are a variety of small-scale structures, considered analogous to structures found in sedimentary rocks, and capable of interpretation using similar techniques. Observations on these small-scale structures are vised to infer the "depositional" and "diagenetic" processes that operated during the solidification of a number of' plutons. Erosion structures and structures associated with lithic fragments indicate that physical redistribution of solids, crystals and rock fragments, was an important process in the evolution of these bodies and that plagioclase was deposited at the floor even where it was less dense than the contemporary magma. From their relationships with lithic fragments normally graded layers are demonstrated to be the solidified remnants of crystal-laden density currents flowing across the transient floor of the magma chamber and are inferred to be the best approximation to truly chronostratigraphic horizons in layered plutons identified to date. The proposition that crystal- and rock-laden density currents can transport material vertically through the magma body is investigated experimentally by examining the nature of such flows in a small tank, Experiments and calculations indicate that such density currents straddle the range of conditions from laminar to fully turbulent. Laminar flows do not mix with the contemporary magma and will transport crystals to the transient chamber floor. It is suggested that such a process may have given rise to lensoid mafic layers of limited areal extent in the Kiglapait intrusion. Structures inferred to have formed during the "diagenetic" stage of the formation of the layered rocks include deformation structures, layers and replacement bodies. Examples of the latter two sets of structures are shown to have textures identical to those in rocks interpreted as cumulates and it is concluded that those textures alone are not sufficient basis on which to infer crystal growth from the contemporary magma. Many of the structures testify to the former presence of mobile pore liquids and the contemporaneity of pore liquids of different compositions. Movement of pore liquid is considered to have been driven by density differences due to variations in pore magma composition and thus the structures can be considered as evidence for interstitial compositional convection. Under certain circumstances pore liquids may be expelled from the crystal mush and mix with the contemporary magma. The chemical consequences of such mixing events are discussed and it is proposed that chromitite layers in the Eastern Layered Series of the Rum intrusion record the operation of the process. Several features of the Rum intrusion suggest that the magma chamber was thermally and compositionally zoned at times during its active history and this leads to the formulation of a new scheme for the formation of cyclic stratigraphy in the Rum layered intrusion, based on the progradation and regression of a liquid/liquid interface and two environments of accumulation.
1984-07-01T00:00:00Z
Young, Iain McKenzie
Many basic and ultrabasic plutons are commonly lithologically, texturally and compositionally layered on several scales. Associated with and defined by, the layering are a variety of small-scale structures, considered analogous to structures found in sedimentary rocks, and capable of interpretation using similar techniques. Observations on these small-scale structures are vised to infer the "depositional" and "diagenetic" processes that operated during the solidification of a number of' plutons. Erosion structures and structures associated with lithic fragments indicate that physical redistribution of solids, crystals and rock fragments, was an important process in the evolution of these bodies and that plagioclase was deposited at the floor even where it was less dense than the contemporary magma. From their relationships with lithic fragments normally graded layers are demonstrated to be the solidified remnants of crystal-laden density currents flowing across the transient floor of the magma chamber and are inferred to be the best approximation to truly chronostratigraphic horizons in layered plutons identified to date. The proposition that crystal- and rock-laden density currents can transport material vertically through the magma body is investigated experimentally by examining the nature of such flows in a small tank, Experiments and calculations indicate that such density currents straddle the range of conditions from laminar to fully turbulent. Laminar flows do not mix with the contemporary magma and will transport crystals to the transient chamber floor. It is suggested that such a process may have given rise to lensoid mafic layers of limited areal extent in the Kiglapait intrusion. Structures inferred to have formed during the "diagenetic" stage of the formation of the layered rocks include deformation structures, layers and replacement bodies. Examples of the latter two sets of structures are shown to have textures identical to those in rocks interpreted as cumulates and it is concluded that those textures alone are not sufficient basis on which to infer crystal growth from the contemporary magma. Many of the structures testify to the former presence of mobile pore liquids and the contemporaneity of pore liquids of different compositions. Movement of pore liquid is considered to have been driven by density differences due to variations in pore magma composition and thus the structures can be considered as evidence for interstitial compositional convection. Under certain circumstances pore liquids may be expelled from the crystal mush and mix with the contemporary magma. The chemical consequences of such mixing events are discussed and it is proposed that chromitite layers in the Eastern Layered Series of the Rum intrusion record the operation of the process. Several features of the Rum intrusion suggest that the magma chamber was thermally and compositionally zoned at times during its active history and this leads to the formulation of a new scheme for the formation of cyclic stratigraphy in the Rum layered intrusion, based on the progradation and regression of a liquid/liquid interface and two environments of accumulation.
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Some stratigraphical and sedimentological studies on the Devonian of the Trondheimsled, Norway
https://hdl.handle.net/10023/15273
The Devonian rocks considered here, outcrop over a distance of 100 kms., along the northern side of a strip of water, known as the Trondheimsled, near Trondheim, Norway. Since time did not permit complete examination, two areas were selected for detailed study: 1) the western end of the outcrop on the large island of Hitra, where fossils suggesting an Upper Silurian or Downtonian age had been found; and 2) the outcrops on the island complex south of the neighbouring island of Smola. The precise age of these beds was unknown. An attempt was made to establish the stratigraphy of both areas, and to deduce the environment of deposition, the nature of the source area, and the direction of derivation of the sediments. Hitra. The succession (1055 m. thick) has been divided into a number of stratigraphical units on the basis of lithology. Much of it is made up of thick sandstones, often pebbly or conglomeratic, and alternating sandstone/siltstone sequences. Study of the sedimentary structures and size distributions of these sequences suggests that the cycles have been produced in an inshore estuarine environment, as a result of the lateral migration of channels. The petrography of the sandstones and conglomerates shown thot the sediments were derived from a source area composed mainly of plutonic rocks, while current direction analysis shows derivation from the northwest. Smola: The Smola Series, composed of 3745 m. of conglomerate, has been divided petrographically into four units. The oldest conglomerate lies unconformably on the beds below and is made up of large boulders of locally derived material. The younger conglomerates are composed of abundant pebbles of green sandstone (possibly the Ordovician Hovin Sandstone), and various igneous and metamorphic PEBBLES which are difficult to match with rocks now exposed in Norway. The sediments wore derived from the north and were probably deposited in a piedmont environment. Relative age of the Hitra and Smola series Consideration of the stratigraphical, petrographical, and sedimentological evidence shows that the Hitra sediments are older than those Smola. A reconsideration of the paleontological evidence suggests that the Hitra beds could be of Upper Welockian or early Ludlovian age, while the Smola beds are probably Lower or Middle Devonian.
1965-01-01T00:00:00Z
Peacock, David Philip Spencer
The Devonian rocks considered here, outcrop over a distance of 100 kms., along the northern side of a strip of water, known as the Trondheimsled, near Trondheim, Norway. Since time did not permit complete examination, two areas were selected for detailed study: 1) the western end of the outcrop on the large island of Hitra, where fossils suggesting an Upper Silurian or Downtonian age had been found; and 2) the outcrops on the island complex south of the neighbouring island of Smola. The precise age of these beds was unknown. An attempt was made to establish the stratigraphy of both areas, and to deduce the environment of deposition, the nature of the source area, and the direction of derivation of the sediments. Hitra. The succession (1055 m. thick) has been divided into a number of stratigraphical units on the basis of lithology. Much of it is made up of thick sandstones, often pebbly or conglomeratic, and alternating sandstone/siltstone sequences. Study of the sedimentary structures and size distributions of these sequences suggests that the cycles have been produced in an inshore estuarine environment, as a result of the lateral migration of channels. The petrography of the sandstones and conglomerates shown thot the sediments were derived from a source area composed mainly of plutonic rocks, while current direction analysis shows derivation from the northwest. Smola: The Smola Series, composed of 3745 m. of conglomerate, has been divided petrographically into four units. The oldest conglomerate lies unconformably on the beds below and is made up of large boulders of locally derived material. The younger conglomerates are composed of abundant pebbles of green sandstone (possibly the Ordovician Hovin Sandstone), and various igneous and metamorphic PEBBLES which are difficult to match with rocks now exposed in Norway. The sediments wore derived from the north and were probably deposited in a piedmont environment. Relative age of the Hitra and Smola series Consideration of the stratigraphical, petrographical, and sedimentological evidence shows that the Hitra sediments are older than those Smola. A reconsideration of the paleontological evidence suggests that the Hitra beds could be of Upper Welockian or early Ludlovian age, while the Smola beds are probably Lower or Middle Devonian.
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The seismic investigation of Loch Lomond readvance glacier limits : evidence from Scottish lochs
https://hdl.handle.net/10023/15272
This study presents a comparative examination of three lochs, located in the S.E. Grampian Highlands, using seismic reflection survey techniques. Lochs Callater, Muick and Lee, lying inside, across and outside probable Loch Lomond Readvance glacier limits respectively, were surveyed using echosounder (200kHz), Pinger (3.5kHz) seismic subbottom profiling, and sidescan sonar equipment. Calibration of seismic records was achieved through analysis of core and surface sediment samples. Geomorphological maps of the subaerial topography were drawn. Construction of bathymetric charts of the lochs reveals significant subaqueous topographic variation. The Loch Muick trough contains numerous mounds and hollows, and is crossed by a series of broken ridges, extending up the basin sides. Pinger profiling indicates that these subaqueous landforms are composed of glacial diamict (Sequence 2, Facies 2.1) overlain by draped sediments (Sequence 1). Additional ridges, buried beneath glacigenic outwash (Facies 2.2), are recognised 1.4km beyond the subaerial margin. It is suggested that the ridges are sublacustrine moraines. Analysis of core material suggests formation of these features during the Loch Lomond Readvance. Two sequences are recognised in Loch Callater; lacustrine sediment, and glacial diamict. Analyses of core sediment suggest respective Holocene and Loch Lomond Stadial ages of the sequences. Pollen analysis indicates that ice may have remained in Glen Callater into the Ninth Millenium. Within Loch Lee, below Sequence 1 (Holocene lacustrine sediment), the Loch Lomond Stadial is represented by glacigenic outwash (Sequence 2, Facies 2.1) and nearshore avalanche detritus (Facies 2.2). Sequence 3 is composed of outwash (Facies 3.2) and glacigenic diamict (Facies 3.1), of proposed Devensian age. The seismic signatures of the loch sediments are assimilated as a model. It is important that the limits of glaciation in the lacustrine environment be examined as extensively as those in the subaerial environment, to provide an accurate database against which models of climatic change can be tested.
1993-07-01T00:00:00Z
Lowe, Philippa A.
This study presents a comparative examination of three lochs, located in the S.E. Grampian Highlands, using seismic reflection survey techniques. Lochs Callater, Muick and Lee, lying inside, across and outside probable Loch Lomond Readvance glacier limits respectively, were surveyed using echosounder (200kHz), Pinger (3.5kHz) seismic subbottom profiling, and sidescan sonar equipment. Calibration of seismic records was achieved through analysis of core and surface sediment samples. Geomorphological maps of the subaerial topography were drawn. Construction of bathymetric charts of the lochs reveals significant subaqueous topographic variation. The Loch Muick trough contains numerous mounds and hollows, and is crossed by a series of broken ridges, extending up the basin sides. Pinger profiling indicates that these subaqueous landforms are composed of glacial diamict (Sequence 2, Facies 2.1) overlain by draped sediments (Sequence 1). Additional ridges, buried beneath glacigenic outwash (Facies 2.2), are recognised 1.4km beyond the subaerial margin. It is suggested that the ridges are sublacustrine moraines. Analysis of core material suggests formation of these features during the Loch Lomond Readvance. Two sequences are recognised in Loch Callater; lacustrine sediment, and glacial diamict. Analyses of core sediment suggest respective Holocene and Loch Lomond Stadial ages of the sequences. Pollen analysis indicates that ice may have remained in Glen Callater into the Ninth Millenium. Within Loch Lee, below Sequence 1 (Holocene lacustrine sediment), the Loch Lomond Stadial is represented by glacigenic outwash (Sequence 2, Facies 2.1) and nearshore avalanche detritus (Facies 2.2). Sequence 3 is composed of outwash (Facies 3.2) and glacigenic diamict (Facies 3.1), of proposed Devensian age. The seismic signatures of the loch sediments are assimilated as a model. It is important that the limits of glaciation in the lacustrine environment be examined as extensively as those in the subaerial environment, to provide an accurate database against which models of climatic change can be tested.
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The use of high resolution geophysics for the investigation of submerged palaeo-glaciomarine environments
https://hdl.handle.net/10023/15271
A multi-disciplinary, high resolution, geophysical investigation of a Scottish Sea loch has facilitated both the reconstruction of a detailed late Quaternary para-stratigraphic model and the critical assessment of the acquisition and analytical methodologies most appropriate for the study of submerged palaeo-glaciomarine environments. Loch Ainort, situated on the eastern coast of the Isle of Skye, has been surveyed using a 192 kHz echosounder, a 400 kHz side scan sonar and a 3.5 kHz sub-bottom profiler. Lithological calibration was provided by the analysis of both in situ core data and extant terrestrial data sets. It is proposed that for the effective reconstruction of these and any other nearshore palaeo-environments a multi-disciplinary geophysical approach is essential. The critical control on success is the adherence, during interpretation, to a single unifying seismo-analytical framework. The seismo-stratigraphical analysis technique has been adapted for high- resolution work in order to provide this rigid framework. Objective descriptive analysis of the seismic traces provides a "seismic para-stratigraphy" which when combined with lithological data is used to construct a "composite para-stratigraphy". This is a process based, litho-stratigraphic interpretation that, by virtue of the detailed spatial extent afforded it by geophysical data, can be placed in a wider environmental context. The composite para-stratigraphy for the Loch Ainort basin is dominated by Loch Lomond Stadial glacial activity. Terminal and readvance limits are identified at several localities within the basin. Variable morphological styles of the glacial sequences show that deglaciation occurred in two distinct, climatically controlled, phases. The first marked by a fluctuating ice margin and the second by uninterrupted retreat and in situ ice stagnation. Sub-aerially induced debris flows occur during the initial paraglacial phase but stabilisation of exposed slopes restricts this input and rapid sedimentation of fines from sediment-rich meltwaters becomes dominant. Modern fjordic sedimentation develops after the disappearance of glacier ice.
1996-07-01T00:00:00Z
Dix, Justin K.
A multi-disciplinary, high resolution, geophysical investigation of a Scottish Sea loch has facilitated both the reconstruction of a detailed late Quaternary para-stratigraphic model and the critical assessment of the acquisition and analytical methodologies most appropriate for the study of submerged palaeo-glaciomarine environments. Loch Ainort, situated on the eastern coast of the Isle of Skye, has been surveyed using a 192 kHz echosounder, a 400 kHz side scan sonar and a 3.5 kHz sub-bottom profiler. Lithological calibration was provided by the analysis of both in situ core data and extant terrestrial data sets. It is proposed that for the effective reconstruction of these and any other nearshore palaeo-environments a multi-disciplinary geophysical approach is essential. The critical control on success is the adherence, during interpretation, to a single unifying seismo-analytical framework. The seismo-stratigraphical analysis technique has been adapted for high- resolution work in order to provide this rigid framework. Objective descriptive analysis of the seismic traces provides a "seismic para-stratigraphy" which when combined with lithological data is used to construct a "composite para-stratigraphy". This is a process based, litho-stratigraphic interpretation that, by virtue of the detailed spatial extent afforded it by geophysical data, can be placed in a wider environmental context. The composite para-stratigraphy for the Loch Ainort basin is dominated by Loch Lomond Stadial glacial activity. Terminal and readvance limits are identified at several localities within the basin. Variable morphological styles of the glacial sequences show that deglaciation occurred in two distinct, climatically controlled, phases. The first marked by a fluctuating ice margin and the second by uninterrupted retreat and in situ ice stagnation. Sub-aerially induced debris flows occur during the initial paraglacial phase but stabilisation of exposed slopes restricts this input and rapid sedimentation of fines from sediment-rich meltwaters becomes dominant. Modern fjordic sedimentation develops after the disappearance of glacier ice.
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Relative sea-level change in Bangladesh during the Holocene.
https://hdl.handle.net/10023/15244
The thesis aims to reconstruct the Holocene sea-level history in Bangladesh. Detailed litho-, bio-, and chrono-stratigraphic techniques have been applied to elucidate the nature of sedimentary sequences in association with the events of the Holocene marine transgressions and regressions. Samples have been collected from two separate sites, one at Panigati near Khulna and another at Matuail near Dhaka. The study shows evidence of five periods of marine transgression, each followed by a regression, during the Holocene. Each minerogenic sediment layer indicates a marine episode and these sediments were deposited under intertidal to estuarine conditions; each peat layer is in situ and indicates a retreat of the sea. It is difficult to separate the eustatic components contributing to these relative sea-level movements, although processes operating locally and regionally are clearly evident. Two separate sea-level curves, together with possible error ranges, have been proposed for Bangladesh; since the early mid-Holocene, an average relative sea-level rise of 1.07 mm. yr -1 has been estimated. The reconstructed sea-level curves show that during the early and mid-Holocene both sedimentation and subsidence rates were much lower than during the last millennium. Differential spatio-temporal progradation and coastline movements have also been evident. The Ganges and Brahmaputra rivers have provided a continuous sediment supply but their convergence is only of recent origin. A possible hypothesis of two separate estuarine systems for these two rivers has been put forward.
1997-01-01T00:00:00Z
Islam, M. Shahidul
The thesis aims to reconstruct the Holocene sea-level history in Bangladesh. Detailed litho-, bio-, and chrono-stratigraphic techniques have been applied to elucidate the nature of sedimentary sequences in association with the events of the Holocene marine transgressions and regressions. Samples have been collected from two separate sites, one at Panigati near Khulna and another at Matuail near Dhaka. The study shows evidence of five periods of marine transgression, each followed by a regression, during the Holocene. Each minerogenic sediment layer indicates a marine episode and these sediments were deposited under intertidal to estuarine conditions; each peat layer is in situ and indicates a retreat of the sea. It is difficult to separate the eustatic components contributing to these relative sea-level movements, although processes operating locally and regionally are clearly evident. Two separate sea-level curves, together with possible error ranges, have been proposed for Bangladesh; since the early mid-Holocene, an average relative sea-level rise of 1.07 mm. yr -1 has been estimated. The reconstructed sea-level curves show that during the early and mid-Holocene both sedimentation and subsidence rates were much lower than during the last millennium. Differential spatio-temporal progradation and coastline movements have also been evident. The Ganges and Brahmaputra rivers have provided a continuous sediment supply but their convergence is only of recent origin. A possible hypothesis of two separate estuarine systems for these two rivers has been put forward.
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A heuristic approach to the evaluation of seafloor bathymetric changes : a case study of Dundee Harbour, Eastern Scotland
https://hdl.handle.net/10023/15213
The phenomena of seabed bathymetric changes in Dundee harbour, eastern Scotland have been investigated, by use of archive bathymetric data. The bathymetric data were available from the Dundee Port Authority, from its past annual harbour maintenance programmes during the period of 1989 to 1993. Archive bathymetric data are seen as under-utilised, after being used for their intended purposes. A methodology was therefore developed to use sequential bathymetric data to estimate the deposition and erosion of sediment over a period of time. This is in the form of a systematic procedure of processing for comparison of data from different dates. The comparison or differencing of bathymetric data in their original form cannot be directly applied. This would require each data point to be located at spatially common positions (i.e. grid points) and could be achieved only through interpolation. A procedure known as 'gridding' is instead used to prepare depths at the spatially fixed points or nodes. Six different methods of interpolation have been examined and trial computations using a common data subset for each individual method conducted. The results of the interpolation were often substantially different from one method to another. A technique known as the Blending Interpolation Technique is proposed to overcome the uncertainty in depth interpolation. Computer programs were specifically written for this study and for the visualisation of the phenomena of deposition and erosion, use was made of the available UNIRAS software package. The methodology and procedures of this study are not only applicable for an estuarine harbour environment, but are also equally applicable to any areas such as large reservoirs, lakes or coastal ports and harbours, that are continuously affected by the phenomena of sedimentation and erosion, where their estimation and quantification are of critical importance. This study, however, has demonstrated the usefulness of the Blending Interpolation Technique which is seen as a future tool to detect, monitor and quantify seabed changes, in particular where bathymetric data of the same area are available from different dates. It also serves to prolong the usefulness of archive bathymetric data kept for an area.
1997-01-01T00:00:00Z
Zin, Harun Shah Bin Mat
The phenomena of seabed bathymetric changes in Dundee harbour, eastern Scotland have been investigated, by use of archive bathymetric data. The bathymetric data were available from the Dundee Port Authority, from its past annual harbour maintenance programmes during the period of 1989 to 1993. Archive bathymetric data are seen as under-utilised, after being used for their intended purposes. A methodology was therefore developed to use sequential bathymetric data to estimate the deposition and erosion of sediment over a period of time. This is in the form of a systematic procedure of processing for comparison of data from different dates. The comparison or differencing of bathymetric data in their original form cannot be directly applied. This would require each data point to be located at spatially common positions (i.e. grid points) and could be achieved only through interpolation. A procedure known as 'gridding' is instead used to prepare depths at the spatially fixed points or nodes. Six different methods of interpolation have been examined and trial computations using a common data subset for each individual method conducted. The results of the interpolation were often substantially different from one method to another. A technique known as the Blending Interpolation Technique is proposed to overcome the uncertainty in depth interpolation. Computer programs were specifically written for this study and for the visualisation of the phenomena of deposition and erosion, use was made of the available UNIRAS software package. The methodology and procedures of this study are not only applicable for an estuarine harbour environment, but are also equally applicable to any areas such as large reservoirs, lakes or coastal ports and harbours, that are continuously affected by the phenomena of sedimentation and erosion, where their estimation and quantification are of critical importance. This study, however, has demonstrated the usefulness of the Blending Interpolation Technique which is seen as a future tool to detect, monitor and quantify seabed changes, in particular where bathymetric data of the same area are available from different dates. It also serves to prolong the usefulness of archive bathymetric data kept for an area.
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Water resources of wadi systems of Southern Saudi Arabia
https://hdl.handle.net/10023/15212
This study is a water resources assessment of two wadi systems in the southern Arabian Shield using seismic refraction, electrical resistivity (VES) and borehole geophysical techniques, pumping tests and ground water quality data and an examination of artificial recharge. Wadi Baysh (flowing southwest to the Red Sea) and Wadi Habawnah (flowing east to the Rub Al Khali) have similar catchment areas (approximately 10000 km2) and are underlain by igneous and metamorphic rocks but contrast in their hydrological cycles. The mean annual rainfall of Wadi Baysh is 350 mm while Wadi Habawnah receives 150 mm. The mean annual water discharges of Wadi Baysh and Wadi Habawnah are 75 and 10 mcm respectively. Hydrochemical classification, evolution of groundwater and its suitability for agricultural and domestic usage were studied in both wadis. In the upper and middle parts of both wadis the solute concentrations reach 1200 mg/l whereas in the lower parts solute concentrations range between 2000 and 3500 mg/l. Both wadis show high average values of transmissivity and storativity determined from pumping tests and grain size analysis. The geophysical surveys confirmed that the unconfined aquifer thickness is less than 42 m in both wadis. The seismic velocities of the aquifers range between 536 and 1817 ms-1 while the resistivities range between 23 and 125 ohm-m in both wadis. The igneous and metamorphic bedrock resistivity range between 3400 and 10260 ohm-m. The sediment has a high potential for water supply in the middle and lower parts of both wadis. The transverse resistance of the saturated part of the aquifers is used for correlation with the hydraulic transmissivity in which a computed empirical function may be applicable to similar aquifers in other Arabian Shield wadis. This study introduces a plan for the surface and subsurface storage that should help to manage the perennial yield and minimise the mining yield. The analysis reveals that building small reservoirs in both wadis is economically justifiable.
1996-01-01T00:00:00Z
Bajabaa, Saleh A. S.
This study is a water resources assessment of two wadi systems in the southern Arabian Shield using seismic refraction, electrical resistivity (VES) and borehole geophysical techniques, pumping tests and ground water quality data and an examination of artificial recharge. Wadi Baysh (flowing southwest to the Red Sea) and Wadi Habawnah (flowing east to the Rub Al Khali) have similar catchment areas (approximately 10000 km2) and are underlain by igneous and metamorphic rocks but contrast in their hydrological cycles. The mean annual rainfall of Wadi Baysh is 350 mm while Wadi Habawnah receives 150 mm. The mean annual water discharges of Wadi Baysh and Wadi Habawnah are 75 and 10 mcm respectively. Hydrochemical classification, evolution of groundwater and its suitability for agricultural and domestic usage were studied in both wadis. In the upper and middle parts of both wadis the solute concentrations reach 1200 mg/l whereas in the lower parts solute concentrations range between 2000 and 3500 mg/l. Both wadis show high average values of transmissivity and storativity determined from pumping tests and grain size analysis. The geophysical surveys confirmed that the unconfined aquifer thickness is less than 42 m in both wadis. The seismic velocities of the aquifers range between 536 and 1817 ms-1 while the resistivities range between 23 and 125 ohm-m in both wadis. The igneous and metamorphic bedrock resistivity range between 3400 and 10260 ohm-m. The sediment has a high potential for water supply in the middle and lower parts of both wadis. The transverse resistance of the saturated part of the aquifers is used for correlation with the hydraulic transmissivity in which a computed empirical function may be applicable to similar aquifers in other Arabian Shield wadis. This study introduces a plan for the surface and subsurface storage that should help to manage the perennial yield and minimise the mining yield. The analysis reveals that building small reservoirs in both wadis is economically justifiable.
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Atmospheric deposition, afforestation and water quality at Loch Dee, S.W. Scotland
https://hdl.handle.net/10023/15210
This work describes an investigation of the factors governing the water quality in three upland streams at Loch Dee, S.W Scotland. Particular emphasis is placed on the factors affecting streamwater acidification in the short and medium time scales. The streams are differentiated from one another by the land-use employed in each of the stream catchments. The details of both the site and methods of data collection are described. Variations in both bulk precipitation and streamwater chemistry are examined at the weekly scale in order to determine the factors regulating streamwater chemistry. The 5 factors are; atmospheric deposition, weathering rates, biological production and consumption, ion-exchange and catchment hydrology. A more detailed examination of one of the processes (ion-exchange) is undertaken at both the catchment and laboratory scale. The data show that short-term streamwater acidification can be induced by ion-exchange of H+ for Na+ in the catchment soils following precipitation inputs heavily laden with sea-silts. The role of hydrology in determining streamwater acidity over storm periods is also considered using a time-series model. The model indicates that significant differences exist between the 3 catchments hydrology in terms of the duration and timing of acidic episodes in the streams.
1986-01-01T00:00:00Z
Langan, Simon Johnathon
This work describes an investigation of the factors governing the water quality in three upland streams at Loch Dee, S.W Scotland. Particular emphasis is placed on the factors affecting streamwater acidification in the short and medium time scales. The streams are differentiated from one another by the land-use employed in each of the stream catchments. The details of both the site and methods of data collection are described. Variations in both bulk precipitation and streamwater chemistry are examined at the weekly scale in order to determine the factors regulating streamwater chemistry. The 5 factors are; atmospheric deposition, weathering rates, biological production and consumption, ion-exchange and catchment hydrology. A more detailed examination of one of the processes (ion-exchange) is undertaken at both the catchment and laboratory scale. The data show that short-term streamwater acidification can be induced by ion-exchange of H+ for Na+ in the catchment soils following precipitation inputs heavily laden with sea-silts. The role of hydrology in determining streamwater acidity over storm periods is also considered using a time-series model. The model indicates that significant differences exist between the 3 catchments hydrology in terms of the duration and timing of acidic episodes in the streams.
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Modelling the impact of acid deposition on the hydrochemistry of the Loch Dee catchments, S.W. Scotland
https://hdl.handle.net/10023/15208
This work describes an investigation into the impact of acid deposition on the hydrochemistry of the three main tributary catchments at Loch Dee in Southwest Scotland. The research covers two main objectives. First, the hydrochemical processes that determine the observed streamwater chemistry are examined empirically through the determination of the hydrochemical budgets for each sub-catchment. Second, the ability of the Integrated Lake Watershed Acidification Study model (ILWAS) to simulate the observed hydrochemical processes is evaluated. From the hydrochemical budgets two major factors are identified as responsible for the spatial variability in the streamwater chemistry at Loch Dee. These factors are the underlying geology and land-use management techniques. The role of afforestation is difficult to judge due to the immaturity of the forest. However, the budgets indicate that any influence is a result of the pre-afforestation ploughing and drainage rather than the presence of the trees. On a temporal basis the hydrochemical budgets show considerable variability on both a monthly and an annual timescale, with the variability in the streamwater outputs of bases and nutrients primarily related to the variability in precipitation quantity. The budgets also indicate that, particularly on an annual timescale, the dry deposition of sulphate and hence of acidity to the catchment varies considerably. Furthermore, on a monthly timescale, the temporal variation in the budgets indicates that the conservative ion chloride can be physically stored within the catchments. This finding has severe implications for the estimation of dry deposition inputs and for the utilisation of simple hydrochemical models. The ILWAS model is generally able to simulate the hydrological response of both catchments. However, the chemical simulations of both catchments are considerably smoothed and bear little resemblance to the observed data. This failure is ascribed to the large number of input variables for which site-specific data are not available, together with the use of monthly averaged precipitation quality to drive the model. Sensitivity analysis of the model indicates that the most critical input variables are the soil depth and soil solution chemistry, and that the majority of the input variables can be considered as calibration parameters. Given the subsequent large number of calibration parameters it is suggested that a unique calibration of the model will rarely be possible. Consequently, it is concluded that the primary use of the ILWAS model will be as an explanatory tool for examining conceptual ideas about the hydrochemical processes that determine acidification. The model's value as a management tool to help mitigate the effects of anthropogenically derived changes in surface water chemistry will be extremely limited.
1989-01-01T00:00:00Z
Farley, David Allan
This work describes an investigation into the impact of acid deposition on the hydrochemistry of the three main tributary catchments at Loch Dee in Southwest Scotland. The research covers two main objectives. First, the hydrochemical processes that determine the observed streamwater chemistry are examined empirically through the determination of the hydrochemical budgets for each sub-catchment. Second, the ability of the Integrated Lake Watershed Acidification Study model (ILWAS) to simulate the observed hydrochemical processes is evaluated. From the hydrochemical budgets two major factors are identified as responsible for the spatial variability in the streamwater chemistry at Loch Dee. These factors are the underlying geology and land-use management techniques. The role of afforestation is difficult to judge due to the immaturity of the forest. However, the budgets indicate that any influence is a result of the pre-afforestation ploughing and drainage rather than the presence of the trees. On a temporal basis the hydrochemical budgets show considerable variability on both a monthly and an annual timescale, with the variability in the streamwater outputs of bases and nutrients primarily related to the variability in precipitation quantity. The budgets also indicate that, particularly on an annual timescale, the dry deposition of sulphate and hence of acidity to the catchment varies considerably. Furthermore, on a monthly timescale, the temporal variation in the budgets indicates that the conservative ion chloride can be physically stored within the catchments. This finding has severe implications for the estimation of dry deposition inputs and for the utilisation of simple hydrochemical models. The ILWAS model is generally able to simulate the hydrological response of both catchments. However, the chemical simulations of both catchments are considerably smoothed and bear little resemblance to the observed data. This failure is ascribed to the large number of input variables for which site-specific data are not available, together with the use of monthly averaged precipitation quality to drive the model. Sensitivity analysis of the model indicates that the most critical input variables are the soil depth and soil solution chemistry, and that the majority of the input variables can be considered as calibration parameters. Given the subsequent large number of calibration parameters it is suggested that a unique calibration of the model will rarely be possible. Consequently, it is concluded that the primary use of the ILWAS model will be as an explanatory tool for examining conceptual ideas about the hydrochemical processes that determine acidification. The model's value as a management tool to help mitigate the effects of anthropogenically derived changes in surface water chemistry will be extremely limited.
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The structure and evolution of relict talus accumulations in the Scottish Highlands
https://hdl.handle.net/10023/15206
The aim of this thesis is to establish the evolutionary history of relict talus accumulations in the Scottish Highlands through study of their distribution, morphology, structure and sedimentology, and through dating and pollen analysis of buried soil horizons. Analyses of talus morphology demonstrates that though the investigated slopes comprise a basal concavity and upper straight slope, features hitherto interpreted as characteristic of unmodified rockfall accumulations, there is considerable variability in upper slope gradient. Surface relief indicates widespread reworking by slope failure, gullying and debris flows. Sections through gully-side exposures exhibit up to 3.5 m of stacked debris flow deposits, wash layers and buried soils overlying rockfall deposits, indicating a complex history of sediment reworking. Sedimentological analyses indicate that 27-30% of the talus sediments at one site (Trottemish) comprise fine (< 2 mm) particles representing granular weathering of the rockwall and syndepositional accumulation of both fine and coarse debris. The volume of talus on Trottemish implies an average rockwall retreat rate of c. 0.3 mm yr-1 since deglaciation, of which 0.08-0.09 mm yr-1 reflects granular weathering rather than rockfall. Failure and reworking of talus is inferred to reflect reduced infiltration rates (and high porewater pressures during rainstorms) caused by progressive accumulation of fines. Radiocarbon dating of buried soils indicates that reworking commenced prior to c. 6 cal ka BP, and has been intermittently active during the Holocene. Pollen analyses and charcoal concentration counts provide no evidence for accelerated reworking as a result of anthropogenic interference with vegetation cover, but the timing of reworking events provides support for enhanced activity associated with climatic deterioration after c. 2.7-2.3 cal ka BP. The characteristics of the investigated slopes show that models that treat talus as a free-draining accumulation of rockfall debris have limited applicability, and an alternative model that incorporates progressive reworking by other processes is proposed.
1998-01-01T00:00:00Z
Hinchliffe, Simon
The aim of this thesis is to establish the evolutionary history of relict talus accumulations in the Scottish Highlands through study of their distribution, morphology, structure and sedimentology, and through dating and pollen analysis of buried soil horizons. Analyses of talus morphology demonstrates that though the investigated slopes comprise a basal concavity and upper straight slope, features hitherto interpreted as characteristic of unmodified rockfall accumulations, there is considerable variability in upper slope gradient. Surface relief indicates widespread reworking by slope failure, gullying and debris flows. Sections through gully-side exposures exhibit up to 3.5 m of stacked debris flow deposits, wash layers and buried soils overlying rockfall deposits, indicating a complex history of sediment reworking. Sedimentological analyses indicate that 27-30% of the talus sediments at one site (Trottemish) comprise fine (< 2 mm) particles representing granular weathering of the rockwall and syndepositional accumulation of both fine and coarse debris. The volume of talus on Trottemish implies an average rockwall retreat rate of c. 0.3 mm yr-1 since deglaciation, of which 0.08-0.09 mm yr-1 reflects granular weathering rather than rockfall. Failure and reworking of talus is inferred to reflect reduced infiltration rates (and high porewater pressures during rainstorms) caused by progressive accumulation of fines. Radiocarbon dating of buried soils indicates that reworking commenced prior to c. 6 cal ka BP, and has been intermittently active during the Holocene. Pollen analyses and charcoal concentration counts provide no evidence for accelerated reworking as a result of anthropogenic interference with vegetation cover, but the timing of reworking events provides support for enhanced activity associated with climatic deterioration after c. 2.7-2.3 cal ka BP. The characteristics of the investigated slopes show that models that treat talus as a free-draining accumulation of rockfall debris have limited applicability, and an alternative model that incorporates progressive reworking by other processes is proposed.
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Temporal variability of flooding in Scottish rivers
https://hdl.handle.net/10023/15203
Over fifty peaks-over-threshold flood records from across Scotland are analysed for temporal and spatial variability over two standard periods, 1954-92 and 1964-1992, using a number of time series statistical techniques. The results of this analysis demonstrate both clear temporal and spatial patterns in the frequency and magnitude of floods. The period 1964-73 is characterised by decreasing flood frequencies, with the early 1970s standing out as being "flood poor", particularly in the eastern regions of Scotland, whilst the 1950s and more recently, the late 1980s and early 1990s can be characterised as "flood rich". A broadly similar pattern is evident in many flood magnitude series. The influence of climatic variability upon flood records is also examined over the same periods of time, using a regional synoptic classification of daily weather types. The Westerly, Cyclonic and South-Westerly weather types are identified as important mechanisms in initiating Scottish flood events. These weather types also show a strong link with catchment location, with the Westerly type being important in the more westerly catchments, the South-Westerly type being important in the south-west and west whilst flood events in the more eastern catchments are often associated with the incidence of the Cyclonic weather type. The annual frequencies of these three key weather types also show clear patterns of temporal variability. However, a seasonal split of weather type frequencies also reveals some contrasting seasonal trends which are masked within the amalgamated annual series. The most dramatic variability is evident within the time series of the South-Westerly weather type, where frequencies have been increasing steadily since the mid 1970s in all seasons. Recent increases in the incidence of the most frequently occurring weather type - the Westerly - appear to be confined to the winter months (December to February). The relationship between temporal variability within flood series and the climate are tentatively explored through a simple comparison exercise using the two sets of time series plots, linked by information obtained on trigger weather types and dominant seasons of flooding. This process suggests that the relationship between flood series and the climate is a complex one which cannot be adequately explained using the results of this research. More likely other factors, such as precipitation variability, need to be introduced into the equation before a more complete picture is acquired. The possible consequences of the variability detected within flood series are highlighted with reference to flood frequency analysis, a technique which makes the assumption that flood records, and ultimately climatic records, are stationary through time. By splitting individual flood records into hydrologically similar sub-periods, it is revealed that frequency-magnitude relationships may vary considerably, depending upon the period of record used. It is recommended that, in future, hydrologists consider splitting flood series (into hydrologically similar sub-periods or in terms of the weather types linked to each flood) in order to examine the range of frequency-magnitude relationships which exist.
1997-01-01T00:00:00Z
Grew, Helen Louise
Over fifty peaks-over-threshold flood records from across Scotland are analysed for temporal and spatial variability over two standard periods, 1954-92 and 1964-1992, using a number of time series statistical techniques. The results of this analysis demonstrate both clear temporal and spatial patterns in the frequency and magnitude of floods. The period 1964-73 is characterised by decreasing flood frequencies, with the early 1970s standing out as being "flood poor", particularly in the eastern regions of Scotland, whilst the 1950s and more recently, the late 1980s and early 1990s can be characterised as "flood rich". A broadly similar pattern is evident in many flood magnitude series. The influence of climatic variability upon flood records is also examined over the same periods of time, using a regional synoptic classification of daily weather types. The Westerly, Cyclonic and South-Westerly weather types are identified as important mechanisms in initiating Scottish flood events. These weather types also show a strong link with catchment location, with the Westerly type being important in the more westerly catchments, the South-Westerly type being important in the south-west and west whilst flood events in the more eastern catchments are often associated with the incidence of the Cyclonic weather type. The annual frequencies of these three key weather types also show clear patterns of temporal variability. However, a seasonal split of weather type frequencies also reveals some contrasting seasonal trends which are masked within the amalgamated annual series. The most dramatic variability is evident within the time series of the South-Westerly weather type, where frequencies have been increasing steadily since the mid 1970s in all seasons. Recent increases in the incidence of the most frequently occurring weather type - the Westerly - appear to be confined to the winter months (December to February). The relationship between temporal variability within flood series and the climate are tentatively explored through a simple comparison exercise using the two sets of time series plots, linked by information obtained on trigger weather types and dominant seasons of flooding. This process suggests that the relationship between flood series and the climate is a complex one which cannot be adequately explained using the results of this research. More likely other factors, such as precipitation variability, need to be introduced into the equation before a more complete picture is acquired. The possible consequences of the variability detected within flood series are highlighted with reference to flood frequency analysis, a technique which makes the assumption that flood records, and ultimately climatic records, are stationary through time. By splitting individual flood records into hydrologically similar sub-periods, it is revealed that frequency-magnitude relationships may vary considerably, depending upon the period of record used. It is recommended that, in future, hydrologists consider splitting flood series (into hydrologically similar sub-periods or in terms of the weather types linked to each flood) in order to examine the range of frequency-magnitude relationships which exist.
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Seasonality of flooding in Scottish rivers
https://hdl.handle.net/10023/15201
The study considers the seasonal distribution of non-tidal peak flows on a large number of rivers draining varied catchments across Scotland and Northumberland. Peaks over threshold (POT) flood series from 156 gauging stations are used, and are subject to two quality control measures. Firstly, threshold values are standardised to give 45 peaks over a ten year period and secondly, records are adjusted to compensate for non-stationarity in the sampled data. The database assembled consists of 3458 station-years of record. A comprehensive description of the seasonal patterns found is presented, based on these quality-controlled data and utilising a number of methods of characterisation. Directional statistics are employed to indicate the central tendency of time-of-year values for each station, a six-season analysis gives more detailed information, and the seasonality of large peaks is compared with that of full POT series. Finally, a classification analysis is used to summarise these patterns. These patterns are related to five catchment characteristics: the seasonality of rainstorms; soil moisture deficit lengths; catchment size; lake storage and snowmelt, although the effect of the last of these is unclear as suitable data were not available for analysis. A discriminant analysis is employed to relate the five physical factors to flood seasonality. The study concludes with a discussion on the implications of its findings. A method of assessing seasonal flood risk using POT series is presented, offering an accurate means of relating flood magnitude to recurrence interval for any period of less than one year. The implications of seasonal heterogeneity, both within and between flood records, are also discussed. The suitability of the exponential model for use with POT records is questioned and it is suggested that explicit recognition of the seasonality of flooding may be necessary in order to make accurate design flood estimates.
1993-01-01T00:00:00Z
Black, Andrew Roger
The study considers the seasonal distribution of non-tidal peak flows on a large number of rivers draining varied catchments across Scotland and Northumberland. Peaks over threshold (POT) flood series from 156 gauging stations are used, and are subject to two quality control measures. Firstly, threshold values are standardised to give 45 peaks over a ten year period and secondly, records are adjusted to compensate for non-stationarity in the sampled data. The database assembled consists of 3458 station-years of record. A comprehensive description of the seasonal patterns found is presented, based on these quality-controlled data and utilising a number of methods of characterisation. Directional statistics are employed to indicate the central tendency of time-of-year values for each station, a six-season analysis gives more detailed information, and the seasonality of large peaks is compared with that of full POT series. Finally, a classification analysis is used to summarise these patterns. These patterns are related to five catchment characteristics: the seasonality of rainstorms; soil moisture deficit lengths; catchment size; lake storage and snowmelt, although the effect of the last of these is unclear as suitable data were not available for analysis. A discriminant analysis is employed to relate the five physical factors to flood seasonality. The study concludes with a discussion on the implications of its findings. A method of assessing seasonal flood risk using POT series is presented, offering an accurate means of relating flood magnitude to recurrence interval for any period of less than one year. The implications of seasonal heterogeneity, both within and between flood records, are also discussed. The suitability of the exponential model for use with POT records is questioned and it is suggested that explicit recognition of the seasonality of flooding may be necessary in order to make accurate design flood estimates.
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Sedimentological effects of aeolian processes active in the Tentsmuir area, Fife, Scotland
https://hdl.handle.net/10023/15197
Present day coastal accretion at Tentsmuir is manifest in the form of hummocky dune accumulations along the shoreline. The mode and variability of the distribution of surface sediments by the wind and the magnitude of accumulation of wind laid deposits in the Tentsmuir beach-dune complex is a measure of Aeolian activity in the area. In the Tentsmuir area fine to medium grained well sorted beach sands are entrained by high to moderate energy, seasonal, directionally unimodal to bimodal winds of low variability. During the winter season the dominant winds are from the south west (blowing towards the sea) whereas, generally during the spring the more effective winds are derived from the east (blowing towards land). The bimodal winds are composed of contrasting unimodally directional winds blowing for shorter durations. Daily sea breezes are observed during the summer. Field measurements of sand transport rates, with the aid of sand traps during anemometer determined wind speeds ranging from 4 m s-1 to 20 m s-1, in the study area show that while the onshore transport vector results in rapid foredune development, the longshore and offshore component contributes to a positive beach sediment budget. However, the net beach sediment budget is a complex interplay of Aeolian, wave and tidal processes. Shear velocities on the Tentsmuir beaches ranged from 18.5 cm s-1 to 52 cm s-1 and the focal point, u' and z' values were 1.75 m s-1 and 0.03 cm respectively. In general, the variability of the short-term Aeolian sand transport rates in the Tentsmuir beach-dune subenvironments is controlled by (i) variation in wind velocity, (ii) presence or absence of vegetation, (iii) ground surface moisture, and (iv) the sand size and source limitation. The potential sand input by the onshore winds during the last eleven years is estimated to have been approximately 28,532 m3. During the same period the potential amount of sand blown towards the sea was 109,570 m3. The amount of predicted onshore sediment input (28,532 m3) compares well with the 33,000 m3 of sand estimated to have accumulated in the lee of the beach at Tentsmuir Point The close agreement of the measured and predicted values of Aeolian transport suggests that the White (1979) expression, used in the present study to predict transport rates on the beach, provides fairly reliable estimates. Very high velocity offshore winds (>9 ms-1 produce a shelly deflation surface along the backshore, surface parallel sand sheets and sand strips on the foreshore; adhesion plane bed and adhesion structures along the moist/wet tidal margin and pyramidal dunes (offshore transport across a dune ridge >2.5m high.). Onshore high velocity winds result in the formation of surface parallel sand strips on the foreshore and a high volume of Aeolian sediment accumulation in the backshore and foredune area. Prolonged days of high velocity unidirectional winds result in the formation of barchans. Medium to high wind velocities (~6-9 ms-1) produce ballistically rippled foreshore sand lobes, lee dunes downwind of tidal debris, adhesion structures (offshore/longshore transport) and some sand accumulation in the foredune area (onshore transport). Abundant parallel laminated sand, pinchout laminae, sand lenses, precipitation deposits, trough crossbeds, plant remains at places overlying beach shell layers constitute a prograding coastal dune facies at Tentsmuir.
1993-01-01T00:00:00Z
Wal, Abhilasha
Present day coastal accretion at Tentsmuir is manifest in the form of hummocky dune accumulations along the shoreline. The mode and variability of the distribution of surface sediments by the wind and the magnitude of accumulation of wind laid deposits in the Tentsmuir beach-dune complex is a measure of Aeolian activity in the area. In the Tentsmuir area fine to medium grained well sorted beach sands are entrained by high to moderate energy, seasonal, directionally unimodal to bimodal winds of low variability. During the winter season the dominant winds are from the south west (blowing towards the sea) whereas, generally during the spring the more effective winds are derived from the east (blowing towards land). The bimodal winds are composed of contrasting unimodally directional winds blowing for shorter durations. Daily sea breezes are observed during the summer. Field measurements of sand transport rates, with the aid of sand traps during anemometer determined wind speeds ranging from 4 m s-1 to 20 m s-1, in the study area show that while the onshore transport vector results in rapid foredune development, the longshore and offshore component contributes to a positive beach sediment budget. However, the net beach sediment budget is a complex interplay of Aeolian, wave and tidal processes. Shear velocities on the Tentsmuir beaches ranged from 18.5 cm s-1 to 52 cm s-1 and the focal point, u' and z' values were 1.75 m s-1 and 0.03 cm respectively. In general, the variability of the short-term Aeolian sand transport rates in the Tentsmuir beach-dune subenvironments is controlled by (i) variation in wind velocity, (ii) presence or absence of vegetation, (iii) ground surface moisture, and (iv) the sand size and source limitation. The potential sand input by the onshore winds during the last eleven years is estimated to have been approximately 28,532 m3. During the same period the potential amount of sand blown towards the sea was 109,570 m3. The amount of predicted onshore sediment input (28,532 m3) compares well with the 33,000 m3 of sand estimated to have accumulated in the lee of the beach at Tentsmuir Point The close agreement of the measured and predicted values of Aeolian transport suggests that the White (1979) expression, used in the present study to predict transport rates on the beach, provides fairly reliable estimates. Very high velocity offshore winds (>9 ms-1 produce a shelly deflation surface along the backshore, surface parallel sand sheets and sand strips on the foreshore; adhesion plane bed and adhesion structures along the moist/wet tidal margin and pyramidal dunes (offshore transport across a dune ridge >2.5m high.). Onshore high velocity winds result in the formation of surface parallel sand strips on the foreshore and a high volume of Aeolian sediment accumulation in the backshore and foredune area. Prolonged days of high velocity unidirectional winds result in the formation of barchans. Medium to high wind velocities (~6-9 ms-1) produce ballistically rippled foreshore sand lobes, lee dunes downwind of tidal debris, adhesion structures (offshore/longshore transport) and some sand accumulation in the foredune area (onshore transport). Abundant parallel laminated sand, pinchout laminae, sand lenses, precipitation deposits, trough crossbeds, plant remains at places overlying beach shell layers constitute a prograding coastal dune facies at Tentsmuir.
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Sediment dynamics on Wemyss beach, South Fife
https://hdl.handle.net/10023/15194
The beaches of South Fife consist of an unusual mix of heterogeneous pebbles, sand and coal waste, and consequently provide a complex environment in which to examine sediment transport. The use of tracers revealed that low density coal pebbles were 'rejected' from the bedload layer of ironstone and sandstone pebbles, and were transported to extreme distances alongshore and potentially offshore. Whereas, the high specific gravity of the ironstone pebbles restricted longshore transport, but enhanced movement in the backwash to low water. Coarse pebbles protruded from the mixed bed of closely packed small pebbles and generated turbulence, thus enhancing the lift forces for entrainment. Once in transport, the coarse pebbles 'overpassed' the small pebbles. Therefore, 'Selective transport' according to pebble composition and size, was an important phenomenon on the mixed beach. On the mixed beach, the sand was readily moved offshore in the backwash and transported by longshore currents. Whereas, pebble transport was restricted to the swash and backwash, in the direction of maximum wave energy. Pebbles were either buried in the sand or lay flat on the surface. The limited protrusion of the pebbles lowered the shear stress available for pebble entrainment. Furthermore, once in motion the sand absorbed the impacts of the saltating pebbles. Vertical cores were used to investigate the structure of the beach. This technique revealed that a homogenous upper layer of coarse pebbles was transported along and upshore, over a less mobile beach layer of compacted poorly sorted sediment. Dense ironstone pebbles armoured the beach face and trapped finer sediments below. Consequently, a mix of sediment and dense coarse pebbles could be used to increase beach stability. Important factors influencing the dynamics of pebbles on mixed beaches were identified, however an adequate formula for mixed sediment transport remains to be calibrated.
1997-01-01T00:00:00Z
Miller, Kathryn Ann
The beaches of South Fife consist of an unusual mix of heterogeneous pebbles, sand and coal waste, and consequently provide a complex environment in which to examine sediment transport. The use of tracers revealed that low density coal pebbles were 'rejected' from the bedload layer of ironstone and sandstone pebbles, and were transported to extreme distances alongshore and potentially offshore. Whereas, the high specific gravity of the ironstone pebbles restricted longshore transport, but enhanced movement in the backwash to low water. Coarse pebbles protruded from the mixed bed of closely packed small pebbles and generated turbulence, thus enhancing the lift forces for entrainment. Once in transport, the coarse pebbles 'overpassed' the small pebbles. Therefore, 'Selective transport' according to pebble composition and size, was an important phenomenon on the mixed beach. On the mixed beach, the sand was readily moved offshore in the backwash and transported by longshore currents. Whereas, pebble transport was restricted to the swash and backwash, in the direction of maximum wave energy. Pebbles were either buried in the sand or lay flat on the surface. The limited protrusion of the pebbles lowered the shear stress available for pebble entrainment. Furthermore, once in motion the sand absorbed the impacts of the saltating pebbles. Vertical cores were used to investigate the structure of the beach. This technique revealed that a homogenous upper layer of coarse pebbles was transported along and upshore, over a less mobile beach layer of compacted poorly sorted sediment. Dense ironstone pebbles armoured the beach face and trapped finer sediments below. Consequently, a mix of sediment and dense coarse pebbles could be used to increase beach stability. Important factors influencing the dynamics of pebbles on mixed beaches were identified, however an adequate formula for mixed sediment transport remains to be calibrated.
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Geomorphological mapping and landform analysis in central Saudi Arabia : with special reference to the characteristics of pediments and fans
https://hdl.handle.net/10023/15191
The aim of this study is to seek for a more detailed understanding of the geomorphology of some parts of Central Saudi Arabia, on the basis of aerial photographic interpretation, field surveys and investigation, and data obtained by field and laboratory analysis. An introduction to the study area is given together with an account of the geology and physiography of Saudi Arabia and especially the study area based upon drilling, field studies, and records from a variety of sources. A procedure for geomorphological mapping is discussed together with a review of the principles, problems, methods, and development of geomorphological mapping. Following these principles and methods, geomorphological maps have been compiled on the basis of the interpretation of air photographs, field surveys, and investigation, and laboratory analysis of surface materials. An attempt has been made to compare the method of geomorphological mapping with the results of landform classification including discussion of the application of the Land System approach to the area. The landform classification has been tabulated and the maps are presented to show the major landform systems and units with sample area showing the smaller units (landform type units) of the landforms. Particle size analysis and pebble shape were employed to give some information about deposition and transportation on selected pediments and alluvial fans. A discussion and critical reviews of relevant literature on the theory of sieving and sedimentation are given, This is followed by an introduction to the procedure for field and laboratory methods of particle size analysis and pebble shape measurements. The terminology for piedmont surfaces is discussed to clarify some of the confusion concerning the use of such terms. This is followed by a review of the theories concerning pediment formation, development, and their relationships to other landforms. The particle sizes of samples taken from pediments and the shapes of pebbles derived from these pediments have been measured, analysed, and discussed in relation to pediment, slope, distance from the mountain fronts and depth. Alluvial fans are another type of the landforms which are discussed in detail. They are well developed in the south-western parts of the study area where they form a series of confluent alluvial fans (bahada). Terminology and the theory of fan formation is discussed on the basis of field investigation and aerial photographic interpretation together with reviews of relevant literature. Size analysis of fan deposits as well as pebble shape are once again used to obtain information about transportation and deposition. Finally these studies are considered in relation to indications of climatic changes within Central Saudi Arabia. Problems of geomorphological mapping and interpretation are discussed and short accounts given of future work needed for detailed understanding of the desert landscape through the regional analysis of the landforms of a part of Central Saudi Arabia (conclusions).
1974-01-01T00:00:00Z
Munshi, Z. M. N.
The aim of this study is to seek for a more detailed understanding of the geomorphology of some parts of Central Saudi Arabia, on the basis of aerial photographic interpretation, field surveys and investigation, and data obtained by field and laboratory analysis. An introduction to the study area is given together with an account of the geology and physiography of Saudi Arabia and especially the study area based upon drilling, field studies, and records from a variety of sources. A procedure for geomorphological mapping is discussed together with a review of the principles, problems, methods, and development of geomorphological mapping. Following these principles and methods, geomorphological maps have been compiled on the basis of the interpretation of air photographs, field surveys, and investigation, and laboratory analysis of surface materials. An attempt has been made to compare the method of geomorphological mapping with the results of landform classification including discussion of the application of the Land System approach to the area. The landform classification has been tabulated and the maps are presented to show the major landform systems and units with sample area showing the smaller units (landform type units) of the landforms. Particle size analysis and pebble shape were employed to give some information about deposition and transportation on selected pediments and alluvial fans. A discussion and critical reviews of relevant literature on the theory of sieving and sedimentation are given, This is followed by an introduction to the procedure for field and laboratory methods of particle size analysis and pebble shape measurements. The terminology for piedmont surfaces is discussed to clarify some of the confusion concerning the use of such terms. This is followed by a review of the theories concerning pediment formation, development, and their relationships to other landforms. The particle sizes of samples taken from pediments and the shapes of pebbles derived from these pediments have been measured, analysed, and discussed in relation to pediment, slope, distance from the mountain fronts and depth. Alluvial fans are another type of the landforms which are discussed in detail. They are well developed in the south-western parts of the study area where they form a series of confluent alluvial fans (bahada). Terminology and the theory of fan formation is discussed on the basis of field investigation and aerial photographic interpretation together with reviews of relevant literature. Size analysis of fan deposits as well as pebble shape are once again used to obtain information about transportation and deposition. Finally these studies are considered in relation to indications of climatic changes within Central Saudi Arabia. Problems of geomorphological mapping and interpretation are discussed and short accounts given of future work needed for detailed understanding of the desert landscape through the regional analysis of the landforms of a part of Central Saudi Arabia (conclusions).
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An assessment of surveying, mapping and cartographic procedures in the presentation of features in two unmapped areas: Ölü Deniz and Kidirak National Parks, S.W. Turkey
https://hdl.handle.net/10023/15188
This thesis examines the problems encountered in the survey, mapping and cartographic reproduction of features in two unmapped National Parks (Olu Deniz and Kidirak) in S.W. Turkey. The role of satellite imagery in modern map production is examined in this context, in both map construction and in combining imagery with field maps produced of the study areas. The methodologies involved in the creation of both field maps and the final cartographic products are discussed. These include the problems of survey without the benefits of modern, bulky survey instruments, and the measures taken to ensure maximum accuracy in both linear and areal dimensions given the inherent problems of the Compass-Traverse technique used. Cartographic procedures and the design problems involved in the transfer of field data to produce a finished full colour map are explained. New technological developments in computer aided cartography are used to produce maps of the parks in both colour and monochrome, at a variety of scales. Limitations of methodology, including legend construction, are discussed and the adjustments required to produce an acceptable end product are explained. Successive editions of the maps were used by a group of Honours Geography students in which biogeographical details and land resource assessments were noted and, where necessary, useful suggestions have been incorporated into the final edition. The possibility of producing a photo-image map using Landsat TM imagery is explored, together with examining the problems of using a Global Positioning System (GPS) to produce a more accurate map. It is concluded that neither offer significant advantages over the methods used in this particular study. Finally the use of these maps as a tool to monitor environmental change and differentiation in the two parks is discussed and the cartographic depiction of change over the 3 year period of survey is demonstrated.
1997-01-01T00:00:00Z
Sandeman, Graeme F.
This thesis examines the problems encountered in the survey, mapping and cartographic reproduction of features in two unmapped National Parks (Olu Deniz and Kidirak) in S.W. Turkey. The role of satellite imagery in modern map production is examined in this context, in both map construction and in combining imagery with field maps produced of the study areas. The methodologies involved in the creation of both field maps and the final cartographic products are discussed. These include the problems of survey without the benefits of modern, bulky survey instruments, and the measures taken to ensure maximum accuracy in both linear and areal dimensions given the inherent problems of the Compass-Traverse technique used. Cartographic procedures and the design problems involved in the transfer of field data to produce a finished full colour map are explained. New technological developments in computer aided cartography are used to produce maps of the parks in both colour and monochrome, at a variety of scales. Limitations of methodology, including legend construction, are discussed and the adjustments required to produce an acceptable end product are explained. Successive editions of the maps were used by a group of Honours Geography students in which biogeographical details and land resource assessments were noted and, where necessary, useful suggestions have been incorporated into the final edition. The possibility of producing a photo-image map using Landsat TM imagery is explored, together with examining the problems of using a Global Positioning System (GPS) to produce a more accurate map. It is concluded that neither offer significant advantages over the methods used in this particular study. Finally the use of these maps as a tool to monitor environmental change and differentiation in the two parks is discussed and the cartographic depiction of change over the 3 year period of survey is demonstrated.
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Compensating for topographic information from satellite imagery in mountain environments
https://hdl.handle.net/10023/15149
The use of satellite image data for vegetation mapping and forestry inventory in mountain environments has been greatly restricted by the scene digital values containing a mixture of variations which are due partly to surface cover (albedo) and partly to topography (illumination). Landsat Thematic Mapper (TM) data were selected for a portion of the Rocky Mountains in the Kananaskis Valley, Alberta, Canada and used to derive secondary data channels that sought to compensate for topographic information, by isolating the response due to surface cover. Two multispectral techniques were used: band ratioing and principal component analysis. In both cases, the generated channels represented the difference between the three spectral groups of bands for TM data: visible, near and middle (shortwave) infra-red. Multi-channel ratio and component combinations were used in an unsupervised clustering procedure that defined homogeneous ground areas. When the original pixel values were replaced by the average brightness for their respective clusters, the resulting image channels represented each of the multispectral bands as if the surface were flat. Selective principal components proved more successful than band ratioing, being less susceptible to noise and allowing input from more than two bands each. These component channels created a final classification which had a higher overall accuracy than those for studies in adjacent mountain environments using supervised classification and was comparable to those which also incorporated topographic data. The study was successful in identifying a different approach to topographic correction without having to acquire digital elevation models and considerable ground knowledge. This technique has much potential for expediting forest cover inventory and vegetation mapping in mountain environments and represents a new and promising application for principal component analysis.
1997-01-01T00:00:00Z
Wheate, Roger
The use of satellite image data for vegetation mapping and forestry inventory in mountain environments has been greatly restricted by the scene digital values containing a mixture of variations which are due partly to surface cover (albedo) and partly to topography (illumination). Landsat Thematic Mapper (TM) data were selected for a portion of the Rocky Mountains in the Kananaskis Valley, Alberta, Canada and used to derive secondary data channels that sought to compensate for topographic information, by isolating the response due to surface cover. Two multispectral techniques were used: band ratioing and principal component analysis. In both cases, the generated channels represented the difference between the three spectral groups of bands for TM data: visible, near and middle (shortwave) infra-red. Multi-channel ratio and component combinations were used in an unsupervised clustering procedure that defined homogeneous ground areas. When the original pixel values were replaced by the average brightness for their respective clusters, the resulting image channels represented each of the multispectral bands as if the surface were flat. Selective principal components proved more successful than band ratioing, being less susceptible to noise and allowing input from more than two bands each. These component channels created a final classification which had a higher overall accuracy than those for studies in adjacent mountain environments using supervised classification and was comparable to those which also incorporated topographic data. The study was successful in identifying a different approach to topographic correction without having to acquire digital elevation models and considerable ground knowledge. This technique has much potential for expediting forest cover inventory and vegetation mapping in mountain environments and represents a new and promising application for principal component analysis.
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Roles, rights, and responsibilities in the sustainable management of red deer populations in Scotland
https://hdl.handle.net/10023/14571
The aim of the project was to explore the acquisition and dissemination of knowledge amongst decision-makers involved in the management of red deer in Scotland. While research exists on the ecology of red deer habitat, no research exists that focuses on the relationship between the deer and the people responsible for their management. Therefore, this thesis is primarily qualitative research which aimed to explore the various aspects of red deer management in Scotland within the socio-ecological context in which it exists. There are numerous groups with interest in red deer management, however this research, due to scope and time restrictions, was limited to two primary groups, the individuals tasked with implementing policy and the practitioners who carry out culling. During the course of the project, under-researched topics surfaced, highlighting areas of practical and theoretical divergence between stakeholders. This thesis therefore aims to explore how differing views and perspectives of two of the key stakeholder groups – the estate-based practitioners (including stalkers, land-managers, and land-owners) and staff of governmental agencies – influence the management of red deer in Scotland. This research indicates that people with different roles hold different relationships with the deer, which affect management decisions and implementation at local, regional, and/or national level. As with other areas within conservation and wildlife management, this research indicates there is a disconnect between blanket governmental policy and site-specific needs, with a lack of inclusion of practitioner knowledge. Potential future research would include additional qualitative research to follow up some of the management issues raised by this research and formulate recommendations for changes to practice, followed by collection of quantitative data assessing the efficacy of interventions.
2018-06-29T00:00:00Z
Witta, Lorin E.
The aim of the project was to explore the acquisition and dissemination of knowledge amongst decision-makers involved in the management of red deer in Scotland. While research exists on the ecology of red deer habitat, no research exists that focuses on the relationship between the deer and the people responsible for their management. Therefore, this thesis is primarily qualitative research which aimed to explore the various aspects of red deer management in Scotland within the socio-ecological context in which it exists. There are numerous groups with interest in red deer management, however this research, due to scope and time restrictions, was limited to two primary groups, the individuals tasked with implementing policy and the practitioners who carry out culling. During the course of the project, under-researched topics surfaced, highlighting areas of practical and theoretical divergence between stakeholders. This thesis therefore aims to explore how differing views and perspectives of two of the key stakeholder groups – the estate-based practitioners (including stalkers, land-managers, and land-owners) and staff of governmental agencies – influence the management of red deer in Scotland. This research indicates that people with different roles hold different relationships with the deer, which affect management decisions and implementation at local, regional, and/or national level. As with other areas within conservation and wildlife management, this research indicates there is a disconnect between blanket governmental policy and site-specific needs, with a lack of inclusion of practitioner knowledge. Potential future research would include additional qualitative research to follow up some of the management issues raised by this research and formulate recommendations for changes to practice, followed by collection of quantitative data assessing the efficacy of interventions.
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A small area analysis of mortality inequalities in Scotland, 1980-2001
https://hdl.handle.net/10023/14059
This thesis examines the changing patterns of mortality in Scotland, with particular emphasis on whether there are widening mortality inequalities among small areas in Scotland. The annual number of deaths in Scotland has decreased steadily since the 1950s, yet mortality rates in Scotland are amongst the highest in Europe for many causes. Furthermore, mortality from some causes, such as suicide, has been increasing over time, particularly among young adults. Evidence suggests that inequalities in mortality have widened over time in Scotland, despite substantial investment in policies aimed at reducing inequalities. Therefore, it is important to seek geographical clues that might help explain what causes these high mortality rates. The changing patterns in Scottish mortality between 1980 and 2001 were examined for small areas, created by the author, known as Consistent Areas Through Time (CATTs). These areas have the same boundaries for each census, so that direct comparisons over time are possible. In this study, CATTs have been used to investigate three aspects of the mortality gap in Scotland. First, the widening mortality gaps between 1980-1982 and 1999-2001 are examined for the total population and for premature mortality (<65 years). Second, the influence that geographic scale and deprivation have on the relationship between population change and premature mortality are assessed. Third, suicide inequalities are examined for the younger (15-44 years), older (45+) and total population, using mortality ratios and statistical modelling. The research found that inequalities in premature mortality (<65) have widened for all causes of death studied, particularly for suicide. The negative association between mortality and population change was affected by geographic scale, but this relationship could not be fully explained by deprivation. Small area analyses found that the Highlands and Islands had higher suicide rates than elsewhere in Scotland for males, but not females, when social variables were controlled for.
2004-01-01T00:00:00Z
Exeter, Daniel J.
This thesis examines the changing patterns of mortality in Scotland, with particular emphasis on whether there are widening mortality inequalities among small areas in Scotland. The annual number of deaths in Scotland has decreased steadily since the 1950s, yet mortality rates in Scotland are amongst the highest in Europe for many causes. Furthermore, mortality from some causes, such as suicide, has been increasing over time, particularly among young adults. Evidence suggests that inequalities in mortality have widened over time in Scotland, despite substantial investment in policies aimed at reducing inequalities. Therefore, it is important to seek geographical clues that might help explain what causes these high mortality rates. The changing patterns in Scottish mortality between 1980 and 2001 were examined for small areas, created by the author, known as Consistent Areas Through Time (CATTs). These areas have the same boundaries for each census, so that direct comparisons over time are possible. In this study, CATTs have been used to investigate three aspects of the mortality gap in Scotland. First, the widening mortality gaps between 1980-1982 and 1999-2001 are examined for the total population and for premature mortality (<65 years). Second, the influence that geographic scale and deprivation have on the relationship between population change and premature mortality are assessed. Third, suicide inequalities are examined for the younger (15-44 years), older (45+) and total population, using mortality ratios and statistical modelling. The research found that inequalities in premature mortality (<65) have widened for all causes of death studied, particularly for suicide. The negative association between mortality and population change was affected by geographic scale, but this relationship could not be fully explained by deprivation. Small area analyses found that the Highlands and Islands had higher suicide rates than elsewhere in Scotland for males, but not females, when social variables were controlled for.
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Habitat preferences of juvenile Scottish ospreys (Pandion haliaetus) at stopover and wintering sites
https://hdl.handle.net/10023/13978
In this study, we use satellite-tracking data from five juvenile Scottish Ospreys Pandion haliaetus to explore habitat preferences at stopover and wintering sites. Daily activity patterns were analysed using a binomial generalised linear model. Kernel density estimation was used to identify core areas at stopover sites and seasonal ranges at the wintering site. A ‘use versus available habitat’ study design was implemented to test whether Ospreys showed preference for a variety of landscape and land-cover variables and for protected areas. Autumn migration strategies varied between individuals, with some Ospreys using stopover sites in France, Spain and Morocco. Ospreys wintered at sites in West Africa. Activity levels varied through the day, with localised peaks at 11:00 and 15:00 h. Ospreys preferred to be near to water features (rivers, lakes, ocean) while avoiding urban areas. Individual differences were observed when considering preference for forest and open-area land-cover classes. Overall, Ospreys did not preferentially use protected areas. Our research confirms already well-established preferences for aquatic habitats, but preference for or avoidance of other habitats, including protected areas, varied between individuals. We highlight the potential of combining satellite-tracking data with environmental data sources to explore the spatial ecology of migratory birds at stopover and wintering sites abroad.
2017-01-01T00:00:00Z
Crawford, Ruth E.
Long, Jed A.
In this study, we use satellite-tracking data from five juvenile Scottish Ospreys Pandion haliaetus to explore habitat preferences at stopover and wintering sites. Daily activity patterns were analysed using a binomial generalised linear model. Kernel density estimation was used to identify core areas at stopover sites and seasonal ranges at the wintering site. A ‘use versus available habitat’ study design was implemented to test whether Ospreys showed preference for a variety of landscape and land-cover variables and for protected areas. Autumn migration strategies varied between individuals, with some Ospreys using stopover sites in France, Spain and Morocco. Ospreys wintered at sites in West Africa. Activity levels varied through the day, with localised peaks at 11:00 and 15:00 h. Ospreys preferred to be near to water features (rivers, lakes, ocean) while avoiding urban areas. Individual differences were observed when considering preference for forest and open-area land-cover classes. Overall, Ospreys did not preferentially use protected areas. Our research confirms already well-established preferences for aquatic habitats, but preference for or avoidance of other habitats, including protected areas, varied between individuals. We highlight the potential of combining satellite-tracking data with environmental data sources to explore the spatial ecology of migratory birds at stopover and wintering sites abroad.
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Remote geotechnical classification of seabed sediments using acoustic techniques
https://hdl.handle.net/10023/13953
Although the sonar amplitude of return is undoubtedly determined by the acoustic-sediment interaction at the seabed, the raw amplitude of return is of little practical use to geotechnical engineers. By focusing upon the relationships between the strength of the acoustic scattering and the roughness of the surficial seabed sediments, this research aims to derive a remote acoustic methodology that can be used to predict the geotechnical characteristics of the seabed sediment. The main field survey areas selected were Loch Earn, Scotland, and the Portsmouth coastal waters in the Solent, England, with the precise location of the field sites being determined by the distribution of differing sediment types. The sonar data was acquired by a 234kHz Interferometric Seabed Inspection Sonar system, which provided not only high precision and high resolution, but also extensive and very dense data coverage. These sonar datasets were then complemented by a sediment ground-truthing programme within the same area. Using trigonometry and the 'sonar equation' parameters, the complex post-processing of the bathymetric and acoustic data resulted in the generation of an acoustic roughness measurement. The sediment grain size analysis then followed standard techniques to derive values for the statistical roughness parameters of the sediment. The correlation between the acoustic and sediment roughness uncovered a good correlation between the mean grain size and also the finest modal value, with an increase in acoustic scattering strength reflecting an increase in the mean and finest modal grain sizes. The reversal of this correlation therefore enables a prediction of mean or finest modal grain size, thereby demonstrating an approach towards an 'unsupervised' acoustic sediment classification scheme. This study was carried out over a very narrow grain size range, from muds to fine sands, and therefore the addition of sonar datasets recorded over coarser sediments are required to complete the classification scheme.
2002-01-01T00:00:00Z
Hadden, Scott Duncan
Although the sonar amplitude of return is undoubtedly determined by the acoustic-sediment interaction at the seabed, the raw amplitude of return is of little practical use to geotechnical engineers. By focusing upon the relationships between the strength of the acoustic scattering and the roughness of the surficial seabed sediments, this research aims to derive a remote acoustic methodology that can be used to predict the geotechnical characteristics of the seabed sediment. The main field survey areas selected were Loch Earn, Scotland, and the Portsmouth coastal waters in the Solent, England, with the precise location of the field sites being determined by the distribution of differing sediment types. The sonar data was acquired by a 234kHz Interferometric Seabed Inspection Sonar system, which provided not only high precision and high resolution, but also extensive and very dense data coverage. These sonar datasets were then complemented by a sediment ground-truthing programme within the same area. Using trigonometry and the 'sonar equation' parameters, the complex post-processing of the bathymetric and acoustic data resulted in the generation of an acoustic roughness measurement. The sediment grain size analysis then followed standard techniques to derive values for the statistical roughness parameters of the sediment. The correlation between the acoustic and sediment roughness uncovered a good correlation between the mean grain size and also the finest modal value, with an increase in acoustic scattering strength reflecting an increase in the mean and finest modal grain sizes. The reversal of this correlation therefore enables a prediction of mean or finest modal grain size, thereby demonstrating an approach towards an 'unsupervised' acoustic sediment classification scheme. This study was carried out over a very narrow grain size range, from muds to fine sands, and therefore the addition of sonar datasets recorded over coarser sediments are required to complete the classification scheme.
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Hydrothermal alteration and mineralisation of the Nigerian anorogenic ring complexes: with special reference to the Saiya Shokobo complex
https://hdl.handle.net/10023/13407
The Nigerian anorogenic province is characterised by more than 50 complexes. In some complexes, the outer limits of the complexes are defined partly or completely by a ring dyke. This intrusion, generally composed of granite porphyry, was the chief structural element of the complex and controlled the distribution of both volcanic and subvolcanic magmatism at high levels in the crust. The complexes are exposed at different erosional levels: in some complexes, particularly in the north, the volcanic products are preserved through caldera collapse. The majority of the volcanics are dominantly rhyolitic, some alkaline centres have preserved occasional successions of hawaiites, mugearites and trachytes confirming the dominantly alkaline trend from transitional ne-normative or ne-normative basalts. In other centres the volcanic cover has been removed so that the subvolcanic granites and syenites have been exposed. The subvolcanic assemblages include minor gabbros, monzogabbros and syenites. However granitic rocks are overwhelmingly dominant with fayalite hedenbergite granites, amphibole granites and syenites, albite-rich and albite-poor aegirine arfvedsonite granites and biotite granites. As far as the granites are concerned there was a natural progression from volcanic feeder intrusions to subvolcanic intrusions with fayalite and hedenbergite. The volcanic feeder intrusions were an important link during the caldera-forming stage between the subvolcanic roots and the overlying volcanic pile. They are represented by quartz and granite porphyries. The mineralogical assemblages of many of these complexes however, is often the result of interaction with residual fluids. Fluids affected the late magmatic and particularly the postmagnatic (subsolidus) crystallisation history of a cooling subvolcanic pluton and to some extent the overlying volcanic pile. Such hydrothermal alteration has undoubtedly modified the original granite chemistry. The residual fluids which were responsible for hydrothermal alteration also carried ore metals which were variously deposited at different stages of hydrothermal alteration. Mineralisation of a pluton generally occurred in the apical or marginal zones or in satellite dykes. Different styles of mineralisation tend to characterise different parts of a granite pluton and five separate zones have been recognised; the roof, marginal and contact zones of a pluton, the enclosing or overlying rocks and the surrounding ring dyke. Nine different styles of mineralisation have been identified including pervasive metasomatic disseminations; pegmatitic pods and lenses; stockworks and lodes. No particular type of hydrothermal alteration is restricted to one particular style of mineralisation and it is possible to have disseminated sodic, potassic, acid or silica metasomatism and altered ring dykes may show the effects of all these processes. The complexity of the subsolidus mineralogical re-equilibration has been appreciated by a detailed study of the Rishi area of the Saiya Shokobo caiplex. The Saiya Shokobo complex forms a distinctive hill mass in north central Nigeria which covers an area of approximately 250km. The main structural feature of the complex is the elliptical fracture 17km in diameter which has largely determined the outline of the central massif of the Saiya Shokobo Hills and has controlled the emplacement of several of the intrusions of the complex. The complex is dominated by volcanic rocks which are confined within this elliptical fracture. During the latest stage of magmatic activity, the emplacement of a granite pluton moved beyond the confines of the main fracture and was intruded eccentrically to the north east of the main part of the complex. Thus the biotite granite intruded both its own volcanic pile and the basement hornblende biotite monzogranite.
1987-01-01T00:00:00Z
Kinnaird, Judith Ann
The Nigerian anorogenic province is characterised by more than 50 complexes. In some complexes, the outer limits of the complexes are defined partly or completely by a ring dyke. This intrusion, generally composed of granite porphyry, was the chief structural element of the complex and controlled the distribution of both volcanic and subvolcanic magmatism at high levels in the crust. The complexes are exposed at different erosional levels: in some complexes, particularly in the north, the volcanic products are preserved through caldera collapse. The majority of the volcanics are dominantly rhyolitic, some alkaline centres have preserved occasional successions of hawaiites, mugearites and trachytes confirming the dominantly alkaline trend from transitional ne-normative or ne-normative basalts. In other centres the volcanic cover has been removed so that the subvolcanic granites and syenites have been exposed. The subvolcanic assemblages include minor gabbros, monzogabbros and syenites. However granitic rocks are overwhelmingly dominant with fayalite hedenbergite granites, amphibole granites and syenites, albite-rich and albite-poor aegirine arfvedsonite granites and biotite granites. As far as the granites are concerned there was a natural progression from volcanic feeder intrusions to subvolcanic intrusions with fayalite and hedenbergite. The volcanic feeder intrusions were an important link during the caldera-forming stage between the subvolcanic roots and the overlying volcanic pile. They are represented by quartz and granite porphyries. The mineralogical assemblages of many of these complexes however, is often the result of interaction with residual fluids. Fluids affected the late magmatic and particularly the postmagnatic (subsolidus) crystallisation history of a cooling subvolcanic pluton and to some extent the overlying volcanic pile. Such hydrothermal alteration has undoubtedly modified the original granite chemistry. The residual fluids which were responsible for hydrothermal alteration also carried ore metals which were variously deposited at different stages of hydrothermal alteration. Mineralisation of a pluton generally occurred in the apical or marginal zones or in satellite dykes. Different styles of mineralisation tend to characterise different parts of a granite pluton and five separate zones have been recognised; the roof, marginal and contact zones of a pluton, the enclosing or overlying rocks and the surrounding ring dyke. Nine different styles of mineralisation have been identified including pervasive metasomatic disseminations; pegmatitic pods and lenses; stockworks and lodes. No particular type of hydrothermal alteration is restricted to one particular style of mineralisation and it is possible to have disseminated sodic, potassic, acid or silica metasomatism and altered ring dykes may show the effects of all these processes. The complexity of the subsolidus mineralogical re-equilibration has been appreciated by a detailed study of the Rishi area of the Saiya Shokobo caiplex. The Saiya Shokobo complex forms a distinctive hill mass in north central Nigeria which covers an area of approximately 250km. The main structural feature of the complex is the elliptical fracture 17km in diameter which has largely determined the outline of the central massif of the Saiya Shokobo Hills and has controlled the emplacement of several of the intrusions of the complex. The complex is dominated by volcanic rocks which are confined within this elliptical fracture. During the latest stage of magmatic activity, the emplacement of a granite pluton moved beyond the confines of the main fracture and was intruded eccentrically to the north east of the main part of the complex. Thus the biotite granite intruded both its own volcanic pile and the basement hornblende biotite monzogranite.
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The geology of the Cairnsmore of Fleet granite and its environs, Southwest Scotland
https://hdl.handle.net/10023/13352
The thesis is divided into three parts relating to (i) the sedimentary rocks, (ii) the granite and minor intrusive rocks and (iii) the Fleet orefield. The Sedimentary successions around the Cairnsmore of Fleet pluton are divided into two new formations; the Craignell and Knockeans Formations. The former is sub-divided into three facies based upon a geochemical classification of greywackes undertaken using cluster analysis. Facies boundaries within the Craignell Formation and interformational boundaries between this formation and the underlying Moffat Shales and the younger Knockeans Formation are all probably diachronous. Tectonically derived structures within the sedimentary rocks are correlated with those reported from areas elsewhere within the Southern Uplands. Certain structures are, however, unique to this area and some may be related to the emplacement of the Fleet pluton. Mineralogical zones within the extensive thermal aureole surrounding, the granite are described and correlated with previously published facies of contact metamorphism: albite-epidote hornfels, hornblende hornfels and K-feldspar-cordierite hornfels facies. Petrological facies within the granite are described and the classification thus produced endorsed geochemically with the aid of cluster analysis. Chemical trends in separated minerals, are correlated with bulk chemical variation in the granite which is outlined using correlation, regression and trend surface analyses. Geo-chemical and petrological data are compared with published experimental mineralogical studies. Minor intrusive rocks are similar in composition to those occurring throughout Galloway with two notable exceptions of more basic composition. The chemistry of the minor of the Fleet pluton are described the western margin to the Fleet pluton are described in detail for the first time. A distinct mineralogical zoning pattern is spatially related to the granite and consists of an inner zone within the pluton and generally close to the contact in the country rocks, containing dominant chalco-pyrite, pyrrhotite, pyrite and high temperature ores such as pentlandite and arsenopyrite with a quartzose gangue. Outer zones contain veins of sphalerite and mixed carbonate and quartz gangue, and give way to an outermost zone of galena with carbonate and barytes gangue. Geochemical studies on separated ore minerals has enabled the distinction of ores from particular zones and give an indication of their relative temperatures of formation. Wallrock alteration is described and is generally consistent in its characteristics with the changing mineralogy of the vein deposits. The ore deposits are related to the geophysically predicted granite batholith beneath the Southern Uplands, but more specifically to the Fleet pluton. The mineralogy and geochemistry of the deposits are consistent with this, but geochronological studies from other areas suggest that the ores may be at least 40 my younger than the granite. A hypothesis for the origin of the hydrothermal deposits is presented and is based upon data outlined above.
1976-01-01T00:00:00Z
Cook, David R.
The thesis is divided into three parts relating to (i) the sedimentary rocks, (ii) the granite and minor intrusive rocks and (iii) the Fleet orefield. The Sedimentary successions around the Cairnsmore of Fleet pluton are divided into two new formations; the Craignell and Knockeans Formations. The former is sub-divided into three facies based upon a geochemical classification of greywackes undertaken using cluster analysis. Facies boundaries within the Craignell Formation and interformational boundaries between this formation and the underlying Moffat Shales and the younger Knockeans Formation are all probably diachronous. Tectonically derived structures within the sedimentary rocks are correlated with those reported from areas elsewhere within the Southern Uplands. Certain structures are, however, unique to this area and some may be related to the emplacement of the Fleet pluton. Mineralogical zones within the extensive thermal aureole surrounding, the granite are described and correlated with previously published facies of contact metamorphism: albite-epidote hornfels, hornblende hornfels and K-feldspar-cordierite hornfels facies. Petrological facies within the granite are described and the classification thus produced endorsed geochemically with the aid of cluster analysis. Chemical trends in separated minerals, are correlated with bulk chemical variation in the granite which is outlined using correlation, regression and trend surface analyses. Geo-chemical and petrological data are compared with published experimental mineralogical studies. Minor intrusive rocks are similar in composition to those occurring throughout Galloway with two notable exceptions of more basic composition. The chemistry of the minor of the Fleet pluton are described the western margin to the Fleet pluton are described in detail for the first time. A distinct mineralogical zoning pattern is spatially related to the granite and consists of an inner zone within the pluton and generally close to the contact in the country rocks, containing dominant chalco-pyrite, pyrrhotite, pyrite and high temperature ores such as pentlandite and arsenopyrite with a quartzose gangue. Outer zones contain veins of sphalerite and mixed carbonate and quartz gangue, and give way to an outermost zone of galena with carbonate and barytes gangue. Geochemical studies on separated ore minerals has enabled the distinction of ores from particular zones and give an indication of their relative temperatures of formation. Wallrock alteration is described and is generally consistent in its characteristics with the changing mineralogy of the vein deposits. The ore deposits are related to the geophysically predicted granite batholith beneath the Southern Uplands, but more specifically to the Fleet pluton. The mineralogy and geochemistry of the deposits are consistent with this, but geochronological studies from other areas suggest that the ores may be at least 40 my younger than the granite. A hypothesis for the origin of the hydrothermal deposits is presented and is based upon data outlined above.
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Towards a holistic understanding of sustainability action : a life history approach
https://hdl.handle.net/10023/12863
Sustainability challenges threaten society and the environment with both formal and
grassroots initiatives to encourage sustainability action achieving limited success.
Contemporary policy approaches to sustainability have focused on individual
responsibility, promoting knowledge-deficit models of behaviour change that fail to take
into account the context in which people live. This thesis employed a life history
approach to holistically examine the relationships between experience, connection and
sustainability action. The roles of experience and transformation in changing
participants’ connection to self, other people and the more-than-human natural world
were investigated. A framework was developed from psychology and sociology
literatures to holistically elucidate the context in which sustainability action takes place.
Thirty-three participants were recruited from educational and environmental sectors
across Scotland and England. Life history interview data were thematically analysed with
emphasis placed on delineating experiences that participants described as formative, as
well as identifying temporal trends both within individual lives and across the dataset.
Experience was instrumental in the creation and reformation of the different
ways of knowing required for both connection and action. Extended periods of time
spent with people or nature were associated with holistic descriptions of connection.
However, the role of infrastructure in supporting sustainability action should not be
underestimated. The life history method illuminated the interplay between temporal
changes at personal and societal levels. These findings promote the current research
agenda into examining sustainability action within the broader context of the life course.
Although connection is instrumental in imbuing experience with the meaning necessary
to sustain action over a prolonged period, the wider context in which action takes place
can supress this effect. If policy is to be conducive to sustainability, it should focus on
creating and sustaining environments in which connection to the self, other people and
the more-than-human natural world are enabled and nurtured.
Electronic version excludes material for which permission has not been granted by the rights holder
2016-06-22T00:00:00Z
Gnanapragasam, Alexander J.
Sustainability challenges threaten society and the environment with both formal and
grassroots initiatives to encourage sustainability action achieving limited success.
Contemporary policy approaches to sustainability have focused on individual
responsibility, promoting knowledge-deficit models of behaviour change that fail to take
into account the context in which people live. This thesis employed a life history
approach to holistically examine the relationships between experience, connection and
sustainability action. The roles of experience and transformation in changing
participants’ connection to self, other people and the more-than-human natural world
were investigated. A framework was developed from psychology and sociology
literatures to holistically elucidate the context in which sustainability action takes place.
Thirty-three participants were recruited from educational and environmental sectors
across Scotland and England. Life history interview data were thematically analysed with
emphasis placed on delineating experiences that participants described as formative, as
well as identifying temporal trends both within individual lives and across the dataset.
Experience was instrumental in the creation and reformation of the different
ways of knowing required for both connection and action. Extended periods of time
spent with people or nature were associated with holistic descriptions of connection.
However, the role of infrastructure in supporting sustainability action should not be
underestimated. The life history method illuminated the interplay between temporal
changes at personal and societal levels. These findings promote the current research
agenda into examining sustainability action within the broader context of the life course.
Although connection is instrumental in imbuing experience with the meaning necessary
to sustain action over a prolonged period, the wider context in which action takes place
can supress this effect. If policy is to be conducive to sustainability, it should focus on
creating and sustaining environments in which connection to the self, other people and
the more-than-human natural world are enabled and nurtured.
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Material geographies of the maker movement : community workshops and the making of sustainability in Edinburgh, Scotland
https://hdl.handle.net/10023/12815
Recent years have seen the emergence of a novel type of community space around the world, labelled variously as makerspaces, hackerspaces, hacklabs, Fab Labs, and repair cafés. These workshops, often known collectively as the ‘maker movement’, have inspired considerable speculation regarding their potential to prefigure a more sustainable economy, including a shift to localised and participatory forms of production and consumption (Smith and Light, 2017). Until recently, the social scientific work on such spaces has been sparse, especially in-depth ethnographic work, though scholars are increasingly turning their attention to them, particularly in the fields of design and science and technology studies.
This thesis, a practice-led ‘enactive ethnography’ drawing from three case study workshops in Edinburgh, Scotland, explores the question of sustainable development and maker spaces along two main axes: firstly, the emergence of sustainable practice in such spaces, and secondly, the relevance of such spaces to the cultivation of human wellbeing. The thesis is the first examination of such spaces drawing from developments in social theory towards relational materialism, more-than-representational approaches, and a focus on social practice.
It draws a number of conclusions. Firstly, that claims of an undifferentiated global ‘maker movement’ may be exaggerated: the grassroots participant-led creation of such spaces results in irreducible diversity and local differentiation. Secondly, while claims about the potential of such spaces for reconfiguring global production and consumption are overstated, when viewed from a practice-oriented perspective, the communities of practice populating such sites comprise potent and potentially-valuable crucibles of knowledge and materials. And thirdly, trying to move away from individualistic conceptions of wellbeing, the case studies provided evidence for the shared workshops playing a crucial role in the contingent emergence of participant wellbeing. These findings are further developed in tandem with a posthuman reading of maker practices, contributing to timely scholarly debates on ‘making’ and ‘craft’.
2018-06-27T00:00:00Z
Smith, Thomas S. J.
Recent years have seen the emergence of a novel type of community space around the world, labelled variously as makerspaces, hackerspaces, hacklabs, Fab Labs, and repair cafés. These workshops, often known collectively as the ‘maker movement’, have inspired considerable speculation regarding their potential to prefigure a more sustainable economy, including a shift to localised and participatory forms of production and consumption (Smith and Light, 2017). Until recently, the social scientific work on such spaces has been sparse, especially in-depth ethnographic work, though scholars are increasingly turning their attention to them, particularly in the fields of design and science and technology studies.
This thesis, a practice-led ‘enactive ethnography’ drawing from three case study workshops in Edinburgh, Scotland, explores the question of sustainable development and maker spaces along two main axes: firstly, the emergence of sustainable practice in such spaces, and secondly, the relevance of such spaces to the cultivation of human wellbeing. The thesis is the first examination of such spaces drawing from developments in social theory towards relational materialism, more-than-representational approaches, and a focus on social practice.
It draws a number of conclusions. Firstly, that claims of an undifferentiated global ‘maker movement’ may be exaggerated: the grassroots participant-led creation of such spaces results in irreducible diversity and local differentiation. Secondly, while claims about the potential of such spaces for reconfiguring global production and consumption are overstated, when viewed from a practice-oriented perspective, the communities of practice populating such sites comprise potent and potentially-valuable crucibles of knowledge and materials. And thirdly, trying to move away from individualistic conceptions of wellbeing, the case studies provided evidence for the shared workshops playing a crucial role in the contingent emergence of participant wellbeing. These findings are further developed in tandem with a posthuman reading of maker practices, contributing to timely scholarly debates on ‘making’ and ‘craft’.
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Lithostratigraphic and structural reconstruction of the Zn-Pb-Cu-Ag-Au Lemarchant volcanogenic massive sulphide (VMS) deposit, Tally Pond group, central Newfoundland, Canada
https://hdl.handle.net/10023/12472
The Lemarchant volcanogenic massive sulphide (VMS) deposit (1.24 Mt grading at 0.58% Cu, 5.38% Zn, 1.19% Pb, 1.01g/t Au, and 59.17g/t Ag) is a bimodal-felsic VMS deposit hosted within the Late Cambrian ($513–509 Ma) Tally Pond group of the Exploit Subzone in central Newfoundland, Canada. The deposit is hosted by andesitic volcaniclastic and volcanic rocks with subordinate dacite flows. The mineralisation is hosted by the dacites and is overlain by pillowed and massive basalts.Four structural breaks offset the local stratigraphic sequences including: 1) the LJ syn-volcanic shear zone; 2) the KJ syn-volcanic shear zone; 3) the Lemarchant thrust; and 4) the Bam normal fault. Deformation of the Lemarchant likely occurred during the Penobscot orogeny (486–478 Ma). Early deformation is marked with the local deformation of the LJ and KJ syn-volcanic shear zones during NW-SE compression which coincided with the development of the Lemarchant thrust. A late (<465Ma) east trending normal fault, the Bam fault, affected the central portion of the Lemarchant area and down-faulted the southern portion of the study area relative to the northern portion.Immobile element systematics of all the sequences from the Lemarchant deposit are tholeiitic with transitional Zr/Y ratios (1.9–6.6), Lan/Smn ratios <1 (normalised to upper crust), and have primitive mantle extended rare earth elements profiles with slight light rare earth element (LREE)-enriched pat- terns with flat heavy REE (HREE), and weak to strong negative Nb, Zr, and Ti anomalies. Together, these geochemical features, coupled with an FIIIa signature, and existing mineralogical and Nd-Pb iso- tope data, are consistent with the rocks at the Lemarchant deposit having formed within a shallow (<1500 m) arc or migrating cross-arc seamount chain located within a young peri-continental rifted arc along the margin of Ganderia, within the Iapetus Ocean. The estimated shallow water emplace- ment of the deposit likely allowed boiling near or at the rock-sea water interface, ultimately resulting in precious metal enrichment of the Lemarchant deposit. It is suggested that cross-arcs within rifted arc environments may represent favourable exploration targets for precious metal-enriched VMS deposits.
Financial support for this project was provided from a Natural Sciences and Engineering Research Council of Canada (NSERC) Collaborative Research and Development Grant to S.J. Piercey. Additional funding was provided by the NSERC-Altius Industrial Research Chair in Mineral Deposits (supported by NSERC, Altius Resources Inc., and the Research and Development Corporation of Newfoundland and Labrador) and an NSERC Discovery Grant to S.J. Piercey.
2017-04-01T00:00:00Z
Cloutier, Jonathan
Piercey, Stephen J.
Lode, Stefanie
Vande Gutche, Michael
Copeland, David A.
The Lemarchant volcanogenic massive sulphide (VMS) deposit (1.24 Mt grading at 0.58% Cu, 5.38% Zn, 1.19% Pb, 1.01g/t Au, and 59.17g/t Ag) is a bimodal-felsic VMS deposit hosted within the Late Cambrian ($513–509 Ma) Tally Pond group of the Exploit Subzone in central Newfoundland, Canada. The deposit is hosted by andesitic volcaniclastic and volcanic rocks with subordinate dacite flows. The mineralisation is hosted by the dacites and is overlain by pillowed and massive basalts.Four structural breaks offset the local stratigraphic sequences including: 1) the LJ syn-volcanic shear zone; 2) the KJ syn-volcanic shear zone; 3) the Lemarchant thrust; and 4) the Bam normal fault. Deformation of the Lemarchant likely occurred during the Penobscot orogeny (486–478 Ma). Early deformation is marked with the local deformation of the LJ and KJ syn-volcanic shear zones during NW-SE compression which coincided with the development of the Lemarchant thrust. A late (<465Ma) east trending normal fault, the Bam fault, affected the central portion of the Lemarchant area and down-faulted the southern portion of the study area relative to the northern portion.Immobile element systematics of all the sequences from the Lemarchant deposit are tholeiitic with transitional Zr/Y ratios (1.9–6.6), Lan/Smn ratios <1 (normalised to upper crust), and have primitive mantle extended rare earth elements profiles with slight light rare earth element (LREE)-enriched pat- terns with flat heavy REE (HREE), and weak to strong negative Nb, Zr, and Ti anomalies. Together, these geochemical features, coupled with an FIIIa signature, and existing mineralogical and Nd-Pb iso- tope data, are consistent with the rocks at the Lemarchant deposit having formed within a shallow (<1500 m) arc or migrating cross-arc seamount chain located within a young peri-continental rifted arc along the margin of Ganderia, within the Iapetus Ocean. The estimated shallow water emplace- ment of the deposit likely allowed boiling near or at the rock-sea water interface, ultimately resulting in precious metal enrichment of the Lemarchant deposit. It is suggested that cross-arcs within rifted arc environments may represent favourable exploration targets for precious metal-enriched VMS deposits.
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Decrypting the crustal evolution of the Mozambique Belt in Malawi
https://hdl.handle.net/10023/12469
Global paleogeography exerts a first order control on both the deep and surficial components of the Earth system. Temporal and spatial constraints on the Mozambique Belt of Eastern Africa are needed to understand its crustal evolution and its role in assembly of Gondwana. This thesis provides detailed data on the timing, sources and nature of tectono-thermal events responsible for magmatism in the Mozambique Belt in southern Malawi.
An integrated approach of petrography, geochemistry, radiogenic isotopes, and single zircon geochronology has been used to determine spatial and temporal constraints and to better constrain models of the assembly of East and West Gondwana, which occurred along the Mozambique Belt. In particular the thesis attempts to address key unresolved questions about the number and timing of accretionary pulses within the orogen.
LA-ICP-MS single zircon U-Pb results show tectono-thermal events in four periods: Mesoproterozoic from 1128 ± 30 Ma to 1033 ± 20 Ma; Neoproterozoic (956 ± 12 Ma – 594 ± 65 Ma); Cambrian (530 ± 3 Ma – 515 ± 12 Ma); and Cretaceous (118 ± 2 Ma). Metamorphism is dated from a charnockitic gneiss that yielded a lower intercept age of 515 ± 18 Ma.
The granitoids are intermediate to acidic with relative enrichment in LILEs and depletion in HFSEs with moderately negative anomalies in Th, Nb, P, Zr and Ti. REE spider plots show enrichment in LREEs and depleted HREEs with negative Eu anomalies. The meta-granites are largely metaluminous with a few peraluminous, I-type granites belonging to the calc-alkaline series.
Radiogenic isotope data reveals slight differences with older, Mesoproterozoic rocks showing positive ɛNd and ɛHf values signifying derivation from depleted mantle material, whilst the younger rocks display negative epsilon values suggestive of crustal material recycling and mixing for their source and origins.
Granitoids of southern Malawi display characteristics consistent with derivation in a continental Andean type arc with some aspects of the chemistry resembling tonalite-trondhjemite-granite (TTG) suites mapped in the Mozambique Belt in Kenya, Tanzania, Mozambique, and Antarctica although the data are not sufficiently compelling to assign the Malawi rocks to classic TTGs.
2016-06-22T00:00:00Z
Manda, Blackwell Chawala
Global paleogeography exerts a first order control on both the deep and surficial components of the Earth system. Temporal and spatial constraints on the Mozambique Belt of Eastern Africa are needed to understand its crustal evolution and its role in assembly of Gondwana. This thesis provides detailed data on the timing, sources and nature of tectono-thermal events responsible for magmatism in the Mozambique Belt in southern Malawi.
An integrated approach of petrography, geochemistry, radiogenic isotopes, and single zircon geochronology has been used to determine spatial and temporal constraints and to better constrain models of the assembly of East and West Gondwana, which occurred along the Mozambique Belt. In particular the thesis attempts to address key unresolved questions about the number and timing of accretionary pulses within the orogen.
LA-ICP-MS single zircon U-Pb results show tectono-thermal events in four periods: Mesoproterozoic from 1128 ± 30 Ma to 1033 ± 20 Ma; Neoproterozoic (956 ± 12 Ma – 594 ± 65 Ma); Cambrian (530 ± 3 Ma – 515 ± 12 Ma); and Cretaceous (118 ± 2 Ma). Metamorphism is dated from a charnockitic gneiss that yielded a lower intercept age of 515 ± 18 Ma.
The granitoids are intermediate to acidic with relative enrichment in LILEs and depletion in HFSEs with moderately negative anomalies in Th, Nb, P, Zr and Ti. REE spider plots show enrichment in LREEs and depleted HREEs with negative Eu anomalies. The meta-granites are largely metaluminous with a few peraluminous, I-type granites belonging to the calc-alkaline series.
Radiogenic isotope data reveals slight differences with older, Mesoproterozoic rocks showing positive ɛNd and ɛHf values signifying derivation from depleted mantle material, whilst the younger rocks display negative epsilon values suggestive of crustal material recycling and mixing for their source and origins.
Granitoids of southern Malawi display characteristics consistent with derivation in a continental Andean type arc with some aspects of the chemistry resembling tonalite-trondhjemite-granite (TTG) suites mapped in the Mozambique Belt in Kenya, Tanzania, Mozambique, and Antarctica although the data are not sufficiently compelling to assign the Malawi rocks to classic TTGs.
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Gender, space and power : discourses on working women in Dundee's jute industry, c. 1870-1930
https://hdl.handle.net/10023/12450
This thesis explores the discourses on working women in Dundee's jute industry c. 1870-1930. It examines how working women became knowable and visible, and some of the ways in which women negotiated the relationships of power within which they became placed. Dundee was dubbed 'a woman's town' because of the central role that women played in the city's jute industry. Although a recent range of historical scholarship has started to ask new questions about women's identities and experiences of work, this study stresses the importance of engaging more widely with questions of geography, gender, discourse and power-knowledge. I explore how working women were observed, represented and categorised through a variety of material spaces - mills and factories, streets and homes, and through a range of conceptual spaces - economic, philanthropic and medical. The thesis focuses on the very processes and gendered discourses through which working women were made known - the practices of domination and resistance, and surveillance and control, and the different forms of knowledge production, including journalism, accountancy and philanthropy. Particular attention is paid to the ways in which divisions between work and home, and boundaries between public and private, were affirmed, reaffirmed and contested by working women and other urban actors. It is suggested that the work of Michel Foucault and a wider range of geographical and feminist theory provide us with a particularly rich and pliable set of conceptual resources with which to probe working women's geographies and the processes of power-knowledge, in the Dundee context. I suggest that the web of discourse that produced Dundee's working women as objects of concern was aimed not at preventing women from working, but at scrutinising and managing every aspect of their lives.
2002-01-01T00:00:00Z
Wainwright, Emma M.
This thesis explores the discourses on working women in Dundee's jute industry c. 1870-1930. It examines how working women became knowable and visible, and some of the ways in which women negotiated the relationships of power within which they became placed. Dundee was dubbed 'a woman's town' because of the central role that women played in the city's jute industry. Although a recent range of historical scholarship has started to ask new questions about women's identities and experiences of work, this study stresses the importance of engaging more widely with questions of geography, gender, discourse and power-knowledge. I explore how working women were observed, represented and categorised through a variety of material spaces - mills and factories, streets and homes, and through a range of conceptual spaces - economic, philanthropic and medical. The thesis focuses on the very processes and gendered discourses through which working women were made known - the practices of domination and resistance, and surveillance and control, and the different forms of knowledge production, including journalism, accountancy and philanthropy. Particular attention is paid to the ways in which divisions between work and home, and boundaries between public and private, were affirmed, reaffirmed and contested by working women and other urban actors. It is suggested that the work of Michel Foucault and a wider range of geographical and feminist theory provide us with a particularly rich and pliable set of conceptual resources with which to probe working women's geographies and the processes of power-knowledge, in the Dundee context. I suggest that the web of discourse that produced Dundee's working women as objects of concern was aimed not at preventing women from working, but at scrutinising and managing every aspect of their lives.
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Environmental conservation across ecosystem boundaries : connecting management and funding
https://hdl.handle.net/10023/12052
Environmental degradation is accelerating worldwide, yet environmental conservation remains limited by funding. Tackling this limitation requires not only absolute increases in funding, but improved prioritisation of actions. On a global scale island ecosystems are of high priority, with invasive species one of their most significant threats. In this thesis I investigate prioritisation of invasive grazing species control, incorporating ecological, economic, and social concerns, on the island of Bonaire, Caribbean Netherlands. To enable the trade-off of potential grazer control options for their ecological impacts I modelled the relationship between of grazer density and vegetation, and watershed vegetation and the coral reef. I found negative relationships for goat and pig grazing with grass presence, and for donkey grazing with ground cover. Coral cover below 10m showed a positive relationship to ground cover, and, surprisingly, a negative relationship to tree biomass. Because conservation action is most likely to be sustainable when connected to funding, I conducted choice experiments with SCUBA divers, which estimated a positive willingness to pay for reef health improvements achieved using terrestrial grazer control. Through communication with local policy makers and practitioners I identified three options for grazer control, eradication, population reduction, or fencing, and estimated costs and social acceptability for each option. Though the ecological models predicted eradication to have the highest impacts on the terrestrial and marine ecosystem, lower costs and higher social acceptability identified fencing as the most suitable option for grazer control on Bonaire in the short term, with the potential to be funded through a fee on SCUBA divers. Through linking ecological, economic, and social considerations within a real world conservation context I illustrate the importance of looking beyond only ecological improvements when prioritising conservation action. This research is directly applicable to policy and practise on Bonaire
2017-12-07T00:00:00Z
Roberts, Michaela Holly
Environmental degradation is accelerating worldwide, yet environmental conservation remains limited by funding. Tackling this limitation requires not only absolute increases in funding, but improved prioritisation of actions. On a global scale island ecosystems are of high priority, with invasive species one of their most significant threats. In this thesis I investigate prioritisation of invasive grazing species control, incorporating ecological, economic, and social concerns, on the island of Bonaire, Caribbean Netherlands. To enable the trade-off of potential grazer control options for their ecological impacts I modelled the relationship between of grazer density and vegetation, and watershed vegetation and the coral reef. I found negative relationships for goat and pig grazing with grass presence, and for donkey grazing with ground cover. Coral cover below 10m showed a positive relationship to ground cover, and, surprisingly, a negative relationship to tree biomass. Because conservation action is most likely to be sustainable when connected to funding, I conducted choice experiments with SCUBA divers, which estimated a positive willingness to pay for reef health improvements achieved using terrestrial grazer control. Through communication with local policy makers and practitioners I identified three options for grazer control, eradication, population reduction, or fencing, and estimated costs and social acceptability for each option. Though the ecological models predicted eradication to have the highest impacts on the terrestrial and marine ecosystem, lower costs and higher social acceptability identified fencing as the most suitable option for grazer control on Bonaire in the short term, with the potential to be funded through a fee on SCUBA divers. Through linking ecological, economic, and social considerations within a real world conservation context I illustrate the importance of looking beyond only ecological improvements when prioritising conservation action. This research is directly applicable to policy and practise on Bonaire
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Generation and preservation of continental crust in collisional orogenic systems
https://hdl.handle.net/10023/11966
The continental crust is the archive of Earth history. Much of what we know about the development of Earth is learned from the continental crust, and it is within the crust that many natural resources are found. Hence, understanding its formation and evolution is a key aspect to a deeper knowledge of the Earth system.
This thesis is a study of the processes that have formed and shaped the distribution of continental crust, with specific focus on crustal development associated with the Rodinian supercontinent and the Grenville Orogeny spanning ca. 1200 to 900 Ma.
Specifically it addresses an aspect of the incompleteness of the record of continental crust formation. The preserved continental crust is punctuated with periods of lesser and greater frequency of geologic features, e.g., the temporal distribution of the ages of mineral deposits, juvenile granitoids, eclogites, granulites, and the U-Pb crystallization ages of zircons now preserved in modern and ancient sediments (see Gastil, 1960; Barley and Groves, 1992; Condie, 1998; Campbell and Allen, 2008; Brown, 2007; Bradley, 2011). In addition, interpretive features in the geologic record also have an apparent episodic distribution such as passive margins (Bradley, 2011) and supercontinents (Condie, 1998). The episodic nature of these geologic phenomena implies either an episodic formation or preferential preservation of continental crust. These two end member models have been explained through a number of geologic processes such as eruption of superplumes, global disruption of thermal structure of the mantle, assembly of supercontinents, collisional orogenesis. Through the chapters outlined below, this thesis explores the connection of these episodic geologic events with key isotopic signals, principally U-Pb, Hf, and O isotopes in zircon supplemented by sedimentology, structural geology, and igneous geochemistry. It comprises a series of chapters developed around manuscripts prepared for publication.
2013-10-01T00:00:00Z
Spencer, Christopher J.
The continental crust is the archive of Earth history. Much of what we know about the development of Earth is learned from the continental crust, and it is within the crust that many natural resources are found. Hence, understanding its formation and evolution is a key aspect to a deeper knowledge of the Earth system.
This thesis is a study of the processes that have formed and shaped the distribution of continental crust, with specific focus on crustal development associated with the Rodinian supercontinent and the Grenville Orogeny spanning ca. 1200 to 900 Ma.
Specifically it addresses an aspect of the incompleteness of the record of continental crust formation. The preserved continental crust is punctuated with periods of lesser and greater frequency of geologic features, e.g., the temporal distribution of the ages of mineral deposits, juvenile granitoids, eclogites, granulites, and the U-Pb crystallization ages of zircons now preserved in modern and ancient sediments (see Gastil, 1960; Barley and Groves, 1992; Condie, 1998; Campbell and Allen, 2008; Brown, 2007; Bradley, 2011). In addition, interpretive features in the geologic record also have an apparent episodic distribution such as passive margins (Bradley, 2011) and supercontinents (Condie, 1998). The episodic nature of these geologic phenomena implies either an episodic formation or preferential preservation of continental crust. These two end member models have been explained through a number of geologic processes such as eruption of superplumes, global disruption of thermal structure of the mantle, assembly of supercontinents, collisional orogenesis. Through the chapters outlined below, this thesis explores the connection of these episodic geologic events with key isotopic signals, principally U-Pb, Hf, and O isotopes in zircon supplemented by sedimentology, structural geology, and igneous geochemistry. It comprises a series of chapters developed around manuscripts prepared for publication.
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'Visions of wildness' : the place of (re)wilding in Scotland’s uplands
https://hdl.handle.net/10023/11903
Notions of ‘wildness’ are increasingly relevant to upland management discussions in the Scottish Highlands as several conservation-focused estates embrace a ‘wildland management ethos’. However, while a range of wildland conservation initiatives have embarked upon pathways towards ‘rewilding’, this research demonstrates that, although members of this creative conservation movement are widely perceived to share a common vision, they prioritise markedly different wildland qualities. Through a series of triangulated phases, this research explores this ‘spectrum of wildness’ and examines the conceptual coherence of wildland restoration discourses. Twenty semi-structured scoping interviews with key stakeholders associated with Scotland’s wildest places provide the foundations for an adapted Delphi model, incorporating a Q-methodology study, which utilises insights from seventeen large upland land-holdings to interrogate the disparate discourses associated with Scotland’s emergent wildland movement. A taxonomy of management approaches is presented based upon (i) different conceptions of ‘wildness’, (ii) differing degrees of concern for ecological and cultural integrity, (iii) conflicting beliefs about the degree of management intervention appropriate and (iv) fundamentally divergent underlying environmental ideologies. A further twenty-three semi-structured interviews exploring wilderness restoration frameworks in the USA, New Zealand and parts of Europe provide an international perspective on Scotland’s distinctive approach to wildland management and demonstrate the challenges of multi-dimensional wilderness frameworks which grow out of conflicting mandates; most notably, a critical faultline exists between restoring ‘wildness’ (focussed on processes) and naturalness (focussed on endpoints). Given that practical tensions can arise from these different ideological perspectives, understanding and accommodating the social and cultural dimensions which shape multiple (re)wilding discourses is considered critical. As such, place-specific and endogenous social representations are called for, in which wild land is both a physical place and a cultural ideal, and in which (re)wilding comprises a heterogeneous mix of different wilds. This research also critically reflects upon how cultural landscapes with wild qualities present opportunities for rethinking the historical and cultural dimensions of established wilderness values. By exploring the framing of ‘wild’ in Scotland’s wildland initiatives, a postmodern wildlands narrative which negotiates the conceptual challenges of (re)wilding in a storied, cultural landscape is presented.
2014-07-01T00:00:00Z
Deary, Holly Angela
Notions of ‘wildness’ are increasingly relevant to upland management discussions in the Scottish Highlands as several conservation-focused estates embrace a ‘wildland management ethos’. However, while a range of wildland conservation initiatives have embarked upon pathways towards ‘rewilding’, this research demonstrates that, although members of this creative conservation movement are widely perceived to share a common vision, they prioritise markedly different wildland qualities. Through a series of triangulated phases, this research explores this ‘spectrum of wildness’ and examines the conceptual coherence of wildland restoration discourses. Twenty semi-structured scoping interviews with key stakeholders associated with Scotland’s wildest places provide the foundations for an adapted Delphi model, incorporating a Q-methodology study, which utilises insights from seventeen large upland land-holdings to interrogate the disparate discourses associated with Scotland’s emergent wildland movement. A taxonomy of management approaches is presented based upon (i) different conceptions of ‘wildness’, (ii) differing degrees of concern for ecological and cultural integrity, (iii) conflicting beliefs about the degree of management intervention appropriate and (iv) fundamentally divergent underlying environmental ideologies. A further twenty-three semi-structured interviews exploring wilderness restoration frameworks in the USA, New Zealand and parts of Europe provide an international perspective on Scotland’s distinctive approach to wildland management and demonstrate the challenges of multi-dimensional wilderness frameworks which grow out of conflicting mandates; most notably, a critical faultline exists between restoring ‘wildness’ (focussed on processes) and naturalness (focussed on endpoints). Given that practical tensions can arise from these different ideological perspectives, understanding and accommodating the social and cultural dimensions which shape multiple (re)wilding discourses is considered critical. As such, place-specific and endogenous social representations are called for, in which wild land is both a physical place and a cultural ideal, and in which (re)wilding comprises a heterogeneous mix of different wilds. This research also critically reflects upon how cultural landscapes with wild qualities present opportunities for rethinking the historical and cultural dimensions of established wilderness values. By exploring the framing of ‘wild’ in Scotland’s wildland initiatives, a postmodern wildlands narrative which negotiates the conceptual challenges of (re)wilding in a storied, cultural landscape is presented.
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Assessing the relationship between poverty and biodiversity, within the context of land use change in the Solomon Islands
https://hdl.handle.net/10023/11852
There is convergence at the international level that conserving biodiversity can contribute to poverty alleviation, but empirical evidence for this relationship is scarce. In this thesis I assess the relationship between poverty and biodiversity, within the context of land use change, using a case-study from the Solomon Islands. This interdisciplinary study is based on both social and ecological data, primarily collected through focus groups, household surveys and avian line transect surveys. Poor households in Kahua were characterised by fewer members of a working age and fewer male members. They were also found to own fewer assets, which were correlated to lower land tenure. Natural resources, including wild foods, were a crucial resource for the consumption and income for poor households, with evidence of wild foods buffering shortfalls in household consumption. The livelihoods of poor households were dependent on natural resources, whereas wealthier households relied on cash crops. The lower involvement of poor households in cash cropping suggests that the poor have less access to such income sources, possibly through a lack of initial land holding assets. Cash crop areas of monoculture cocoa were the most intensive land use in Kahua and were found to be a poor habitat for many bird species, including most endemics. Overall, the relationship between poverty and biodiversity was found to be complex, context dependent and influenced by various social and institutional factors. Household inequalities in access to land and resources indicate that a social-ecological trap may be occurring for poorer households in Kahua, possibly perpetuated by the livelihoods of wealthier households. More research is required in translating the concept of social-ecological traps into management actions, but this thesis concludes that this could be a useful concept for improving poverty alleviation and biodiversity conservation initiatives.
2014-05-01T00:00:00Z
Davies, Tamara Ellen
There is convergence at the international level that conserving biodiversity can contribute to poverty alleviation, but empirical evidence for this relationship is scarce. In this thesis I assess the relationship between poverty and biodiversity, within the context of land use change, using a case-study from the Solomon Islands. This interdisciplinary study is based on both social and ecological data, primarily collected through focus groups, household surveys and avian line transect surveys. Poor households in Kahua were characterised by fewer members of a working age and fewer male members. They were also found to own fewer assets, which were correlated to lower land tenure. Natural resources, including wild foods, were a crucial resource for the consumption and income for poor households, with evidence of wild foods buffering shortfalls in household consumption. The livelihoods of poor households were dependent on natural resources, whereas wealthier households relied on cash crops. The lower involvement of poor households in cash cropping suggests that the poor have less access to such income sources, possibly through a lack of initial land holding assets. Cash crop areas of monoculture cocoa were the most intensive land use in Kahua and were found to be a poor habitat for many bird species, including most endemics. Overall, the relationship between poverty and biodiversity was found to be complex, context dependent and influenced by various social and institutional factors. Household inequalities in access to land and resources indicate that a social-ecological trap may be occurring for poorer households in Kahua, possibly perpetuated by the livelihoods of wealthier households. More research is required in translating the concept of social-ecological traps into management actions, but this thesis concludes that this could be a useful concept for improving poverty alleviation and biodiversity conservation initiatives.
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Stratigraphy, sedimentology and petrology of the Cambrian rocks in the subsurface of Southern Alberta, Canada
https://hdl.handle.net/10023/11694
The Cambrian section in the subsurface of southern
Alberta has a maximum thickness of 1860'. It is composed of sandstones, shales, limestones, and dolomites.
The grand cycles characteristic of the Cambrian
Sections in the Foothills and Front Ranges can be traced to some distance in the subsurface. However, the section changes facies eastwards into clastics and the grand cycles become less defined. The present correlations indicate that the Waterfowl-Arctomys grand cycle extends to the subsurface but is restricted to the northwest corner of the study area.
Two new stratigraphic units have been informally defined in this study: The Crow Indian Formation of fine clastics and restricted to the southeast corner of Alberta. It is equivalent to the Cathedral, Stephen and Eldon Formations. The second unit is the Sakwatamau Member of the Eldon Formation, a clastic and carbonate deltaic unit restricted to the northwest corner of the study area.
The Cambrian sediments were deposited in a broad shallow shelf-lagoon bordered to the east by the Canadian Shield and to the west by a shoal (the Kicking Horse Rim). Facies and thickness of the Cambrian section were controlled by six paleogeographic elements: 1) The Peace River Arch, 2) the Sweet Grass Arch, 3) the West Alberta Ridge, 4) the Kicking Horse Rim, 5) a shoal area immediately south of the Peace River Arch, and 6) a shoal area immediately north of the Sweet Grass Arch. When circulation in the shelf-lagoon was restricted, carbonate deposition dominated, especially in the shoal areas, and when open marine conditions prevailed, deposition of quartzarenites and glauconitic sandstones took place.
Nine lithofacies have been recognized; 1) Mottled dolomitic mudstones and wackestones; 2) Mudstones, wackestones, and packstones; 3) Grainstones; 4) Cryptalgalaminates, cryptalgalaminate breccia, and algal-laminated sediments;
5) Flat-pebble conglomerates; 6) Glauconitic sandstones; 7) Quartzarenites; 8) Hybrid sandstones or iron-formations, and 9) Coquinas. These facies reflect deposition in environments ranging from supratidal to subtidal. Facies analysis also suggests that storms played a major role during the deposition of these sediments.
Diagenesis (in both clastics and carbonates) appears
to be the product of early, shallow freshwater phreatic-, marine phreatic-, and mixing zones. Dolomitization has developed in the mixing zone, as a result of pressure-solution,
and/or dolomitization of glauconitic illites. Illite, kaolinite, authigenic K-feldspars, and quartz overgrowths were formed in the mixing zone depending on the K⁺ and H₄SiO₄ activity of the solutions.
Fibrous calcite cement was formed in the marine-phreatic zone. Blocky calcite cement, syntaxial rims around echinoderm fragments, and fracture-filling sparry calcite were probably precipitated in the freshwater phreatic zone. Saddle dolomite occurs as burrow-filling and pore-filling in carbonates and as poikilotopic cement and in burrows (concretions) in sandstones. Saddledolomite (in carbonates and clastics) and chlorite (in clastics) were probably the last diagenetic products to form at deep burial and higher temperatures.
1988-01-01T00:00:00Z
Tawadros, Ezzat Edward
The Cambrian section in the subsurface of southern
Alberta has a maximum thickness of 1860'. It is composed of sandstones, shales, limestones, and dolomites.
The grand cycles characteristic of the Cambrian
Sections in the Foothills and Front Ranges can be traced to some distance in the subsurface. However, the section changes facies eastwards into clastics and the grand cycles become less defined. The present correlations indicate that the Waterfowl-Arctomys grand cycle extends to the subsurface but is restricted to the northwest corner of the study area.
Two new stratigraphic units have been informally defined in this study: The Crow Indian Formation of fine clastics and restricted to the southeast corner of Alberta. It is equivalent to the Cathedral, Stephen and Eldon Formations. The second unit is the Sakwatamau Member of the Eldon Formation, a clastic and carbonate deltaic unit restricted to the northwest corner of the study area.
The Cambrian sediments were deposited in a broad shallow shelf-lagoon bordered to the east by the Canadian Shield and to the west by a shoal (the Kicking Horse Rim). Facies and thickness of the Cambrian section were controlled by six paleogeographic elements: 1) The Peace River Arch, 2) the Sweet Grass Arch, 3) the West Alberta Ridge, 4) the Kicking Horse Rim, 5) a shoal area immediately south of the Peace River Arch, and 6) a shoal area immediately north of the Sweet Grass Arch. When circulation in the shelf-lagoon was restricted, carbonate deposition dominated, especially in the shoal areas, and when open marine conditions prevailed, deposition of quartzarenites and glauconitic sandstones took place.
Nine lithofacies have been recognized; 1) Mottled dolomitic mudstones and wackestones; 2) Mudstones, wackestones, and packstones; 3) Grainstones; 4) Cryptalgalaminates, cryptalgalaminate breccia, and algal-laminated sediments;
5) Flat-pebble conglomerates; 6) Glauconitic sandstones; 7) Quartzarenites; 8) Hybrid sandstones or iron-formations, and 9) Coquinas. These facies reflect deposition in environments ranging from supratidal to subtidal. Facies analysis also suggests that storms played a major role during the deposition of these sediments.
Diagenesis (in both clastics and carbonates) appears
to be the product of early, shallow freshwater phreatic-, marine phreatic-, and mixing zones. Dolomitization has developed in the mixing zone, as a result of pressure-solution,
and/or dolomitization of glauconitic illites. Illite, kaolinite, authigenic K-feldspars, and quartz overgrowths were formed in the mixing zone depending on the K⁺ and H₄SiO₄ activity of the solutions.
Fibrous calcite cement was formed in the marine-phreatic zone. Blocky calcite cement, syntaxial rims around echinoderm fragments, and fracture-filling sparry calcite were probably precipitated in the freshwater phreatic zone. Saddle dolomite occurs as burrow-filling and pore-filling in carbonates and as poikilotopic cement and in burrows (concretions) in sandstones. Saddledolomite (in carbonates and clastics) and chlorite (in clastics) were probably the last diagenetic products to form at deep burial and higher temperatures.
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Explaining cultural participation in the UK : a geographical approach
https://hdl.handle.net/10023/11382
This thesis addresses the subject of cultural participation, specifically attendance at
cultural venues in the UK. This is a topic that interests sociologists, in terms of the
social construction of cultural judgements, and how cultural consumption reinforces
and perpetuates social stratification. It also interests cultural funders, in understanding
who benefits from the public subsidy of cultural organisations. However, the
relationship between cultural participation and geographical access to cultural facilities,
a conceptually simple idea, has hardly been addressed in either of these literatures.
Within geography there is extensive evidence for the significant effect of distance on
use of public facilities. The differences in provision of public services or “spatial equity”
that people experience according to where they live means that neighbourhoods act as
“opportunity structures”.
The empirical work in this thesis is presented in four chapters written as standalone
papers. Nonetheless the thesis represents a unified piece of work, addressing common
research questions, as elaborated in the conceptual framework and research design
chapters, through four case studies. This thesis overall, and in each study, extends the
explanation of cultural participation being driven by social stratification, to understand
the effect of access to cultural infrastructure on participation. Using both survey and
administrative data, covering Scotland and London, a range of analytical techniques and
innovative accessibility measures are used to assess the impact of access to facilities on
participation. The effect of access, as well as other spatial variables including access to
public transport, commuting behaviour and competing destinations, are found to be
highly significant, with comparable effects to the social stratification previously
identified.
These findings have important implications for cultural policy. Arts funders may justify
the continued regional differences in levels of cultural funding on their support of the
creative industries, which demonstrate spatial agglomeration. However, on the
evidence presented here, it is not sustainable to continue to claim that the supply of
arts venues has little effect on cultural participation (Marsh et al. 2010b, 112).
2015-01-01T00:00:00Z
Brook, Orian
This thesis addresses the subject of cultural participation, specifically attendance at
cultural venues in the UK. This is a topic that interests sociologists, in terms of the
social construction of cultural judgements, and how cultural consumption reinforces
and perpetuates social stratification. It also interests cultural funders, in understanding
who benefits from the public subsidy of cultural organisations. However, the
relationship between cultural participation and geographical access to cultural facilities,
a conceptually simple idea, has hardly been addressed in either of these literatures.
Within geography there is extensive evidence for the significant effect of distance on
use of public facilities. The differences in provision of public services or “spatial equity”
that people experience according to where they live means that neighbourhoods act as
“opportunity structures”.
The empirical work in this thesis is presented in four chapters written as standalone
papers. Nonetheless the thesis represents a unified piece of work, addressing common
research questions, as elaborated in the conceptual framework and research design
chapters, through four case studies. This thesis overall, and in each study, extends the
explanation of cultural participation being driven by social stratification, to understand
the effect of access to cultural infrastructure on participation. Using both survey and
administrative data, covering Scotland and London, a range of analytical techniques and
innovative accessibility measures are used to assess the impact of access to facilities on
participation. The effect of access, as well as other spatial variables including access to
public transport, commuting behaviour and competing destinations, are found to be
highly significant, with comparable effects to the social stratification previously
identified.
These findings have important implications for cultural policy. Arts funders may justify
the continued regional differences in levels of cultural funding on their support of the
creative industries, which demonstrate spatial agglomeration. However, on the
evidence presented here, it is not sustainable to continue to claim that the supply of
arts venues has little effect on cultural participation (Marsh et al. 2010b, 112).
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"I wasnae on anyone's list for haeing a heart attack. I thought I wis bullet proof!" : understanding men's and women's experiences of and their responses to heart attack and recovery in post-industrial Fife, Scotland
https://hdl.handle.net/10023/11375
Coronary heart disease (including heart attacks) is a major cause of mortality and
morbidity and within the UK the highest rates of CHD are observed in Scotland.
Geographical health inequalities are observed for CHD and this continues to be a policy
priority for government. Place effects exist for understanding health variations but there
is uncertainty about how place shapes lives and influences individual behaviour. This
mixed methods thesis evolved from a largely quantitative study initially interested in
measuring geographical variations of CHD outcomes in Fife, to a primarily qualitative
study. Fifty participants were interviewed to illuminate how they constructed their heart
attack and recovery experiences. Recovery from the heart attack was explored in relation
to cardiac rehabilitation, a programme designed to improve health after heart attack.
Additionally, interviews were conducted with eight NHS Fife cardiac staff involved in
cardiac rehabilitation. Often research into CHD (and heart attack) has primarily focused
on symptoms, risk factors and treatment and there is a limited amount of qualitative
research exploring men’s and women’s experiences of heart attacks and/or recovery in
place. Experiences of and responses to heart attack take place within the wider social
contexts where people live their lives, therefore it was important to situate these
experiences in and through place. Places are socially constructed and beliefs about
health, ill health and heart attacks are influenced by social, historical and local contexts.
The findings indicated that a heart attack is an often disruptive experience with physical,
emotional and psychological consequences. Participants attempted to ‘make sense’ of
their heart attack in myriad ways and the impact and consequences which the heart
attack produces for participants’ day to day lives suggested that heart attack and recovery
are experienced in different ways for men and women from different social locations in
Fife. Additionally, places produce opportunities and obstacles for health, ill health and
recovery and specific barriers to engagement with cardiac rehabilitation were found
including organisational, infrastructural, situated and gendered experience factors. This
thesis explores the complex interaction between gender, health and place with regards to
how heart attack experiences and recovery are influenced and shaped within Fife,
Scotland.
2014-01-01T00:00:00Z
McGarrol, Sarah
Coronary heart disease (including heart attacks) is a major cause of mortality and
morbidity and within the UK the highest rates of CHD are observed in Scotland.
Geographical health inequalities are observed for CHD and this continues to be a policy
priority for government. Place effects exist for understanding health variations but there
is uncertainty about how place shapes lives and influences individual behaviour. This
mixed methods thesis evolved from a largely quantitative study initially interested in
measuring geographical variations of CHD outcomes in Fife, to a primarily qualitative
study. Fifty participants were interviewed to illuminate how they constructed their heart
attack and recovery experiences. Recovery from the heart attack was explored in relation
to cardiac rehabilitation, a programme designed to improve health after heart attack.
Additionally, interviews were conducted with eight NHS Fife cardiac staff involved in
cardiac rehabilitation. Often research into CHD (and heart attack) has primarily focused
on symptoms, risk factors and treatment and there is a limited amount of qualitative
research exploring men’s and women’s experiences of heart attacks and/or recovery in
place. Experiences of and responses to heart attack take place within the wider social
contexts where people live their lives, therefore it was important to situate these
experiences in and through place. Places are socially constructed and beliefs about
health, ill health and heart attacks are influenced by social, historical and local contexts.
The findings indicated that a heart attack is an often disruptive experience with physical,
emotional and psychological consequences. Participants attempted to ‘make sense’ of
their heart attack in myriad ways and the impact and consequences which the heart
attack produces for participants’ day to day lives suggested that heart attack and recovery
are experienced in different ways for men and women from different social locations in
Fife. Additionally, places produce opportunities and obstacles for health, ill health and
recovery and specific barriers to engagement with cardiac rehabilitation were found
including organisational, infrastructural, situated and gendered experience factors. This
thesis explores the complex interaction between gender, health and place with regards to
how heart attack experiences and recovery are influenced and shaped within Fife,
Scotland.
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The impact of alcohol consumption on patterns of union formation in Russia 1998–2010 : an assessment using longitudinal data
https://hdl.handle.net/10023/11337
Using data from the Russian Longitudinal Monitoring Survey, 1998–2010, we investigated the extent to which patterns of alcohol consumption in Russia are associated with the subsequent likelihood of entry into cohabitation and marriage. Using discrete-time event history analysis we estimated for 16–50 year olds the extent to which the probabilities of entry into the two types of union were affected by the amount of alcohol drunk and the pattern of drinking, adjusted to allow for social and demographic factors including income, employment, and health. The results show that individuals who did not drink alcohol were less likely to embark on either cohabitation or marriage, that frequent consumption of alcohol was associated with a greater chance of entering unmarried cohabitation than of entering into a marriage, and that heavy drinkers were less likely to convert their relationship from cohabitation to marriage.
Research for this paper was funded by Economic and Social Research Council grant: ES/I903224/1.
2014-10-01T00:00:00Z
Keenan, Katherine
Kenward, Michael G.
Grundy, Emily
Leon, David A.
Using data from the Russian Longitudinal Monitoring Survey, 1998–2010, we investigated the extent to which patterns of alcohol consumption in Russia are associated with the subsequent likelihood of entry into cohabitation and marriage. Using discrete-time event history analysis we estimated for 16–50 year olds the extent to which the probabilities of entry into the two types of union were affected by the amount of alcohol drunk and the pattern of drinking, adjusted to allow for social and demographic factors including income, employment, and health. The results show that individuals who did not drink alcohol were less likely to embark on either cohabitation or marriage, that frequent consumption of alcohol was associated with a greater chance of entering unmarried cohabitation than of entering into a marriage, and that heavy drinkers were less likely to convert their relationship from cohabitation to marriage.
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Life-course partnership history and midlife health behaviours in a population-based birth cohort
https://hdl.handle.net/10023/11273
Background: Marital and partnership history is strongly associated with health in midlife and later life. However, the role of health behaviours as an explanatory mechanism remains unclear. The aim of this study was to investigate prospective associations between life-course partnership trajectories (taking into account timing, non-marital cohabitation, remarriage and marital transitions) and health behaviours measured in midlife. Methods: We analysed data from the British National Child Development Study, a prospective cohort study that includes all people born in 1 week of March 1958 (N=10 226). This study included men and women with prospective data on partnership history from age 23 to 42–44 and health behaviours collected at ages 42–46 (2000–2004). Latent class analysis was used to derive longitudinal trajectories of partnership history. We used multivariable regression models to estimate the association between midlife health behaviours and partnership trajectory, adjusting for various early and young adult characteristics. Results: After adjustment for a range of potential selection factors in childhood and early adulthood, we found that problem drinking, heavy drinking and smoking were more common in men and women who experienced divorce or who had never married or cohabited. Women who married later had a lower prevalence of smoking and were less likely to be overweight than those who married earlier. Overall marriage was associated with a higher body mass index. Individuals who never married or cohabited spent less time exercising. Conclusions: Some aspects of partnership history such as remaining unpartnered and experiencing divorce are associated with more smoking and drinking in midlife, whereas marriage is associated with midlife weight gain. Despite these offsetting influences, differences in health behaviours probably account for much of the association between partnership trajectories and health found in previous studies.
The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013)/ ERC grant agreement n° 324055.
2017-03-01T00:00:00Z
Keenan, Katherine
Ploubidis, George B.
Silverwood, Richard J.
Grundy, Emily
Background: Marital and partnership history is strongly associated with health in midlife and later life. However, the role of health behaviours as an explanatory mechanism remains unclear. The aim of this study was to investigate prospective associations between life-course partnership trajectories (taking into account timing, non-marital cohabitation, remarriage and marital transitions) and health behaviours measured in midlife. Methods: We analysed data from the British National Child Development Study, a prospective cohort study that includes all people born in 1 week of March 1958 (N=10 226). This study included men and women with prospective data on partnership history from age 23 to 42–44 and health behaviours collected at ages 42–46 (2000–2004). Latent class analysis was used to derive longitudinal trajectories of partnership history. We used multivariable regression models to estimate the association between midlife health behaviours and partnership trajectory, adjusting for various early and young adult characteristics. Results: After adjustment for a range of potential selection factors in childhood and early adulthood, we found that problem drinking, heavy drinking and smoking were more common in men and women who experienced divorce or who had never married or cohabited. Women who married later had a lower prevalence of smoking and were less likely to be overweight than those who married earlier. Overall marriage was associated with a higher body mass index. Individuals who never married or cohabited spent less time exercising. Conclusions: Some aspects of partnership history such as remaining unpartnered and experiencing divorce are associated with more smoking and drinking in midlife, whereas marriage is associated with midlife weight gain. Despite these offsetting influences, differences in health behaviours probably account for much of the association between partnership trajectories and health found in previous studies.
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Late Quaternary glaciation and environmental change in Southern Ross-shire, Scotland
https://hdl.handle.net/10023/11114
Despite considerable active research in the realm of Quaternary studies in Scotland, some parts of the Scottish Highlands remain largely uninvestigated in terms of both glacial and environmental history. For many areas of Scotland the glacial history has been examined: researchers have ascertained aspects of the nature of the Late Devensian (Weichselian) ice sheet that covered most of Scotland and subsequent readvances, chiefly the Loch Lomond Readvance. In a 1979 review of the Loch Lomond Readvance in the British Isles, Sissons published a map of the glacial limits relating to this latest period of glacial activity in Scotland (Figure 1.1).
Since then this map has been only slightly modified with certain limits having been established in the western Grampians. For the area further north, little accurate information has been added to this picture. One of the most noticeable omissions in
relation to the Loch Lomond Readvance is in the area between Glen Carron and Glen
Shiel in southern Ross-shire. Published research regarding the earlier Late Devensian ice sheet is also sparse. Information regarding other aspects of the Quaternary such as those detailed in other parts of the Scottish Highlands are similarly lacking for this area. There are no published accounts of the vegetation history of the area nor of Late Quaternary sea-level changes. This study seeks to fill in some of these gaps with specific reference to the Late Devensian glaciation and aims to relate the patterns of glaciation with other contemporaneous environmental changes through to the establishing of interglacial conditions in the early Flandrian period. Recent studies have demonstrated that aspects of the Late Quaternary environment can usefully be related and this study attempts to follow a similar procedure.
1996-01-01T00:00:00Z
Tate, C. Jill
Despite considerable active research in the realm of Quaternary studies in Scotland, some parts of the Scottish Highlands remain largely uninvestigated in terms of both glacial and environmental history. For many areas of Scotland the glacial history has been examined: researchers have ascertained aspects of the nature of the Late Devensian (Weichselian) ice sheet that covered most of Scotland and subsequent readvances, chiefly the Loch Lomond Readvance. In a 1979 review of the Loch Lomond Readvance in the British Isles, Sissons published a map of the glacial limits relating to this latest period of glacial activity in Scotland (Figure 1.1).
Since then this map has been only slightly modified with certain limits having been established in the western Grampians. For the area further north, little accurate information has been added to this picture. One of the most noticeable omissions in
relation to the Loch Lomond Readvance is in the area between Glen Carron and Glen
Shiel in southern Ross-shire. Published research regarding the earlier Late Devensian ice sheet is also sparse. Information regarding other aspects of the Quaternary such as those detailed in other parts of the Scottish Highlands are similarly lacking for this area. There are no published accounts of the vegetation history of the area nor of Late Quaternary sea-level changes. This study seeks to fill in some of these gaps with specific reference to the Late Devensian glaciation and aims to relate the patterns of glaciation with other contemporaneous environmental changes through to the establishing of interglacial conditions in the early Flandrian period. Recent studies have demonstrated that aspects of the Late Quaternary environment can usefully be related and this study attempts to follow a similar procedure.
-
Accessory mineral growth histories : implications for granitoid petrogenesis
https://hdl.handle.net/10023/11059
Accessory minerals in granitoids are major repositories of several geochemically-important trace elements and isotopes and in order to quantify the influence that they have over granitoid petrogenesis it is necessary to characterize fully their behaviour. In particular it is necessary to understand accessory mineral/melt partitioning of trace elements and within grain elemental diffusivities, the latter is of relevance when assessing the state of isotopic equilibration between a refractory accessory phase and a contacting melt.
In this study the backscattered electron (BSE) imaging technique, coupled with quantitative electron microprobe analysis indicate that granitoid zircons and titanites (mainly taken from Caledonian intrusive complexes) are commonly compositionally zoned. The zoning textures observed in these minerals, namely crystal face-parallel zoning, non-planar compositional zoning (included here are subhedral and anhedral core structures) and compositional sector zoning, indicate that the kinetic factors of crystal growth, i.e. within magma elemental diffusion rates, crystal growth rates, interface kinetics and dissolution kinetics, are largely responsible for the patterns of compositional zoning that have been observed. This fording is in marked contrast to other studies which have assumed that kinetics are not important in crystallizing plutonic granitoid magmas.
Accessory mineral growth histories have been studied in a few well constrained samples from the Caledonian-age Strontian Complex of NW Scotland. The zircons from the central intrusion of this composite pluton have abundant inherited cores. The cores contain a variety
of zoning structures and have a wide range of composition, which are taken to indicate that
the cores had a wide variety of ultimate sources. Titanites from both the outer and inner
intrusions have compositional sector zoning and the range of composition shown by the titanites is largely due to this fact. In this pluton magma composition appears to have little
influence on titanite chemistry. The REE abundances in both parts to the intrusion are largely controlled by the accessory phases and each of these phases have very different rock-normalised REE distribution patterns. These abundance patterns are dependent on the
relative partition coefficients that each phase has for the REE, the accessory mineral assemblage present and the crystallization order of that assemblage.
The zircons from the central acid member of the Strontian Complex, which are known to have substantial U-Pb inheritance were extracted and analysed for their Sm-Nd isotopic composition. The results apparently indicate that refractory zircons can also preserve their
Sm-Nd isotopic composition, a phenomenon not previously reported. That is diffusion of Sm and Nd (and presumably the other REE) within refractory zircon at elevated temperatures
appears to be sufficiently slow that complete isotopic equilibration between a zircon and a
contacting melt may not always occur. Such disequilibrium potentially enables granitoid
magma provenance to be studied with much greater resolution than hitherto possible.
1990-01-01T00:00:00Z
Paterson, Bruce Andrew
Accessory minerals in granitoids are major repositories of several geochemically-important trace elements and isotopes and in order to quantify the influence that they have over granitoid petrogenesis it is necessary to characterize fully their behaviour. In particular it is necessary to understand accessory mineral/melt partitioning of trace elements and within grain elemental diffusivities, the latter is of relevance when assessing the state of isotopic equilibration between a refractory accessory phase and a contacting melt.
In this study the backscattered electron (BSE) imaging technique, coupled with quantitative electron microprobe analysis indicate that granitoid zircons and titanites (mainly taken from Caledonian intrusive complexes) are commonly compositionally zoned. The zoning textures observed in these minerals, namely crystal face-parallel zoning, non-planar compositional zoning (included here are subhedral and anhedral core structures) and compositional sector zoning, indicate that the kinetic factors of crystal growth, i.e. within magma elemental diffusion rates, crystal growth rates, interface kinetics and dissolution kinetics, are largely responsible for the patterns of compositional zoning that have been observed. This fording is in marked contrast to other studies which have assumed that kinetics are not important in crystallizing plutonic granitoid magmas.
Accessory mineral growth histories have been studied in a few well constrained samples from the Caledonian-age Strontian Complex of NW Scotland. The zircons from the central intrusion of this composite pluton have abundant inherited cores. The cores contain a variety
of zoning structures and have a wide range of composition, which are taken to indicate that
the cores had a wide variety of ultimate sources. Titanites from both the outer and inner
intrusions have compositional sector zoning and the range of composition shown by the titanites is largely due to this fact. In this pluton magma composition appears to have little
influence on titanite chemistry. The REE abundances in both parts to the intrusion are largely controlled by the accessory phases and each of these phases have very different rock-normalised REE distribution patterns. These abundance patterns are dependent on the
relative partition coefficients that each phase has for the REE, the accessory mineral assemblage present and the crystallization order of that assemblage.
The zircons from the central acid member of the Strontian Complex, which are known to have substantial U-Pb inheritance were extracted and analysed for their Sm-Nd isotopic composition. The results apparently indicate that refractory zircons can also preserve their
Sm-Nd isotopic composition, a phenomenon not previously reported. That is diffusion of Sm and Nd (and presumably the other REE) within refractory zircon at elevated temperatures
appears to be sufficiently slow that complete isotopic equilibration between a zircon and a
contacting melt may not always occur. Such disequilibrium potentially enables granitoid
magma provenance to be studied with much greater resolution than hitherto possible.
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Younger Dryas moraines in the NW Highlands of Scotland : genesis, significance and potential modern analogues
https://hdl.handle.net/10023/10993
The Younger Dryas was the last period during which glaciers shaped large parts of the Scottish
landscape. Reconstructing the palaeoclimate and glacial processes that operated during this time is crucial for the understanding of past atmosphere-cryosphere interactions and predicting future climate change.
This thesis presents results from geomorphological and geological mapping in the NW
Highlands of Scotland that have resulted in the reconstruction of a Younger Dryas ice cap.
Reconstruction of equilibrium-line altitudes and palaeo-precipitation values suggest that the Scottish west coast was wetter than at present.
Detailed sedimentological analyses of "hummocky moraines" allow the modes of moraine
formation to be reconstructed in great detail and existing models to be tested. "Hummocky moraines" largely represent terrestrial ice-contact fans consisting of supraglacial debris flows and intercalated glaciofluvial units indicating an ice-marginal mode of formation. Different stages of deformation in these fans indicate highly dynamic glaciers that oscillated during retreat, partly or completely overriding previously formed landforms during readvances. Clast shape analyses reveal that debris was mostly subglacially derived and transported. The evidence is incompatible with a morphological model according to which the moraines could be formed by englacial thrusting.
Comparison with modem glacial landsystems indicates the following similarities with Scottish
Younger Dryas glaciers. Low winter temperatures are similar to those on Svalbard, the marginal
response of Younger Dryas glaciers to temperate environments and the modes of deposition to less responsive debris-covered glaciers. High precipitation along the Scottish west coast probably suppressed continuous permafrost development and caused high mass turnover and very dynamic, dominantly temperate Younger Dryas glaciers. Only a narrow zone around the margins appears to have been frozen to the ground, aiding elevation of basal debris and rapid deposition near the snout. The specific climatic and glaciological conditions during the Younger Dryas appear not to have a single modem analogue.
2005-01-01T00:00:00Z
Lukas, Sven
The Younger Dryas was the last period during which glaciers shaped large parts of the Scottish
landscape. Reconstructing the palaeoclimate and glacial processes that operated during this time is crucial for the understanding of past atmosphere-cryosphere interactions and predicting future climate change.
This thesis presents results from geomorphological and geological mapping in the NW
Highlands of Scotland that have resulted in the reconstruction of a Younger Dryas ice cap.
Reconstruction of equilibrium-line altitudes and palaeo-precipitation values suggest that the Scottish west coast was wetter than at present.
Detailed sedimentological analyses of "hummocky moraines" allow the modes of moraine
formation to be reconstructed in great detail and existing models to be tested. "Hummocky moraines" largely represent terrestrial ice-contact fans consisting of supraglacial debris flows and intercalated glaciofluvial units indicating an ice-marginal mode of formation. Different stages of deformation in these fans indicate highly dynamic glaciers that oscillated during retreat, partly or completely overriding previously formed landforms during readvances. Clast shape analyses reveal that debris was mostly subglacially derived and transported. The evidence is incompatible with a morphological model according to which the moraines could be formed by englacial thrusting.
Comparison with modem glacial landsystems indicates the following similarities with Scottish
Younger Dryas glaciers. Low winter temperatures are similar to those on Svalbard, the marginal
response of Younger Dryas glaciers to temperate environments and the modes of deposition to less responsive debris-covered glaciers. High precipitation along the Scottish west coast probably suppressed continuous permafrost development and caused high mass turnover and very dynamic, dominantly temperate Younger Dryas glaciers. Only a narrow zone around the margins appears to have been frozen to the ground, aiding elevation of basal debris and rapid deposition near the snout. The specific climatic and glaciological conditions during the Younger Dryas appear not to have a single modem analogue.
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Women and citizenship post-trafficking : the case of Nepal
https://hdl.handle.net/10023/10786
This article analyses the relationship between gender, sexuality and citizenship embedded in models of citizenship in the Global South, specifically in South Asia, and the meanings associated with having - or not having - citizenship. It does this through an examination of women's access to citizenship in Nepal in the context of the construction of the emergent nation state in the 'new' Nepal 'post-conflict'. Our analysis explores gendered and sexualized constructions of citizenship in this context through a specific focus on women who have experienced trafficking, and are beginning to organize around rights to sustainable livelihoods and actively lobby for changes in citizenship rules which discriminate against women. Building from this, in the final section we consider important implications of this analysis of post-trafficking experiences for debates about gender, sexuality and citizenship more broadly.
The research for this paper was funded by the Economic and Social Research Council – ESRC Res-062-23-1490: ‘Post Trafficking in Nepal: Sexuality and Citizenship in Livelihood Strategies’. Diane Richardson would like to acknowledge the support provided by the award of a Leverhulme TrustMajor Research Fellowship, ‘Transforming Citizenship: Sexuality, Gender and Citizenship Struggles’ [award MRF-2012-106].
2016-05-01T00:00:00Z
Richardson, Diane
Laurie, Nina
Poudel, Meena
Townsend, Janet
This article analyses the relationship between gender, sexuality and citizenship embedded in models of citizenship in the Global South, specifically in South Asia, and the meanings associated with having - or not having - citizenship. It does this through an examination of women's access to citizenship in Nepal in the context of the construction of the emergent nation state in the 'new' Nepal 'post-conflict'. Our analysis explores gendered and sexualized constructions of citizenship in this context through a specific focus on women who have experienced trafficking, and are beginning to organize around rights to sustainable livelihoods and actively lobby for changes in citizenship rules which discriminate against women. Building from this, in the final section we consider important implications of this analysis of post-trafficking experiences for debates about gender, sexuality and citizenship more broadly.
-
Late-Holocene land surface change in a coupled social-ecological system, southern Iceland : a cross-scale tephrochronology approach
https://hdl.handle.net/10023/10712
The chronological challenge of cross-scale analysis within coupled socio-ecological systems can be met with tephrochronology based on numerous well-dated tephra layers. We illustrate this with an enhanced chronology from Skaftártunga, south Iceland that is based on 200 stratigraphic profiles and 2635 individual tephra deposits from 23 different eruptions within the last 1140 years. We present new sediment-accumulation rate based dating of tephra layers from Grímsvötn in AD 1432 ± 5 and AD 1457 ± 5. These and other tephras underpin an analysis of land surface stability across multiple scales. The aggregate regional sediment accumulation records suggest a relatively slow rate of land surface change which can be explained by climate and land use change over the period of human occupation of the island (after AD ∼870), but the spatial patterning of change shows that it is more complex, with landscape scale hysteresis and path dependency making the relationship between climate and land surface instability contingent. An alternative steady state of much higher rates of sediment accumulation is seen in areas below 300 m asl after AD ∼870 despite large variations in climate, with two phases of increased erosion, one related to vegetation change (AD 870–1206) and another related to climate (AD 1597–1918). In areas above 300 m asl there is a short lived increase in erosion and related deposition after settlement (AD ∼870–935) and then relatively little additional change to present. Spatial correlation between rates of sediment accumulation at different profiles decreases rapidly after AD ∼935 from ∼4 km to less than 250 m as the landscape becomes more heterogeneous. These new insights are only possible using high-resolution tephrochronology applied spatially across a landscape, an approach that can be applied to the large areas of the Earth's surface affected by the repeated fallout of cm-scale tephra layers.
This work is supported by a UK Natural Environment Research Council (NERC) PhD studentship (NE/F00799X/1)
2014-02-15T00:00:00Z
Streeter, Richard Thomas
Dugmore, Andrew
The chronological challenge of cross-scale analysis within coupled socio-ecological systems can be met with tephrochronology based on numerous well-dated tephra layers. We illustrate this with an enhanced chronology from Skaftártunga, south Iceland that is based on 200 stratigraphic profiles and 2635 individual tephra deposits from 23 different eruptions within the last 1140 years. We present new sediment-accumulation rate based dating of tephra layers from Grímsvötn in AD 1432 ± 5 and AD 1457 ± 5. These and other tephras underpin an analysis of land surface stability across multiple scales. The aggregate regional sediment accumulation records suggest a relatively slow rate of land surface change which can be explained by climate and land use change over the period of human occupation of the island (after AD ∼870), but the spatial patterning of change shows that it is more complex, with landscape scale hysteresis and path dependency making the relationship between climate and land surface instability contingent. An alternative steady state of much higher rates of sediment accumulation is seen in areas below 300 m asl after AD ∼870 despite large variations in climate, with two phases of increased erosion, one related to vegetation change (AD 870–1206) and another related to climate (AD 1597–1918). In areas above 300 m asl there is a short lived increase in erosion and related deposition after settlement (AD ∼870–935) and then relatively little additional change to present. Spatial correlation between rates of sediment accumulation at different profiles decreases rapidly after AD ∼935 from ∼4 km to less than 250 m as the landscape becomes more heterogeneous. These new insights are only possible using high-resolution tephrochronology applied spatially across a landscape, an approach that can be applied to the large areas of the Earth's surface affected by the repeated fallout of cm-scale tephra layers.
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Co-producing a post-trafficking agenda : collaborating on transforming citizenship in Nepal
https://hdl.handle.net/10023/10341
This article discusses how a new agenda on post-trafficking is gaining momentum through academic and activist anti-trafficking collaborations focused on co-producing knowledge with women who have returned from trafficking situations. Co-production of this nature is important as the issues raised by post-trafficking scenarios are largely ignored in anti-trafficking strategies, and the stigmatisation and poverty which women in these circumstances encounter means they rarely have a voice in policy-making. Drawing on research in Nepal, we present four types of co-produced data around transforming citizenship post-trafficking, and reflect on the strategies for generating and using them for advocacy purposes.
2015-05-19T00:00:00Z
Laurie, Nina
Richardson, Diane
Poudel, Meena
Samuha, Shakti
Townsend, Janet
This article discusses how a new agenda on post-trafficking is gaining momentum through academic and activist anti-trafficking collaborations focused on co-producing knowledge with women who have returned from trafficking situations. Co-production of this nature is important as the issues raised by post-trafficking scenarios are largely ignored in anti-trafficking strategies, and the stigmatisation and poverty which women in these circumstances encounter means they rarely have a voice in policy-making. Drawing on research in Nepal, we present four types of co-produced data around transforming citizenship post-trafficking, and reflect on the strategies for generating and using them for advocacy purposes.
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Modelling melt beneath supraglacial debris : implications for the climatic response of debris-covered glaciers
https://hdl.handle.net/10023/10264
Understanding how debris-covered glaciers respond to climate is necessary in order to
evaluate future water resources and glacier flood hazard potential, and to make sense of the
glacier chronology in mountain regions, In order achieve this, it is necessary to improve the
current understanding of how surface debris affects glacier ablation rate, and to develop
methods by which the ablation of debris-covered glaciers can be predicted under various
climatic scenarios.
This thesis develops a numerical surface energy balance model that uses simple
meteorological data to calculate melt beneath a debris layer of given thickness and thermal
characteristics. Field data from three contrasting sites demonstrate that the assumptions
made within the model concerning the thermal properties of supraglacial debris are valid
during most ablation conditions and that model performance is considerably better than
previous models.
Model results indicate that the effect of debris on melt rate is highly dependent on
meteorological conditions. Under colder climates, thin debris can accelerate ice melt by
extending the ablation period at both diurnal and seasonal scales. However, in milder mid-
summer conditions, even a very thin debris cover inhibits melt rate compared to that of
exposed ice.
The new melt model is applied to produce the first quantified ablation gradients for debris-
covered glaciers, and to model the evolution of ice surfaces under a debris layer of variable
thickness. Modelled ablation gradients are qualitatively similar to hypothetical ones outlined
previously, and quantitatively similar to those measured in the field. The ablation gradients
are used to explore the factors affecting the response of debris-covered glaciers to climate
change. Beneath a debris layer of variable thickness, the melt model produced ablation
topography, as observed in the field, which underwent topographic inversion over time in
response to debris redistribution. Debris thickness variability was found to cause calculated
ablation rate to increase compared to that calculated using a mean debris thickness by one to
two orders of magnitude, suggesting that melt calculations made on the basis of spatially
averaged debris thickness may be inaccurate.
2005-01-01T00:00:00Z
Nicholson, Lindsey
Understanding how debris-covered glaciers respond to climate is necessary in order to
evaluate future water resources and glacier flood hazard potential, and to make sense of the
glacier chronology in mountain regions, In order achieve this, it is necessary to improve the
current understanding of how surface debris affects glacier ablation rate, and to develop
methods by which the ablation of debris-covered glaciers can be predicted under various
climatic scenarios.
This thesis develops a numerical surface energy balance model that uses simple
meteorological data to calculate melt beneath a debris layer of given thickness and thermal
characteristics. Field data from three contrasting sites demonstrate that the assumptions
made within the model concerning the thermal properties of supraglacial debris are valid
during most ablation conditions and that model performance is considerably better than
previous models.
Model results indicate that the effect of debris on melt rate is highly dependent on
meteorological conditions. Under colder climates, thin debris can accelerate ice melt by
extending the ablation period at both diurnal and seasonal scales. However, in milder mid-
summer conditions, even a very thin debris cover inhibits melt rate compared to that of
exposed ice.
The new melt model is applied to produce the first quantified ablation gradients for debris-
covered glaciers, and to model the evolution of ice surfaces under a debris layer of variable
thickness. Modelled ablation gradients are qualitatively similar to hypothetical ones outlined
previously, and quantitatively similar to those measured in the field. The ablation gradients
are used to explore the factors affecting the response of debris-covered glaciers to climate
change. Beneath a debris layer of variable thickness, the melt model produced ablation
topography, as observed in the field, which underwent topographic inversion over time in
response to debris redistribution. Debris thickness variability was found to cause calculated
ablation rate to increase compared to that calculated using a mean debris thickness by one to
two orders of magnitude, suggesting that melt calculations made on the basis of spatially
averaged debris thickness may be inaccurate.
-
Discourses of energy justice : the case of nuclear energy
https://hdl.handle.net/10023/10255
The energy sector faces sustainability challenges that are re-working the established patterns of energy supply, distribution and consumption (Anderson et al. 2008; Haas et al. 2008; Stern 2008; Shove and Walker 2010). Amidst these challenges, socio-technical energy transitions frameworks have evolved that focus on transitions towards decarbonised, sustainable energy systems (Bridge et al. 2013). However, the ‘socio-‘ or social is typically missing as we confront climate and energy risks in a moral vacuum (Sovacool et al. 2016). The energy justice framework provides a structure to think about such energy dilemmas. However, the full extent and diversity of justice implications within the energy system have been neglected. Thus, borrowing from and advancing the framework this research explores how energy justice is being articulated with attention to three emergent areas of growth, the themes of: (1) time, (2) systems component and (3) actor. It does so through a case study of nuclear energy, which was chosen because of its points of enquiry with regards to these three areas of growth, and its historical and on-going importance in the UK energy mix. Using results from 36 semi-structured interviews with non-governmental organisations and policy actors across two case studies representative of the nuclear energy stages of energy production and of waste storage, disposal and reprocessing – the Hinkley Point and Sellafield nuclear complexes – this research presents new insights within each of these previously identified areas of development. It offers the contributions of (1) facility lifecycles, (2) systems approaches and (3) the question of ‘justice by whom?’ and concludes that the energy justice framework can aid energy decision-making in a way that not only mitigates the environmental impacts of energy via socio-technical change, but also does so in an ethically defensible, socially just, way.
2017-06-21T00:00:00Z
Jenkins, Kirsten
The energy sector faces sustainability challenges that are re-working the established patterns of energy supply, distribution and consumption (Anderson et al. 2008; Haas et al. 2008; Stern 2008; Shove and Walker 2010). Amidst these challenges, socio-technical energy transitions frameworks have evolved that focus on transitions towards decarbonised, sustainable energy systems (Bridge et al. 2013). However, the ‘socio-‘ or social is typically missing as we confront climate and energy risks in a moral vacuum (Sovacool et al. 2016). The energy justice framework provides a structure to think about such energy dilemmas. However, the full extent and diversity of justice implications within the energy system have been neglected. Thus, borrowing from and advancing the framework this research explores how energy justice is being articulated with attention to three emergent areas of growth, the themes of: (1) time, (2) systems component and (3) actor. It does so through a case study of nuclear energy, which was chosen because of its points of enquiry with regards to these three areas of growth, and its historical and on-going importance in the UK energy mix. Using results from 36 semi-structured interviews with non-governmental organisations and policy actors across two case studies representative of the nuclear energy stages of energy production and of waste storage, disposal and reprocessing – the Hinkley Point and Sellafield nuclear complexes – this research presents new insights within each of these previously identified areas of development. It offers the contributions of (1) facility lifecycles, (2) systems approaches and (3) the question of ‘justice by whom?’ and concludes that the energy justice framework can aid energy decision-making in a way that not only mitigates the environmental impacts of energy via socio-technical change, but also does so in an ethically defensible, socially just, way.
-
Small tourism businesses in rural Scotland : exploring owner-managers' understandings of social sustainability
https://hdl.handle.net/10023/9907
Tourism plays an ever more important role in Scotland’s rural economy. Although the
tourism industry in rural areas is typically presented by small firms, knowledge of their
role in sustainable rural development is limited. In particular, there has been little
discussion about small tourism businesses’ (STB) contribution to social sustainability
(SS). However, the literature suggests that STBs can contribute to SS through their
relationship with the local community. While there is evidence to indicate that owner-
managers’ (OM) views and beliefs relate to their business’ relationship with the local
community, this aspect has received little attention by STB scholars to date.
This thesis explores how STB OMs’ views of their business’ local community and its
relationship with it can contribute to developing a better understanding of STBs’ role
in SS. The research is informed by an interpretive-constructionist paradigm, and seeks
to examine OMs’ views from a different angle. Semi-structured interviews were
conducted with 26 OMs of small accommodation businesses across 19 villages and
towns in three rural areas in Scotland. These were specifically selected for their
differences regarding the geographic, economic and policy environment. Participants’
responses were analysed inductively and deductively to explore differences in their
views, and to examine how their understandings reflect the current conceptualisation
of lifestyle and profit oriented STB OMs.
The results showed that the bifurcated conceptualisation of OMs was unsuitable for
addressing the research aim. An inductive threefold typology of OMs emerged based
on their views of their business’ local community and its relationship with it. Notably,
the typology revealed additional and critical differences in OMs’ understandings to
those that emerged from the deductive analysis of lifestyle and profit oriented OMs’
views. The differences revealed by the new typology have implications for STBs’
potential to contribute to SS locally and in the wider area.
2016-01-01T00:00:00Z
McLaren-Thomson, Annabelle April
Tourism plays an ever more important role in Scotland’s rural economy. Although the
tourism industry in rural areas is typically presented by small firms, knowledge of their
role in sustainable rural development is limited. In particular, there has been little
discussion about small tourism businesses’ (STB) contribution to social sustainability
(SS). However, the literature suggests that STBs can contribute to SS through their
relationship with the local community. While there is evidence to indicate that owner-
managers’ (OM) views and beliefs relate to their business’ relationship with the local
community, this aspect has received little attention by STB scholars to date.
This thesis explores how STB OMs’ views of their business’ local community and its
relationship with it can contribute to developing a better understanding of STBs’ role
in SS. The research is informed by an interpretive-constructionist paradigm, and seeks
to examine OMs’ views from a different angle. Semi-structured interviews were
conducted with 26 OMs of small accommodation businesses across 19 villages and
towns in three rural areas in Scotland. These were specifically selected for their
differences regarding the geographic, economic and policy environment. Participants’
responses were analysed inductively and deductively to explore differences in their
views, and to examine how their understandings reflect the current conceptualisation
of lifestyle and profit oriented STB OMs.
The results showed that the bifurcated conceptualisation of OMs was unsuitable for
addressing the research aim. An inductive threefold typology of OMs emerged based
on their views of their business’ local community and its relationship with it. Notably,
the typology revealed additional and critical differences in OMs’ understandings to
those that emerged from the deductive analysis of lifestyle and profit oriented OMs’
views. The differences revealed by the new typology have implications for STBs’
potential to contribute to SS locally and in the wider area.
-
Home-ing in on domestic energy research : home comfort and energy demand
https://hdl.handle.net/10023/9887
Climate change has become a major concern for research and policy in recent decades, and housing has been an important area to tackle as globally this sector accounts for roughly a quarter of energy demand, and its resulting carbon emissions (Staffell et al., 2015). Behaviour change campaigns constitute a significant strand within government responses to reduce carbon emissions. However, on the grounds that environmental impact has little to do with individual’s intentions, there is growing interest in the ordinary, rather than the extraordinary (e.g. pro-environmental values), and the socio-material transformation of collective conventions (Shove, 2010). Research emerging from this ‘practice turn’ is often underpinned by evidence of changing expectations of comfort that undermine improvements in energy efficiency (Hitchings and Lee, 2008; Walker et al., 2016). Notably, research indicates that it is increasingly common for indoor environments to be maintained within a narrow range of temperatures through mechanical heating and cooling, which has significant implications for energy (Shove, 2003).
While these practice-informed studies have successfully offered new avenues for intervention in sustainable consumption, home comfort has been rather narrowly investigated and has often been equated with thermal comfort. Yet expectations of home comfort and household management decisions are much more complex and multifaceted than the desire to be sufficiently warm or cool. A focus on thermal comfort has arguably trivialised other meanings of home comfort that might also be significant to understanding patterns of domestic energy demand. The aim of this thesis therefore was to develop a concept of home comfort to inform understandings, debates and policy related to domestic energy demand, and this thesis presents data from whole-household interviews, house tours, ideal drawings and home energy adviser interviews to address this aim.
A key finding of this thesis was that home comfort is a sense of relaxation and wellbeing, which results from companionship and having some sense of control in the home. Broadening out understandings of occupant satisfaction to account for some of this complexity draws attention to householder’s perception of the space per person ‘needed’ to facilitate comfortably sharing the home with others. Engaging with the trend towards increasing space per person is important because it has the potential to reduce energy demand for space heating without falling back into emphasising technical intervention or questioning the standardisation of thermal comfort. Furthermore, householder’s actions to reduce domestic energy demand were found to be tightly, if implicitly, linked to expectations of home comfort and processes of homemaking. It is important to remember that changes to the home are not simply the result of financial rationalisation or attempts to improve thermal comfort. There is certainly scope for the concept of home comfort to inform understanding of domestic energy demand and to highlight alternative strategies to ‘steer’ towards more sustainable forms of everyday life.
2017-06-21T00:00:00Z
Ellsworth-Krebs, Katherine
Climate change has become a major concern for research and policy in recent decades, and housing has been an important area to tackle as globally this sector accounts for roughly a quarter of energy demand, and its resulting carbon emissions (Staffell et al., 2015). Behaviour change campaigns constitute a significant strand within government responses to reduce carbon emissions. However, on the grounds that environmental impact has little to do with individual’s intentions, there is growing interest in the ordinary, rather than the extraordinary (e.g. pro-environmental values), and the socio-material transformation of collective conventions (Shove, 2010). Research emerging from this ‘practice turn’ is often underpinned by evidence of changing expectations of comfort that undermine improvements in energy efficiency (Hitchings and Lee, 2008; Walker et al., 2016). Notably, research indicates that it is increasingly common for indoor environments to be maintained within a narrow range of temperatures through mechanical heating and cooling, which has significant implications for energy (Shove, 2003).
While these practice-informed studies have successfully offered new avenues for intervention in sustainable consumption, home comfort has been rather narrowly investigated and has often been equated with thermal comfort. Yet expectations of home comfort and household management decisions are much more complex and multifaceted than the desire to be sufficiently warm or cool. A focus on thermal comfort has arguably trivialised other meanings of home comfort that might also be significant to understanding patterns of domestic energy demand. The aim of this thesis therefore was to develop a concept of home comfort to inform understandings, debates and policy related to domestic energy demand, and this thesis presents data from whole-household interviews, house tours, ideal drawings and home energy adviser interviews to address this aim.
A key finding of this thesis was that home comfort is a sense of relaxation and wellbeing, which results from companionship and having some sense of control in the home. Broadening out understandings of occupant satisfaction to account for some of this complexity draws attention to householder’s perception of the space per person ‘needed’ to facilitate comfortably sharing the home with others. Engaging with the trend towards increasing space per person is important because it has the potential to reduce energy demand for space heating without falling back into emphasising technical intervention or questioning the standardisation of thermal comfort. Furthermore, householder’s actions to reduce domestic energy demand were found to be tightly, if implicitly, linked to expectations of home comfort and processes of homemaking. It is important to remember that changes to the home are not simply the result of financial rationalisation or attempts to improve thermal comfort. There is certainly scope for the concept of home comfort to inform understanding of domestic energy demand and to highlight alternative strategies to ‘steer’ towards more sustainable forms of everyday life.
-
The geology of Ben Nevis, South-west Highlands, Scotland
https://hdl.handle.net/10023/9766
The Ben Nevis volcanic-plutonic Complex was intruded into garnet grade
Precambrian metasediments in the Southwest Highlands of Scotland towards the end of the
Caledonian Orogeny. A variety of techniques have been applied to the Ben Nevis Complex in
order to model its volcanic and plutonic evolution; these include: field mapping,
petrography, mineral chemistry, whole rock major and trace element geochemistry and a
combined study of the isotopes of neodymium and strontium.
Rocks of the volcanic pile are subdivided into the following formations; the Allt a'
Mhuillin formation, the Coire na Ciste formation, the Ledge Route formation and the Summit
formation, and these overlie a basement of Dalradian schist. Fine grained metasediments of
the Allt a' Mhuillin formation were deposited in a lacustrine basin into which entered a
series of non-volcanic mass flow units. Non-volcanic deposition was terminated with the
entry of the first volcaniclastic lahars of the Coire na Ciste formation into the Ben Nevis
basin. Block and ash flows, lava flows and sills are also found in this formation. The Ledge
Route formation testifies to a complex period of quiescence, airfall deposition and mass flow
movement after which localised flows of lava dominate the overlying Summit formation. A
single felsite dyke is found intruding the volcanic pile and is correlated with early members
of the Ben Nevis dyke swarm in the northern area of the Ben Nevis Complex.
Plutonic rocks of the Ben Nevis Complex are subdivided into the Fine Quartz Diorite,
Sgurr Finnisg-aig Quartz Diorite, Coarse Quartz Diorite, Porphyritic Outer Granite and
Inner Granite; these were intruded to a high level in the crust. A dextral stress regime
operated during the intrusion of the plutonic rocks. Each of the above units was intruded as a
series of pulses.
Mass balance and qualitative trace element vector modelling (Rayleigh
crystallisation) is able to model the geochemical evolution of the Porphyritic Outer Granite
using plagioclase, amphibole, biotite and magnetite as the fractionating assemblage.
Pyroxene is found as a phenocryst and as a groundmass phase in the quartz diorites with
calcic amphibole found mainly as a replacement mineral after pyroxene; however, trace
element modelling identifies amphibole as a fractionating phase.
Isotopic modelling of the Ben Nevis Complex indicates the involvement of at least
three components; these being a mantle source, a lower crustal source with similar isotopic
characteristics to the Islay-Colonsay-Basement and, of lesser importance, Dalradian
metasediments. No single parental magma can explain the geochemical and isotopic variation
of the Ben Nevis Complex.
1994-01-01T00:00:00Z
Burt, Rodney Michael
The Ben Nevis volcanic-plutonic Complex was intruded into garnet grade
Precambrian metasediments in the Southwest Highlands of Scotland towards the end of the
Caledonian Orogeny. A variety of techniques have been applied to the Ben Nevis Complex in
order to model its volcanic and plutonic evolution; these include: field mapping,
petrography, mineral chemistry, whole rock major and trace element geochemistry and a
combined study of the isotopes of neodymium and strontium.
Rocks of the volcanic pile are subdivided into the following formations; the Allt a'
Mhuillin formation, the Coire na Ciste formation, the Ledge Route formation and the Summit
formation, and these overlie a basement of Dalradian schist. Fine grained metasediments of
the Allt a' Mhuillin formation were deposited in a lacustrine basin into which entered a
series of non-volcanic mass flow units. Non-volcanic deposition was terminated with the
entry of the first volcaniclastic lahars of the Coire na Ciste formation into the Ben Nevis
basin. Block and ash flows, lava flows and sills are also found in this formation. The Ledge
Route formation testifies to a complex period of quiescence, airfall deposition and mass flow
movement after which localised flows of lava dominate the overlying Summit formation. A
single felsite dyke is found intruding the volcanic pile and is correlated with early members
of the Ben Nevis dyke swarm in the northern area of the Ben Nevis Complex.
Plutonic rocks of the Ben Nevis Complex are subdivided into the Fine Quartz Diorite,
Sgurr Finnisg-aig Quartz Diorite, Coarse Quartz Diorite, Porphyritic Outer Granite and
Inner Granite; these were intruded to a high level in the crust. A dextral stress regime
operated during the intrusion of the plutonic rocks. Each of the above units was intruded as a
series of pulses.
Mass balance and qualitative trace element vector modelling (Rayleigh
crystallisation) is able to model the geochemical evolution of the Porphyritic Outer Granite
using plagioclase, amphibole, biotite and magnetite as the fractionating assemblage.
Pyroxene is found as a phenocryst and as a groundmass phase in the quartz diorites with
calcic amphibole found mainly as a replacement mineral after pyroxene; however, trace
element modelling identifies amphibole as a fractionating phase.
Isotopic modelling of the Ben Nevis Complex indicates the involvement of at least
three components; these being a mantle source, a lower crustal source with similar isotopic
characteristics to the Islay-Colonsay-Basement and, of lesser importance, Dalradian
metasediments. No single parental magma can explain the geochemical and isotopic variation
of the Ben Nevis Complex.
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Valuing culture : a mixed-methods approach to the comparative investigation of the roles and importance of cultural resources in Edinburgh and Dundee
https://hdl.handle.net/10023/9446
In Scotland, as the UK and internationally, publicly funded cultural organisations face a precarious future, characterised by funding cuts and a growing need to justify investments. This practical need to understand and articulate the importance of cultural resources has underpinned an intense debate in the field of cultural studies, about the nature of cultural value and the best methodological tools to explore it. The appropriateness of relying upon cultural strategies to pursue urban development and regeneration has also been subject to extensive discussions in the field of urban studies. This study approaches these problems through mixed-methods, comparative case studies set in Edinburgh and Dundee.
This research employs Contingent Valuation (CV) in combination with focus groups. It provides a contextualised understanding of the diverging notions of culture emerging in the two cities. A higher valuation for culture was registered in Edinburgh, with stronger preference for museums and performing arts. In Dundee, higher importance was placed on community-based activities. These patterns are linked to the mix of demographic and socio-economic backgrounds characterising each city. Therefore, this study highlights a need for a tailored approach to cultural valuation and cultural policy, in contrast with the tendency for these to be implemented on a one-size-fit-all basis.
The study also concludes that greater consideration is needed for the intangible and non-use related elements of cultural value, reinforcing a dominant critique in the literature. In addition, it highlights potential for negative sides to the impacts of cultural activities. Examples include issues of gentrification and displacement. Their inclusion is shown to be neglected in the typologies of value predominantly associated with culture, pointing at the need for their amendment.
Finally, this study shows the use of CV alongside qualitative methods to be particularly advantageous in overcoming the dichotomous approach characterising this debate. The study avoided the single monetary valuation strongly rejected within the cultural sector, while still managing to yield grounded insight that is potentially valuable for policy-makers.
2016-11-30T00:00:00Z
Pergola, Lorenzo
In Scotland, as the UK and internationally, publicly funded cultural organisations face a precarious future, characterised by funding cuts and a growing need to justify investments. This practical need to understand and articulate the importance of cultural resources has underpinned an intense debate in the field of cultural studies, about the nature of cultural value and the best methodological tools to explore it. The appropriateness of relying upon cultural strategies to pursue urban development and regeneration has also been subject to extensive discussions in the field of urban studies. This study approaches these problems through mixed-methods, comparative case studies set in Edinburgh and Dundee.
This research employs Contingent Valuation (CV) in combination with focus groups. It provides a contextualised understanding of the diverging notions of culture emerging in the two cities. A higher valuation for culture was registered in Edinburgh, with stronger preference for museums and performing arts. In Dundee, higher importance was placed on community-based activities. These patterns are linked to the mix of demographic and socio-economic backgrounds characterising each city. Therefore, this study highlights a need for a tailored approach to cultural valuation and cultural policy, in contrast with the tendency for these to be implemented on a one-size-fit-all basis.
The study also concludes that greater consideration is needed for the intangible and non-use related elements of cultural value, reinforcing a dominant critique in the literature. In addition, it highlights potential for negative sides to the impacts of cultural activities. Examples include issues of gentrification and displacement. Their inclusion is shown to be neglected in the typologies of value predominantly associated with culture, pointing at the need for their amendment.
Finally, this study shows the use of CV alongside qualitative methods to be particularly advantageous in overcoming the dichotomous approach characterising this debate. The study avoided the single monetary valuation strongly rejected within the cultural sector, while still managing to yield grounded insight that is potentially valuable for policy-makers.
-
Palaeohydrodynamics and computer simulation of turbidites in the Marnoso-Arenacea, Northern Apennines, Italy
https://hdl.handle.net/10023/9407
Observation of turbidite features including areal development and
thickness of Bouma units, grainsize and grading are used to define the
flow parameters of a turbidity current. Observations have been made
on four beds in the Marnoso-Arenacea formation in the Northern
Apennines, Italy. This allows the estimation of turbidity current
depth, volume, velocity, deceleration and density variation. A
computer simulation of sediment deposition at a single locality from a
turbidity current flow has been developed. The latter enables
theoretical units derived from experimental and theoretical studies to
be compared with field observations.
Studies of a large turbidite, the 'Contessa bed' show that it was
introduced into a long, narrow basin from a southeasterly source and
continued to flow northwestwards before turning on itself with the
consequent reversing of structures. It is postulated the reversal was
due to the collision of the turbidity current against an intra-basin
fault scarp. This reversed the current before it had reached the full
length of the basin.
Syndepositional mudflows have been discovered in three beds,
occurring at the Bouma 'C' and 'D' interface. They are related to
sediment highs, fan-fringe positions and inherent instabilities in the
sediment. After liquefaction, movement and freezing the mudflows were
succeeded by normal Bouma ‘D’ sedimentation.
1982-06-01T00:00:00Z
Ellis, David
Observation of turbidite features including areal development and
thickness of Bouma units, grainsize and grading are used to define the
flow parameters of a turbidity current. Observations have been made
on four beds in the Marnoso-Arenacea formation in the Northern
Apennines, Italy. This allows the estimation of turbidity current
depth, volume, velocity, deceleration and density variation. A
computer simulation of sediment deposition at a single locality from a
turbidity current flow has been developed. The latter enables
theoretical units derived from experimental and theoretical studies to
be compared with field observations.
Studies of a large turbidite, the 'Contessa bed' show that it was
introduced into a long, narrow basin from a southeasterly source and
continued to flow northwestwards before turning on itself with the
consequent reversing of structures. It is postulated the reversal was
due to the collision of the turbidity current against an intra-basin
fault scarp. This reversed the current before it had reached the full
length of the basin.
Syndepositional mudflows have been discovered in three beds,
occurring at the Bouma 'C' and 'D' interface. They are related to
sediment highs, fan-fringe positions and inherent instabilities in the
sediment. After liquefaction, movement and freezing the mudflows were
succeeded by normal Bouma ‘D’ sedimentation.
-
Styles, textural evolution, and sulfur isotope systematics of Cu-rich sulfides from the Cambrian Whalesback volcanogenic massive sulfide deposit, central Newfoundland, Canada
https://hdl.handle.net/10023/9234
The Whalesback Cu-rich volcanogenic massive sulfide deposit in the Newfoundland Appalachians is a highly deformed deposit found on a steep limb of a closed and boudinaged overturned fold. The deposit was intensely deformed at low temperature but medium pressure (>175 MPa) during the accretion of the composite Lushs Bight oceanic tract-Dashwoods terrane onto the Humber margin at ca. 480 Ma. The ore mineralogy consists of chalcopyrite, pyrrhotite, and pyrite with lesser sphalerite and trace Ag, Bi, and Hg tellurides. Four styles of sulfide mineralization are present: (1) disseminated (5%); (2) vein (50%); (3) breccia (25%); and (4) semimassive to massive (20%). Independent of mineralization style, massive pyrite and pyrrhotite (and some chalcopyrite) are commonly parallel to main S2 schistosity in the deposit, whereas late chalcopyrite piercement veins occur at a high angle to S2. The progressive increase in pressure and temperature produced a remobilization sequence wherein sphalerite was the first sulfide phase to cross the brittle-ductile boundary, followed by pyrrhotite and, finally, chalcopyrite. Maximum temperature was not high enough for the pyrite to cross the brittle-ductile boundary. Instead, pyrite grains were incorporated and transported by pyrrhotite and chalcopyrite during the ductile remobilization events, rounding and fracturing them. Remobilization of the sulfides occurred mainly by plastic flow, but some solution transport and reprecipitation is locally observed. In situ secondary ion mass spectrometry sulfur isotope geochemistry of sulfides yielded values of δ34S ranging from 2.7‰ to 4.7‰ for pyrite, 2.1‰ to 4.0‰ for pyrrhotite, and 1.3‰ to 4.7‰ for chalcopyrite. Sulfur isotope modeling suggests that at least 60% of the sulfur was derived from leaching of igneous rocks (i.e., basalts), with the remainder derived from thermochemical sulfate reduction of seawater sulfate during alteration of the basalts by seawater. At the deposit scale, sulfur isotopes retained their original signature and did not reequilibrate during the secondary deformation and remobilization events.
2015-08-01T00:00:00Z
Cloutier, Jonathan
Piercey, Stephen J.
Layne, Graham
Heslop, John
Hussey, Andrew
Piercey, Glenn
The Whalesback Cu-rich volcanogenic massive sulfide deposit in the Newfoundland Appalachians is a highly deformed deposit found on a steep limb of a closed and boudinaged overturned fold. The deposit was intensely deformed at low temperature but medium pressure (>175 MPa) during the accretion of the composite Lushs Bight oceanic tract-Dashwoods terrane onto the Humber margin at ca. 480 Ma. The ore mineralogy consists of chalcopyrite, pyrrhotite, and pyrite with lesser sphalerite and trace Ag, Bi, and Hg tellurides. Four styles of sulfide mineralization are present: (1) disseminated (5%); (2) vein (50%); (3) breccia (25%); and (4) semimassive to massive (20%). Independent of mineralization style, massive pyrite and pyrrhotite (and some chalcopyrite) are commonly parallel to main S2 schistosity in the deposit, whereas late chalcopyrite piercement veins occur at a high angle to S2. The progressive increase in pressure and temperature produced a remobilization sequence wherein sphalerite was the first sulfide phase to cross the brittle-ductile boundary, followed by pyrrhotite and, finally, chalcopyrite. Maximum temperature was not high enough for the pyrite to cross the brittle-ductile boundary. Instead, pyrite grains were incorporated and transported by pyrrhotite and chalcopyrite during the ductile remobilization events, rounding and fracturing them. Remobilization of the sulfides occurred mainly by plastic flow, but some solution transport and reprecipitation is locally observed. In situ secondary ion mass spectrometry sulfur isotope geochemistry of sulfides yielded values of δ34S ranging from 2.7‰ to 4.7‰ for pyrite, 2.1‰ to 4.0‰ for pyrrhotite, and 1.3‰ to 4.7‰ for chalcopyrite. Sulfur isotope modeling suggests that at least 60% of the sulfur was derived from leaching of igneous rocks (i.e., basalts), with the remainder derived from thermochemical sulfate reduction of seawater sulfate during alteration of the basalts by seawater. At the deposit scale, sulfur isotopes retained their original signature and did not reequilibrate during the secondary deformation and remobilization events.
-
Integrating entrepreneurship with urban and neighbourhood studies : lessons for future research
https://hdl.handle.net/10023/9015
The seminar series ‘Entrepreneurship in Homes and Neighbourhoods’ this volume draws on is funded by the ESRC grant ES/L001489/1 to Darja Reuschke, Colin Mason, Stephen Syrett, Maarten van Ham and Duncan Maclennan.
2015-12-18T00:00:00Z
Reuschke, Darja
Mason, Colin
Syrett, Stephen
Van Ham, Maarten
-
Urban home-based businesses : how distinct are they and their owners?
https://hdl.handle.net/10023/9013
Little attention has been paid to the geography of home-based businesses and how potential differences in characteristics and business operations are manifested across space. This chapter seeks to shed light on the characteristics of urban home-based businesses (HBBs) and their owners. It has three aims: first, to identify peculiarities of HBBs in urban areas; second, to test whether there exist ‘typical’ urban HBB entrepreneurs; and third, to make recommendations how cities and national government can support home-based businesses. The empirical findings drawn from a survey of the members of the Federation of Small Businesses Scotland clearly show that urban HBBs possess distinct characteristics and motivations. Key findings are: urban HBBs are concentrated in business services and creative services, urban economies benefit from the local supplier network of HBBs and HBBs that are operated around disability/care are more likely to be found in urban areas. It concludes that HBBs are diverse with distinct sub-groups having distinct needs. For city policy-makers it is therefore important not to adopt a ‘one size fits all’ approach. Different business needs shall be identified not only on the business of characteristics of the businesses (industry, number of employees) but also on characteristics of the owner (gender, disability/health).
2015-12-18T00:00:00Z
Reuschke, Darja
Mason, Colin
Little attention has been paid to the geography of home-based businesses and how potential differences in characteristics and business operations are manifested across space. This chapter seeks to shed light on the characteristics of urban home-based businesses (HBBs) and their owners. It has three aims: first, to identify peculiarities of HBBs in urban areas; second, to test whether there exist ‘typical’ urban HBB entrepreneurs; and third, to make recommendations how cities and national government can support home-based businesses. The empirical findings drawn from a survey of the members of the Federation of Small Businesses Scotland clearly show that urban HBBs possess distinct characteristics and motivations. Key findings are: urban HBBs are concentrated in business services and creative services, urban economies benefit from the local supplier network of HBBs and HBBs that are operated around disability/care are more likely to be found in urban areas. It concludes that HBBs are diverse with distinct sub-groups having distinct needs. For city policy-makers it is therefore important not to adopt a ‘one size fits all’ approach. Different business needs shall be identified not only on the business of characteristics of the businesses (industry, number of employees) but also on characteristics of the owner (gender, disability/health).
-
Drivers of atmospheric methane uptake by montane forest soils in the southern Peruvian Andes
https://hdl.handle.net/10023/8908
The soils of tropical montane forests can act as sources or sinks of atmospheric methane (CH4). Understanding this activity is important in regional atmospheric CH4 budgets, given that these ecosystems account for substantial portions of the landscape in mountainous areas like the Andes. Here we investigate the drivers of CH4 fluxes from premontane, lower and upper montane forests, experiencing a seasonal climate, in southeastern Peru. Between February 2011 and June 2013, these soils all functioned as net sinks for atmospheric CH4. Mean (standard error) net CH4 fluxes for the dry and wet season were −1.6 (0.1) and −1.1 (0.1) mg CH4 – C m−2 d−1 in the upper montane forest; −1.1 (0.1) and −1.0 (0.1) mg CH4 – C m−2 d−1 in the lower montane forest; and −0.2 (0.1) and −0.1 (0.1) mg CH4 – C m−2 d−1 in the premontane forest. Variations among forest types were best explained by available nitrate and water-filled pore space, indicating that nitrate inhibition of oxidation or diffusional constraints imposed by changes in water-filled pore space on methanotrophic communities represent important controls on soil-atmosphere CH4 exchange. Seasonality in CH4 exchange varied among forests with an increase in wet season net CH4 flux only apparent in the upper montane forest. Net CH4 flux was inversely related to elevation; a pattern that differs to that observed in Ecuador, the only other extant study site of soil-atmosphere CH4 exchange in the tropical Andes. This may result from differences in rainfall patterns between the regions, suggesting that attention should be paid to the role of rainfall and soil moisture dynamics in modulating CH4 uptake by the organic-rich soils typical of high elevation tropical forests.
The authors would like to acknowledge the agencies that funded this research; the UK Natural Environment Research Council (NERC; joint grant references NE/G018278/1, NE/H006583, NE/H007849 and NE/H006753) and the Norwegian Agency for Development Cooperation (Norad; via a sub-contract to Yit Arn Teh managed by the Amazon Conservation Association). Patrick Meir was also supported by an Australian Research Council Fellowship (FT110100457).
2016-01-27T00:00:00Z
Jones, S
Diem, Torsten
Huaraca Quispe, L
Cahuana, A
Reay, D
Meir, P
Teh, Yit Arn
The soils of tropical montane forests can act as sources or sinks of atmospheric methane (CH4). Understanding this activity is important in regional atmospheric CH4 budgets, given that these ecosystems account for substantial portions of the landscape in mountainous areas like the Andes. Here we investigate the drivers of CH4 fluxes from premontane, lower and upper montane forests, experiencing a seasonal climate, in southeastern Peru. Between February 2011 and June 2013, these soils all functioned as net sinks for atmospheric CH4. Mean (standard error) net CH4 fluxes for the dry and wet season were −1.6 (0.1) and −1.1 (0.1) mg CH4 – C m−2 d−1 in the upper montane forest; −1.1 (0.1) and −1.0 (0.1) mg CH4 – C m−2 d−1 in the lower montane forest; and −0.2 (0.1) and −0.1 (0.1) mg CH4 – C m−2 d−1 in the premontane forest. Variations among forest types were best explained by available nitrate and water-filled pore space, indicating that nitrate inhibition of oxidation or diffusional constraints imposed by changes in water-filled pore space on methanotrophic communities represent important controls on soil-atmosphere CH4 exchange. Seasonality in CH4 exchange varied among forests with an increase in wet season net CH4 flux only apparent in the upper montane forest. Net CH4 flux was inversely related to elevation; a pattern that differs to that observed in Ecuador, the only other extant study site of soil-atmosphere CH4 exchange in the tropical Andes. This may result from differences in rainfall patterns between the regions, suggesting that attention should be paid to the role of rainfall and soil moisture dynamics in modulating CH4 uptake by the organic-rich soils typical of high elevation tropical forests.
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Education for sustainability through action research: an exploration through theory, policy and practice in Scottish secondary schools
https://hdl.handle.net/10023/8506
Environmental deterioration and social injustice highlight the discrepancy between ‘educated’ and ‘wise’ and, by corollary, call into question our approach to education. In order to investigate how we might advance Education for Sustainability (EfS) in a Scottish secondary school context this research engages with: relevant theory, the educational policy context, and practice in the form of two action research pilot projects. The concepts of utopianism and design are proposed as original and potentially useful to understand, guide and evaluate EfS and are linked to an analytical framework to clarify the concept of EfS endorsed in this thesis.
The analytical framework developed comprises four thinking modes: systems thinking; future thinking; an emphasis on values and priorities; and action competency, each qualified through reference to practice. The pilot projects highlighted the challenges of monitoring and evaluating; illustrated opportunities and challenges to deliver EfS theory; offered new theoretical insights into EfS implementation; and enabled reflection on the status of EfS in the wider curriculum. The challenge of undertaking action research as a postgraduate student led to critical analysis of action research in academia.
The thesis highlights the potentially promising policy context to facilitate EfS, particularly in Scotland, but also the practical challenges to implement EfS. Such challenges include: concerns over the clarity of policy documents; teachers’ interest and ability to facilitate pupil-led learning; and resources to support the quality of EfS being delivered. Recommendations for future research include additional classroom-based projects; policy implementation analysis; and investigation of teachers’ values, attitudes and capacity. It was concluded that utopianism, design, and the four thinking modes can potentially contribute to qualifying EfS in current policy and facilitate pupils to critique the status quo, and develop and share alternative visions of a sustainable future.
2015-12-18T00:00:00Z
Lloyd, Zoé Alise
Environmental deterioration and social injustice highlight the discrepancy between ‘educated’ and ‘wise’ and, by corollary, call into question our approach to education. In order to investigate how we might advance Education for Sustainability (EfS) in a Scottish secondary school context this research engages with: relevant theory, the educational policy context, and practice in the form of two action research pilot projects. The concepts of utopianism and design are proposed as original and potentially useful to understand, guide and evaluate EfS and are linked to an analytical framework to clarify the concept of EfS endorsed in this thesis.
The analytical framework developed comprises four thinking modes: systems thinking; future thinking; an emphasis on values and priorities; and action competency, each qualified through reference to practice. The pilot projects highlighted the challenges of monitoring and evaluating; illustrated opportunities and challenges to deliver EfS theory; offered new theoretical insights into EfS implementation; and enabled reflection on the status of EfS in the wider curriculum. The challenge of undertaking action research as a postgraduate student led to critical analysis of action research in academia.
The thesis highlights the potentially promising policy context to facilitate EfS, particularly in Scotland, but also the practical challenges to implement EfS. Such challenges include: concerns over the clarity of policy documents; teachers’ interest and ability to facilitate pupil-led learning; and resources to support the quality of EfS being delivered. Recommendations for future research include additional classroom-based projects; policy implementation analysis; and investigation of teachers’ values, attitudes and capacity. It was concluded that utopianism, design, and the four thinking modes can potentially contribute to qualifying EfS in current policy and facilitate pupils to critique the status quo, and develop and share alternative visions of a sustainable future.
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Dendroclimatic reconstruction of late Holocene summer temperatures in the Scottish Highlands
https://hdl.handle.net/10023/8418
This thesis focuses on reconstructing past temperatures using Scots pine (Pinus
sylvestris L.) tree-ring chronologies developed from Scotland. The research aims to fill
a spatial and temporal gap in understanding northwest European climate dynamics, thus
providing the context for assessing future climate changes in this region. Development
of both a spatially complete reconstruction from an extensive network of 44 'living'
Scottish tree-ring chronologies for the last few centuries, but also a near-millennium
length chronology from central Scotland using mainly lake-derived 'subfossil' wood
material was undertaken. Before reconstruction development, a combination of treegrowth
modelling and disturbance removal methodologies was utilised in order to
understand the drivers of pine growth in the Scottish Highlands, and to assess and
remove anthropogenic disturbance and other non-climatic influences on growth. The
advantages and limitations of utilising the relatively new 'Blue Intensity' (BI) parameter
was also explored and assessed, particularly in relation to its possible utilization as a
more affordable surrogate for maximum latewood density in the development of
temperature reconstructions and for crossdating validation of undated samples.
Although BI showed much promise for dendroclimatology, elimination of low
frequency biases resulting from sample discolouration still requires further attention.
Chronologies from the Cairngorms in central Scotland were identified as most suitable
for reconstruction development, while reconstructions based on chronologies from other
areas in the west were found to be weaker due to a range of factors including
disturbance. In order to maximise reconstruction strength, BI and ring width (RW) data
were combined to produce composite high-frequency BI / low-frequency RW
chronologies. Although it was possible to develop an ~800 year reconstruction of
temperature from central Scotland, there is substantial potential to further extend this
reconstruction back in time.
2016-06-22T00:00:00Z
Rydval, Miloš
This thesis focuses on reconstructing past temperatures using Scots pine (Pinus
sylvestris L.) tree-ring chronologies developed from Scotland. The research aims to fill
a spatial and temporal gap in understanding northwest European climate dynamics, thus
providing the context for assessing future climate changes in this region. Development
of both a spatially complete reconstruction from an extensive network of 44 'living'
Scottish tree-ring chronologies for the last few centuries, but also a near-millennium
length chronology from central Scotland using mainly lake-derived 'subfossil' wood
material was undertaken. Before reconstruction development, a combination of treegrowth
modelling and disturbance removal methodologies was utilised in order to
understand the drivers of pine growth in the Scottish Highlands, and to assess and
remove anthropogenic disturbance and other non-climatic influences on growth. The
advantages and limitations of utilising the relatively new 'Blue Intensity' (BI) parameter
was also explored and assessed, particularly in relation to its possible utilization as a
more affordable surrogate for maximum latewood density in the development of
temperature reconstructions and for crossdating validation of undated samples.
Although BI showed much promise for dendroclimatology, elimination of low
frequency biases resulting from sample discolouration still requires further attention.
Chronologies from the Cairngorms in central Scotland were identified as most suitable
for reconstruction development, while reconstructions based on chronologies from other
areas in the west were found to be weaker due to a range of factors including
disturbance. In order to maximise reconstruction strength, BI and ring width (RW) data
were combined to produce composite high-frequency BI / low-frequency RW
chronologies. Although it was possible to develop an ~800 year reconstruction of
temperature from central Scotland, there is substantial potential to further extend this
reconstruction back in time.
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Neighbourhood ethnic mix and the formation of mixed-ethnic unions in Britain : a longitudinal analysis
https://hdl.handle.net/10023/8328
Although developed societies are becoming increasingly ethnically diverse, relatively little research has been conducted on geographies of mixed-ethnic unions (married or cohabiting). There is some recent evidence from the US that mixed-ethnic couples are more likely to be found in mixed-ethnic neighbourhoods, but this research is based on cross-sectional data. Therefore it is not possible to determine whether mixed-ethnic couples are more likely to form in mixed-ethnic neighbourhoods or whether they are more likely to move there. Our longitudinal analysis allows us to tease out the relative importance of these two processes, furthering our understanding of the formation of mixed-ethnic unions. Using data from the Office for National Statistics Longitudinal Study we examine neighbourhood effects on the formation of mixed-ethnic unions in England and Wales. We find that mixed-ethnic unions are more likely to form in neighbourhoods with low concentrations of co-ethnic population. The results from this study lend support to the contact theory that geographical proximity to other ethnic groups enhances mutual understanding between people from different ethnic groups and could lead to the development of intimate partnerships.
This research is funded by the ESRC under the Understanding Population Trends and Processes (UPT AP) programme (Award Ref: RE S-163-25-0045).
2014-02-28T00:00:00Z
Feng, Zhiqiang
Van Ham, Maarten
Boyle, Paul Joseph
Raab, Gillian Mary
Although developed societies are becoming increasingly ethnically diverse, relatively little research has been conducted on geographies of mixed-ethnic unions (married or cohabiting). There is some recent evidence from the US that mixed-ethnic couples are more likely to be found in mixed-ethnic neighbourhoods, but this research is based on cross-sectional data. Therefore it is not possible to determine whether mixed-ethnic couples are more likely to form in mixed-ethnic neighbourhoods or whether they are more likely to move there. Our longitudinal analysis allows us to tease out the relative importance of these two processes, furthering our understanding of the formation of mixed-ethnic unions. Using data from the Office for National Statistics Longitudinal Study we examine neighbourhood effects on the formation of mixed-ethnic unions in England and Wales. We find that mixed-ethnic unions are more likely to form in neighbourhoods with low concentrations of co-ethnic population. The results from this study lend support to the contact theory that geographical proximity to other ethnic groups enhances mutual understanding between people from different ethnic groups and could lead to the development of intimate partnerships.
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A time geographic approach to delineating areas of sustained wildlife use
https://hdl.handle.net/10023/8218
Geographic information systems (GIS) are widely used for mapping wildlife movement patterns, and observed wildlife locations are surrogates for inferring on wildlife movement and habitat selection. We present a new approach to mapping areas where wildlife exhibit sustained use, which we term slow movement areas (SMAs). Nested within the habitat selection concepts of home range and core areas, SMAs are an additional approach to identifying areas important for wildlife. Our method for delineating SMAs is demonstrated on a grizzly bear (Ursus arctos) case study examining road density. Our results showed that subadult females had significantly higher road densities within SMAs than in their potential path area home ranges. The lowest road density was found in the SMAs of adult male grizzly bears. Given increased mortality risks associated with roads, female encampment near roads may have negative conservation implications. The methods presented in this manuscript compliment recent developments to identify movement suspension and intensively exploited areas defined from wildlife telemetry data. SMA delineation is sensitive to missing data and best applied to telemetry data collected with a consistent resolution.
2015-01-01T00:00:00Z
Nelson, Trisalyn
Long, Jed
Laberee, Karen
Stewart, Benjamin
Geographic information systems (GIS) are widely used for mapping wildlife movement patterns, and observed wildlife locations are surrogates for inferring on wildlife movement and habitat selection. We present a new approach to mapping areas where wildlife exhibit sustained use, which we term slow movement areas (SMAs). Nested within the habitat selection concepts of home range and core areas, SMAs are an additional approach to identifying areas important for wildlife. Our method for delineating SMAs is demonstrated on a grizzly bear (Ursus arctos) case study examining road density. Our results showed that subadult females had significantly higher road densities within SMAs than in their potential path area home ranges. The lowest road density was found in the SMAs of adult male grizzly bears. Given increased mortality risks associated with roads, female encampment near roads may have negative conservation implications. The methods presented in this manuscript compliment recent developments to identify movement suspension and intensively exploited areas defined from wildlife telemetry data. SMA delineation is sensitive to missing data and best applied to telemetry data collected with a consistent resolution.
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The parallel tracks of Partition, India-Pakistan 1947 : histories, geographies, cartographies
https://hdl.handle.net/10023/8063
On 15 August 1947, the British government withdrew from India and partitioned the subcontinent to create two new nation-states: India and Pakistan. The Partition of India and Pakistan has been studied chiefly as a historical phenomenon with legacies that reach into the present. Questions of geography and space are crucial to this history, yet have hitherto received scant attention. This dissertation is a historical geography of Partition that probes the interplay of temporality and spatiality, and the historical and geographical layering, at work in the making of India and Pakistan. It treats Partition as both an event and a process, examining how the 1947 borders were rooted in a set of imaginative geographies and material geographical practices that were fashioned for and applied to the purpose of refashioning territory as part of a transfer of colonial power to independent postcolonial states and the making of new (national, religious) identities. The dissertation teases out the constitutive role of ideals and practices of territorial and cultural imagining, classification, mapping and boundary-making in this historical geography, but also highlights their contingent and contested qualities. It critically analyses and reframes Partition historiography using a range of theoretical literatures (especially critical geographical work on empire and strands of postcolonial and subaltern theory) that foster a sensitivity to the entanglements of power, knowledge, geography, expertise in the context of Partition, and draws on an eclectic range of primary sources, including the hitherto unused papers of the geographer Oskar Spate. Parts I and II trace strands of geographical and cartographic representations of ‘India’ and ‘Pakistan’ before 1947. Part III examines the geographies and spaces of the Punjab Boundary Commission of July 1947, in which Spate participated as an advisor to the Muslim League. Part IV points to the continued relevance of these geographies of Partition and their critical framing in this dissertation as lines of power.
2016-06-22T00:00:00Z
Fitzpatrick, Hannah
On 15 August 1947, the British government withdrew from India and partitioned the subcontinent to create two new nation-states: India and Pakistan. The Partition of India and Pakistan has been studied chiefly as a historical phenomenon with legacies that reach into the present. Questions of geography and space are crucial to this history, yet have hitherto received scant attention. This dissertation is a historical geography of Partition that probes the interplay of temporality and spatiality, and the historical and geographical layering, at work in the making of India and Pakistan. It treats Partition as both an event and a process, examining how the 1947 borders were rooted in a set of imaginative geographies and material geographical practices that were fashioned for and applied to the purpose of refashioning territory as part of a transfer of colonial power to independent postcolonial states and the making of new (national, religious) identities. The dissertation teases out the constitutive role of ideals and practices of territorial and cultural imagining, classification, mapping and boundary-making in this historical geography, but also highlights their contingent and contested qualities. It critically analyses and reframes Partition historiography using a range of theoretical literatures (especially critical geographical work on empire and strands of postcolonial and subaltern theory) that foster a sensitivity to the entanglements of power, knowledge, geography, expertise in the context of Partition, and draws on an eclectic range of primary sources, including the hitherto unused papers of the geographer Oskar Spate. Parts I and II trace strands of geographical and cartographic representations of ‘India’ and ‘Pakistan’ before 1947. Part III examines the geographies and spaces of the Punjab Boundary Commission of July 1947, in which Spate participated as an advisor to the Muslim League. Part IV points to the continued relevance of these geographies of Partition and their critical framing in this dissertation as lines of power.
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The changing role of the Dutch social rented sector
https://hdl.handle.net/10023/7976
The article traces the evolution of the research interests of Frans Dieleman, an academic who combined the development of analytical models with explorations of the policy implications of the changing structure of housing markets. During his long career as a professor of geography, he championed international cooperation in research and played a major role in disseminating the results of Dutch academic studies to an international audience. His own work was concentrated on the analysis of residential mobility. But much of that work also revealed his interest in applying scholarly insights to policy issues. Throughout his career he showed a deep commitment to improving the functioning of the social rented sector in the Dutch housing market. After reviewing some of Frans Dieleman’s major contributions to the understanding of the housing market, the article follows in his footsteps by analyzing the current use of social rented housing. In this way, this article provides an update on his field of interest based on recent survey data that underlines the validity of his insights.
2006-09-01T00:00:00Z
Van Ham, Maarten
Van Kempen, R
Van Weesep, J
The article traces the evolution of the research interests of Frans Dieleman, an academic who combined the development of analytical models with explorations of the policy implications of the changing structure of housing markets. During his long career as a professor of geography, he championed international cooperation in research and played a major role in disseminating the results of Dutch academic studies to an international audience. His own work was concentrated on the analysis of residential mobility. But much of that work also revealed his interest in applying scholarly insights to policy issues. Throughout his career he showed a deep commitment to improving the functioning of the social rented sector in the Dutch housing market. After reviewing some of Frans Dieleman’s major contributions to the understanding of the housing market, the article follows in his footsteps by analyzing the current use of social rented housing. In this way, this article provides an update on his field of interest based on recent survey data that underlines the validity of his insights.
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Immigrant integration and the global recession : a case study using Swedish register data
https://hdl.handle.net/10023/7598
In many immigrant-receiving countries, the increased rate and diversification of immigration has placed immigrant integration high on academic and political agendas. Immigrant integration must also be understood within increasingly complex contexts due to the global recession and new geographies of immigrant settlement. The aim of this thesis is to deepen understanding of immigrant integration processes during the recession by using Sweden as an empirical lens. Using Swedish register data, this thesis examines the registered population during the recent economic boom and bust to explore how the recession may have resulted in differential labour market and migration outcomes between immigrants and natives. The first empirical chapter highlights how long-term processes have produced a spatial, immigrant division of labour that results in differential risks of unemployment during the recession. The second empirical chapter examines internal migration to show that although cyclical patterns of the economy offer some explanation of the differences in experiences between immigrant and natives, long-term, deeper processes are more important in understanding geographies of immigrant integration. The final empirical
chapter examines a recent immigrant cohort to show that labour market entry is by no
means uniform across time, space and immigrant origin. Conceptually, the thesis shows that existing theories of immigrant integration processes during recessions are underdeveloped and that processes taking place across other temporal and spatial scales offer deeper explanation for the differential outcomes between immigrants and natives. The thesis also reveals what is knowable from register data and how such data allows future research to present a more holistic picture of how various forms of immigrant integration play out across time (economic cycles, lifecourse, generations) and across space (urban, rural areas, old and new immigrant destinations). This methodological contribution is significant given that social scientists are currently evaluating the relative merits of population censuses versus administrative register data.
2015-11-30T00:00:00Z
Macpherson, Robert Allan
In many immigrant-receiving countries, the increased rate and diversification of immigration has placed immigrant integration high on academic and political agendas. Immigrant integration must also be understood within increasingly complex contexts due to the global recession and new geographies of immigrant settlement. The aim of this thesis is to deepen understanding of immigrant integration processes during the recession by using Sweden as an empirical lens. Using Swedish register data, this thesis examines the registered population during the recent economic boom and bust to explore how the recession may have resulted in differential labour market and migration outcomes between immigrants and natives. The first empirical chapter highlights how long-term processes have produced a spatial, immigrant division of labour that results in differential risks of unemployment during the recession. The second empirical chapter examines internal migration to show that although cyclical patterns of the economy offer some explanation of the differences in experiences between immigrant and natives, long-term, deeper processes are more important in understanding geographies of immigrant integration. The final empirical
chapter examines a recent immigrant cohort to show that labour market entry is by no
means uniform across time, space and immigrant origin. Conceptually, the thesis shows that existing theories of immigrant integration processes during recessions are underdeveloped and that processes taking place across other temporal and spatial scales offer deeper explanation for the differential outcomes between immigrants and natives. The thesis also reveals what is knowable from register data and how such data allows future research to present a more holistic picture of how various forms of immigrant integration play out across time (economic cycles, lifecourse, generations) and across space (urban, rural areas, old and new immigrant destinations). This methodological contribution is significant given that social scientists are currently evaluating the relative merits of population censuses versus administrative register data.
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Sustainable development and the Arctic : An imperative in search of a uniting agenda
https://hdl.handle.net/10023/7332
2015-08-01T00:00:00Z
McCauley, Darren
Rehner, Robert Wilhelm Michael
Khubaeva, Alisa
Ryabova, Maria
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Mineral dissolution in silicate melts
https://hdl.handle.net/10023/7278
Quartz and orthopyroxene in mafic rocks are commonly observed to be
surrounded by fringes of granular pyroxene, and of olivine and clinopyroxene,
respectively. This study reproduces the conditions of formation of these textures,
and investigates their origins, kinetics and phase relations.
Pieces of silica glass or crystals of orthopyroxene were dissolved into
tholeiitic and slightly alkaline basalts, suspended from wire loops in an atmospheric
pressure quenching furnace, and run for 10 minutes to 32 days at subliquidus
temperatures between 1120° and 1190°C and oxygen fugacities close to the QFM
buffer. Polished sections of charges were examined primarily by backscattered
electron imagery and by microprobe analysis.
The textures developed in silica dissolution experiments consist of fringes
of elongate skeletal pyroxenes radially arranged around the silica. The pyroxenes
first nucleate on the surface of the silica. As dissolution continues, growth
continues mostly on existing crystals, rather than by the nucleation of additional
crystals.
Dissolution rates for silica range from 2.8*10⁻¹¹ to 4.4*10⁻¹⁰ms⁻¹, and are
time-independent until growth of the pyroxene fringe hinders transport processes in
the melt. This causes dissolution to slow down, until it ceases altogether after 3 to
8 days. A silica-rich layer of melt forms around the surface of charges run at higher
temperatures, suggesting that convection driven by variations in surface tension
may operate in the charges.
The textures developed in orthopyroxene dissolution experiments consist of
granular olivines, some of which nucleate on the pyroxene surface, whereas
others nucleate within the pyroxene as a result of the decomposition of included
phases. With time, olivine crystals become connected and form complex grain
shapes.
Dissolution rates for orthopyroxene range from 1.7*10⁻¹¹ to 1.2*10⁻⁹ ms⁻¹.
At higher temperatures dissolution rates are constant, but at lower temperatures
dissolution is time-dependent. Unlike silica dissolution, orthopyroxene dissolution
does not cease as a result of continued neocryst growth hindering melt transport,
indicating that the fringe remains permeable.
For both systems, the neocryst compositions are strongly dependent on the
chemistry of the melt formed at the interface between the dissolving crystal and the
bulk melt, and the neocrysts may be metastable with respect to the bulk melt.
Chemical equilibration of olivine neocrysts with time is observed for longer
experiments. Textural equilibration of olivine grains occurs by the processes of
liquid-phase sintering in runs longer than 12 hours.
Subliquidus dissolution data are applied to textures from natural samples
collected from dykes, lava flows and lava lakes, to estimate the residence time of
reacted crystals; values range from 0.6 to 208 days for reacted quartz, and from
0.7 to 462 days for reacted orthopyroxenes. The rates of cooling of the magma and
the size of the magma body in which the reaction occurred are also estimated.
1990-01-01T00:00:00Z
Curry, Richard M.
Quartz and orthopyroxene in mafic rocks are commonly observed to be
surrounded by fringes of granular pyroxene, and of olivine and clinopyroxene,
respectively. This study reproduces the conditions of formation of these textures,
and investigates their origins, kinetics and phase relations.
Pieces of silica glass or crystals of orthopyroxene were dissolved into
tholeiitic and slightly alkaline basalts, suspended from wire loops in an atmospheric
pressure quenching furnace, and run for 10 minutes to 32 days at subliquidus
temperatures between 1120° and 1190°C and oxygen fugacities close to the QFM
buffer. Polished sections of charges were examined primarily by backscattered
electron imagery and by microprobe analysis.
The textures developed in silica dissolution experiments consist of fringes
of elongate skeletal pyroxenes radially arranged around the silica. The pyroxenes
first nucleate on the surface of the silica. As dissolution continues, growth
continues mostly on existing crystals, rather than by the nucleation of additional
crystals.
Dissolution rates for silica range from 2.8*10⁻¹¹ to 4.4*10⁻¹⁰ms⁻¹, and are
time-independent until growth of the pyroxene fringe hinders transport processes in
the melt. This causes dissolution to slow down, until it ceases altogether after 3 to
8 days. A silica-rich layer of melt forms around the surface of charges run at higher
temperatures, suggesting that convection driven by variations in surface tension
may operate in the charges.
The textures developed in orthopyroxene dissolution experiments consist of
granular olivines, some of which nucleate on the pyroxene surface, whereas
others nucleate within the pyroxene as a result of the decomposition of included
phases. With time, olivine crystals become connected and form complex grain
shapes.
Dissolution rates for orthopyroxene range from 1.7*10⁻¹¹ to 1.2*10⁻⁹ ms⁻¹.
At higher temperatures dissolution rates are constant, but at lower temperatures
dissolution is time-dependent. Unlike silica dissolution, orthopyroxene dissolution
does not cease as a result of continued neocryst growth hindering melt transport,
indicating that the fringe remains permeable.
For both systems, the neocryst compositions are strongly dependent on the
chemistry of the melt formed at the interface between the dissolving crystal and the
bulk melt, and the neocrysts may be metastable with respect to the bulk melt.
Chemical equilibration of olivine neocrysts with time is observed for longer
experiments. Textural equilibration of olivine grains occurs by the processes of
liquid-phase sintering in runs longer than 12 hours.
Subliquidus dissolution data are applied to textures from natural samples
collected from dykes, lava flows and lava lakes, to estimate the residence time of
reacted crystals; values range from 0.6 to 208 days for reacted quartz, and from
0.7 to 462 days for reacted orthopyroxenes. The rates of cooling of the magma and
the size of the magma body in which the reaction occurred are also estimated.
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Geology of the Ordovician rocks between Leadhills and Abington, Lanarkshire
https://hdl.handle.net/10023/7132
NE-SW faults in the Abington area of the Northern Belt of the Southern Uplands define blocks up to 3.2 km wide. The strata, folded and locally overturned, young predominantly to the NW but blocks to the SW contain younger sequences. Analogous configurations occur in modern accretionary margins. The oldest rocks, generally of pelagic and hemipelagic origin, are Arenig basalts, dolerites, cherts and brown mudstones underlying red mudstones, possibly Llanvirn, and black fossiliferous mudstones and cherts of Llandeilo and Caradoc age. Trench sediments overlying pelagic sequences represent a range of depositional mechanisms. Rudites and associated fine-grained lithologies of lateral origin relate to a lower trench-slope canyon system, whilst axially transported sands, originating on the lower trench slope, were deposited by turbidity currents and related flows. Sandstone petrography varies markedly across strike, with quartz-rich compositions suggesting a recycled orogen source, and ferromagnesian-rich compositions a dissected magmatic arc provenance. Faults, initially low-angle thrusts, facilitated thrust nappe formation; faults and bedding were rotated through the vertical within the accretionary complex, predating or accompanying slaty cleavage development. Soft sediment deformation, two fold phases and a kink-band set are recognised. Imbricate fault zones, located in incompetent pelagic sequences, are equated with tectonic melange of other accretionary complexes. Index minerals, illite crystallinity and 'vitrinite' reflectance establish metamorphic grade as prehnitepumpellyite facies.
1981-01-01T00:00:00Z
Hepworth, Barry C.
NE-SW faults in the Abington area of the Northern Belt of the Southern Uplands define blocks up to 3.2 km wide. The strata, folded and locally overturned, young predominantly to the NW but blocks to the SW contain younger sequences. Analogous configurations occur in modern accretionary margins. The oldest rocks, generally of pelagic and hemipelagic origin, are Arenig basalts, dolerites, cherts and brown mudstones underlying red mudstones, possibly Llanvirn, and black fossiliferous mudstones and cherts of Llandeilo and Caradoc age. Trench sediments overlying pelagic sequences represent a range of depositional mechanisms. Rudites and associated fine-grained lithologies of lateral origin relate to a lower trench-slope canyon system, whilst axially transported sands, originating on the lower trench slope, were deposited by turbidity currents and related flows. Sandstone petrography varies markedly across strike, with quartz-rich compositions suggesting a recycled orogen source, and ferromagnesian-rich compositions a dissected magmatic arc provenance. Faults, initially low-angle thrusts, facilitated thrust nappe formation; faults and bedding were rotated through the vertical within the accretionary complex, predating or accompanying slaty cleavage development. Soft sediment deformation, two fold phases and a kink-band set are recognised. Imbricate fault zones, located in incompetent pelagic sequences, are equated with tectonic melange of other accretionary complexes. Index minerals, illite crystallinity and 'vitrinite' reflectance establish metamorphic grade as prehnitepumpellyite facies.
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Downwasting and supraglacial lake evolution on the debris-covered Ngozumpa Glacier, Khumbu Himal, Nepal
https://hdl.handle.net/10023/7128
In recent decades, the downwasting of several debris-covered glaciers in the
Himalaya has led to the formation of large and potentially hazardous moraine-
dammed lakes. The frequency of Glacial Lake Outburst Flood (GLOF) events in
the Himalaya has steadily increased since the 1970s and as global temperatures
continue to rise this trend is set to continue in the future.
Downwasting of the debris-covered Ngozumpa Glacier in the Khumbu Himal,
Nepal, has resulted in the abandonment of the lateral and terminal moraine crests,
leaving them standing several tens of metres above the glacier surface. The
moraines have exerted a control on the drainage of meltwater from the glacier
surface and have encouraged ponding of meltwater on the glacier surface. The
present study examines the evolution of perched supraglacial ponds on the
Ngozumpa Glacier and assesses how the growth of these ponds affects the rate of
downwasting of the glacier surface. The expansion rates of perched ponds can be
rapid, up to 21,609 m ² a⁻¹, but the growth of these ponds tends to be terminated
when contact is made with the englacial drainage network. The thesis documents
for the first time a complete cycle of perched supra glacial pond growth and
drainage and also provides direct evidence for internal ablation during pond
drainage, a process that has only been inferred in previous research.
The western lateral moraine has dammed back drainage from the western
tributary valleys, resulting in the formation of laterally-dammed lakes. The
research presented here examines the processes and rates of paraglacial
reworking of the Ngozumpa moraines in order to assess the stability and
longevity of the moraine dam.
Approximately 1 km from the Ngozumpa terminus a large Spillway Lake has
formed. Meltwater from upglacier is channelled into the lake and exits the glacier
surface through an over-spill channel cut down through the western lateral
moraine. The level of the Spillway Lake is thereby controlled by the height of the
spillway channel through the western lateral moraine. The rate of expansion of
the Spillway Lake is lower than that of the perched ponds upglacier, but as the
Spillway Lake continues to enlarge and surface downwasting of the glacier
surface proceeds, the lake could enter a period of rapid and unstable growth. By
analogy with other glaciers in the Khumbu Rimal, it is possible that a large and
potentially hazardous lake will form on the Ngozumpa within the next two
decades.
2004-01-01T00:00:00Z
Hands, Kathryn Ann
In recent decades, the downwasting of several debris-covered glaciers in the
Himalaya has led to the formation of large and potentially hazardous moraine-
dammed lakes. The frequency of Glacial Lake Outburst Flood (GLOF) events in
the Himalaya has steadily increased since the 1970s and as global temperatures
continue to rise this trend is set to continue in the future.
Downwasting of the debris-covered Ngozumpa Glacier in the Khumbu Himal,
Nepal, has resulted in the abandonment of the lateral and terminal moraine crests,
leaving them standing several tens of metres above the glacier surface. The
moraines have exerted a control on the drainage of meltwater from the glacier
surface and have encouraged ponding of meltwater on the glacier surface. The
present study examines the evolution of perched supraglacial ponds on the
Ngozumpa Glacier and assesses how the growth of these ponds affects the rate of
downwasting of the glacier surface. The expansion rates of perched ponds can be
rapid, up to 21,609 m ² a⁻¹, but the growth of these ponds tends to be terminated
when contact is made with the englacial drainage network. The thesis documents
for the first time a complete cycle of perched supra glacial pond growth and
drainage and also provides direct evidence for internal ablation during pond
drainage, a process that has only been inferred in previous research.
The western lateral moraine has dammed back drainage from the western
tributary valleys, resulting in the formation of laterally-dammed lakes. The
research presented here examines the processes and rates of paraglacial
reworking of the Ngozumpa moraines in order to assess the stability and
longevity of the moraine dam.
Approximately 1 km from the Ngozumpa terminus a large Spillway Lake has
formed. Meltwater from upglacier is channelled into the lake and exits the glacier
surface through an over-spill channel cut down through the western lateral
moraine. The level of the Spillway Lake is thereby controlled by the height of the
spillway channel through the western lateral moraine. The rate of expansion of
the Spillway Lake is lower than that of the perched ponds upglacier, but as the
Spillway Lake continues to enlarge and surface downwasting of the glacier
surface proceeds, the lake could enter a period of rapid and unstable growth. By
analogy with other glaciers in the Khumbu Rimal, it is possible that a large and
potentially hazardous lake will form on the Ngozumpa within the next two
decades.
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Geology and petrology of the margin of the Rhum ultrabasic intrusion, Inner Hebrides, Scotland
https://hdl.handle.net/10023/7123
Country rocks surrounding the Rhum Tertiary ultrabasic
complex have experienced severe thermal metamorphism, partial
melting and mobilization resulting in the formation of extensive
areas of intrusion breccia. Evidence from several sources
indicates a maximum temperature in the country rocks of 960 ±40⁰C. Contrary to previous suggestions the complex was not
emplaced as a fault block enclosed by a "Marginal Gabbro", but
formed in situ at a depth of less than lKm. Large-scale layering
continues to within 2m of the country rocks, and shows no change
in either thickness or orientation close to the contact. Small-scale
layers at Harris Bay thin and terminate towards the
contact with the Western Granophyre.
Strontium isotope data shows that the margins of the
complex have experienced considerable crustal contamination.
Contamination may have taken place by mixing of anatectic country
rock melt with the resident basaltic liquid during boundary
flow. Whole-rock and isotope geochemistry suggests that marginal
microgranodiorite ("hybrid rocks") formed during a process of
combined assimilation and fractional crystallization. Lead
isotope data indicate that rocks of the ultrabasic complex, as
well as earlier Tertiary granophres and felsites, were
contaminated with Lewisian lead. The crustal level at which this
took place and the processes involved remain unclear.
Oxygen isotope analyses show that rocks of the contact
zone have undergone large-scale exchange with heated, meteoric
fluids. In response to inflation of the complex the country rocks
experienced considerable deformation, and in places the chamber
roof underwent gravity collapse. Deformation resulted in
increased country rock permeability, thus enhancing hydrothermal
circulation and promoting high-cooling rates along the ·contact
zone. A consequence of this process is the local preservation
of quenched ultrabasic material at Harris Bay, and the
ubiquitous development of rapid growth textures in all
lithologies within the contact zone.
1988-01-01T00:00:00Z
Greenwood, Richard C.
Country rocks surrounding the Rhum Tertiary ultrabasic
complex have experienced severe thermal metamorphism, partial
melting and mobilization resulting in the formation of extensive
areas of intrusion breccia. Evidence from several sources
indicates a maximum temperature in the country rocks of 960 ±40⁰C. Contrary to previous suggestions the complex was not
emplaced as a fault block enclosed by a "Marginal Gabbro", but
formed in situ at a depth of less than lKm. Large-scale layering
continues to within 2m of the country rocks, and shows no change
in either thickness or orientation close to the contact. Small-scale
layers at Harris Bay thin and terminate towards the
contact with the Western Granophyre.
Strontium isotope data shows that the margins of the
complex have experienced considerable crustal contamination.
Contamination may have taken place by mixing of anatectic country
rock melt with the resident basaltic liquid during boundary
flow. Whole-rock and isotope geochemistry suggests that marginal
microgranodiorite ("hybrid rocks") formed during a process of
combined assimilation and fractional crystallization. Lead
isotope data indicate that rocks of the ultrabasic complex, as
well as earlier Tertiary granophres and felsites, were
contaminated with Lewisian lead. The crustal level at which this
took place and the processes involved remain unclear.
Oxygen isotope analyses show that rocks of the contact
zone have undergone large-scale exchange with heated, meteoric
fluids. In response to inflation of the complex the country rocks
experienced considerable deformation, and in places the chamber
roof underwent gravity collapse. Deformation resulted in
increased country rock permeability, thus enhancing hydrothermal
circulation and promoting high-cooling rates along the ·contact
zone. A consequence of this process is the local preservation
of quenched ultrabasic material at Harris Bay, and the
ubiquitous development of rapid growth textures in all
lithologies within the contact zone.
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Paraglacial modification of drift-mantled hillslopes
https://hdl.handle.net/10023/7115
The aim of the research reported in this thesis is to establish the
characteristics of paraglacial modification of drift-mantled hillslopes in glaciated
upland valleys in Norway and Scotland. Debris flow represents the principal
agent of paraglacial sediment reworking, though snow avalanches and slopewash
are locally important. Paraglacial hillslope modification is most widespread in
areas of thick drift where initial slopes exceed c. 30°, void ratio exceeds c. 0.35,
and water input is focused both spatially and temporally. Paraglacially-reworked
sediments preserve most of the characteristics of the parent tills, but differ in
terms of preferred clast orientation and structural and lithofacies characteristics.
Stratigraphic relations between tills and reworked sediments imply cyclic
alternation of glacial and paraglacial sediment transport. Paraglacial slope
adjustment follows a sequence involving (1) rapid gully incision; (2) widening of
gullies, and accumulation of debris cones at the slope foot; (3) reduction and
destruction of inter-gully divides, and formation of a slope-foot apron of
coalescing cones; (4) extensive exposure of bedrock at the crest of the slope,
resulting in sediment exhaustion and progressive stabilisation. Slope profiles tend
to converge on a maximum gradient of c. 28° and a concavity index of c. 0.22. At
the most active sites, 2-4 m of gully lowering has occurred within decades of
deglaciation, implying minimum erosion rates averaging c. 90 mm yr ⁻¹. In
Scotland delayed or renewed reworking of drift-mantled slopes has occurred
several millennia after deglaciation. Radiocarbon dating of buried palaeosols
indicates intermittent drift reworking by debris flows throughout the past 6.5 ka,
with some evidence for accelerated activity at c. 2.7-1.7 cal ka BP and after c. 0.7
cal ka BP. Three-dimensional conceptual models are developed to describe the
sequence of both immediate and delayed or renewed paraglacial hillslope
modification, and the landforms and sediment associations characteristic (and
diagnostic) of paraglaciallandsystems in passive continental margins.
1998-01-01T00:00:00Z
Curry, Alastair M.
The aim of the research reported in this thesis is to establish the
characteristics of paraglacial modification of drift-mantled hillslopes in glaciated
upland valleys in Norway and Scotland. Debris flow represents the principal
agent of paraglacial sediment reworking, though snow avalanches and slopewash
are locally important. Paraglacial hillslope modification is most widespread in
areas of thick drift where initial slopes exceed c. 30°, void ratio exceeds c. 0.35,
and water input is focused both spatially and temporally. Paraglacially-reworked
sediments preserve most of the characteristics of the parent tills, but differ in
terms of preferred clast orientation and structural and lithofacies characteristics.
Stratigraphic relations between tills and reworked sediments imply cyclic
alternation of glacial and paraglacial sediment transport. Paraglacial slope
adjustment follows a sequence involving (1) rapid gully incision; (2) widening of
gullies, and accumulation of debris cones at the slope foot; (3) reduction and
destruction of inter-gully divides, and formation of a slope-foot apron of
coalescing cones; (4) extensive exposure of bedrock at the crest of the slope,
resulting in sediment exhaustion and progressive stabilisation. Slope profiles tend
to converge on a maximum gradient of c. 28° and a concavity index of c. 0.22. At
the most active sites, 2-4 m of gully lowering has occurred within decades of
deglaciation, implying minimum erosion rates averaging c. 90 mm yr ⁻¹. In
Scotland delayed or renewed reworking of drift-mantled slopes has occurred
several millennia after deglaciation. Radiocarbon dating of buried palaeosols
indicates intermittent drift reworking by debris flows throughout the past 6.5 ka,
with some evidence for accelerated activity at c. 2.7-1.7 cal ka BP and after c. 0.7
cal ka BP. Three-dimensional conceptual models are developed to describe the
sequence of both immediate and delayed or renewed paraglacial hillslope
modification, and the landforms and sediment associations characteristic (and
diagnostic) of paraglaciallandsystems in passive continental margins.
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A geological investigation of a tertiary intrusive centre in the Vididalur-Vatnsdalur area, Northern Iceland
https://hdl.handle.net/10023/7094
This thesis is an account of an investigation into the structure, petrology and mineralogy of a small Tertiary intrusive centre in the Vididalur-Vatnsdalur area near the north coast of Iceland. The area concerned lies in the Tertiary area west of the neovolcanic zone. In upper Tertiary times the extrusion of flood basalts in the area studied was locally interrupted by the building of a central volcano characterized by distinctive basalts, andesites and pyroclastics, some of which interfingered with contemporaneously extruded flood basalts. The first episode of this central volcanic activity, of which only the top is seen in the area studied, was subsequently buried by the transgressing flood basalts, and slow downsagging occurred in parts of the area along the prevailing north to north-northeast fracture system. A second central volcanic episode produced basalt, andesite and rhyolite extrusions and some pyroclastics in the northeastern part of the area following the flood transgression. Injection of thin basic dykes proceeded parallel to the two phases of central activity and continued during a final episode in which thin pale grey basalts similar to the Lower Pleistocene to Recent flows elsewhere in Iceland were extruded on to the irregular central volcano land surface.
Two phases of intrusive activity proceeded parallel to the extrusive activity, the older More deeply eroded First Phase products being emplaced in the time interval during which the older flood basalts buried the newly extruded earlier central volcano lavas. A consecutive Second Phase of intrusive activity proceeded simultaneously with the second central volcanic episode and its less deeply eroded products show many similarities to the contemporaneous extrusions. These First and Second Phase intrusions are probably the upper apophyses of larger bodies concealed at depth. The intrusions which form the main part of the study are concentrated about an intrusive/extrusive centre in northern Vididalsfjall, and consist of coarse- and fine-grained basic to acid series, ranging in the First Phase from olivineeucrites (bytownite cumulates) through gabbros (labradorite cumulates), hybrid diorite and intermediate-acid hybrid types to acid granophyres. The First Phase was initiated by the intrusion of the eucrites and a dense swarm of tholeiitic cone-sheets centred on a focus about 5 km below northern Vididalsfjall. Commingling of the simultaneously available diorite and granophyre magma later in the First Phase resulted in the formation of small volumes of acid-intermediate hybrid rocks. The Second Phase intrusive activity is expressed as small high-level intrusions and began with a new supply of olivinetholeiite magmas which was injected along cone-fractures to form a late set of high-level cone-sheets centred on a focus about 2 km below northern Vididalsfjall. Cogenetic bytownite cumulates were emplaced as small high-level intrusions, but coarse-grained rocks and acid rocks of Second Phase age are rare in the area studied. iii. A broad aureole of hydrothermally altered rocks surrounds northern Vididalsfjall and smaller alteration zones surround other smaller regions cut by vents and intrusions; these altered and injected zones are taken to represent the eruptive channels at the core of the Vididalur-Vatnsdalur volcano. The intrusive rocks are all plagioclase-pyroxene-ore assemblages with or without olivine, alkali feldspar and quartz, and the First Phase types show a gradation from basic rocks bearing calcic plagioclase and magnesian augite to acid rocks containing sodic plagioclase anorthoclase and ferrian augite. The Second Phase rocks show broad petrographic similarity to those of the First Phase but coarse-grained intermediate and acid types are not found, and the basic rocks are richer in olivine than corresponding First Phase types. All the rocks examined show textural and mineralogical evidence of a high degree of fractionation and rapid final cooling at high crustal levels; the plagioclase of phenocryst rims and groundmasses is in a high-temperature structural state, the calcium-rich pyroxenes have immature exsolution textures, the olivines are strongly zoned and interstitial glassy or salic material is abundant. Many of the acid minor intrusions contain tridynlite paramorphed by quartz. Chemical analyses of 14 Vididalur-Vatnsdalur rocks show that they are low in alumina, combined alkalis and magnesia, and are relatively rich in iron, and titania, as are other Tertiary Icelandic tholeiites, with soda present in greater quantity than potash. The analyses of these basic intermediate and acid rocks fit on the iron-enriched trend for tholeiites (Nockolds a.nd AlIen, 1956) which suggests that the First and Second Phase sequences may have originated by -contiriuous fractionation of basic tholeiitic uuterinl. However there is little direct evidence of a tholeiite fractionation origin for the First Phase granitic acid rocks, and the presence of a few small veins of remelted acid material at some localities casts doubt on a fractionation origin for these granophyres and granites of the Vididalur-Vatnsdalur area.
1968-01-01T00:00:00Z
Annells, R. N.
This thesis is an account of an investigation into the structure, petrology and mineralogy of a small Tertiary intrusive centre in the Vididalur-Vatnsdalur area near the north coast of Iceland. The area concerned lies in the Tertiary area west of the neovolcanic zone. In upper Tertiary times the extrusion of flood basalts in the area studied was locally interrupted by the building of a central volcano characterized by distinctive basalts, andesites and pyroclastics, some of which interfingered with contemporaneously extruded flood basalts. The first episode of this central volcanic activity, of which only the top is seen in the area studied, was subsequently buried by the transgressing flood basalts, and slow downsagging occurred in parts of the area along the prevailing north to north-northeast fracture system. A second central volcanic episode produced basalt, andesite and rhyolite extrusions and some pyroclastics in the northeastern part of the area following the flood transgression. Injection of thin basic dykes proceeded parallel to the two phases of central activity and continued during a final episode in which thin pale grey basalts similar to the Lower Pleistocene to Recent flows elsewhere in Iceland were extruded on to the irregular central volcano land surface.
Two phases of intrusive activity proceeded parallel to the extrusive activity, the older More deeply eroded First Phase products being emplaced in the time interval during which the older flood basalts buried the newly extruded earlier central volcano lavas. A consecutive Second Phase of intrusive activity proceeded simultaneously with the second central volcanic episode and its less deeply eroded products show many similarities to the contemporaneous extrusions. These First and Second Phase intrusions are probably the upper apophyses of larger bodies concealed at depth. The intrusions which form the main part of the study are concentrated about an intrusive/extrusive centre in northern Vididalsfjall, and consist of coarse- and fine-grained basic to acid series, ranging in the First Phase from olivineeucrites (bytownite cumulates) through gabbros (labradorite cumulates), hybrid diorite and intermediate-acid hybrid types to acid granophyres. The First Phase was initiated by the intrusion of the eucrites and a dense swarm of tholeiitic cone-sheets centred on a focus about 5 km below northern Vididalsfjall. Commingling of the simultaneously available diorite and granophyre magma later in the First Phase resulted in the formation of small volumes of acid-intermediate hybrid rocks. The Second Phase intrusive activity is expressed as small high-level intrusions and began with a new supply of olivinetholeiite magmas which was injected along cone-fractures to form a late set of high-level cone-sheets centred on a focus about 2 km below northern Vididalsfjall. Cogenetic bytownite cumulates were emplaced as small high-level intrusions, but coarse-grained rocks and acid rocks of Second Phase age are rare in the area studied. iii. A broad aureole of hydrothermally altered rocks surrounds northern Vididalsfjall and smaller alteration zones surround other smaller regions cut by vents and intrusions; these altered and injected zones are taken to represent the eruptive channels at the core of the Vididalur-Vatnsdalur volcano. The intrusive rocks are all plagioclase-pyroxene-ore assemblages with or without olivine, alkali feldspar and quartz, and the First Phase types show a gradation from basic rocks bearing calcic plagioclase and magnesian augite to acid rocks containing sodic plagioclase anorthoclase and ferrian augite. The Second Phase rocks show broad petrographic similarity to those of the First Phase but coarse-grained intermediate and acid types are not found, and the basic rocks are richer in olivine than corresponding First Phase types. All the rocks examined show textural and mineralogical evidence of a high degree of fractionation and rapid final cooling at high crustal levels; the plagioclase of phenocryst rims and groundmasses is in a high-temperature structural state, the calcium-rich pyroxenes have immature exsolution textures, the olivines are strongly zoned and interstitial glassy or salic material is abundant. Many of the acid minor intrusions contain tridynlite paramorphed by quartz. Chemical analyses of 14 Vididalur-Vatnsdalur rocks show that they are low in alumina, combined alkalis and magnesia, and are relatively rich in iron, and titania, as are other Tertiary Icelandic tholeiites, with soda present in greater quantity than potash. The analyses of these basic intermediate and acid rocks fit on the iron-enriched trend for tholeiites (Nockolds a.nd AlIen, 1956) which suggests that the First and Second Phase sequences may have originated by -contiriuous fractionation of basic tholeiitic uuterinl. However there is little direct evidence of a tholeiite fractionation origin for the First Phase granitic acid rocks, and the presence of a few small veins of remelted acid material at some localities casts doubt on a fractionation origin for these granophyres and granites of the Vididalur-Vatnsdalur area.
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Wish you were here?: experiences of moving through stigmatised neighbourhoods in urban Scotland
https://hdl.handle.net/10023/7087
This thesis is about the use of the term social exclusion in contemporary Scotland and
how it has given rise to the idea of 'excluded spaces' in political and academic
commentaries on deprived neighbourhoods. It argues that, despite criticism, the term
offers a useful way of re-assessing disadvantaged places, such that space (for
example, in the guise of socio-spatial segregation) should be considered not only an
outcome but also an input into processes of exclusion. This is illustrated through
exploration of the reproduction of the frequently negative place-images surrounding
two deprived neighbourhoods in urban Scotland. The thesis explores how such
representation may stigmatise residents therein, ultimately resulting in the production
of landscapes of exclusion. Use of a range of qualitative methods (though primarily
biographical interviews) demonstrates how negative place-images are constructed and
remain resilient to change while also revealing the concrete outcomes of such
'imagined' geographies. Overall, the thesis makes three main points. First, that the
construction of 'imagined' and 'real' places are fluid and dynamic processes and
differences between 'images' and 'realities' of places are neither as clear cut, nor as
'true' or 'inaccurate' as might be assumed. Second, that 'real' and 'imagined'
representations of place are reproduced through practices in, and attitudes towards,
place. And third, that migration processes are influenced by, and influential to, the
construction of social and place identities. Construction of socio-spatial stereotypes
reveals space to be both an outcome and input into processes of exclusion while also
demonstrating how many of the taken-for-granted assumptions about disadvantaged
neighbourhoods might be considered place-myths.
2004-01-01T00:00:00Z
Clark, Andrew J.
This thesis is about the use of the term social exclusion in contemporary Scotland and
how it has given rise to the idea of 'excluded spaces' in political and academic
commentaries on deprived neighbourhoods. It argues that, despite criticism, the term
offers a useful way of re-assessing disadvantaged places, such that space (for
example, in the guise of socio-spatial segregation) should be considered not only an
outcome but also an input into processes of exclusion. This is illustrated through
exploration of the reproduction of the frequently negative place-images surrounding
two deprived neighbourhoods in urban Scotland. The thesis explores how such
representation may stigmatise residents therein, ultimately resulting in the production
of landscapes of exclusion. Use of a range of qualitative methods (though primarily
biographical interviews) demonstrates how negative place-images are constructed and
remain resilient to change while also revealing the concrete outcomes of such
'imagined' geographies. Overall, the thesis makes three main points. First, that the
construction of 'imagined' and 'real' places are fluid and dynamic processes and
differences between 'images' and 'realities' of places are neither as clear cut, nor as
'true' or 'inaccurate' as might be assumed. Second, that 'real' and 'imagined'
representations of place are reproduced through practices in, and attitudes towards,
place. And third, that migration processes are influenced by, and influential to, the
construction of social and place identities. Construction of socio-spatial stereotypes
reveals space to be both an outcome and input into processes of exclusion while also
demonstrating how many of the taken-for-granted assumptions about disadvantaged
neighbourhoods might be considered place-myths.
-
The vertical dimensions of the last ice sheet and late quaternary events in northern Ross-shire, Scotland
https://hdl.handle.net/10023/7079
Despite more than 100 years of research, surprisingly
little is known about the precise dimensions of the last
ice sheet in Northern Scotland, though recent work has
suggested that it may have been much less laterally
extensive than was previously assumed. This raises the
possibility that some higher mountain summits in this area
may have remained as nunataks above the level of the ice
sheet at its greatest thickness.
Detailed geomorphological mapping of a west-east
transect across northern Ross-shire has revealed the
existence of a periglacial trimline or 'trimzone' well
outside and usually well above the limits of glaciers that
developed during the Loch Lomond Stadial of ~11-10 ka.
B.P. This trimzone usually consists of a zone of
mass-moved frost-weathered detritus that separates in situ
mountain-top detritus and frost-weathered bedrock upslope
from relatively unweathered ice-scoured bedrock downslope.
The trimzone declines in altitude to both the east and west
of the present watershed and is interpreted as marking the
approximate altitude of a former ice-sheet surface. The
degree and depth of per1glacial weathering above the level
of the trimzone strongly suggests that it relates to the
last Scottish ice sheet at its maximum thickness rather
than any subsequent ice-sheet readvance, though the
possibility that thin cold-based ice-caps developed locally
on plateaux above the level of the ice sheet cannot be
excluded.
Strong independent support for
nunataks is provided by comparison
the survival of
of the clay mineral
content of soils developed above the level of the ice-sheet
trimzone and those developed on ice-scoured areas or thin
incipient mountain-top detritus below the level of this
zone. Clay minerals thought to be 'inherited' from
pre-Late Devensian weathering were found to be either
significantly more abundant (kaolinite and halloysite) or
exclusively developed (gibbsite) above the trimzone, thus
indicating that mature in situ mountain-top detritus above
the trimzone escaped glaciation throughout the Late
Devensian or possibly much longer.
Trimzone evidence and evidence for former directions
of ice-sheet movement was used to reconstruct the three
dimensional form of the last ice sheet in northern
Ross-shire. This reconstruction indicated that the former
ice-sheet surface rose in altitude from ~600m in the west
of the area to in excess of 850m in the Beinn Dearg massif
and Fannich Mountains, and declined eastwards to ~700m in
the vicinity of Carn Chuinneag and Ben Wyvis. The former
ice divide was located close to the present watershed.
Finally, re-investigation of the dimensions of Loch
Lomond Readvance glaciers in northern Ross-shire has shown
that these former glaciers may have been much more
extensive than has previously been believed.
1989-01-01T00:00:00Z
Reed, William J.
Despite more than 100 years of research, surprisingly
little is known about the precise dimensions of the last
ice sheet in Northern Scotland, though recent work has
suggested that it may have been much less laterally
extensive than was previously assumed. This raises the
possibility that some higher mountain summits in this area
may have remained as nunataks above the level of the ice
sheet at its greatest thickness.
Detailed geomorphological mapping of a west-east
transect across northern Ross-shire has revealed the
existence of a periglacial trimline or 'trimzone' well
outside and usually well above the limits of glaciers that
developed during the Loch Lomond Stadial of ~11-10 ka.
B.P. This trimzone usually consists of a zone of
mass-moved frost-weathered detritus that separates in situ
mountain-top detritus and frost-weathered bedrock upslope
from relatively unweathered ice-scoured bedrock downslope.
The trimzone declines in altitude to both the east and west
of the present watershed and is interpreted as marking the
approximate altitude of a former ice-sheet surface. The
degree and depth of per1glacial weathering above the level
of the trimzone strongly suggests that it relates to the
last Scottish ice sheet at its maximum thickness rather
than any subsequent ice-sheet readvance, though the
possibility that thin cold-based ice-caps developed locally
on plateaux above the level of the ice sheet cannot be
excluded.
Strong independent support for
nunataks is provided by comparison
the survival of
of the clay mineral
content of soils developed above the level of the ice-sheet
trimzone and those developed on ice-scoured areas or thin
incipient mountain-top detritus below the level of this
zone. Clay minerals thought to be 'inherited' from
pre-Late Devensian weathering were found to be either
significantly more abundant (kaolinite and halloysite) or
exclusively developed (gibbsite) above the trimzone, thus
indicating that mature in situ mountain-top detritus above
the trimzone escaped glaciation throughout the Late
Devensian or possibly much longer.
Trimzone evidence and evidence for former directions
of ice-sheet movement was used to reconstruct the three
dimensional form of the last ice sheet in northern
Ross-shire. This reconstruction indicated that the former
ice-sheet surface rose in altitude from ~600m in the west
of the area to in excess of 850m in the Beinn Dearg massif
and Fannich Mountains, and declined eastwards to ~700m in
the vicinity of Carn Chuinneag and Ben Wyvis. The former
ice divide was located close to the present watershed.
Finally, re-investigation of the dimensions of Loch
Lomond Readvance glaciers in northern Ross-shire has shown
that these former glaciers may have been much more
extensive than has previously been believed.
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Exploring the incidence of lung cancer in small areas across Scotland
https://hdl.handle.net/10023/7078
Lung cancer is one of the most important causes of 'avoidable deaths' globally and is
responsible for approximately 900,000 deaths per year. However, lung cancer rates
tend to be higher for males than for females and the disease also varies
geographically, as rates are far higher in developed countries compared to
developing countries. Scotland has the highest rate of lung cancer of any country
where lung cancer data is available. However, explaining the spatial distribution of
this disease is difficult because lung cancer has a number of known causes that
operate at a range of different spatial scales. This is further complicated by the lag
time between the period of exposure to a risk factor and the date of diagnosis.
This thesis examines the causes of lung cancer across Scotland, using lung cancer
registrations for the period 1988 to 1991. Exploratory methods are presented for
examining the geographical distribution of the disease in small areas using methods
of age-standardisation and cluster detection to identify areas with unusual rates.
Estimates of the key risk factors potentially associated with lung cancer are
calculated for the same small areas. These include estimates of smoking behaviour,
air pollution levels in 1971 and 1991, radon gas potential, coal mining activity,
quarrying activity and area deprivation. The risk factors are incorporated into a set
of regression models to examine which factors are significant in explaining lung
cancer incidence. Finally, the residual values derived from the optimum model of
lung cancer incidence in Scotland are examined to identify areas where lung cancer
incidence is particularly high and low.
This study revealed that there were marked geographical differences in lung cancer
rates, with higher rates in the large urban areas, especially Glasgow, and also the
more deprived areas of Scotland. Smoking was consistently significant in explaining
lung cancer incidence for all cohorts, types of lung cancer and urban-rural areas.
The estimated air pollution levels in 1971 were also found to be significant, but the
1991 estimates were not. Exposure to radon was only significant in explaining lung
cancer in the younger age groups. However, the coal mining and quarrying variables
did not independently influence the incidence of the disease. Area deprivation and
measure of urbanness both had a significant effect on lung cancer incidence in
Scotland that was independent of the key risk factors. The analysis of the residual
values showed that, having controlled for the key risk factors, lung cancer incidence
is higher than expected in rural rather than urban areas.
2003-01-01T00:00:00Z
Pearce, James R,
Lung cancer is one of the most important causes of 'avoidable deaths' globally and is
responsible for approximately 900,000 deaths per year. However, lung cancer rates
tend to be higher for males than for females and the disease also varies
geographically, as rates are far higher in developed countries compared to
developing countries. Scotland has the highest rate of lung cancer of any country
where lung cancer data is available. However, explaining the spatial distribution of
this disease is difficult because lung cancer has a number of known causes that
operate at a range of different spatial scales. This is further complicated by the lag
time between the period of exposure to a risk factor and the date of diagnosis.
This thesis examines the causes of lung cancer across Scotland, using lung cancer
registrations for the period 1988 to 1991. Exploratory methods are presented for
examining the geographical distribution of the disease in small areas using methods
of age-standardisation and cluster detection to identify areas with unusual rates.
Estimates of the key risk factors potentially associated with lung cancer are
calculated for the same small areas. These include estimates of smoking behaviour,
air pollution levels in 1971 and 1991, radon gas potential, coal mining activity,
quarrying activity and area deprivation. The risk factors are incorporated into a set
of regression models to examine which factors are significant in explaining lung
cancer incidence. Finally, the residual values derived from the optimum model of
lung cancer incidence in Scotland are examined to identify areas where lung cancer
incidence is particularly high and low.
This study revealed that there were marked geographical differences in lung cancer
rates, with higher rates in the large urban areas, especially Glasgow, and also the
more deprived areas of Scotland. Smoking was consistently significant in explaining
lung cancer incidence for all cohorts, types of lung cancer and urban-rural areas.
The estimated air pollution levels in 1971 were also found to be significant, but the
1991 estimates were not. Exposure to radon was only significant in explaining lung
cancer in the younger age groups. However, the coal mining and quarrying variables
did not independently influence the incidence of the disease. Area deprivation and
measure of urbanness both had a significant effect on lung cancer incidence in
Scotland that was independent of the key risk factors. The analysis of the residual
values showed that, having controlled for the key risk factors, lung cancer incidence
is higher than expected in rural rather than urban areas.
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The economic development of second-tier city-regions in the United Kingdom : using “absorptive capacity” to theorise the “firm-territory nexus”
https://hdl.handle.net/10023/7070
The economic development challenges facing second-tier city-regions in the United Kingdom reflect a critical dimension of policy debates concerning spatial rebalancing. The integration of multi-location firms at second-tier territorial contexts is an important aspect of rebalancing narratives, and this thesis examines what such integration may entail for the economic development of these places. Given the label of the “firm-territory nexus” by other economic geographers (Dicken and Malmberg, 2001), integration brings into focus a complex set of factors, processes and conditions. In order to grapple with and order such complexity, the conceptual framework of city-region absorptive capacity has been proposed and developed in this research.
Four case studies across two second-tier UK cities, Edinburgh and Manchester, comprising interviews with elites and the collection of extensive documentary material, provides the empirical material for framework development. The research hinges on an analytical process that: first, deploys the functional form of “absorptive capacity” to provide language and broad parameters by which to approach the empirical object; and second, generates abstract categories from the empirical data to flesh out a contextually sensitive conceptual framework. Network position relative to London and labour appear as important integrating mechanisms across the case studies, though the conceptual framework demonstrates contingencies in terms of territorial and relational processes, shifting moments of structure and agency, and the overlapping institutional mosaics at play. By providing portraits of city economies in the middle ground of global economic networks, the need to articulate economic geographies of the “outside” and “inside” are also given emphasis.
2015-11-30T00:00:00Z
Waite, David Andrew
The economic development challenges facing second-tier city-regions in the United Kingdom reflect a critical dimension of policy debates concerning spatial rebalancing. The integration of multi-location firms at second-tier territorial contexts is an important aspect of rebalancing narratives, and this thesis examines what such integration may entail for the economic development of these places. Given the label of the “firm-territory nexus” by other economic geographers (Dicken and Malmberg, 2001), integration brings into focus a complex set of factors, processes and conditions. In order to grapple with and order such complexity, the conceptual framework of city-region absorptive capacity has been proposed and developed in this research.
Four case studies across two second-tier UK cities, Edinburgh and Manchester, comprising interviews with elites and the collection of extensive documentary material, provides the empirical material for framework development. The research hinges on an analytical process that: first, deploys the functional form of “absorptive capacity” to provide language and broad parameters by which to approach the empirical object; and second, generates abstract categories from the empirical data to flesh out a contextually sensitive conceptual framework. Network position relative to London and labour appear as important integrating mechanisms across the case studies, though the conceptual framework demonstrates contingencies in terms of territorial and relational processes, shifting moments of structure and agency, and the overlapping institutional mosaics at play. By providing portraits of city economies in the middle ground of global economic networks, the need to articulate economic geographies of the “outside” and “inside” are also given emphasis.
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The effect of land-use on soil organic carbon dynamics in the Peruvian Andes
https://hdl.handle.net/10023/7064
Soil carbon storage in tropical ecosystems is important in the global carbon cycle, yet consensus is lacking on how soil organic carbon stocks are altered under anthropogenic land-use change. This thesis seeks to quantify soil carbon stocks, the associated soil carbon emissions and explores the drivers of soil respiration in managed tropical Andean lands over a 2600 m elevation gradient. It investigates: grazing and burning on high altitude montane grasslands, burning in montane forests and agriculture in premontane forests. Changes among land-uses were quantified using belowground carbon stocks, the carbon distribution among density fractions, soil carbon emissions and environmental drivers of soil respiration. Soil respiration was a good proxy of soil carbon loss in premontane pastures and montane grassland soils. The total carbon stocks on some land-uses appeared to be unaffected but the distribution of carbon within the soil had changed and even when there were no net changes in soil carbon emissions, the drivers of respiration were different. The synergistic effect of burning and grazing in montane grasslands was the most detrimental to soil carbon stocks, whereas montane forests were unaffected. In the premontane elevation, soil carbon loss was dependent on the type of agricultural practice but the succession of secondary forest allowed soil carbon to recover to similar levels measured in the mature forest. These findings highlight the fact that although land-use does not always appear to have an obvious effect on total soil carbon stocks, the loss of carbon from short-term labile pools can cause higher carbon emissions and dominate soil-atmospheric feedbacks. Furthermore, the drivers of soil respiration and the synergistic relationship between soil moisture and temperature alter under different land uses. These factors should be taken into consideration with regards to predictions of regional temperature/precipitation climate change and soil carbon management policy in order to arrive at more realistic decisions.
2015-06-26T00:00:00Z
Oliver, Viktoria
Soil carbon storage in tropical ecosystems is important in the global carbon cycle, yet consensus is lacking on how soil organic carbon stocks are altered under anthropogenic land-use change. This thesis seeks to quantify soil carbon stocks, the associated soil carbon emissions and explores the drivers of soil respiration in managed tropical Andean lands over a 2600 m elevation gradient. It investigates: grazing and burning on high altitude montane grasslands, burning in montane forests and agriculture in premontane forests. Changes among land-uses were quantified using belowground carbon stocks, the carbon distribution among density fractions, soil carbon emissions and environmental drivers of soil respiration. Soil respiration was a good proxy of soil carbon loss in premontane pastures and montane grassland soils. The total carbon stocks on some land-uses appeared to be unaffected but the distribution of carbon within the soil had changed and even when there were no net changes in soil carbon emissions, the drivers of respiration were different. The synergistic effect of burning and grazing in montane grasslands was the most detrimental to soil carbon stocks, whereas montane forests were unaffected. In the premontane elevation, soil carbon loss was dependent on the type of agricultural practice but the succession of secondary forest allowed soil carbon to recover to similar levels measured in the mature forest. These findings highlight the fact that although land-use does not always appear to have an obvious effect on total soil carbon stocks, the loss of carbon from short-term labile pools can cause higher carbon emissions and dominate soil-atmospheric feedbacks. Furthermore, the drivers of soil respiration and the synergistic relationship between soil moisture and temperature alter under different land uses. These factors should be taken into consideration with regards to predictions of regional temperature/precipitation climate change and soil carbon management policy in order to arrive at more realistic decisions.
-
An extension of geographically weighted regression with flexible bandwidths
https://hdl.handle.net/10023/7052
Various statistical methods have been developed for local spatial analysis. Among
them Geographically Weighted Regression (GWR) is a simple yet powerful method
to explore spatially varying relationships between variables. This thesis examines how
GWR can be extended to investigate spatially varying relationships at various
geographical scales within one model.
GWR assumes that observations near to a regression location have more influence on
the estimation of local regression coefficients than do observations farther away. A
single bandwidth is employed in basic GWR to control the rate of distance-decay in
this influence. The magnitude of the bandwidth affects the scale of variation in the
estimated regression coefficients and thus usefully reflects the appropriate spatial
scale at which the processes being modelled operate. A small bandwidth suggests the
processes operate over a local spatial scale, whilst a large bandwidth indicates a more
regional process.
In practice, a single bandwidth as in basic GWR may not be sufficient to reflect the
potentially complex spatial variations in relationships between variables in a
multivariate spatial model. Therefore, in order to estimate coefficient surfaces that
may vary at different spatial scales for different variables, Flexible Bandwidth GWR
(FBGWR) is proposed to allow different bandwidths to be individually specified for
each independent variable in a regression framework. An algorithm based on back-
fitting is developed to calibrate the FBGWR model.
The performance of FBGWR is investigated with simulated datasets where
coefficients are predefined at various levels of non-stationarity across space. A case
study is then carried out on data relating to the Irish Famine to demonstrate the
application of FBGWR to real-world processes. The results suggest that FBGWR can
distinguish various scales of non-stationarity in spatial processes and provide an
improved model over basic GWR. FBGWR therefore represents a useful development
in the modelling of spatially varying processes.
2014-01-01T00:00:00Z
Yang, Wenbai
Various statistical methods have been developed for local spatial analysis. Among
them Geographically Weighted Regression (GWR) is a simple yet powerful method
to explore spatially varying relationships between variables. This thesis examines how
GWR can be extended to investigate spatially varying relationships at various
geographical scales within one model.
GWR assumes that observations near to a regression location have more influence on
the estimation of local regression coefficients than do observations farther away. A
single bandwidth is employed in basic GWR to control the rate of distance-decay in
this influence. The magnitude of the bandwidth affects the scale of variation in the
estimated regression coefficients and thus usefully reflects the appropriate spatial
scale at which the processes being modelled operate. A small bandwidth suggests the
processes operate over a local spatial scale, whilst a large bandwidth indicates a more
regional process.
In practice, a single bandwidth as in basic GWR may not be sufficient to reflect the
potentially complex spatial variations in relationships between variables in a
multivariate spatial model. Therefore, in order to estimate coefficient surfaces that
may vary at different spatial scales for different variables, Flexible Bandwidth GWR
(FBGWR) is proposed to allow different bandwidths to be individually specified for
each independent variable in a regression framework. An algorithm based on back-
fitting is developed to calibrate the FBGWR model.
The performance of FBGWR is investigated with simulated datasets where
coefficients are predefined at various levels of non-stationarity across space. A case
study is then carried out on data relating to the Irish Famine to demonstrate the
application of FBGWR to real-world processes. The results suggest that FBGWR can
distinguish various scales of non-stationarity in spatial processes and provide an
improved model over basic GWR. FBGWR therefore represents a useful development
in the modelling of spatially varying processes.
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Neil Smith, 1954–2012 : "the future is indeed radically open"
https://hdl.handle.net/10023/6932
2013-01-01T00:00:00Z
Doherty, Joe
-
Trends in alluvial channel geometry and streamflow : an investigation of patterns and controls
https://hdl.handle.net/10023/6913
Alluvial river channels are self-formed by the sediment-laden flow that is supplied to them from upstream and the interactions between this flow and the materials forming the channel bed and banks. Thus, any changes in the volumes of solid and liquid discharge or the resistance of the boundary materials can produce adjustments in the form of river channels over time. These shifts may increase or decrease the capacity of a channel to contain flood flows. However, despite a wealth of studies on the average geometry of river channels across different scales and climatic regimes, there has not yet been a systematic assessment of the rates and controls of trends in channel form. Using a combination of USGS data, including manual field measurements and mean daily streamflow data at hundreds of stream gages, this work is the first attempt to quantify how trends in channel geometry develop over decadal timescales and how they contribute to shifts in flood hazard, in comparison with trends in streamflow. Findings reveal that two-thirds of all channel cross-sections studied exhibit significant trends in channel geometry. The majority of the investigated US river channels are eroding, with widening and deepening trends partially offset by decreases in average flow velocity. Rates of change are principally controlled by the channel size. Although large channels develop larger trends, changes are proportionally greater in small channels in percentage terms. A secondary major control is hydrology: rates of change in channel geometry are heightened by the variability and flashiness of flow regimes. Finally, results show that changing flood frequencies can only be accurately quantified when both hydrologic and geomorphic trends are accounted for, and that flood hazard is significantly increasing across the studied sites. These documented trends in channel geometry, hydraulics, and flood hazard have important implications for the management of alluvial channels, navigation, and riverside infrastructure.
2015-06-01T00:00:00Z
Slater, Louise J.
Alluvial river channels are self-formed by the sediment-laden flow that is supplied to them from upstream and the interactions between this flow and the materials forming the channel bed and banks. Thus, any changes in the volumes of solid and liquid discharge or the resistance of the boundary materials can produce adjustments in the form of river channels over time. These shifts may increase or decrease the capacity of a channel to contain flood flows. However, despite a wealth of studies on the average geometry of river channels across different scales and climatic regimes, there has not yet been a systematic assessment of the rates and controls of trends in channel form. Using a combination of USGS data, including manual field measurements and mean daily streamflow data at hundreds of stream gages, this work is the first attempt to quantify how trends in channel geometry develop over decadal timescales and how they contribute to shifts in flood hazard, in comparison with trends in streamflow. Findings reveal that two-thirds of all channel cross-sections studied exhibit significant trends in channel geometry. The majority of the investigated US river channels are eroding, with widening and deepening trends partially offset by decreases in average flow velocity. Rates of change are principally controlled by the channel size. Although large channels develop larger trends, changes are proportionally greater in small channels in percentage terms. A secondary major control is hydrology: rates of change in channel geometry are heightened by the variability and flashiness of flow regimes. Finally, results show that changing flood frequencies can only be accurately quantified when both hydrologic and geomorphic trends are accounted for, and that flood hazard is significantly increasing across the studied sites. These documented trends in channel geometry, hydraulics, and flood hazard have important implications for the management of alluvial channels, navigation, and riverside infrastructure.
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Magma chamber dynamics in the peralkaline magmas of the Kakortokite Series, South Greenland
https://hdl.handle.net/10023/6900
Understanding crystallisation in magma chambers is a key challenge for igneous petrology. It is particularly important to understand the origins of layering in peralkaline rocks, e.g. the kakortokite (nepheline syenite), Ilímaussaq Complex, S. Greenland, as these are commonly associated with high value multi-element economic deposits. The kakortokite is a spectacular example of macrorhythmic (>5 m) layering. Each unit consists of three layers comprising arfvedsonite-rich (sodic-amphibole) black kakortokite at the base, grading into eudialyte-rich (sodic-zirconosilicate) red kakortokite, then alkali feldspar- and nepheline-rich white kakortokite. Each unit is numbered -19 to +17 relative to a characteristic well-developed horizon (Unit 0), however there is little consensus on their development.
This project applies a multidisciplinary approach through field observations combined with petrography, crystal size distributions (CSDs), mineral and whole rock chemistries on Units 0, -8 to -11 and a phonolite/micro-nephelinolite (“hybrid”) sequence that crosscuts the layered kakortokite.
Textures and compositions are laterally consistent across outcrop and indicators of current activity are rare. CSDs indicate in situ crystallisation with gravitational settling as a minor process. Chemical discontinuities occur across unit boundaries.
The layering developed through large-scale processes under exceptionally quiescent conditions. The discontinuities reflect open-system behaviour; units were formed by an influx of volatile-rich magma that initiated crystallisation in a bottom layer. Nucleation was initially suppressed by high volatile element concentrations, which decreased to allow for crystallisation of arfvedsonite, followed by eudialyte, then alkali feldspar and nepheline to form each tripartite unit. The chemistry of the hybrid indicates mixing between a primitive (sub-alkaline) magma and kakortokite. Thus injections of magmas of varying compositions occurred, indicating a complex plumbing system below current exposure. The lessons learned at Ilímaussaq, which is extremely well exposed and preserved, are relevant to understanding magma chamber dynamics in the more common instances of pervasively altered peralkaline rocks.
2015-03-30T00:00:00Z
Hunt, Emma J.
Understanding crystallisation in magma chambers is a key challenge for igneous petrology. It is particularly important to understand the origins of layering in peralkaline rocks, e.g. the kakortokite (nepheline syenite), Ilímaussaq Complex, S. Greenland, as these are commonly associated with high value multi-element economic deposits. The kakortokite is a spectacular example of macrorhythmic (>5 m) layering. Each unit consists of three layers comprising arfvedsonite-rich (sodic-amphibole) black kakortokite at the base, grading into eudialyte-rich (sodic-zirconosilicate) red kakortokite, then alkali feldspar- and nepheline-rich white kakortokite. Each unit is numbered -19 to +17 relative to a characteristic well-developed horizon (Unit 0), however there is little consensus on their development.
This project applies a multidisciplinary approach through field observations combined with petrography, crystal size distributions (CSDs), mineral and whole rock chemistries on Units 0, -8 to -11 and a phonolite/micro-nephelinolite (“hybrid”) sequence that crosscuts the layered kakortokite.
Textures and compositions are laterally consistent across outcrop and indicators of current activity are rare. CSDs indicate in situ crystallisation with gravitational settling as a minor process. Chemical discontinuities occur across unit boundaries.
The layering developed through large-scale processes under exceptionally quiescent conditions. The discontinuities reflect open-system behaviour; units were formed by an influx of volatile-rich magma that initiated crystallisation in a bottom layer. Nucleation was initially suppressed by high volatile element concentrations, which decreased to allow for crystallisation of arfvedsonite, followed by eudialyte, then alkali feldspar and nepheline to form each tripartite unit. The chemistry of the hybrid indicates mixing between a primitive (sub-alkaline) magma and kakortokite. Thus injections of magmas of varying compositions occurred, indicating a complex plumbing system below current exposure. The lessons learned at Ilímaussaq, which is extremely well exposed and preserved, are relevant to understanding magma chamber dynamics in the more common instances of pervasively altered peralkaline rocks.
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The detrital mineral record of Cenozoic sedimentary rocks in the Central Burma Basin : implications for the evolution of the eastern Himalayan orogen and timing of large scale river capture
https://hdl.handle.net/10023/6730
This study contributes to the understanding of major river evolution in Southeast Asia during the Cenozoic. In order to trace the evolution of a hypothesized palaeo-Yarlung Tsangpo-Irrawaddy River, this work undertakes the first systematic provenance study of detrital minerals from Cenozoic synorogenic fluvial and deltaic sedimentary rocks of the Central Burma Basin, employing a combination of high precision geochronology, thermochronology, and geochemistry analytical techniques on single grain detrital zircon and white mica. The dataset is compared to published isotopic data from potential source terranes in order to determine source provenance and exhumation history from source to sink.
A Yarlung Tsangpo-Irrawaddy connection existed as far back as ca. 42 Ma and disconnection occurred at 18–20 Ma, based on provenance changes detected using a combination of U-Pb ages and εHf(t) values on detrital zircons, and ⁴ºAr/³⁹Ar dating on detrital micas. During the Eocene and Oligocene, units are dominated by U-Pb age and high positive εHf(t) values, characteristic of a southern Lhasa Gangdese magmatic arc source. An antecedent Yarlung Tsangpo-Irrawaddy River system formed the major river draining the eastern Himalaya at this time. A significant change in provenance is seen in the early Miocene, where detritus is predominantly derived from bedrock of the eastern Himalayan syntaxis, western Yunnan and Burma, a region drained by the modern Irrawaddy-Chindwin river system characterized by Cenozoic U-Pb ages and negative εHf(t) values. This is attributed to the disconnection of the Yarlung-Irrawaddy River and capture by the proto-Brahmaputra River, re-routing Tibetan Transhimalayan detritus to the eastern Himalayan foreland basin. Re-set zircon fission track ages of 14-8 Ma present in all units is used to infer post-depositional basin evolution related to changes in the stress regime accommodating the continued northward migration of India. The early Miocene initiation of the Jiali-Parlung-Gaoligong-Sagaing dextral shear zone and the continued northward movement of the coupled India-Burma plate aided in focusing deformation inside the syntaxis contributing to the disconnection of the Yarlung Tsangpo-Irrawaddy system, linking surface deformation and denudation with processes occurring at deeper crustal levels.
2015-06-23T00:00:00Z
Brezina, Cynthia A.
This study contributes to the understanding of major river evolution in Southeast Asia during the Cenozoic. In order to trace the evolution of a hypothesized palaeo-Yarlung Tsangpo-Irrawaddy River, this work undertakes the first systematic provenance study of detrital minerals from Cenozoic synorogenic fluvial and deltaic sedimentary rocks of the Central Burma Basin, employing a combination of high precision geochronology, thermochronology, and geochemistry analytical techniques on single grain detrital zircon and white mica. The dataset is compared to published isotopic data from potential source terranes in order to determine source provenance and exhumation history from source to sink.
A Yarlung Tsangpo-Irrawaddy connection existed as far back as ca. 42 Ma and disconnection occurred at 18–20 Ma, based on provenance changes detected using a combination of U-Pb ages and εHf(t) values on detrital zircons, and ⁴ºAr/³⁹Ar dating on detrital micas. During the Eocene and Oligocene, units are dominated by U-Pb age and high positive εHf(t) values, characteristic of a southern Lhasa Gangdese magmatic arc source. An antecedent Yarlung Tsangpo-Irrawaddy River system formed the major river draining the eastern Himalaya at this time. A significant change in provenance is seen in the early Miocene, where detritus is predominantly derived from bedrock of the eastern Himalayan syntaxis, western Yunnan and Burma, a region drained by the modern Irrawaddy-Chindwin river system characterized by Cenozoic U-Pb ages and negative εHf(t) values. This is attributed to the disconnection of the Yarlung-Irrawaddy River and capture by the proto-Brahmaputra River, re-routing Tibetan Transhimalayan detritus to the eastern Himalayan foreland basin. Re-set zircon fission track ages of 14-8 Ma present in all units is used to infer post-depositional basin evolution related to changes in the stress regime accommodating the continued northward migration of India. The early Miocene initiation of the Jiali-Parlung-Gaoligong-Sagaing dextral shear zone and the continued northward movement of the coupled India-Burma plate aided in focusing deformation inside the syntaxis contributing to the disconnection of the Yarlung Tsangpo-Irrawaddy system, linking surface deformation and denudation with processes occurring at deeper crustal levels.
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Policy delivery for low carbon energy infrastructure in the UK
https://hdl.handle.net/10023/6627
The ambition of this conference was to deliver a first examination of how policy is delivered in the context of low-carbon energy infrastructure in the UK. The UK has been developing policy in this area since 2002 (Heffron, 2013). Finally, as the decade passed, in November 2012 an Energy Bill was put before the UK Parliament. One of the chief purposes of this Energy Bill is to establish the right environment for new electricity generation infrastructure in the low-carbon sector. There is significant debate on how this will be achieved and, indeed, whether this piece of legislation will actually deliver this outcome. This conference aimed to examine the dynamics of policy delivery. Throughout the day, there was entertaining discussion as a variety of conference presenters provided interesting contributions on how to deliver such policy goals. In total, there were twelve speakers throughout the day representing the UK (University of Oxford, Pinsent Masons Law Firm, University of Stirling, University of Dundee and University of Aberdeen), and also those who provided lessons from abroad from the University of Copenhagen, Central European University, Milieu Ltd., Pillsbury Law Firm (Washington DC, US) and the Conservation Law Foundation (MA, US).
The authors acknowledge the ESRC and the law firm Simpson and Marwick for supporting the conference.
2013-10-01T00:00:00Z
Heffron, Raphael
Johnson, Angus
McCauley, Darren
Jenkins, Kirsten Elizabeth Harrison
The ambition of this conference was to deliver a first examination of how policy is delivered in the context of low-carbon energy infrastructure in the UK. The UK has been developing policy in this area since 2002 (Heffron, 2013). Finally, as the decade passed, in November 2012 an Energy Bill was put before the UK Parliament. One of the chief purposes of this Energy Bill is to establish the right environment for new electricity generation infrastructure in the low-carbon sector. There is significant debate on how this will be achieved and, indeed, whether this piece of legislation will actually deliver this outcome. This conference aimed to examine the dynamics of policy delivery. Throughout the day, there was entertaining discussion as a variety of conference presenters provided interesting contributions on how to deliver such policy goals. In total, there were twelve speakers throughout the day representing the UK (University of Oxford, Pinsent Masons Law Firm, University of Stirling, University of Dundee and University of Aberdeen), and also those who provided lessons from abroad from the University of Copenhagen, Central European University, Milieu Ltd., Pillsbury Law Firm (Washington DC, US) and the Conservation Law Foundation (MA, US).
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Right to buy … time to move? Investigating the moving behaviour of right to buy owners in the UK
https://hdl.handle.net/10023/6562
Part of the political argument in favour of the right to buy (RTB) was that it would stimulate the economy by encouraging the inter-regional mobility of those in public sector housing. This is the first study to examine whether RTB-owners are indeed more mobile than those in social housing. Using longitudinal data from the British household panel survey and panel regression models we show that the probability of a RTB-owner making a long distance move falls between that of social renters and owner occupiers. However, the difference between RTB-owners and homeowners or social renters is not significant. Social renters are significantly less likely to move over long distances than traditional owners. The results also suggest that RTB-owners are less likely than traditional owners to move for job related reasons, but more likely than social renters.
The authors acknowledge financial support from the Economic and Social Research Council (ESRC) (RES-000-22-2460)
2013-03-01T00:00:00Z
Van Ham, Maarten
Williamson, Lee
Feijten, Petra Maria
Boyle, Paul Joseph
Part of the political argument in favour of the right to buy (RTB) was that it would stimulate the economy by encouraging the inter-regional mobility of those in public sector housing. This is the first study to examine whether RTB-owners are indeed more mobile than those in social housing. Using longitudinal data from the British household panel survey and panel regression models we show that the probability of a RTB-owner making a long distance move falls between that of social renters and owner occupiers. However, the difference between RTB-owners and homeowners or social renters is not significant. Social renters are significantly less likely to move over long distances than traditional owners. The results also suggest that RTB-owners are less likely than traditional owners to move for job related reasons, but more likely than social renters.
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Validating a calcium tracer based tree-ring dating method for tropical wood
https://hdl.handle.net/10023/6389
The tropics are a key part of the global biosphere. Specifically, the woodland environments not only moderate large scale climate dynamics, but are also crucial in the global carbon cycle. Despite this, tropical dendrochronological studies are rare due to the uncertainty in annual dating from the minimal seasonality in most tropic environments. Without distinct annual tree rings, dendrochronological dating methods do not work, therefore other dating methods are required before long term forest growth analyses can be made. Alternatives such as radiocarbon and stable isotope measurements can be expensive and require high resolution measurement in order to identify seasonality. This thesis introduces a novel dating method for tropical trees using calcium as a tracer of annual wood formation. Laser Ablation-ICP-MS provides a fast, high resolution method for measuring mineral elements which could potentially provide a solution to the dating of tropical trees.
Initially, Scots pine provided an excellent testing species for the development of both the methodological and analytical dating methods proposed through this thesis. It’s well defined, annually dated ring structure formed the basis of seasonal signal detection and the development of an objective analysis for dating. This was achieved by the continuous measurement of calcium, and utilising a threshold detection approach to define annual growth cycles with respect to extreme peaks in the tracer data-series.
The initial success of the calcium dating method using pine allowed for testing the technique on a tropical trees species from Cameroon which lacks distinct rings. Along with radiocarbon dating, the robustness of the calcium dating method for this tropical species was assessed. Promising results were initially found however, these could not be replicated and validation of this method proved problematic.
Finally, radiocarbon dates were used to assess the nature of the oxygen and carbon stable isotopic series from the single tree of the same species from the tropical calcium tests. Results showed that despite the clear cyclic signal present in the oxygen isotope record, this did not represent an annual signal. These results reinforce the problems associated with tropical dendro analysis.
2014-04-04T00:00:00Z
Wood, Cheryl Victoria
The tropics are a key part of the global biosphere. Specifically, the woodland environments not only moderate large scale climate dynamics, but are also crucial in the global carbon cycle. Despite this, tropical dendrochronological studies are rare due to the uncertainty in annual dating from the minimal seasonality in most tropic environments. Without distinct annual tree rings, dendrochronological dating methods do not work, therefore other dating methods are required before long term forest growth analyses can be made. Alternatives such as radiocarbon and stable isotope measurements can be expensive and require high resolution measurement in order to identify seasonality. This thesis introduces a novel dating method for tropical trees using calcium as a tracer of annual wood formation. Laser Ablation-ICP-MS provides a fast, high resolution method for measuring mineral elements which could potentially provide a solution to the dating of tropical trees.
Initially, Scots pine provided an excellent testing species for the development of both the methodological and analytical dating methods proposed through this thesis. It’s well defined, annually dated ring structure formed the basis of seasonal signal detection and the development of an objective analysis for dating. This was achieved by the continuous measurement of calcium, and utilising a threshold detection approach to define annual growth cycles with respect to extreme peaks in the tracer data-series.
The initial success of the calcium dating method using pine allowed for testing the technique on a tropical trees species from Cameroon which lacks distinct rings. Along with radiocarbon dating, the robustness of the calcium dating method for this tropical species was assessed. Promising results were initially found however, these could not be replicated and validation of this method proved problematic.
Finally, radiocarbon dates were used to assess the nature of the oxygen and carbon stable isotopic series from the single tree of the same species from the tropical calcium tests. Results showed that despite the clear cyclic signal present in the oxygen isotope record, this did not represent an annual signal. These results reinforce the problems associated with tropical dendro analysis.
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Automobility and injury inequality : road safety for a diverse society
https://hdl.handle.net/10023/6378
Most knowledge of road accidents patterns derives from datasets. Heightened risk of involvement in road accidents can be shown to be associated with, inter alia, membership of minority ethnic groups and poverty. In addition, males are involved in a greater number of road accidents than are females. Very little work has been done to explain why these patterns should occur or why some places are linked to a greater risk of road accidents for specific groups of road users. This thesis adopts qualitative methodologies to examine reasons for the apparent over-representation in road accidents of Black teenage male pedestrians living in London, an exercise that not only suggests why Black teenagers should be over-represented in datasets but identifies factors that may explain the dynamics behind many accidents in road space.
The thesis focuses on the nature of road space as social space, and a road accident as a unique event that is brought into being through an interaction between users as they meet, each user importing his or her own expectations, feelings and interpretations to the experience. Data are used to argue that no one road user independently ‘causes’ a road accident and the thesis concludes that an apparently higher rate of road accidents involving Black teenagers is a function of the constructed social space of the road. Rather than anything intrinsic to the individual, the circumstances of a road accident involving a Black teenage pedestrian can reveal many tensions that underpin society. The final chapter proposes a variety of ways of tackling road accidents, concluding that to be effective, road safety programmes should be developed for diverse societies or communities, rather than discrete groups within communities.
2014-06-25T00:00:00Z
Pringle, Susan Mary
Most knowledge of road accidents patterns derives from datasets. Heightened risk of involvement in road accidents can be shown to be associated with, inter alia, membership of minority ethnic groups and poverty. In addition, males are involved in a greater number of road accidents than are females. Very little work has been done to explain why these patterns should occur or why some places are linked to a greater risk of road accidents for specific groups of road users. This thesis adopts qualitative methodologies to examine reasons for the apparent over-representation in road accidents of Black teenage male pedestrians living in London, an exercise that not only suggests why Black teenagers should be over-represented in datasets but identifies factors that may explain the dynamics behind many accidents in road space.
The thesis focuses on the nature of road space as social space, and a road accident as a unique event that is brought into being through an interaction between users as they meet, each user importing his or her own expectations, feelings and interpretations to the experience. Data are used to argue that no one road user independently ‘causes’ a road accident and the thesis concludes that an apparently higher rate of road accidents involving Black teenagers is a function of the constructed social space of the road. Rather than anything intrinsic to the individual, the circumstances of a road accident involving a Black teenage pedestrian can reveal many tensions that underpin society. The final chapter proposes a variety of ways of tackling road accidents, concluding that to be effective, road safety programmes should be developed for diverse societies or communities, rather than discrete groups within communities.
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'Placing value' : reframing conceptions of the importance of the community park
https://hdl.handle.net/10023/6320
In the UK, urban parks face a precarious future and, with projected cuts of over 65% to local authority discretionary funding (Local Government Association, 2012:2), it is ever more important to understand their value. This study interrogates the value of these resources from the perspective of the individual and, through a mixed method comparative case study of two community parks in Leeds, West Yorkshire, identifies four key challenges to existing framings of their significance.
Drawing on primary observational, social survey and interview data, boundaries constructed between forms of value are, firstly, problematized with fluidity recognised between use and non-use aspects. Secondly, a range of previously-omitted past-related values are identified. Negative elements of significance are, then, thirdly, highlighted as heavily interwoven with positive accounts of importance and emphasised as key omissions in prior representations of value. Before, finally, value is stressed as spatially relative, with comparison with other leisure resources noted as an inherent facet of accounts. Taken together, these challenges demarcate an individual perspective of value as notably distinct from those levelled at other scales, such as the firm or community, as it emphasised that, from this perspective, the value of a resource must be rethought as a relational property created in the interaction between people and their environment, rather than an absolute property assigned to a space.
Organisations, such as Nesta (Neal, 2013:21) have emphasised a need to ‘rethink’ the funding and management of urban parks, moving towards “mixed funding models”, incorporating some level of community voluntarism. This assumed involvement is, however, premised on community engagement which is far from certain. As such, there is a pressing need to understand the value attached to urban parks to understand the scope for expectations of voluntarism to be truly fulfilled.
2014-12-01T00:00:00Z
Oldfield, Alice E.
In the UK, urban parks face a precarious future and, with projected cuts of over 65% to local authority discretionary funding (Local Government Association, 2012:2), it is ever more important to understand their value. This study interrogates the value of these resources from the perspective of the individual and, through a mixed method comparative case study of two community parks in Leeds, West Yorkshire, identifies four key challenges to existing framings of their significance.
Drawing on primary observational, social survey and interview data, boundaries constructed between forms of value are, firstly, problematized with fluidity recognised between use and non-use aspects. Secondly, a range of previously-omitted past-related values are identified. Negative elements of significance are, then, thirdly, highlighted as heavily interwoven with positive accounts of importance and emphasised as key omissions in prior representations of value. Before, finally, value is stressed as spatially relative, with comparison with other leisure resources noted as an inherent facet of accounts. Taken together, these challenges demarcate an individual perspective of value as notably distinct from those levelled at other scales, such as the firm or community, as it emphasised that, from this perspective, the value of a resource must be rethought as a relational property created in the interaction between people and their environment, rather than an absolute property assigned to a space.
Organisations, such as Nesta (Neal, 2013:21) have emphasised a need to ‘rethink’ the funding and management of urban parks, moving towards “mixed funding models”, incorporating some level of community voluntarism. This assumed involvement is, however, premised on community engagement which is far from certain. As such, there is a pressing need to understand the value attached to urban parks to understand the scope for expectations of voluntarism to be truly fulfilled.
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Carbon and the commons in the Zambezi teak (Baikiaea plurijuga, Harms) forests of western Zambia : sustainable forest management for commodity and community
https://hdl.handle.net/10023/6317
This study attempted a holistic synthesis of the problems of Sustainable Development (SD) and Sustainable Forest Management (SFM) in the dry deciduous forests of south western Zambia.
There are scale-based implications across the entire range of actions required for SFM and REDD+ implementation in tropical forests. Addressing scale mismatches in ecological, social and socio-ecological systems is essential and may help resolve epistemological differences in interdisciplinary research.
The importance of local context to SD and SFM supported a case study approach to the social-ecological system. Leaf phenology shows regional variation in deciduousness and varies spatially on a local scale. This highlights the need for researching the eco-physiological source of this variation to assess the effects of climate change on forest phenology. Livelihood analysis in forest communities showed that high levels of social and natural capital confer community resilience to climate change.
Land use change was mapped between 1975 and 2005. Zambezi Teak forests decreased in area by 54% between 1975 and 2005. However, changes in area weighted Above Ground Biomass (AGB) are negligible because Zambezi Teak forests are replaced by other woody vegetation. The differences in AGB between plot-based field measurements of AGB and published global biomass maps mean that these maps are not useful for REDD+ projects at the project scale (~10,000 ha).
Governance arrangements for Zambezi Teak forests differ between Zambia and Zimbabwe. Although the forests in Zimbabwe have an age structure skewed towards smaller age classes than forests in Zambia, possibly indicating a recovery from logging, this study has not accounted for other covariates which determine forest condition.
This research emphasises the importance of case studies for building a global database for inclusion in a meta-analysis, and for the contextual focus which a holistic approach brings to the action-based agenda at the heart of SD and SFM.
2014-12-01T00:00:00Z
Musgrave, Michael K.
This study attempted a holistic synthesis of the problems of Sustainable Development (SD) and Sustainable Forest Management (SFM) in the dry deciduous forests of south western Zambia.
There are scale-based implications across the entire range of actions required for SFM and REDD+ implementation in tropical forests. Addressing scale mismatches in ecological, social and socio-ecological systems is essential and may help resolve epistemological differences in interdisciplinary research.
The importance of local context to SD and SFM supported a case study approach to the social-ecological system. Leaf phenology shows regional variation in deciduousness and varies spatially on a local scale. This highlights the need for researching the eco-physiological source of this variation to assess the effects of climate change on forest phenology. Livelihood analysis in forest communities showed that high levels of social and natural capital confer community resilience to climate change.
Land use change was mapped between 1975 and 2005. Zambezi Teak forests decreased in area by 54% between 1975 and 2005. However, changes in area weighted Above Ground Biomass (AGB) are negligible because Zambezi Teak forests are replaced by other woody vegetation. The differences in AGB between plot-based field measurements of AGB and published global biomass maps mean that these maps are not useful for REDD+ projects at the project scale (~10,000 ha).
Governance arrangements for Zambezi Teak forests differ between Zambia and Zimbabwe. Although the forests in Zimbabwe have an age structure skewed towards smaller age classes than forests in Zambia, possibly indicating a recovery from logging, this study has not accounted for other covariates which determine forest condition.
This research emphasises the importance of case studies for building a global database for inclusion in a meta-analysis, and for the contextual focus which a holistic approach brings to the action-based agenda at the heart of SD and SFM.
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Testing the ‘residential rootedness’ hypothesis of self-employment for Germany and the UK
https://hdl.handle.net/10023/6294
Based on the notion that entrepreneurship is a ‘local event’, the literature argues that entrepreneurs are ‘rooted’ in place. This paper tests the ‘residential rootedness’‒hypothesis of self-employment by examining for Germany and the UK whether the self-employed are less likely to move over long distances (internal migration) than workers in paid employment. Using longitudinal data from the German Socio-economic Panel Study (SOEP) and the British Household Panel Survey (BHPS) and accounting for transitions in employment status we found little evidence that the self-employed in Germany and the UK are more rooted in place than workers in paid employment. Generally speaking, the self-employed were not less likely than workers in paid employment to migrate over longer distance. In contrast to the residential rootedness–hypothesis we found that an entry into self-employment and female self-employment are associated with internal migration, and that the self-employed who work from home (home-based businesses) are fairly geographically mobile. The gendered results suggest that women might use self-employment as a strategy to be spatially mobile with their household, or as a strategy to stay in the workforce after having moved residence until they find a job in the more secure wage and salary sector.
The work on this paper was funded by a Marie Curie grant from the European Commission within the 7th Framework Program (ID 252752).
2013-01-01T00:00:00Z
Reuschke, Darja
Van Ham, Maarten
Based on the notion that entrepreneurship is a ‘local event’, the literature argues that entrepreneurs are ‘rooted’ in place. This paper tests the ‘residential rootedness’‒hypothesis of self-employment by examining for Germany and the UK whether the self-employed are less likely to move over long distances (internal migration) than workers in paid employment. Using longitudinal data from the German Socio-economic Panel Study (SOEP) and the British Household Panel Survey (BHPS) and accounting for transitions in employment status we found little evidence that the self-employed in Germany and the UK are more rooted in place than workers in paid employment. Generally speaking, the self-employed were not less likely than workers in paid employment to migrate over longer distance. In contrast to the residential rootedness–hypothesis we found that an entry into self-employment and female self-employment are associated with internal migration, and that the self-employed who work from home (home-based businesses) are fairly geographically mobile. The gendered results suggest that women might use self-employment as a strategy to be spatially mobile with their household, or as a strategy to stay in the workforce after having moved residence until they find a job in the more secure wage and salary sector.
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A longitudinal study of migration propensities for mixed-ethnic unions in England and Wales
https://hdl.handle.net/10023/6292
Most studies investigating residential segregation of ethnic minorities ignore the fact that the majority of adults live in couples. In recent years there has been a growth in the number of mixed-ethnic unions that involve a minority member and a white member. To our knowledge, hardly any research has been undertaken to explicitly examine whether the ethnic mix within households has an impact on the residential mobility of households in terms of the ethnic mix of destination neighbourhoods. Our study addresses this research gap and examines the tendencies of mobility among mixed-ethnic unions in comparison with their co-ethnic peers. We used data from the Longitudinal Study for England and Wales. Our statistical analysis supports the spatial assimilation theory; ethnic minorities move towards less deprived areas and to a lesser extent also towards less ethnically concentrated areas. However, the types of destination neighbourhood of minority people living in mixed-ethnic unions varied greatly with the ethnicity of the ethnic minority partner.
This research was funded by the ESRC under the Understanding Population Trends and Processes (UPTAP) programme (Award Ref: RES-163-25-0045).
2013-01-01T00:00:00Z
Feng, Z.
van Ham, M.
Boyle, P.
Raab, G.M.
Most studies investigating residential segregation of ethnic minorities ignore the fact that the majority of adults live in couples. In recent years there has been a growth in the number of mixed-ethnic unions that involve a minority member and a white member. To our knowledge, hardly any research has been undertaken to explicitly examine whether the ethnic mix within households has an impact on the residential mobility of households in terms of the ethnic mix of destination neighbourhoods. Our study addresses this research gap and examines the tendencies of mobility among mixed-ethnic unions in comparison with their co-ethnic peers. We used data from the Longitudinal Study for England and Wales. Our statistical analysis supports the spatial assimilation theory; ethnic minorities move towards less deprived areas and to a lesser extent also towards less ethnically concentrated areas. However, the types of destination neighbourhood of minority people living in mixed-ethnic unions varied greatly with the ethnicity of the ethnic minority partner.
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The subjective experiences of Muslim women in family-related migration to Scotland
https://hdl.handle.net/10023/6273
Muslim family members constitute a significant migration flow to the UK (Kofman et al., 2013). Despite such observations, this form of mobility is under-explored in geographic scholarship on migration. Accordingly, this thesis examines the subjective experiences of migration of a small group of Muslim women, who migrated either with or to join their families in Scotland. Participant observation, focus groups and the life narratives of eight women are used to gain an in-depth understanding of both the reasons for and the consequences of migration for this group of Muslim women. In addition, this thesis examines the role of a secular community-based organisation in supporting migrants in their everyday lives.
Drawing on conceptual approaches to migration, this study reveals diverse and complex motivations among participants in “choosing” to migrate. Far from “victims” or “trailing wives”, participants privileged their children’s needs but also the possibility to transform their sense of self through migration. The study draws attention to the struggles of daily life in Scotland where, bereft of extended family, the synchronisation of migration with childbirth resulted in some participants enduring years of isolation. Such struggles resulted in changes in the home, with husbands providing both physical and emotional support. The experience of migration affected the women’s religious identities, providing solace as well as a way to assert belonging in Scotland by drawing on Islamic theology. The community-based organisation provided a “safe space”, bridging the secular and non-secular and offering women the chance to socialise, learn and volunteer. The study shows that volunteering provided not only a way into paid work but also shaped women’s subjectivities and home lives. However, the re-direction of national government funding towards “Muslim problems” threatens to undermine the organisation’s ability to continue to meet the local needs of Muslim migrant women.
2015-06-24T00:00:00Z
Folly, Rebecca P.F.
Muslim family members constitute a significant migration flow to the UK (Kofman et al., 2013). Despite such observations, this form of mobility is under-explored in geographic scholarship on migration. Accordingly, this thesis examines the subjective experiences of migration of a small group of Muslim women, who migrated either with or to join their families in Scotland. Participant observation, focus groups and the life narratives of eight women are used to gain an in-depth understanding of both the reasons for and the consequences of migration for this group of Muslim women. In addition, this thesis examines the role of a secular community-based organisation in supporting migrants in their everyday lives.
Drawing on conceptual approaches to migration, this study reveals diverse and complex motivations among participants in “choosing” to migrate. Far from “victims” or “trailing wives”, participants privileged their children’s needs but also the possibility to transform their sense of self through migration. The study draws attention to the struggles of daily life in Scotland where, bereft of extended family, the synchronisation of migration with childbirth resulted in some participants enduring years of isolation. Such struggles resulted in changes in the home, with husbands providing both physical and emotional support. The experience of migration affected the women’s religious identities, providing solace as well as a way to assert belonging in Scotland by drawing on Islamic theology. The community-based organisation provided a “safe space”, bridging the secular and non-secular and offering women the chance to socialise, learn and volunteer. The study shows that volunteering provided not only a way into paid work but also shaped women’s subjectivities and home lives. However, the re-direction of national government funding towards “Muslim problems” threatens to undermine the organisation’s ability to continue to meet the local needs of Muslim migrant women.
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Eye-hand coordination during visual search on geographic displays
https://hdl.handle.net/10023/5957
Eye movement analysis can provide insights into the cognitive processes in human mind and have been successfully utilized to study visual tasks such as reading and exploration of digital displays. However recording eye movements requires costly equipment and the face-to-face individual data collection forces us to work with only a limited number of participants. Interactive displays are alternatively evaluated through mouse movements which can be collected considerably easier than eye movements. It is however an open question if and how these two types of movement are linked. In this project, we study the link between eye and mouse movements to understand the eye-hand coordination specifically with visual search tasks in geographic displays.
This work is supported by the Royal Society grant IE120643. The authors thank Floris Heim from University of Zurich for data collection. JV and UD are supported by the EU FP7 Marie Curie ITN GEOCROWD (FP7-PEOPLE-2010-ITN-264994)
2014-01-01T00:00:00Z
Çöltekin, A.
Demsar, Urska
Brychtová, A.
Vandrol, J.
Eye movement analysis can provide insights into the cognitive processes in human mind and have been successfully utilized to study visual tasks such as reading and exploration of digital displays. However recording eye movements requires costly equipment and the face-to-face individual data collection forces us to work with only a limited number of participants. Interactive displays are alternatively evaluated through mouse movements which can be collected considerably easier than eye movements. It is however an open question if and how these two types of movement are linked. In this project, we study the link between eye and mouse movements to understand the eye-hand coordination specifically with visual search tasks in geographic displays.
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Speciation of metals and metalloids in tobacco and tobacco smoke : implications for health and regulation
https://hdl.handle.net/10023/5728
Some metals and metalloids make significant contributions to the harmful effects of tobacco
consumption although understanding the mechanisms involved in toxicity is hampered by the
lack of information on their chemical and valence species, both in tobacco and in smoke.
This research addresses the speciation of the metals and metalloids most frequently
implicated, particularly those elements that exist in nature in multiple valence states, namely
arsenic (As) and chromium (Cr), there being considerable differences in toxicity with
oxidation state.
A strategy was devised to overcome some of the problems that have thwarted earlier
attempts at speciation. Firstly tobacco plants were cultivated under controlled conditions in
compost burdened with high levels of metals and metalloids resulting in leaf with up to 250 µg g⁻¹
As, although Cr uptake was less successful. Secondly valence speciation even at the
exceptionally low concentrations of As and Cr in smoke from unburdened tobacco was
achieved with XANES analysis using the exceptionally bright Diamond synchrotron source.
This revealed that combustion of tobacco has a marked effect on valence speciation with
As(III), the reduced form of As, dominating (and persisting) in condensate of tobacco smoke
while ash is dominated by the oxidised form, As(V). Chromium also appears to be present in
smoke mainly as reduced Cr(III) species. HPLC-ICPMS analysis of arsenic indicates the
dominance of inorganic over organic species (~4:1). Other metals were investigated in less
detail.
These findings establish that arsenic is present in smoke in its most toxic form and
represents a significant risk to health. Conversely smokers appear to be exposed to the less
harmful species of chromium. These results support a recent WHO report that includes As
but not Cr in a list of four metals and metalloids recommended for regulation in crops and
commercial products in the interests of public health.
Electronic version excludes material for which permission has not been granted by the rights holder
2014-01-01T00:00:00Z
Campbell, Robert Charles James
Some metals and metalloids make significant contributions to the harmful effects of tobacco
consumption although understanding the mechanisms involved in toxicity is hampered by the
lack of information on their chemical and valence species, both in tobacco and in smoke.
This research addresses the speciation of the metals and metalloids most frequently
implicated, particularly those elements that exist in nature in multiple valence states, namely
arsenic (As) and chromium (Cr), there being considerable differences in toxicity with
oxidation state.
A strategy was devised to overcome some of the problems that have thwarted earlier
attempts at speciation. Firstly tobacco plants were cultivated under controlled conditions in
compost burdened with high levels of metals and metalloids resulting in leaf with up to 250 µg g⁻¹
As, although Cr uptake was less successful. Secondly valence speciation even at the
exceptionally low concentrations of As and Cr in smoke from unburdened tobacco was
achieved with XANES analysis using the exceptionally bright Diamond synchrotron source.
This revealed that combustion of tobacco has a marked effect on valence speciation with
As(III), the reduced form of As, dominating (and persisting) in condensate of tobacco smoke
while ash is dominated by the oxidised form, As(V). Chromium also appears to be present in
smoke mainly as reduced Cr(III) species. HPLC-ICPMS analysis of arsenic indicates the
dominance of inorganic over organic species (~4:1). Other metals were investigated in less
detail.
These findings establish that arsenic is present in smoke in its most toxic form and
represents a significant risk to health. Conversely smokers appear to be exposed to the less
harmful species of chromium. These results support a recent WHO report that includes As
but not Cr in a list of four metals and metalloids recommended for regulation in crops and
commercial products in the interests of public health.
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Rethinking deindustrialization and health across time and space
https://hdl.handle.net/10023/5553
The transition towards a service-based society, defined as deindustrialization, has led to an extensive body of research exploring the socio-economic and health impacts of industrial decline. The literature has been mainly confined to the regional effects of unemployment and inactivity. However, considering the morbidity and mortality outcomes of this event, most studies have focused on single cases such as regions and specific industrial occupational groups. Within this context, this thesis aims to assess the health-related implications of deindustrialization by considering the elements of contrast, magnitude and time. Those elements capture the dynamic nature and uneven pace of industrial decline across different levels, aggregated and individual.
This thesis measures and compares the severity of industrial decline across Europe and seeks to identify whether deindustrialization is associated with mortality variations. By including fixed effects modeling it distinguishes between the long and short-term relationship of industrial decline and mortality. Furthermore, this thesis adopts a longitudinal perspective and aims to explore the long-term self-assessed morbidity of various occupational groups by following their transition towards unemployment, inactivity and re-employment. The analysis follows a logistic regression approach based on the evaluation of self-assessed morbidity.
It concludes that deindustrialization is a transitional event that progresses unevenly and disproportionately affects health at national, regional and individual levels. At a population level, industrial decline appears to be beneficial for health as countries have progressed towards the creation of safer contemporary working environments. At an individual level, the transitional effects of occupational mobility do not uniformly influence the morbidity of individuals.
The extent of the susceptibility of certain countries, regions and population groups towards this event is a result of various internal and external socio-economic factors, health-related and political decisions. Subsequently, this thesis introduces the necessity of rethinking the health consequences of deindustrialization, whereas future research should consider the changing nature of employment within the industrial and service sectors.
2014-12-01T00:00:00Z
Kampanellou, Eleni
The transition towards a service-based society, defined as deindustrialization, has led to an extensive body of research exploring the socio-economic and health impacts of industrial decline. The literature has been mainly confined to the regional effects of unemployment and inactivity. However, considering the morbidity and mortality outcomes of this event, most studies have focused on single cases such as regions and specific industrial occupational groups. Within this context, this thesis aims to assess the health-related implications of deindustrialization by considering the elements of contrast, magnitude and time. Those elements capture the dynamic nature and uneven pace of industrial decline across different levels, aggregated and individual.
This thesis measures and compares the severity of industrial decline across Europe and seeks to identify whether deindustrialization is associated with mortality variations. By including fixed effects modeling it distinguishes between the long and short-term relationship of industrial decline and mortality. Furthermore, this thesis adopts a longitudinal perspective and aims to explore the long-term self-assessed morbidity of various occupational groups by following their transition towards unemployment, inactivity and re-employment. The analysis follows a logistic regression approach based on the evaluation of self-assessed morbidity.
It concludes that deindustrialization is a transitional event that progresses unevenly and disproportionately affects health at national, regional and individual levels. At a population level, industrial decline appears to be beneficial for health as countries have progressed towards the creation of safer contemporary working environments. At an individual level, the transitional effects of occupational mobility do not uniformly influence the morbidity of individuals.
The extent of the susceptibility of certain countries, regions and population groups towards this event is a result of various internal and external socio-economic factors, health-related and political decisions. Subsequently, this thesis introduces the necessity of rethinking the health consequences of deindustrialization, whereas future research should consider the changing nature of employment within the industrial and service sectors.
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A Bayesian space-time model for discrete spread processes on a lattice
https://hdl.handle.net/10023/5418
In this article we present a Bayesian Markov model for investigating environmental spread processes. We formulate a model where the spread of a disease over a heterogeneous landscape through time is represented as a probabilistic function of two processes: local diffusion and random-jump dispersal. This formulation represents two mechanisms of spread which result in highly peaked and long-tailed distributions of dispersal distances (i.e., local and long-distance spread), commonly observed in the spread of infectious diseases and biological invasions. We demonstrate the properties of this model using a simulation experiment and an empirical case study - the spread of mountain pine beetle in western Canada. Posterior predictive checking was used to validate the number of newly inhabited regions in each time period. The model performed well in the simulation study in which a goodness-of-fit statistic measuring the number of newly inhabited regions in each time interval fell within the 95% posterior predictive credible interval in over 97% of simulations. The case study of a mountain pine beetle infestation in western Canada (1999-2009) extended the base model in two ways. First, spatial covariates thought to impact the local diffusion parameters, elevation and forest cover, were included in the model. Second, a refined definition for translocation or jump-dispersal based on mountain pine beetle ecology was incorporated improving the fit of the model. Posterior predictive checks on the mountain pine beetle model found that the observed goodness-of-fit test statistic fell within the 95% posterior predictive credible interval for 8 out of 10. years. The simulation study and case study provide evidence that the model presented here is both robust and flexible; and is therefore appropriate for a wide range of spread processes in epidemiology and ecology.
Funding for this work was provided by GEOIDE through the Government of Canada’s Networks for Centres of Excellence program.
2012-06-01T00:00:00Z
Long, J.A.
Nelson, T.A.
Robertson, Colin
Nathoo, F.S.
In this article we present a Bayesian Markov model for investigating environmental spread processes. We formulate a model where the spread of a disease over a heterogeneous landscape through time is represented as a probabilistic function of two processes: local diffusion and random-jump dispersal. This formulation represents two mechanisms of spread which result in highly peaked and long-tailed distributions of dispersal distances (i.e., local and long-distance spread), commonly observed in the spread of infectious diseases and biological invasions. We demonstrate the properties of this model using a simulation experiment and an empirical case study - the spread of mountain pine beetle in western Canada. Posterior predictive checking was used to validate the number of newly inhabited regions in each time period. The model performed well in the simulation study in which a goodness-of-fit statistic measuring the number of newly inhabited regions in each time interval fell within the 95% posterior predictive credible interval in over 97% of simulations. The case study of a mountain pine beetle infestation in western Canada (1999-2009) extended the base model in two ways. First, spatial covariates thought to impact the local diffusion parameters, elevation and forest cover, were included in the model. Second, a refined definition for translocation or jump-dispersal based on mountain pine beetle ecology was incorporated improving the fit of the model. Posterior predictive checks on the mountain pine beetle model found that the observed goodness-of-fit test statistic fell within the 95% posterior predictive credible interval for 8 out of 10. years. The simulation study and case study provide evidence that the model presented here is both robust and flexible; and is therefore appropriate for a wide range of spread processes in epidemiology and ecology.
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Does area regeneration improve residents' health and well-being?
https://hdl.handle.net/10023/4899
This thesis investigates the implications of area-based regeneration for residents’ health and well-being. The last three decades have seen significant investment in area-based initiatives in the UK to regenerate declining areas. However, there is a dearth of robust evidence on the impact that area regeneration practices have on health and health inequalities. This is particularly so in the case of the Scottish Area Regeneration Partnership (SARP) Programmes initiated in the mid-1990s, the evaluation of which was beset by a lack of baseline data and poor data collection generally. This study therefore seeks to address the lack of evidence by employing a rigorous mixed methods approach to evaluate the SARP programmes.
Firstly, a quasi-experimental analysis of data from the Scottish Longitudinal Study (SLS) is undertaken. Comparator areas were identified using propensity score matching and a series of models was fitted to examine whether health outcomes of residents and migrants differed between regeneration areas and comparator areas. This is followed by a qualitative study exploring experiences of regeneration, carried out to provide insight into the results of the quasi-experiment.
The findings provide no evidence that the programme had a positive impact on the health and well-being of SARP area residents relative to comparator area residents, and moreover, suggest that the programme may even have had a negative impact. Nor do they support the often stated hypothesis that those who move out of regeneration areas have done so because they have benefited from the programme and been replaced with residents who are likely to be more deprived. In addition, interviews with regeneration professionals and residents found that smaller initiatives overlapped with the SARPs, making it difficult to isolate the impacts of the programme under study. The conclusion reflects on the implications of these findings for the evaluation of public policy programmes.
2014-06-25T00:00:00Z
Archibald, Daryll G.
This thesis investigates the implications of area-based regeneration for residents’ health and well-being. The last three decades have seen significant investment in area-based initiatives in the UK to regenerate declining areas. However, there is a dearth of robust evidence on the impact that area regeneration practices have on health and health inequalities. This is particularly so in the case of the Scottish Area Regeneration Partnership (SARP) Programmes initiated in the mid-1990s, the evaluation of which was beset by a lack of baseline data and poor data collection generally. This study therefore seeks to address the lack of evidence by employing a rigorous mixed methods approach to evaluate the SARP programmes.
Firstly, a quasi-experimental analysis of data from the Scottish Longitudinal Study (SLS) is undertaken. Comparator areas were identified using propensity score matching and a series of models was fitted to examine whether health outcomes of residents and migrants differed between regeneration areas and comparator areas. This is followed by a qualitative study exploring experiences of regeneration, carried out to provide insight into the results of the quasi-experiment.
The findings provide no evidence that the programme had a positive impact on the health and well-being of SARP area residents relative to comparator area residents, and moreover, suggest that the programme may even have had a negative impact. Nor do they support the often stated hypothesis that those who move out of regeneration areas have done so because they have benefited from the programme and been replaced with residents who are likely to be more deprived. In addition, interviews with regeneration professionals and residents found that smaller initiatives overlapped with the SARPs, making it difficult to isolate the impacts of the programme under study. The conclusion reflects on the implications of these findings for the evaluation of public policy programmes.
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Does having a migrant parent reduce the risk of undernutrition for children who stay behind in South-East Asia?
https://hdl.handle.net/10023/4833
Many parents from South-East Asia who go overseas to work are motivated by a desire to secure a better future for their children, yet the health consequences for children who stay behind are poorly understood. This study is the first cross-country comparison to explore the relationships between parental migration and the risk of undernutrition (stunting) for primary school-aged children. The analysis uses data from the CHAMPSEA project for children aged 9 to 11 years in the Philippines (N = 480) and Vietnam (N = 482). A series of logistic regression models compares outcomes for children living in transnational households and children living with both parents in non-migrant households in the same communities. We find no general advantage of having a migrant parent. Rather there is a reduced risk of stunting only for some left-behind children in the Philippines, whereas having a caregiver with low educational attainment is a major risk factor for all children. The findings point to a complex set of relationships between parental migration and child nutrition, possibly reflecting differential opportunities for accumulating household wealth through overseas earnings. Moreover, differences between the two countries caution against generalizing across national or cultural groups. We conclude by considering the implications of the findings for theories of transnationalism and for the UN Millennium Development Goal of reducing childhood undernutrition.
This article is part of a special issue which represents findings from a major research project investigating health and migrant parents in South-East Asia (CHAMPSEA). This research was funded by the Wellcome Trust [GR079946/B/06/Z and GR079946/Z/06/Z].
2013-12-01T00:00:00Z
Graham, Elspeth
Jordan, Lucy Porter
Many parents from South-East Asia who go overseas to work are motivated by a desire to secure a better future for their children, yet the health consequences for children who stay behind are poorly understood. This study is the first cross-country comparison to explore the relationships between parental migration and the risk of undernutrition (stunting) for primary school-aged children. The analysis uses data from the CHAMPSEA project for children aged 9 to 11 years in the Philippines (N = 480) and Vietnam (N = 482). A series of logistic regression models compares outcomes for children living in transnational households and children living with both parents in non-migrant households in the same communities. We find no general advantage of having a migrant parent. Rather there is a reduced risk of stunting only for some left-behind children in the Philippines, whereas having a caregiver with low educational attainment is a major risk factor for all children. The findings point to a complex set of relationships between parental migration and child nutrition, possibly reflecting differential opportunities for accumulating household wealth through overseas earnings. Moreover, differences between the two countries caution against generalizing across national or cultural groups. We conclude by considering the implications of the findings for theories of transnationalism and for the UN Millennium Development Goal of reducing childhood undernutrition.
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Child Health and Migrant Parents in South-East Asia
https://hdl.handle.net/10023/4832
This special issue represents findings from a major research project investigating health and migrant parents in South-East Asia (CHAMPSEA). This research was funded by the Wellcome Trust [GR079946/B/06/Z and GR079946/Z/06/Z].
2013-12-01T00:00:00Z
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Assessing Arctica islandica as a proxy for Scottish marine climate change
https://hdl.handle.net/10023/4817
This thesis investigates the potential of the bivalve Arctica islandica (Linnaeus, 1767) from
fjordic sites in NW Scotland for reconstructing past marine environmental /climatic variability.
Using dendrochronological and sclerochronological techniques, six master chronologies were
created which when compared show little common variability between the sites, indicating no
common response to regional scale forcing. The chronologies were compared to local and
regional scale SST and land based datasets, with no significant, time stable responses to
climate found. It is clear the growth/climate response of A. islandica from these sites is
complex, potentially due to the shallow nature of the sample sites, direct local drivers such as
food availability and, potentially, anthropogenic activity in the region.
Geochemical analyses of the shell material were undertaken to examine the timing and
magnitude of the radiocarbon bomb-peak and the stable carbon isotope signature of the
oceanic Suess Effect. The timing of the radiocarbon bomb-peak in Loch Etive does not appear
to match previously published results from other marine locations and are a potentially serious
challenge to the assumption that A. islandica GI are always annual features. Results comparing
δ¹³C values and the age of the specimen when these values are incorporated into the shell
material strongly indicate an ontogenetic control over δ¹³C, meaning the Suess Effect could not
be effectively investigated. To take these ontogenetic influences into account it is suggested
that any data from the juvenile period of shell life is not used.
Analysis of shell biometrics and morphology indicate significant relationships between shell
age and height and age and weight, however the errors for these are large (±78 years and ±80
years respectively). These results indicate that despite large errors shell height, as a predictor
of age, has the potential to be used for in situ population studies.
2014-06-25T00:00:00Z
Stott, Keziah J.
This thesis investigates the potential of the bivalve Arctica islandica (Linnaeus, 1767) from
fjordic sites in NW Scotland for reconstructing past marine environmental /climatic variability.
Using dendrochronological and sclerochronological techniques, six master chronologies were
created which when compared show little common variability between the sites, indicating no
common response to regional scale forcing. The chronologies were compared to local and
regional scale SST and land based datasets, with no significant, time stable responses to
climate found. It is clear the growth/climate response of A. islandica from these sites is
complex, potentially due to the shallow nature of the sample sites, direct local drivers such as
food availability and, potentially, anthropogenic activity in the region.
Geochemical analyses of the shell material were undertaken to examine the timing and
magnitude of the radiocarbon bomb-peak and the stable carbon isotope signature of the
oceanic Suess Effect. The timing of the radiocarbon bomb-peak in Loch Etive does not appear
to match previously published results from other marine locations and are a potentially serious
challenge to the assumption that A. islandica GI are always annual features. Results comparing
δ¹³C values and the age of the specimen when these values are incorporated into the shell
material strongly indicate an ontogenetic control over δ¹³C, meaning the Suess Effect could not
be effectively investigated. To take these ontogenetic influences into account it is suggested
that any data from the juvenile period of shell life is not used.
Analysis of shell biometrics and morphology indicate significant relationships between shell
age and height and age and weight, however the errors for these are large (±78 years and ±80
years respectively). These results indicate that despite large errors shell height, as a predictor
of age, has the potential to be used for in situ population studies.
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Transcriptional Response of Selenopolypeptide Genes and Selenocysteine Biosynthesis Machinery Genes in Escherichia coli during Selenite Reduction
https://hdl.handle.net/10023/4682
Bacteria can reduce toxic selenite into less toxic, elemental selenium (Se0), but the mechanism on how bacterial cells reduce selenite at molecular level is still not clear. We used Escherichia coli strain K12, a common bacterial strain, as a model to study its growth response to sodium selenite (Na2SeO3) treatment and then used quantitative real-time PCR (qRT-PCR) to quantify transcript levels of three E. coli selenopolypeptide genes and a set of machinery genes for selenocysteine (SeCys) biosynthesis and incorporation into polypeptides, whose involvements in the selenite reduction are largely unknown. We determined that 5 mM Na2SeO3 treatment inhibited growth by ∼50% while 0.001 to 0.01 mM treatments stimulated cell growth by ∼30%. Under 50% inhibitory or 30% stimulatory Na2SeO3 concentration, selenopolypeptide genes (fdnG, fdoG, and fdhF) whose products require SeCys but not SeCys biosynthesis machinery genes were found to be induced ≥2-fold. In addition, one sulfur (S) metabolic gene iscS and two previously reported selenite-responsive genes sodA and gutS were also induced ≥2-fold under 50% inhibitory concentration. Our findings provide insight about the detoxification of selenite in E. coli via induction of these genes involved in the selenite reduction process.
This work was supported by a United States Department of Agriculture-Cooperative State Research, Education, and Extension Service grant (no. 2009-35318-05032), a Biotechnology Research grant (no. 2007-BRG-1223) from the North Carolina Biotechnology Center, and a startup fund from the Golden LEAF Foundation to the Biomanufacturing Research Institute and Technology Enterprise (BRITE).
2014-04-15T00:00:00Z
Tetteh, Antonia Y.
Sun, Katherine H.
Hung, Chiu-Yueh
Kittur, Farooqahmed S.
Ibeanu, Gordon C.
Williams, Daniel
Xie, Jiahua
Bacteria can reduce toxic selenite into less toxic, elemental selenium (Se0), but the mechanism on how bacterial cells reduce selenite at molecular level is still not clear. We used Escherichia coli strain K12, a common bacterial strain, as a model to study its growth response to sodium selenite (Na2SeO3) treatment and then used quantitative real-time PCR (qRT-PCR) to quantify transcript levels of three E. coli selenopolypeptide genes and a set of machinery genes for selenocysteine (SeCys) biosynthesis and incorporation into polypeptides, whose involvements in the selenite reduction are largely unknown. We determined that 5 mM Na2SeO3 treatment inhibited growth by ∼50% while 0.001 to 0.01 mM treatments stimulated cell growth by ∼30%. Under 50% inhibitory or 30% stimulatory Na2SeO3 concentration, selenopolypeptide genes (fdnG, fdoG, and fdhF) whose products require SeCys but not SeCys biosynthesis machinery genes were found to be induced ≥2-fold. In addition, one sulfur (S) metabolic gene iscS and two previously reported selenite-responsive genes sodA and gutS were also induced ≥2-fold under 50% inhibitory concentration. Our findings provide insight about the detoxification of selenite in E. coli via induction of these genes involved in the selenite reduction process.
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Challenging the Norm? The 'EthoPolitics' of Low Cost Homeownership in Scotland
https://hdl.handle.net/10023/4488
Influenced by Nikolas Rose’s concept of ‘ethopolitics’ this paper explores attitudes to home and tenure amongst low-cost homeowners in Scotland. In doing so, it seeks to highlight the contested nature of contemporary governing practices and the way in which ‘governable subjects’ can challenge, reinterpret and resist dominant policy discourses, which promote homeownership as the preferred tenure of choice, whilst simultaneously pathologising and problematising social housing.
2011-12-01T00:00:00Z
McKee, Kim
Influenced by Nikolas Rose’s concept of ‘ethopolitics’ this paper explores attitudes to home and tenure amongst low-cost homeowners in Scotland. In doing so, it seeks to highlight the contested nature of contemporary governing practices and the way in which ‘governable subjects’ can challenge, reinterpret and resist dominant policy discourses, which promote homeownership as the preferred tenure of choice, whilst simultaneously pathologising and problematising social housing.
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An introduction to the special issue - Housing in hard times: marginality, inequality and class : (Special Issue Editors)
https://hdl.handle.net/10023/4473
‘Housing in Hard Times’ was the theme of the Housing Studies Association annual conference in April 2011. The papers featured in this special issue are drawn from that conference. They examine the uneven impact of economic change on housing policy and related areas, with reference to conceptual ideas pertaining to urban marginality, inequality and class. Whilst the empirical focus of the papers is the UK, their intellectual contribution represents an attempt to ‘bring class back in’ to the housing studies literature and encourage more critical, theoretically informed scholarship.
2013-01-01T00:00:00Z
‘Housing in Hard Times’ was the theme of the Housing Studies Association annual conference in April 2011. The papers featured in this special issue are drawn from that conference. They examine the uneven impact of economic change on housing policy and related areas, with reference to conceptual ideas pertaining to urban marginality, inequality and class. Whilst the empirical focus of the papers is the UK, their intellectual contribution represents an attempt to ‘bring class back in’ to the housing studies literature and encourage more critical, theoretically informed scholarship.
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Ageing and mobility in Britain : past trends, present patterns and future implications
https://hdl.handle.net/10023/4471
Over the next decade the ‘Baby Boomer’ cohort will increasingly contribute to the proportion
of those aged 60 and over in Britain. The issue of how the mobility of older people has
changed for different cohort groups has not been considered in a historical context. Ryder
(1965) argued that cohort groups could be important in determining behaviour as have other
social structural factors, such as socioeconomic status. This thesis merges the disciplines of
transport geography and population studies using a novel approach of cohort analysis, which
has not been used widely for studying mobility trends.
Using National Travel Survey data from 1995-2008, the mobility trends of older people in
Britain are explored by creating pseudo cohorts. Pseudo cohorts are artificially created
datasets which are constructed from using repeated cross-sectional data (McIntosh, 2005,
Uren, 2006). This technique can differentiate ‘age’, ‘period’ and ‘cohort’ effects in mobility
trends. Age effects are differences in behaviour between age groups i.e. changes in mobility
associated with age itself. Period effects relate to changes in behaviour in all age groups over
a period of time. Cohort effects are those associated with behaviour common to particular
groups born around the same time (Glenn, 2005, Yang, 2007).
The influence of the Scottish concessionary travel policy on the mobility of older people at the
aggregate level is also considered using Scottish Household Survey data from 1999-2008.
This policy is very blunt and based on assumptions about older age. As cohorts differ, these
assumptions may no longer hold and therefore the policy may not be effective.
This thesis argues, using a longitudinal demographic perspective, that structural effects shape
mobility of cohorts differently over time. The findings reveal although mobility amongst older
people is rising in general, there would actually be declining mobility were it not for the
Boomer cohort. Amongst younger cohorts mobility is lower. The analysis also shows that
women travel further than men, a fundamental break with the past, specific to this generation.
This thesis illustrates the importance of cohort membership in explaining mobility change.
2013-01-01T00:00:00Z
Tilley, Sara
Over the next decade the ‘Baby Boomer’ cohort will increasingly contribute to the proportion
of those aged 60 and over in Britain. The issue of how the mobility of older people has
changed for different cohort groups has not been considered in a historical context. Ryder
(1965) argued that cohort groups could be important in determining behaviour as have other
social structural factors, such as socioeconomic status. This thesis merges the disciplines of
transport geography and population studies using a novel approach of cohort analysis, which
has not been used widely for studying mobility trends.
Using National Travel Survey data from 1995-2008, the mobility trends of older people in
Britain are explored by creating pseudo cohorts. Pseudo cohorts are artificially created
datasets which are constructed from using repeated cross-sectional data (McIntosh, 2005,
Uren, 2006). This technique can differentiate ‘age’, ‘period’ and ‘cohort’ effects in mobility
trends. Age effects are differences in behaviour between age groups i.e. changes in mobility
associated with age itself. Period effects relate to changes in behaviour in all age groups over
a period of time. Cohort effects are those associated with behaviour common to particular
groups born around the same time (Glenn, 2005, Yang, 2007).
The influence of the Scottish concessionary travel policy on the mobility of older people at the
aggregate level is also considered using Scottish Household Survey data from 1999-2008.
This policy is very blunt and based on assumptions about older age. As cohorts differ, these
assumptions may no longer hold and therefore the policy may not be effective.
This thesis argues, using a longitudinal demographic perspective, that structural effects shape
mobility of cohorts differently over time. The findings reveal although mobility amongst older
people is rising in general, there would actually be declining mobility were it not for the
Boomer cohort. Amongst younger cohorts mobility is lower. The analysis also shows that
women travel further than men, a fundamental break with the past, specific to this generation.
This thesis illustrates the importance of cohort membership in explaining mobility change.
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A population-based exposure assessment of risk factors associated with gastrointestinal pathogens : a Campylobacter study
https://hdl.handle.net/10023/4430
A questionnaire survey was undertaken to determine the exposure of a study population to campylobacteriosis source risk factors (environmental, water, food) and results were stratified by age, population density and deprivation. Data were gathered using an exposure assessment carried out by telephone in the Grampian region of Scotland. Univariate analysis showed that children aged 5-14 years, living in low population density (0-44·4 persons/km2) and affluent areas had elevated exposure to environmental and water risk factors. Multivariate logistic regression analysis revealed that younger age groups and lower population density were significant indicators for most environmental risk factors. The results compared to reported disease incidence in Grampian showed that greater exposure to risk factors does not necessarily coincide with greater disease incidence for age groups, particularly for the 0-4 years age group. Further research is required to explain the relationship between exposure and disease incidence. © 2012 Cambridge University Press.
This research was undertaken by a Rural Economy and Land Use (RELU) linked studentship funded by the Economic and Social Research Council, entitled ‘Campylobacteriosis: elucidating the disease burden, risk perception and costs to rural communities and their families’ (RES 229-25-0012).
2013-05-01T00:00:00Z
MacRitchie, Laura
Hunter, Colin John
Strachan, Norval
A questionnaire survey was undertaken to determine the exposure of a study population to campylobacteriosis source risk factors (environmental, water, food) and results were stratified by age, population density and deprivation. Data were gathered using an exposure assessment carried out by telephone in the Grampian region of Scotland. Univariate analysis showed that children aged 5-14 years, living in low population density (0-44·4 persons/km2) and affluent areas had elevated exposure to environmental and water risk factors. Multivariate logistic regression analysis revealed that younger age groups and lower population density were significant indicators for most environmental risk factors. The results compared to reported disease incidence in Grampian showed that greater exposure to risk factors does not necessarily coincide with greater disease incidence for age groups, particularly for the 0-4 years age group. Further research is required to explain the relationship between exposure and disease incidence. © 2012 Cambridge University Press.
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The East Sands, St Andrews : beach dynamics, harbour development and major shipwrecks
https://hdl.handle.net/10023/4420
The coastline is a dynamic and constantly changing environment with processes that continually work and modify the coastal margin.
This research was initiated in an attempt to understand the changes along the coastline at East Sands, St Andrews. Fundamental to this is the examination of the shore profile: a vertical section along a line drawn perpendicular to the shore.
Sometimes known as a ‘profile of equilibrium’, this is where all parts of the beach are adjusted to the prevailing conditions of wave intensity, in particular storm waves, and longshore currents. Combining what is learned from such a profile with information about the forces acting parallel to the shore, it is possible to construct a three-dimensional picture of coastal activities.
The project aims to measure the changing profile of the East Sands using GPS surveying equipment. Collation of this data will allow the current coastline to be compared with a past database of East Sands profile results, in order to create a historical archive of the dynamics of the site over the last 2 years. Further, the profile changes will be compared to local weather records, in an attempt to reconcile known seasonal fluctuations of a coastal system to that of the changing profile. These ongoing processes have been further complicated with the construction of both a jetty and seawall. This adds a new dimension to the variations within the system, and ultimately the beach profile.
2005-01-01T00:00:00Z
Blake-Johnston, Pauline
The coastline is a dynamic and constantly changing environment with processes that continually work and modify the coastal margin.
This research was initiated in an attempt to understand the changes along the coastline at East Sands, St Andrews. Fundamental to this is the examination of the shore profile: a vertical section along a line drawn perpendicular to the shore.
Sometimes known as a ‘profile of equilibrium’, this is where all parts of the beach are adjusted to the prevailing conditions of wave intensity, in particular storm waves, and longshore currents. Combining what is learned from such a profile with information about the forces acting parallel to the shore, it is possible to construct a three-dimensional picture of coastal activities.
The project aims to measure the changing profile of the East Sands using GPS surveying equipment. Collation of this data will allow the current coastline to be compared with a past database of East Sands profile results, in order to create a historical archive of the dynamics of the site over the last 2 years. Further, the profile changes will be compared to local weather records, in an attempt to reconcile known seasonal fluctuations of a coastal system to that of the changing profile. These ongoing processes have been further complicated with the construction of both a jetty and seawall. This adds a new dimension to the variations within the system, and ultimately the beach profile.
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Femtosecond optoinjection of intact tobacco BY-2 cells using a reconfigurable photoporation platform
https://hdl.handle.net/10023/4234
A tightly-focused ultrashort pulsed laser beam incident upon a cell membrane has previously been shown to transiently increase cell membrane permeability while maintaining the viability of the cell, a technique known as photoporation. This permeability can be used to aid the passage of membrane-impermeable biologically-relevant substances such as dyes, proteins and nucleic acids into the cell. Ultrashort-pulsed lasers have proven to be indispensable for photoporating mammalian cells but they have rarely been applied to plant cells due to their larger sizes and rigid and thick cell walls, which significantly hinders the intracellular delivery of exogenous substances. Here we demonstrate and quantify femtosecond optical injection of membrane impermeable dyes into intact BY-2 tobacco plant cells growing in culture, investigating both optical and biological parameters. Specifically, we show that the long axial extent of a propagation invariant (“diffraction-free”) Bessel beam, which relaxes the requirements for tight focusing on the cell membrane, outperforms a standard Gaussian photoporation beam, achieving up to 70% optoinjection efficiency. Studies on the osmotic effects of culture media show that a hypertonic extracellular medium was found to be necessary to reduce turgor pressure and facilitate molecular entry into the cells.
2013-11-14T00:00:00Z
Mitchell, C.A.
Kalies, S.
Cizmár, T.
Heisterkamp, A.
Torrance, L.
Roberts, A.G.
Gunn-Moore, F.J.
Dholakia, K.
A tightly-focused ultrashort pulsed laser beam incident upon a cell membrane has previously been shown to transiently increase cell membrane permeability while maintaining the viability of the cell, a technique known as photoporation. This permeability can be used to aid the passage of membrane-impermeable biologically-relevant substances such as dyes, proteins and nucleic acids into the cell. Ultrashort-pulsed lasers have proven to be indispensable for photoporating mammalian cells but they have rarely been applied to plant cells due to their larger sizes and rigid and thick cell walls, which significantly hinders the intracellular delivery of exogenous substances. Here we demonstrate and quantify femtosecond optical injection of membrane impermeable dyes into intact BY-2 tobacco plant cells growing in culture, investigating both optical and biological parameters. Specifically, we show that the long axial extent of a propagation invariant (“diffraction-free”) Bessel beam, which relaxes the requirements for tight focusing on the cell membrane, outperforms a standard Gaussian photoporation beam, achieving up to 70% optoinjection efficiency. Studies on the osmotic effects of culture media show that a hypertonic extracellular medium was found to be necessary to reduce turgor pressure and facilitate molecular entry into the cells.
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Geographically weighted spatial interaction (GWSI)
https://hdl.handle.net/10023/4112
One of the key concerns in spatial analysis and modelling is to study and analyse similarities or dissimilarities between places over geographical space. However, ”global“ spatial models may fail to identify spatial variations of relationships (spatial heterogeneity) by assuming spatial stationarity of relationships. In many real-life situations spatial variation in relationships possibly exists and the assumption of global stationarity might be highly unrealistic leading to ignorance of a large amount of spatial information. In contrast, local spatial models emphasise differences or dissimilarity over space and focus on identifying spatial variations in relationships. These models allow the parameters of models to vary locally and can provide more useful information on the processes generating the data in different parts of the study area.
In this study, a framework for localising spatial interaction models, based on geographically weighted (GW) techniques, has been developed. This framework can help in detecting, visualising and analysing spatial heterogeneity in spatial interaction systems. In order to apply the GW concept to spatial interaction models, we investigate several approaches differing mainly in the way calibration points (flows) are defined and spatial separation (distance) between flows is calculated. As a result, a series of localised geographically weighted spatial interaction (GWSI) models are developed.
Using custom-built algorithms and computer code, we apply the GWSI models to a journey-to-work dataset in Switzerland for validation and comparison with the related global models. The results of the model calibrations are visualised using a series of conventional and flow maps along with some matrix visualisations. The comparison of the results indicates that in most cases local GWSI models exhibit an improvement over the global models both in providing more useful local information and also in model performance and goodness-of-fit.
2013-11-30T00:00:00Z
Kordi, Maryam
One of the key concerns in spatial analysis and modelling is to study and analyse similarities or dissimilarities between places over geographical space. However, ”global“ spatial models may fail to identify spatial variations of relationships (spatial heterogeneity) by assuming spatial stationarity of relationships. In many real-life situations spatial variation in relationships possibly exists and the assumption of global stationarity might be highly unrealistic leading to ignorance of a large amount of spatial information. In contrast, local spatial models emphasise differences or dissimilarity over space and focus on identifying spatial variations in relationships. These models allow the parameters of models to vary locally and can provide more useful information on the processes generating the data in different parts of the study area.
In this study, a framework for localising spatial interaction models, based on geographically weighted (GW) techniques, has been developed. This framework can help in detecting, visualising and analysing spatial heterogeneity in spatial interaction systems. In order to apply the GW concept to spatial interaction models, we investigate several approaches differing mainly in the way calibration points (flows) are defined and spatial separation (distance) between flows is calculated. As a result, a series of localised geographically weighted spatial interaction (GWSI) models are developed.
Using custom-built algorithms and computer code, we apply the GWSI models to a journey-to-work dataset in Switzerland for validation and comparison with the related global models. The results of the model calibrations are visualised using a series of conventional and flow maps along with some matrix visualisations. The comparison of the results indicates that in most cases local GWSI models exhibit an improvement over the global models both in providing more useful local information and also in model performance and goodness-of-fit.
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A price not worth paying : using causal effect modelling to examine the relationship between worklessness and mortality for male individuals in Scotland
https://hdl.handle.net/10023/4036
The research conducted in this thesis examines the relationship between forms of
worklessness (both active unemployment and inactivity due to sickness and disability) and
mortality for working age men. Previous research has shown that being out of work is
associated with a greater risk of mortality relative to being in work. However, there remains
debate as to whether this association is the result of a causal pathway leading from
worklessness to mortality or whether it reflects the ‘selection’ of individuals who are already
at greater risk of mortality from pre-existing poor health or other characteristics. In the UK,
many studies rely on the use of ‘wear-off’ periods in which mortality events occurring within
five years after the observation of employment status are ignored to allow the confounding
effects of selection to diminish. Generally these studies concluded in support of a causal
relationship. In contrast, more recent studies making use of innovative methodological
designs such as natural experiments and linked register and health datasets have found less
evidence for this explanation with many emphasising the role of confounding and selection.
The thesis aims to firstly, examine the effectiveness of wear-off periods and secondly, to
develop an alternative counterfactual approach to examine the relationship between
worklessness (both active unemployment and health related inactivity) and mortality. These
questions are addressed in three stand-alone papers.
In the first paper, data from the Scottish Longitudinal Study and the England & Wales
Longitudinal Study was used in logistic regression models which estimated the odds of death
in a given time period after the 1991 Census for those aged 35–64 in 1991. The odds ratios
for the different economic positions (in work, unemployed, retired, permanently sick and
other inactive) were compared, as well as the changes in risk associated with cumulatively
increasing the length of wear-off prior to follow-up. No evidence was found of health related
selection for the unemployed in 1991 suggesting that the use of the five year wear-off period
in many studies of mortality and unemployment may be an ineffective and unnecessary
technique for mitigating the effects of health-related selection.
The second paper examined men aged between 35 and 54 who were in work in 1991.
Subsequent employment status in 2001 was observed (in work or unemployed) and the
relative all-cause mortality risk of unemployment between 2001 and 2007 was estimated. To
account for potential selection into unemployment of those in poor health, a counterfactual
propensity score matching framework was used to construct unbiased and comparable samples of in work and unemployed individuals. Matching was based on a wide range of
explanatory variables including health status prior to year of unemployment (hospital
admissions and self-reported limiting long term illness) as well as measures of socio-economic position. The findings showed that unemployment was associated with a doubling
(hazard ratio 2.1 95% CI 1.30 - 3.38) of the subsequent risk of mortality from all causes
relative to employment. This scale of effect was consistent across different samples and was
robust controlling for prior health and socio-demographic characteristics. These findings
were interpreted as evidence that the often observed association between unemployment and
mortality may contain a causal component.
The second paper implemented a similar analytical design to address the lack of evidence for
the independent mortality effect of inactivity due to sickness. The results showed that the
mortality risk of economic inactivity due to sickness relative to active employment was
significant (HR. 3.18, 95% CI 2.53-3.98) and suggest that economic inactivity due to
sickness poses a mortality risk that is independent of prior health. The findings could be
interpreted in two ways; either economic inactivity due to sickness is worse for health than
actively seeking work or previous studies of unemployment and mortality have
underestimated the true effect of being out of work generally.
Across the three studies, the main contribution of the thesis is to reassert the importance of
worklessness as a determinant of individual mortality. In doing so the studies also found
little evidence of systematic confounding by either health or other characteristics. The thesis
concludes with a comprehensive discussion of the wider implications of the findings in
relation to both general methodological issues in observational epidemiology and possible
policy interventions that could be implemented to tackle work-related inequalities in male
mortality.
2012-01-01T00:00:00Z
Clemens, Thomas Laurie
The research conducted in this thesis examines the relationship between forms of
worklessness (both active unemployment and inactivity due to sickness and disability) and
mortality for working age men. Previous research has shown that being out of work is
associated with a greater risk of mortality relative to being in work. However, there remains
debate as to whether this association is the result of a causal pathway leading from
worklessness to mortality or whether it reflects the ‘selection’ of individuals who are already
at greater risk of mortality from pre-existing poor health or other characteristics. In the UK,
many studies rely on the use of ‘wear-off’ periods in which mortality events occurring within
five years after the observation of employment status are ignored to allow the confounding
effects of selection to diminish. Generally these studies concluded in support of a causal
relationship. In contrast, more recent studies making use of innovative methodological
designs such as natural experiments and linked register and health datasets have found less
evidence for this explanation with many emphasising the role of confounding and selection.
The thesis aims to firstly, examine the effectiveness of wear-off periods and secondly, to
develop an alternative counterfactual approach to examine the relationship between
worklessness (both active unemployment and health related inactivity) and mortality. These
questions are addressed in three stand-alone papers.
In the first paper, data from the Scottish Longitudinal Study and the England & Wales
Longitudinal Study was used in logistic regression models which estimated the odds of death
in a given time period after the 1991 Census for those aged 35–64 in 1991. The odds ratios
for the different economic positions (in work, unemployed, retired, permanently sick and
other inactive) were compared, as well as the changes in risk associated with cumulatively
increasing the length of wear-off prior to follow-up. No evidence was found of health related
selection for the unemployed in 1991 suggesting that the use of the five year wear-off period
in many studies of mortality and unemployment may be an ineffective and unnecessary
technique for mitigating the effects of health-related selection.
The second paper examined men aged between 35 and 54 who were in work in 1991.
Subsequent employment status in 2001 was observed (in work or unemployed) and the
relative all-cause mortality risk of unemployment between 2001 and 2007 was estimated. To
account for potential selection into unemployment of those in poor health, a counterfactual
propensity score matching framework was used to construct unbiased and comparable samples of in work and unemployed individuals. Matching was based on a wide range of
explanatory variables including health status prior to year of unemployment (hospital
admissions and self-reported limiting long term illness) as well as measures of socio-economic position. The findings showed that unemployment was associated with a doubling
(hazard ratio 2.1 95% CI 1.30 - 3.38) of the subsequent risk of mortality from all causes
relative to employment. This scale of effect was consistent across different samples and was
robust controlling for prior health and socio-demographic characteristics. These findings
were interpreted as evidence that the often observed association between unemployment and
mortality may contain a causal component.
The second paper implemented a similar analytical design to address the lack of evidence for
the independent mortality effect of inactivity due to sickness. The results showed that the
mortality risk of economic inactivity due to sickness relative to active employment was
significant (HR. 3.18, 95% CI 2.53-3.98) and suggest that economic inactivity due to
sickness poses a mortality risk that is independent of prior health. The findings could be
interpreted in two ways; either economic inactivity due to sickness is worse for health than
actively seeking work or previous studies of unemployment and mortality have
underestimated the true effect of being out of work generally.
Across the three studies, the main contribution of the thesis is to reassert the importance of
worklessness as a determinant of individual mortality. In doing so the studies also found
little evidence of systematic confounding by either health or other characteristics. The thesis
concludes with a comprehensive discussion of the wider implications of the findings in
relation to both general methodological issues in observational epidemiology and possible
policy interventions that could be implemented to tackle work-related inequalities in male
mortality.
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The effect of storage upon sediment transfer processes in a small Scottish gravel-bed river
https://hdl.handle.net/10023/3844
A detailed morphological approach is used to determine the effect of storage location upon
sediment mobility, providing partial explanation for previously reported non systematic characteristics of sediment transfer. Data were collected over a period of 2 years from a small river in the Highlands of Scotland. Sediment transfer fluxes and volumetric storage were
measured using an integrated data collection programme utilising 990 magnetic tracers and 225 cross sections spaced at c1 m intervals over two contrasting reaches (A and B).
Scaled tracer fluxes were monitored between 6 numerically defined storage types (very active, active, semi active, stable, inactive and dormant). Storage characteristics were determined using
response time, defined as the time at which cumulative output from a store exceeds sediment in storage. Activity progressively declined from very active to inactive stores, the exact magnitude being a function of local morphology, particularly the presence of fixed bars.
Inter store exchanges of sediment were assessed using descriptive matrices categorised into individual types according to transfer and storage proportions. A relative dimensionless shear stress scale used to differentiate the storage conditions responsible for the occurrence of each
matrix type indicated that transfer in reach A is a function of hydraulic conditions, grain size and storage, in reach B grain size is the only dominant factor. These controlling factors were subdivided into peak stage, duration, relative and absolute grain size, morphology and burial and
assessed with reference to fractional transfer distances. The relative importance of each factor to transfer depends upon storage location and the incidence of morphological change. Comparison between tracer and volumetric fluxes provides explanation for sediment transfer distributions and allows assessment of morphological controls upon channel pattern maintenance. The results from this study were summarised in two conceptual models describing downstream and within reach
sediment transfer.
1995-01-01T00:00:00Z
Wathen, Simon John
A detailed morphological approach is used to determine the effect of storage location upon
sediment mobility, providing partial explanation for previously reported non systematic characteristics of sediment transfer. Data were collected over a period of 2 years from a small river in the Highlands of Scotland. Sediment transfer fluxes and volumetric storage were
measured using an integrated data collection programme utilising 990 magnetic tracers and 225 cross sections spaced at c1 m intervals over two contrasting reaches (A and B).
Scaled tracer fluxes were monitored between 6 numerically defined storage types (very active, active, semi active, stable, inactive and dormant). Storage characteristics were determined using
response time, defined as the time at which cumulative output from a store exceeds sediment in storage. Activity progressively declined from very active to inactive stores, the exact magnitude being a function of local morphology, particularly the presence of fixed bars.
Inter store exchanges of sediment were assessed using descriptive matrices categorised into individual types according to transfer and storage proportions. A relative dimensionless shear stress scale used to differentiate the storage conditions responsible for the occurrence of each
matrix type indicated that transfer in reach A is a function of hydraulic conditions, grain size and storage, in reach B grain size is the only dominant factor. These controlling factors were subdivided into peak stage, duration, relative and absolute grain size, morphology and burial and
assessed with reference to fractional transfer distances. The relative importance of each factor to transfer depends upon storage location and the incidence of morphological change. Comparison between tracer and volumetric fluxes provides explanation for sediment transfer distributions and allows assessment of morphological controls upon channel pattern maintenance. The results from this study were summarised in two conceptual models describing downstream and within reach
sediment transfer.
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The genesis of Late Caledonian granitoid-related mineralization in northern Britain
https://hdl.handle.net/10023/3834
The main aim of this study was to develop a model for the sources of sulphur in Late Caledonian granitoids of Northern Britain in relation to their tectonic framework, and to constrain the sources of sulphur, fluids and metals
in related mineralization. Using an approach of combined stable isotopic (S, C, H and O), fluid inclusion, geochemical (XRF) and mineralogical (electron probe, XRD, microscopy) techniques, it has been possible to estimate temperatures and conditions of formation. A further aim was to group the mineralization "styles" and to develop a model for each with implications for the sources of their host granitoids. The relative importance of magmatic processes and terrane characteristics in the formation of ore deposits of Northern Britain has been evaluated.
The study of 23 mineralized granitoids amongst four terranes has yielded a range of δ³⁴S values between -21‰ and +24‰, and values for host rock lithologies between -22‰ and +29‰. Porphyry-style mineralization has δ³⁴S H₂S values restricted to the range -2‰ to +2‰. Fluid inclusions in porphyry related mineralization homogenize at temperatures up to 580°C with salinities of 5-60 eq.wt.% NaCl, and CO₂ is rare.
Fluid inclusions, sulphur isotope geothermometry and mineral stabilities suggest that late veins hosted by plutonic rocks formed below 450°C, contained salinities of <15 eq.wt.% NaCl, and that CO2 was often an important primary component. External fluids commonly entered the magmatic systems at temperatures below 200°C in both porphyry systems and deeper veins. Parageneses of the porphyry-style mineralization generally contains early pyritohedra, followed by quartz, chalcopyrite, tetrahedrite, bornite and carbonate. The plutonic-hosted veins contain a more complex mineralogy, commonly including galena and sphalerite, and accompanied by minerals new to Scotland including berryite, gladite, hammarite, joseite-B, krupkaite, matildite, pearcite and tetradymite. Calcite is commonly the only carbonate present in plutonic-hosted mineralization, and wallrock alteration is restricted to propylitic type, except for vein selvages. Porphyry systems show more intensive
wallrock alteration of sericitic or phyllic type, dolomite is the primary carbonate and is followed by late calcite.
A model for the Late Caledonian mineralization has been developed. The sulphur and metals involved in the formation of a granitoid-related mineral deposit are commonly derived from the same sources. In the Northern Highland Terrane the Lewisian craton was an important source, whereas most components in the Grampian Terrane were derived from the sub-crustal magmas. In the Southern Uplands and North of England Terranes, the Lower Palaeozoic sediments hosting the granitoids provided a major component of metals, sulphur and fluids, either at the level of intrusion or as a source for S-type magmas at depth. The 834S values of the granitoids and related mineral deposits in the paratectonic Caledonides reflect the signatures of the host sediments. It is concluded that only in the Grampian Terrane do the characteristics of mineralization predominantly represent magmatic processes. In the remaining terranes, a significant contribution of fluids, sulphur and metals, from the craton or upper crustal sediments, modified magmatic and fluid conditions which controlled subsequent mineralizing processes. As a consequence of the behaviour of sulphur isotopes in sediment formation and with variation of ƒO₂ and pH in the mineralizing fluids, the sulphur isotope technique provides a robust indicator of magma sources and major crustal discontinuities such as terrane boundaries. The technique developed in this study may find wider application.
1992-01-01T00:00:00Z
Lowry, David
The main aim of this study was to develop a model for the sources of sulphur in Late Caledonian granitoids of Northern Britain in relation to their tectonic framework, and to constrain the sources of sulphur, fluids and metals
in related mineralization. Using an approach of combined stable isotopic (S, C, H and O), fluid inclusion, geochemical (XRF) and mineralogical (electron probe, XRD, microscopy) techniques, it has been possible to estimate temperatures and conditions of formation. A further aim was to group the mineralization "styles" and to develop a model for each with implications for the sources of their host granitoids. The relative importance of magmatic processes and terrane characteristics in the formation of ore deposits of Northern Britain has been evaluated.
The study of 23 mineralized granitoids amongst four terranes has yielded a range of δ³⁴S values between -21‰ and +24‰, and values for host rock lithologies between -22‰ and +29‰. Porphyry-style mineralization has δ³⁴S H₂S values restricted to the range -2‰ to +2‰. Fluid inclusions in porphyry related mineralization homogenize at temperatures up to 580°C with salinities of 5-60 eq.wt.% NaCl, and CO₂ is rare.
Fluid inclusions, sulphur isotope geothermometry and mineral stabilities suggest that late veins hosted by plutonic rocks formed below 450°C, contained salinities of <15 eq.wt.% NaCl, and that CO2 was often an important primary component. External fluids commonly entered the magmatic systems at temperatures below 200°C in both porphyry systems and deeper veins. Parageneses of the porphyry-style mineralization generally contains early pyritohedra, followed by quartz, chalcopyrite, tetrahedrite, bornite and carbonate. The plutonic-hosted veins contain a more complex mineralogy, commonly including galena and sphalerite, and accompanied by minerals new to Scotland including berryite, gladite, hammarite, joseite-B, krupkaite, matildite, pearcite and tetradymite. Calcite is commonly the only carbonate present in plutonic-hosted mineralization, and wallrock alteration is restricted to propylitic type, except for vein selvages. Porphyry systems show more intensive
wallrock alteration of sericitic or phyllic type, dolomite is the primary carbonate and is followed by late calcite.
A model for the Late Caledonian mineralization has been developed. The sulphur and metals involved in the formation of a granitoid-related mineral deposit are commonly derived from the same sources. In the Northern Highland Terrane the Lewisian craton was an important source, whereas most components in the Grampian Terrane were derived from the sub-crustal magmas. In the Southern Uplands and North of England Terranes, the Lower Palaeozoic sediments hosting the granitoids provided a major component of metals, sulphur and fluids, either at the level of intrusion or as a source for S-type magmas at depth. The 834S values of the granitoids and related mineral deposits in the paratectonic Caledonides reflect the signatures of the host sediments. It is concluded that only in the Grampian Terrane do the characteristics of mineralization predominantly represent magmatic processes. In the remaining terranes, a significant contribution of fluids, sulphur and metals, from the craton or upper crustal sediments, modified magmatic and fluid conditions which controlled subsequent mineralizing processes. As a consequence of the behaviour of sulphur isotopes in sediment formation and with variation of ƒO₂ and pH in the mineralizing fluids, the sulphur isotope technique provides a robust indicator of magma sources and major crustal discontinuities such as terrane boundaries. The technique developed in this study may find wider application.
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The Lewisian and Torridonian geology of Iona
https://hdl.handle.net/10023/3812
The island of Iona is composed predominantly of Lewisian gneisses with Torridonian sediments outcropping on the east side.
The Lewisian gneisses include a wide range of lithological types. The prevalent quartzfeldspathic gneisses are biotite-hornblende-bearing, potash-rich and potash-poor varieties and hypersthene-biotite-garnet gneisses. Metasediments outcrop in two associations (i) within a sequence of basic and ultrabasic rocks (the ‘Amphibolite Group’) and (ii) in the NW of Iona (the NW Paragneisses). The Amphibolite Group contains concordant marble and iron-rich horizons which delineate the major fold structures in south and west Iona. Chemical analyses of the metasediments and basic rocks in the Amphibolite Group indicate that the sequence was probably originally a supracrustal group composed of tuffs, lavas, impure limestone and iron-rich chemical deposits. The NW paragneiss group may be a younger group of metasediments comprising graphite-quartz marbles, calc-silicate layers, graphitic schists, and garnet schists.
The tectonic history of the gneisses divides into six main deformations. The first (D₁) is represented by isoclinal intrafolial hinges with a penetrative S₁ foliation. The second deformation produced isoclinal folds with rounded hinges deforming the S₁ foliation. D₃ generated tight asymmetrical folds accompanied by a hornblende granulite facies metamorphism with syntectonic mineral growths defining S₃ and L₃, and axial planar pegmatite veins. The axial planes are generally at low angles to the foliation, which typically trends NE or E. D₄ folds are mostly large close folds with shallow short limbs and axial planes trending NE with NW dips, whilst D₆ formed open folds with N-trending axial planes, and accompanied by a high amphibolite facies metamorphism.
Basic dykes were intruded at various stages of the tectonic sequence: before D₁, between D₁ and D₂, D₂ and D₃, and D₅ and D₆. The dykes can be divided into distinct types on petrographical, chemical, and structural grounds. One set, the Banded Dykes, is composed of two intimately associated assemblages, hornblende-two-pyroxene-plagioclase and garnet-quartz-clinopyroxene-plagioclase. The latter is thought to have developed from the former during waning temperatures at constant pressure during D₃. The Banded Dykes also have distinct selvedges of an unusual mineral assemblage, garnet-orthopyroxene-plagioclase, probably due in part to chilling of the dyke on intrusion but mostly formed by metasomatic interchange with the enclosing gneisses during D₂ and D₃. Another dyke set, the Well-Lineated Dykes, also has these distinctive selvedges. These dykes also display a very well defined lineation formed by elongated clots of mafic minerals, and have a more basic chemistry than any of the other dyke sets. They appear to be comparable to the two-pyroxene norites of the Assynt district.
The Torridonian(?) sediments were deposited on the Lewisian after uplift and erosion. After consolidation they were probably metamorphosed at low greenschist facies. Activity on the Moine Thrust thrust the Moinian on to the Torridonian. Thrusting was accompanied by dynamic metamorphism, mylonitization of the Lewisian/Torridonian boundary, rotation of the Torridonian bedding planes to a steep SE dip and the formation of isoclinal folds, in association with a steep SE-dipping cleavage and an ESE elongation lineation. This deformation (D[subscript(t1)]) was followed by a generation of tight asymmetrical folds (D[subscript(t2)]) which deformed the mylonite foliation and was accompanied by a weak N-trending axial planar cleavage. D[subscript(t3)] produced kink bands and monoclonal folds with sub-horizontal fold axes, whilst D[subscript(t4)] caused conjugate or knee folds with NE- and SE-, and N- and E- trending axial planes. A pluton of adamellite, the Ross of Mull Granite, was intruded along the Moine Thrust plane after [subscript(t2)], and caused the thermal metamorphism of the Torridonian sediments, the mylonites and nearby Lewisian gneisses. The D[subscript(t1)] - D[subscript(t4)] events correlate closely with those occurring in the Moine Thrust zone between Durness and Skye.
1977-01-01T00:00:00Z
Fraser, Fiona M.
The island of Iona is composed predominantly of Lewisian gneisses with Torridonian sediments outcropping on the east side.
The Lewisian gneisses include a wide range of lithological types. The prevalent quartzfeldspathic gneisses are biotite-hornblende-bearing, potash-rich and potash-poor varieties and hypersthene-biotite-garnet gneisses. Metasediments outcrop in two associations (i) within a sequence of basic and ultrabasic rocks (the ‘Amphibolite Group’) and (ii) in the NW of Iona (the NW Paragneisses). The Amphibolite Group contains concordant marble and iron-rich horizons which delineate the major fold structures in south and west Iona. Chemical analyses of the metasediments and basic rocks in the Amphibolite Group indicate that the sequence was probably originally a supracrustal group composed of tuffs, lavas, impure limestone and iron-rich chemical deposits. The NW paragneiss group may be a younger group of metasediments comprising graphite-quartz marbles, calc-silicate layers, graphitic schists, and garnet schists.
The tectonic history of the gneisses divides into six main deformations. The first (D₁) is represented by isoclinal intrafolial hinges with a penetrative S₁ foliation. The second deformation produced isoclinal folds with rounded hinges deforming the S₁ foliation. D₃ generated tight asymmetrical folds accompanied by a hornblende granulite facies metamorphism with syntectonic mineral growths defining S₃ and L₃, and axial planar pegmatite veins. The axial planes are generally at low angles to the foliation, which typically trends NE or E. D₄ folds are mostly large close folds with shallow short limbs and axial planes trending NE with NW dips, whilst D₆ formed open folds with N-trending axial planes, and accompanied by a high amphibolite facies metamorphism.
Basic dykes were intruded at various stages of the tectonic sequence: before D₁, between D₁ and D₂, D₂ and D₃, and D₅ and D₆. The dykes can be divided into distinct types on petrographical, chemical, and structural grounds. One set, the Banded Dykes, is composed of two intimately associated assemblages, hornblende-two-pyroxene-plagioclase and garnet-quartz-clinopyroxene-plagioclase. The latter is thought to have developed from the former during waning temperatures at constant pressure during D₃. The Banded Dykes also have distinct selvedges of an unusual mineral assemblage, garnet-orthopyroxene-plagioclase, probably due in part to chilling of the dyke on intrusion but mostly formed by metasomatic interchange with the enclosing gneisses during D₂ and D₃. Another dyke set, the Well-Lineated Dykes, also has these distinctive selvedges. These dykes also display a very well defined lineation formed by elongated clots of mafic minerals, and have a more basic chemistry than any of the other dyke sets. They appear to be comparable to the two-pyroxene norites of the Assynt district.
The Torridonian(?) sediments were deposited on the Lewisian after uplift and erosion. After consolidation they were probably metamorphosed at low greenschist facies. Activity on the Moine Thrust thrust the Moinian on to the Torridonian. Thrusting was accompanied by dynamic metamorphism, mylonitization of the Lewisian/Torridonian boundary, rotation of the Torridonian bedding planes to a steep SE dip and the formation of isoclinal folds, in association with a steep SE-dipping cleavage and an ESE elongation lineation. This deformation (D[subscript(t1)]) was followed by a generation of tight asymmetrical folds (D[subscript(t2)]) which deformed the mylonite foliation and was accompanied by a weak N-trending axial planar cleavage. D[subscript(t3)] produced kink bands and monoclonal folds with sub-horizontal fold axes, whilst D[subscript(t4)] caused conjugate or knee folds with NE- and SE-, and N- and E- trending axial planes. A pluton of adamellite, the Ross of Mull Granite, was intruded along the Moine Thrust plane after [subscript(t2)], and caused the thermal metamorphism of the Torridonian sediments, the mylonites and nearby Lewisian gneisses. The D[subscript(t1)] - D[subscript(t4)] events correlate closely with those occurring in the Moine Thrust zone between Durness and Skye.
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The development of X-ray excited optical luminescence (XEOL) spectroscopic techniques for mineralogical and petrological applications
https://hdl.handle.net/10023/3739
This thesis investigates the use of X-ray Excited Optical Luminescence (XEOL) and Time
Resolved X-ray Excited Optical Luminescence (TR XEOL) within the Earth sciences. The
project contains two primary objectives, the first of which is the design and building of a high-resolution luminescence spectroscopy facility. This includes the installation and
commissioning of the facility on the I18 microfocus beamline at Diamond, the UK's
national synchrotron facility. In describing the system's design and commissioning, I
explore many implications of the technique.
The second objective is using this new facility to investigate a suite of minerals to develop new analytical techniques utilizing XEOL and TR XEOL spectroscopy for
applications within the Earth sciences. An aspect of this investigation is to explore the potential of Time Resolved Optically Derived X-ray Absorption Spectroscopy (TR OD XAS) of substitute trace elements in minerals. To date CW OD XAS has been shown to have very limited application within the Earth sciences. (Soderholm et al., 1998-120) The thesis explores differences between photoluminescence (PL) and XEOL responses in
mineral systems, and investigates how these differences can be exploited.
Luminescence, the phenomenon upon which the thesis is based, is a complex and poorly
utilised phenomena within Earth sciences, it is however, orders of magnitude more
sensitive, than many of the more accepted techniques used for the detection of trace
elements, on this basis alone I would suggest it deserves further consideration.
Luminescence techniques have developed much further in other disciplines; I therefore
have incorporated many descriptions, models, and interpretations from other disciplines in order to identify methodologies and techniques that have the potential to be utilized in the study and interpretation of luminescence within the Earth sciences.
The thesis demonstrates that luminescence in minerals with measured lifetimes, as fast
as ~ 20 ps exist. Previously the recorded luminescent lifetimes, for minerals, in the
literature are measured in ns. This finding leads to the novel concept that the
measurement of TR XEOL with ps resolution combined with the measurement of the
intensity of a luminescent signal as a function of excitation can provide significant new insights into the nature of the emission and the luminescent processes. I explore and demonstrate the potential of using dose dependence techniques of continuous wave and TR XEOL as a new analytical technique.
I also demonstrate the use of a technique used extensively within Biology has an
application with Earth sciences. The methodology incorporates the calculation of the natural lifetime of an emission through the relationship between the absorption and
emission coefficients. (Strickler and Berg, 1962). I discuss how knowledge of the natural
lifetime of an emission allows quantification of luminescence through measurement of a modified lifetime of emission. The quantification of a luminescent emission has significant potential within the geosciences one example being the identification of disputed emissions. I also consider the potential to use TR XEOL techniques in mapping
complex heterogeneous rocks and minerals.
2013-01-01T00:00:00Z
Taylor, Richard Peter
This thesis investigates the use of X-ray Excited Optical Luminescence (XEOL) and Time
Resolved X-ray Excited Optical Luminescence (TR XEOL) within the Earth sciences. The
project contains two primary objectives, the first of which is the design and building of a high-resolution luminescence spectroscopy facility. This includes the installation and
commissioning of the facility on the I18 microfocus beamline at Diamond, the UK's
national synchrotron facility. In describing the system's design and commissioning, I
explore many implications of the technique.
The second objective is using this new facility to investigate a suite of minerals to develop new analytical techniques utilizing XEOL and TR XEOL spectroscopy for
applications within the Earth sciences. An aspect of this investigation is to explore the potential of Time Resolved Optically Derived X-ray Absorption Spectroscopy (TR OD XAS) of substitute trace elements in minerals. To date CW OD XAS has been shown to have very limited application within the Earth sciences. (Soderholm et al., 1998-120) The thesis explores differences between photoluminescence (PL) and XEOL responses in
mineral systems, and investigates how these differences can be exploited.
Luminescence, the phenomenon upon which the thesis is based, is a complex and poorly
utilised phenomena within Earth sciences, it is however, orders of magnitude more
sensitive, than many of the more accepted techniques used for the detection of trace
elements, on this basis alone I would suggest it deserves further consideration.
Luminescence techniques have developed much further in other disciplines; I therefore
have incorporated many descriptions, models, and interpretations from other disciplines in order to identify methodologies and techniques that have the potential to be utilized in the study and interpretation of luminescence within the Earth sciences.
The thesis demonstrates that luminescence in minerals with measured lifetimes, as fast
as ~ 20 ps exist. Previously the recorded luminescent lifetimes, for minerals, in the
literature are measured in ns. This finding leads to the novel concept that the
measurement of TR XEOL with ps resolution combined with the measurement of the
intensity of a luminescent signal as a function of excitation can provide significant new insights into the nature of the emission and the luminescent processes. I explore and demonstrate the potential of using dose dependence techniques of continuous wave and TR XEOL as a new analytical technique.
I also demonstrate the use of a technique used extensively within Biology has an
application with Earth sciences. The methodology incorporates the calculation of the natural lifetime of an emission through the relationship between the absorption and
emission coefficients. (Strickler and Berg, 1962). I discuss how knowledge of the natural
lifetime of an emission allows quantification of luminescence through measurement of a modified lifetime of emission. The quantification of a luminescent emission has significant potential within the geosciences one example being the identification of disputed emissions. I also consider the potential to use TR XEOL techniques in mapping
complex heterogeneous rocks and minerals.
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Palaeobiology, taphonomy and diagenesis of a lower carboniferous fish fauna
https://hdl.handle.net/10023/3723
Chapters one and two of this work contain a study of helically-coiled spiral coprolites. Spiral coprolites with complex microstructures have been interpreted as enterospirae – fossilized valvular intestines (Fritsch 1907, Williams 1972). However other evidence seems to indicate that recent dogfish produce spiral faecal pellets with complex microstructures (McAllister 1985). The search for an answer to the problem of whether certain spiral coprolites are fossilized intestines or faecal pellets includes a study of diet and the physiology of digestion in fishes, with particular attention to those with valvular intestines; the sharks, skates and rays. The faunal associations of various coprolite assemblages and the fossil evidence for the presence of the valvular intestine in fishes and other groups are also reviewed. Chapter one includes a revision of the definitions, terminology and taxonomy of coprolites. In the second chapter the various forms of spiral coprolites in the Lower Carboniferous of Scotland are examined.
Actualistic research into taphonomic processes in fishes is divided into two areas described in chapters three and five. Chapter three covers various aspects of the physical processes which affect fish carcasses, with particular emphasis on small sharks. A major aspect of this work is concerned with the post mortem build-up of gas
in the body cavity and its taphonomic consequences. Chemical aspects of decay and mineralization form the basis of chapter five. The roles of changes in pH and the levels of calcium magnesium and phosphates in early mineralization are investigated.
An investigation of the taphonomy and diagenesis of the Wardle Shales fish beds is contained in chapter four. The Lower Carboniferous Wardie Shales fish fauna consists of palaeoniscoids, sharks and acanthodians preserved in siderite concretions. The
preservation of uncrushed calcified cartilage is particularly striking. Well-preserved spiral coprolites are exceedingly common.
Wide-ranging conclusions help to clarify the processes that have led to the preservation of the remarkable assemblages of coprolites at Anstruther and Wardie and of the Wardie fishes.
1991-01-01T00:00:00Z
Sumner, Daphne
Chapters one and two of this work contain a study of helically-coiled spiral coprolites. Spiral coprolites with complex microstructures have been interpreted as enterospirae – fossilized valvular intestines (Fritsch 1907, Williams 1972). However other evidence seems to indicate that recent dogfish produce spiral faecal pellets with complex microstructures (McAllister 1985). The search for an answer to the problem of whether certain spiral coprolites are fossilized intestines or faecal pellets includes a study of diet and the physiology of digestion in fishes, with particular attention to those with valvular intestines; the sharks, skates and rays. The faunal associations of various coprolite assemblages and the fossil evidence for the presence of the valvular intestine in fishes and other groups are also reviewed. Chapter one includes a revision of the definitions, terminology and taxonomy of coprolites. In the second chapter the various forms of spiral coprolites in the Lower Carboniferous of Scotland are examined.
Actualistic research into taphonomic processes in fishes is divided into two areas described in chapters three and five. Chapter three covers various aspects of the physical processes which affect fish carcasses, with particular emphasis on small sharks. A major aspect of this work is concerned with the post mortem build-up of gas
in the body cavity and its taphonomic consequences. Chemical aspects of decay and mineralization form the basis of chapter five. The roles of changes in pH and the levels of calcium magnesium and phosphates in early mineralization are investigated.
An investigation of the taphonomy and diagenesis of the Wardle Shales fish beds is contained in chapter four. The Lower Carboniferous Wardie Shales fish fauna consists of palaeoniscoids, sharks and acanthodians preserved in siderite concretions. The
preservation of uncrushed calcified cartilage is particularly striking. Well-preserved spiral coprolites are exceedingly common.
Wide-ranging conclusions help to clarify the processes that have led to the preservation of the remarkable assemblages of coprolites at Anstruther and Wardie and of the Wardie fishes.
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Ethnic inequalities in social mobility at the neighbourhood scale : evidence from the Office for National Statistics Longitudinal Study in England
https://hdl.handle.net/10023/3666
Compared to their White peers, ethnic minorities in England are often at higher risk of becoming unemployed, unable to find employment, and more likely to experience downward, rather than upward social mobility. Qualifications, gender, age, marital status and migrant generation all play a role; but do not explain these ethnic inequalities, or ethnic penalties. Despite ethnic minorities being more likely to live in deprived neighbourhoods than Whites, research on ethnic inequalities in social mobility has rarely taken account of the role of context. Neighbourhood deprivation may reduce life-chances for various reasons,
and the concentration of ethnic minorities into deprived neighbourhoods may have additional influences for social mobility: some positive, but also some negative. In this thesis, I ask: does neighbourhood
deprivation and ethnic composition explain the ethnic inequalities in social mobility?
Using a longitudinal analysis of the Office for National Statistics Longitudinal Study, I tracked the intragenerational social mobility of people living in urban areas of England between 1991 and 2001.
Binary and multinomial logit regression models were fit with ethnicity as an independent variable to
explore statistical differences between groups, and also for the White, Indian and Black Caribbean groups separately. My research shows that after controlling for education, couple status, and a number of other important characteristics, geography does play a role in life-chances; but does not fully explain the ethnic inequalities in social mobility. People in more deprived neighbourhoods tended to fare worse in all
economic outcomes: more at risk of unemployment; less likely to find employment; more at risk of downward social class mobility; less likely to experience upward social class mobility. However, these
results were statistically significant only among White people, with less consistent associations for ethnic minorities. Ethnic diversity had a positive influence upon outcomes (e.g. upward social class mobility), but only among White people. Positive outcomes were also more common among people living in the south of
England. Place of birth was less important for social mobility. For policymakers attempting to reduce the geographical inequalities of deprivation and affluence, dissolving residential concentrations of minorities alone is unlikely to reduce the gap in life chances between Whites and ethnic minorities. No evidence was
found to support the pejorative stereotyping of so-called ‘ethnically segregated’ neighbourhoods, which are some of the most diverse in England and, on balance, appear to improve the life chances of White people.
2012-01-01T00:00:00Z
Feng, Xiaoqi
Compared to their White peers, ethnic minorities in England are often at higher risk of becoming unemployed, unable to find employment, and more likely to experience downward, rather than upward social mobility. Qualifications, gender, age, marital status and migrant generation all play a role; but do not explain these ethnic inequalities, or ethnic penalties. Despite ethnic minorities being more likely to live in deprived neighbourhoods than Whites, research on ethnic inequalities in social mobility has rarely taken account of the role of context. Neighbourhood deprivation may reduce life-chances for various reasons,
and the concentration of ethnic minorities into deprived neighbourhoods may have additional influences for social mobility: some positive, but also some negative. In this thesis, I ask: does neighbourhood
deprivation and ethnic composition explain the ethnic inequalities in social mobility?
Using a longitudinal analysis of the Office for National Statistics Longitudinal Study, I tracked the intragenerational social mobility of people living in urban areas of England between 1991 and 2001.
Binary and multinomial logit regression models were fit with ethnicity as an independent variable to
explore statistical differences between groups, and also for the White, Indian and Black Caribbean groups separately. My research shows that after controlling for education, couple status, and a number of other important characteristics, geography does play a role in life-chances; but does not fully explain the ethnic inequalities in social mobility. People in more deprived neighbourhoods tended to fare worse in all
economic outcomes: more at risk of unemployment; less likely to find employment; more at risk of downward social class mobility; less likely to experience upward social class mobility. However, these
results were statistically significant only among White people, with less consistent associations for ethnic minorities. Ethnic diversity had a positive influence upon outcomes (e.g. upward social class mobility), but only among White people. Positive outcomes were also more common among people living in the south of
England. Place of birth was less important for social mobility. For policymakers attempting to reduce the geographical inequalities of deprivation and affluence, dissolving residential concentrations of minorities alone is unlikely to reduce the gap in life chances between Whites and ethnic minorities. No evidence was
found to support the pejorative stereotyping of so-called ‘ethnically segregated’ neighbourhoods, which are some of the most diverse in England and, on balance, appear to improve the life chances of White people.
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Landuse change and organic carbon exports from a peat catchment of the Halladale River in the Flow Country of Sutherland and Caithness, Scotland
https://hdl.handle.net/10023/3626
Upland peat catchments are usually assumed to function as carbon sinks, however, there have been extensive studies witnessing increasing trends in concentrations and fluxes of organic carbon in UK rivers over the last few decades. A number of controls on dissolved organic carbon (DOC) release from peatlands, such as climatic changes and landuse management, have been
proposed. This study examines the effects of land use and management on
organic carbon exports in the Dyke catchment of the River Halladale (northern
Scotland) with a nested catchment approach. This study provides insight into
the processes controlling the DOC dynamics in the Dyke catchment, and the
impact of disturbance caused by landuse changes such as afforestation and tree
felling for restoration. The results from factor analysis, end-member mixing,
absorbance (E4/E6), and hysteresis analyses on stream water chemistry from
individual sub-catchments identified the major hydrological pathways during
storm events, and based on these results, conceptual models were developed to
explain DOC evolution during storm events. At all the sites studied, nearsurface
soil water was identified as the major controlling end-member for
stream DOC concentrations.
The calculated annual flux of DOC from the Dyke catchment, up-scaled
from the results of the individual sub-catchments, is 521.6 kg C ha⁻¹
yr⁻¹,
which is
significantly (~5 times) higher than the previously published value (103.4 kg C
ha⁻¹
yr⁻¹)
for the River Halladale catchment (Hope et al., 1997). In this study, it is
shown that about 57 - 95% of the DOC export occur during 5 - 10% of the high
flows, therefore, it is crucial that quantitative records of DOC export are
developed using high frequency storm event measurements, as well as lower
frequency low flow sampling.
Climatic changes related to precipitation, temperature, coupled with
water yield capacity of the sub-catchments, are identified as significant controls
on DOC fluxes, rather than landuse change, as the intact site releases more
organic carbon per unit area compared to the disturbed and re-wetted site
undergoing restoration. In addition, the results from this study provide
landowners, policy makers and organisations with the evidence they require for
initiating future peatland restoration works, as felling of forestry coupled with
drain-blocking is shown to be an effective restoration technique that may help a
catchment to eventually return to a near-pristine state.
2012-01-01T00:00:00Z
Vinjili, Shailaja
Upland peat catchments are usually assumed to function as carbon sinks, however, there have been extensive studies witnessing increasing trends in concentrations and fluxes of organic carbon in UK rivers over the last few decades. A number of controls on dissolved organic carbon (DOC) release from peatlands, such as climatic changes and landuse management, have been
proposed. This study examines the effects of land use and management on
organic carbon exports in the Dyke catchment of the River Halladale (northern
Scotland) with a nested catchment approach. This study provides insight into
the processes controlling the DOC dynamics in the Dyke catchment, and the
impact of disturbance caused by landuse changes such as afforestation and tree
felling for restoration. The results from factor analysis, end-member mixing,
absorbance (E4/E6), and hysteresis analyses on stream water chemistry from
individual sub-catchments identified the major hydrological pathways during
storm events, and based on these results, conceptual models were developed to
explain DOC evolution during storm events. At all the sites studied, nearsurface
soil water was identified as the major controlling end-member for
stream DOC concentrations.
The calculated annual flux of DOC from the Dyke catchment, up-scaled
from the results of the individual sub-catchments, is 521.6 kg C ha⁻¹
yr⁻¹,
which is
significantly (~5 times) higher than the previously published value (103.4 kg C
ha⁻¹
yr⁻¹)
for the River Halladale catchment (Hope et al., 1997). In this study, it is
shown that about 57 - 95% of the DOC export occur during 5 - 10% of the high
flows, therefore, it is crucial that quantitative records of DOC export are
developed using high frequency storm event measurements, as well as lower
frequency low flow sampling.
Climatic changes related to precipitation, temperature, coupled with
water yield capacity of the sub-catchments, are identified as significant controls
on DOC fluxes, rather than landuse change, as the intact site releases more
organic carbon per unit area compared to the disturbed and re-wetted site
undergoing restoration. In addition, the results from this study provide
landowners, policy makers and organisations with the evidence they require for
initiating future peatland restoration works, as felling of forestry coupled with
drain-blocking is shown to be an effective restoration technique that may help a
catchment to eventually return to a near-pristine state.
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The impacts of climate change on estuarine ecosystems : a case study on the Eden estuary, Fife, Scotland
https://hdl.handle.net/10023/3625
The Eden Estuary is a small, coastal inlet situated in Fife between the Tay and Forth
Estuaries on the east coast of Scotland. A multidisciplinary case study of the estuary was conducted over a three year period observing the dynamic responses of biotic and abiotic behaviour to long term patterns of climate variability. Historical Trend Analysis (HTA) was combined with autocorrelation and spectral density analysis to identify trends, patterns
and periodicity in natural cycles. River flow and wind direction data were cross-correlated with the North Atlantic Oscillation Index (NAOI) to link local responses to patterns of northern hemisphere circulation, and with Wolfe Sunspot Numbers representing variable solar activity as a potential driving mechanism for climate driven change. Assessment of the current state of ‘estuary health’ used a proxy analysis of ecosystem function, combining Bray-Curtis similarity nMDS of macrofaunal community diversity with species functional traits. The observed estuary responses were subsequently projected onto the forecasted climate change scenarios reported by the IPCCAR4, UKCIP09 and to modelled
projections of solar activity to propose future trajectories of change for the estuary. Autocorrelation analysis of river flow and wind direction data identified significant (95%) correlations corresponding to solar, lunar, planetary and volcanic events. Spectral density analysis similarly identified significant (>95%) frequencies corresponding to known periods of solar activity, lunar cycles and Bruckner climatic cycles. Formal cross -correlation
revealed significant (95%) relationships between both river flow and wind data with the NAOI, and using a longer times series, between river Thames annual flow and Wolfe
sunspot numbers; correlating solar maximums with high flow. Periods consistent to
Schwabe and Hale solar cycles were evident in the wind and river data however the NAOI
only displayed Hale periodicity, inferring the river and wind data are not solely influenced (or potentially driven) by the NAO. No detrimental impact of estuary change was observed in the biotic responses inferring maintenance of estuary health.
This study identifies potential driving mechanisms of estuary perturbation and whilst
causal mechanisms can only be proposed, these observations form a baseline for future
targeted modelling, monitoring and management.
2013-01-01T00:00:00Z
Chocholek, Melanie
The Eden Estuary is a small, coastal inlet situated in Fife between the Tay and Forth
Estuaries on the east coast of Scotland. A multidisciplinary case study of the estuary was conducted over a three year period observing the dynamic responses of biotic and abiotic behaviour to long term patterns of climate variability. Historical Trend Analysis (HTA) was combined with autocorrelation and spectral density analysis to identify trends, patterns
and periodicity in natural cycles. River flow and wind direction data were cross-correlated with the North Atlantic Oscillation Index (NAOI) to link local responses to patterns of northern hemisphere circulation, and with Wolfe Sunspot Numbers representing variable solar activity as a potential driving mechanism for climate driven change. Assessment of the current state of ‘estuary health’ used a proxy analysis of ecosystem function, combining Bray-Curtis similarity nMDS of macrofaunal community diversity with species functional traits. The observed estuary responses were subsequently projected onto the forecasted climate change scenarios reported by the IPCCAR4, UKCIP09 and to modelled
projections of solar activity to propose future trajectories of change for the estuary. Autocorrelation analysis of river flow and wind direction data identified significant (95%) correlations corresponding to solar, lunar, planetary and volcanic events. Spectral density analysis similarly identified significant (>95%) frequencies corresponding to known periods of solar activity, lunar cycles and Bruckner climatic cycles. Formal cross -correlation
revealed significant (95%) relationships between both river flow and wind data with the NAOI, and using a longer times series, between river Thames annual flow and Wolfe
sunspot numbers; correlating solar maximums with high flow. Periods consistent to
Schwabe and Hale solar cycles were evident in the wind and river data however the NAOI
only displayed Hale periodicity, inferring the river and wind data are not solely influenced (or potentially driven) by the NAO. No detrimental impact of estuary change was observed in the biotic responses inferring maintenance of estuary health.
This study identifies potential driving mechanisms of estuary perturbation and whilst
causal mechanisms can only be proposed, these observations form a baseline for future
targeted modelling, monitoring and management.
-
Residential mobility desires and behaviour over the life course : linking lives through time
https://hdl.handle.net/10023/3476
As residential mobility recursively links individual life courses and the characteristics of places, it is unsurprising that geographers have long sought to understand how people make moving decisions. However, much of our knowledge of residential mobility processes derives from cross-sectional analyses of either mobility decision-making or moving events. Comparatively few studies have linked these separate literatures by analysing how residential (im)mobility decisions unfold over time within particular biographical, household and spatio-temporal contexts. This is problematic, as life course theories suggest that people frequently do not act in accordance with their underlying moving desires. To evaluate the extent to which residential (im)mobility is volitional or the product of constraints therefore requires a longitudinal approach linking moving desires to subsequent moving behaviour.
This thesis develops this longitudinal perspective through four linked empirical studies, which each use British Household Panel Survey data to analyse how the life course context affects the expression and realisation of moving desires. The first study investigates how people make moving decisions in different ways in response to different motivations, triggers and life events. The second study harnesses the concept of ‘linked lives’, exploring the extent to which the likelihood of realising a desire to move is dependent upon the desires of a person’s partner. The third study analyses the biographical dimension of mobility decision-making, investigating how the long-term trajectories of life course careers are associated with particular mobility biographies. The final empirical chapter develops these insights, exploring the duration and abandonment of moving desires. Taken together, these studies test and extend conceptual models of mobility decision-making by empirically engaging with neglected facets of life course theories. Fundamentally, the thesis uncovers how aggregate mobility patterns are produced by the interactions between individual choices and multi-scalar constraints.
2013-06-01T00:00:00Z
Coulter, Rory
As residential mobility recursively links individual life courses and the characteristics of places, it is unsurprising that geographers have long sought to understand how people make moving decisions. However, much of our knowledge of residential mobility processes derives from cross-sectional analyses of either mobility decision-making or moving events. Comparatively few studies have linked these separate literatures by analysing how residential (im)mobility decisions unfold over time within particular biographical, household and spatio-temporal contexts. This is problematic, as life course theories suggest that people frequently do not act in accordance with their underlying moving desires. To evaluate the extent to which residential (im)mobility is volitional or the product of constraints therefore requires a longitudinal approach linking moving desires to subsequent moving behaviour.
This thesis develops this longitudinal perspective through four linked empirical studies, which each use British Household Panel Survey data to analyse how the life course context affects the expression and realisation of moving desires. The first study investigates how people make moving decisions in different ways in response to different motivations, triggers and life events. The second study harnesses the concept of ‘linked lives’, exploring the extent to which the likelihood of realising a desire to move is dependent upon the desires of a person’s partner. The third study analyses the biographical dimension of mobility decision-making, investigating how the long-term trajectories of life course careers are associated with particular mobility biographies. The final empirical chapter develops these insights, exploring the duration and abandonment of moving desires. Taken together, these studies test and extend conceptual models of mobility decision-making by empirically engaging with neglected facets of life course theories. Fundamentally, the thesis uncovers how aggregate mobility patterns are produced by the interactions between individual choices and multi-scalar constraints.
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The deglaciation of the northwest sector of the last British-Irish ice sheet : integrating onshore and offshore data relating to chronology and behaviour
https://hdl.handle.net/10023/3410
It is now accepted that the last British-Irish Ice Sheet (BIIS) was highly dynamic and drained by numerous fast flowing ice streams. This dynamic nature combined with its maritime location made the BIIS sensitive to the rapid climate change that characterised the Last Glacial Interglacial Transition. Gaining an understanding of the behaviour of the BIIS at this time is important to explore the nature of forcing between ice sheets and climate. This thesis presents new chronological data relating to the deglaciation of the northwest sector of the BIIS (NW-BIIS) from onshore dating of moraines using cosmogenic exposure dating. This improved chronological framework is supported by offshore data in the form of a newly constructed Ice Rafted Detritus (IRD) record from the offshore sediment core MD95-2007. These data suggest that deglaciation commenced sometime after 18 ka and that the NW-BIIS was located close to the present day shoreline by 16 ka. Further provenance analysis of the IRD using U-Pb dating of detrital minerals demonstrates that during the Last Glacial-Interglacial Transition MD95-2007 was being supplied distal IRD from a source(s) to the west. The absence of diagnostic Scottish material suggests that after retreat to the coastline at 16 ka calving margins were not re-established during Greenland Interstadial 1. By combining these results with existing data relating to the deglaciation of the NW-BIIS it is possible to summarise the deglaciation history of the NW-BIIS from the continental shelf to mountainous source regions and compare this to
numerical models of BIIS behaviour during this time. With a better understanding of the chronology of NW-BIIS retreat it is possible to relate the timing of initial deglaciation to possible forcing factors and gain a better understanding of the response of a marine based sector of an ice sheet to rapid climate change.
2013-06-15T00:00:00Z
Small, David
It is now accepted that the last British-Irish Ice Sheet (BIIS) was highly dynamic and drained by numerous fast flowing ice streams. This dynamic nature combined with its maritime location made the BIIS sensitive to the rapid climate change that characterised the Last Glacial Interglacial Transition. Gaining an understanding of the behaviour of the BIIS at this time is important to explore the nature of forcing between ice sheets and climate. This thesis presents new chronological data relating to the deglaciation of the northwest sector of the BIIS (NW-BIIS) from onshore dating of moraines using cosmogenic exposure dating. This improved chronological framework is supported by offshore data in the form of a newly constructed Ice Rafted Detritus (IRD) record from the offshore sediment core MD95-2007. These data suggest that deglaciation commenced sometime after 18 ka and that the NW-BIIS was located close to the present day shoreline by 16 ka. Further provenance analysis of the IRD using U-Pb dating of detrital minerals demonstrates that during the Last Glacial-Interglacial Transition MD95-2007 was being supplied distal IRD from a source(s) to the west. The absence of diagnostic Scottish material suggests that after retreat to the coastline at 16 ka calving margins were not re-established during Greenland Interstadial 1. By combining these results with existing data relating to the deglaciation of the NW-BIIS it is possible to summarise the deglaciation history of the NW-BIIS from the continental shelf to mountainous source regions and compare this to
numerical models of BIIS behaviour during this time. With a better understanding of the chronology of NW-BIIS retreat it is possible to relate the timing of initial deglaciation to possible forcing factors and gain a better understanding of the response of a marine based sector of an ice sheet to rapid climate change.
-
Dynamics of the British Ice Sheet and prevailing hydrographic conditions for the last 175,000 years : an investigation of marine sediment core MD04-2822 from the Rockall Trough
https://hdl.handle.net/10023/3136
This study presents a stratigraphic investigation of the marine sediment core MD04-2822 from the Rockall Trough (56° 50.54’ N, 11° 22.96’ W; 2344 m water depth). This core is currently the only available high resolution record for the calibration of Late Quaternary sedimentary sequences of the British (Hebridean) margin. It therefore offers an unprecedented archive of changing sedimentological and climatological conditions for the last 175,000 years. The high resolution, multi-proxy records have enabled surface and deep water conditions within the Rockall Trough to be reconstructed. In addition, the fluctuating nature of ice-rafted debris (IRD) inputs to the MD04-2822 site allows a first order attempt of BIS dynamics for the entirety of the last glacial period (i.e. from the demise of the last interglacial to the decay of the Devensian/Weichselian ice sheet) as well as the majority of the penultimate (Saalian/MIS 6) glaciation.
Sediment core MD04-2822 is ideally located to capture the dynamics of the British Ice Sheet (BIS) via a continuous record of IRD and fine-grained terrigenous inputs. Fundamental to this is the construction of a robust chronology. This was achieved via: the correlation of the benthic δ¹⁸O record to a global δ¹⁸O stack (SPECMAP); the correlation of the surface proxies (% N. pachyderma (sinistral) and XRF Ca) to the Greenland δ¹⁸O and Antarctic methane ice core records; and radiocarbon dating. This chronology was validated using both radiocarbon dating and tephra horizons. An evaluation of the event stratigraphy approach used in the construction of the MD04-2822 chronology is presented.
The marine record provides a valuable archive of past ice sheet dynamics as much terrestrial evidence is removed or obscured by subsequent ice sheet oscillations MD04-2822 provides the first evidence for the expansion of the BIS onto the Hebridean Margin during MIS6 (thereby confirming previous long-range seismic correlations).
The continuous sedimentation at MD04-2822 enabled the first insights into the early dynamics of the last BIS. Increases in IRD and fine grained terrigenous material delivered to the MD04-2822 at ca. 72 kyr represent the first significant delivery of material from the BIS across the continental shelf to the core site. The BIS would therefore have attained a marine calving margin by this time. A multi-proxy investigation of provenance was undertaken, however unequivocal provenance determinations remain problematic. The location of the core suggest the proximal BIS as the most likely source of terrigenous inputs.
The expanded nature of the MD04-2822 sediments during the penultimate deglacial (Termination II) provides the first details of BIS dynamics for this period: the interplay of large inputs of freshwater from the decay of the Saalian (MIS 6) ice sheets (including the BIS) upon the surface and deep water circulation of the North Atlantic is investigated. In addition, sub-orbital climatic variability is documented at this location throughout the last interglacial (MIS 5e) and appears to be an intrinsic feature of both the N.E. Atlantic surface and deep water circulation of the last 175 kyr.
Electronic version excludes material for which permission has not been granted by the rights holder
2011-01-01T00:00:00Z
Hibbert, Fiona Danielle
This study presents a stratigraphic investigation of the marine sediment core MD04-2822 from the Rockall Trough (56° 50.54’ N, 11° 22.96’ W; 2344 m water depth). This core is currently the only available high resolution record for the calibration of Late Quaternary sedimentary sequences of the British (Hebridean) margin. It therefore offers an unprecedented archive of changing sedimentological and climatological conditions for the last 175,000 years. The high resolution, multi-proxy records have enabled surface and deep water conditions within the Rockall Trough to be reconstructed. In addition, the fluctuating nature of ice-rafted debris (IRD) inputs to the MD04-2822 site allows a first order attempt of BIS dynamics for the entirety of the last glacial period (i.e. from the demise of the last interglacial to the decay of the Devensian/Weichselian ice sheet) as well as the majority of the penultimate (Saalian/MIS 6) glaciation.
Sediment core MD04-2822 is ideally located to capture the dynamics of the British Ice Sheet (BIS) via a continuous record of IRD and fine-grained terrigenous inputs. Fundamental to this is the construction of a robust chronology. This was achieved via: the correlation of the benthic δ¹⁸O record to a global δ¹⁸O stack (SPECMAP); the correlation of the surface proxies (% N. pachyderma (sinistral) and XRF Ca) to the Greenland δ¹⁸O and Antarctic methane ice core records; and radiocarbon dating. This chronology was validated using both radiocarbon dating and tephra horizons. An evaluation of the event stratigraphy approach used in the construction of the MD04-2822 chronology is presented.
The marine record provides a valuable archive of past ice sheet dynamics as much terrestrial evidence is removed or obscured by subsequent ice sheet oscillations MD04-2822 provides the first evidence for the expansion of the BIS onto the Hebridean Margin during MIS6 (thereby confirming previous long-range seismic correlations).
The continuous sedimentation at MD04-2822 enabled the first insights into the early dynamics of the last BIS. Increases in IRD and fine grained terrigenous material delivered to the MD04-2822 at ca. 72 kyr represent the first significant delivery of material from the BIS across the continental shelf to the core site. The BIS would therefore have attained a marine calving margin by this time. A multi-proxy investigation of provenance was undertaken, however unequivocal provenance determinations remain problematic. The location of the core suggest the proximal BIS as the most likely source of terrigenous inputs.
The expanded nature of the MD04-2822 sediments during the penultimate deglacial (Termination II) provides the first details of BIS dynamics for this period: the interplay of large inputs of freshwater from the decay of the Saalian (MIS 6) ice sheets (including the BIS) upon the surface and deep water circulation of the North Atlantic is investigated. In addition, sub-orbital climatic variability is documented at this location throughout the last interglacial (MIS 5e) and appears to be an intrinsic feature of both the N.E. Atlantic surface and deep water circulation of the last 175 kyr.
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An investigation into the controls of granite plutonism in the Sierra da Freita region, Northern Portugal
https://hdl.handle.net/10023/2973
The Serra da Freita region of north central Portugal was chosen for study
as it displays the complex relationships between regional structure,
plutonism, regional and contact metamorphism typical of this part of
Iberia. The region was mapped on a scale of 1:10000.
The Serra da Freita pluton, which intrudes the core of the Porto-Viseu
metamorphic belt developed in the late Pre-Cambrian - Cambrian Beira Schists,
is shown to lie in a sinistral transpressive shear zone, the Serra da
Freita shear zone. Early structures are progressively modified over a
protracted period by shear zone deformation, during which time
metamorphism reached a peak and the granite was emplaced. Mapping of the
intrusive contacts of the granite show that following initial intrusion of
a steeply inclined sheet of magma into the zone of highest strain, magmas
were injected into a region of progressively lower strain where the magma
was acconunodated as a nearly flat sheet. The distal end of this mass
ballooned upvards to form the small intrusion of Castanheira which has
abundant biotite nodules which acted as near perfect strain markers.
The main pluton is shown to intrude obliquely the core of a narrow
metamorphic belt characterized by parageneses of biotite,
andalusite/staurolite, sillimanite, which maps distinctly from a younger
cordierite sillimanite contact aureole around an adjacent quartz diorite
body.
Several facies of granite within the pluton have been recognized;
petrographical and structural studies allow the interpreted emplacemen~
mechanism of these units to be integrated within a more general model for
the evolution of the shear zone.
Geochemical analyses of major and trace elements show that certain
compositional trends within these facies cannot be simply related as part
of a fractionation sequence. A model is put forward in which repeated
melting of a heterogeneous source is followed by sequential emplacement of
discrete batches of magma as sheets and wedges wi thin the acti ve shear
zone. A Rb-Sr whole rock isochron age of 324 Ma was obtained and this
dates not only the emplacement age of the syn-tectonic granite, but also
constrains the time of movement along the shear zone.
Radiogenic and stable isotope data strongly point to the local high grade
Beira Schists as being sui table source rocks for generation of magmas wi th
marked S-type characteristics which now form the Serra da Freita pluton.
180 values for the granites of 10.64 ± 0.24 - 13.00 ± 0.12 overlap those
of the schists which lie in the range 12.38 ± 0.24 - 14.15 ± 0.4. The
whole rock Rb-Sr isochron for the granite has an initial ratio of 0.7136 ±
0.0008 (MSWD = 3.2).
A regional and tectonothennal model is put forward in which
end-Palaeozoic oblique strike slip collision took place in the
Ibero-Armorican Arc. The resulting peturbation in continental heat flow,
coupled with the possible effects of shear heating, fluid concentration
and local high ductility contrasts in the heterogeneous metasediments, are
invoked as being responsible for causing anatexis of the Beira Schists at
a depth of 10-12 km, and the generation of granitic melts. Emplacement of
these bodies gave rise to the Porto-Viseu metamorphic belt, into which
later smaller higher-level melts were injected. It is argued that some of
these later magmas which reached higher levels are now exposed as the
constituent facies of the Serra da Freita pluton. The Serra cia Freita
shear zone, active throughout metamorphism, anatexis and magma emplacement
was a dominant feature of the geological history of the region.
1988-01-01T00:00:00Z
Reavy, Reginald John
The Serra da Freita region of north central Portugal was chosen for study
as it displays the complex relationships between regional structure,
plutonism, regional and contact metamorphism typical of this part of
Iberia. The region was mapped on a scale of 1:10000.
The Serra da Freita pluton, which intrudes the core of the Porto-Viseu
metamorphic belt developed in the late Pre-Cambrian - Cambrian Beira Schists,
is shown to lie in a sinistral transpressive shear zone, the Serra da
Freita shear zone. Early structures are progressively modified over a
protracted period by shear zone deformation, during which time
metamorphism reached a peak and the granite was emplaced. Mapping of the
intrusive contacts of the granite show that following initial intrusion of
a steeply inclined sheet of magma into the zone of highest strain, magmas
were injected into a region of progressively lower strain where the magma
was acconunodated as a nearly flat sheet. The distal end of this mass
ballooned upvards to form the small intrusion of Castanheira which has
abundant biotite nodules which acted as near perfect strain markers.
The main pluton is shown to intrude obliquely the core of a narrow
metamorphic belt characterized by parageneses of biotite,
andalusite/staurolite, sillimanite, which maps distinctly from a younger
cordierite sillimanite contact aureole around an adjacent quartz diorite
body.
Several facies of granite within the pluton have been recognized;
petrographical and structural studies allow the interpreted emplacemen~
mechanism of these units to be integrated within a more general model for
the evolution of the shear zone.
Geochemical analyses of major and trace elements show that certain
compositional trends within these facies cannot be simply related as part
of a fractionation sequence. A model is put forward in which repeated
melting of a heterogeneous source is followed by sequential emplacement of
discrete batches of magma as sheets and wedges wi thin the acti ve shear
zone. A Rb-Sr whole rock isochron age of 324 Ma was obtained and this
dates not only the emplacement age of the syn-tectonic granite, but also
constrains the time of movement along the shear zone.
Radiogenic and stable isotope data strongly point to the local high grade
Beira Schists as being sui table source rocks for generation of magmas wi th
marked S-type characteristics which now form the Serra da Freita pluton.
180 values for the granites of 10.64 ± 0.24 - 13.00 ± 0.12 overlap those
of the schists which lie in the range 12.38 ± 0.24 - 14.15 ± 0.4. The
whole rock Rb-Sr isochron for the granite has an initial ratio of 0.7136 ±
0.0008 (MSWD = 3.2).
A regional and tectonothennal model is put forward in which
end-Palaeozoic oblique strike slip collision took place in the
Ibero-Armorican Arc. The resulting peturbation in continental heat flow,
coupled with the possible effects of shear heating, fluid concentration
and local high ductility contrasts in the heterogeneous metasediments, are
invoked as being responsible for causing anatexis of the Beira Schists at
a depth of 10-12 km, and the generation of granitic melts. Emplacement of
these bodies gave rise to the Porto-Viseu metamorphic belt, into which
later smaller higher-level melts were injected. It is argued that some of
these later magmas which reached higher levels are now exposed as the
constituent facies of the Serra da Freita pluton. The Serra cia Freita
shear zone, active throughout metamorphism, anatexis and magma emplacement
was a dominant feature of the geological history of the region.
-
River channel planform changes in upland Scotland : with specific reference to climate fluctuation and landuse changes over the last 250 years
https://hdl.handle.net/10023/2957
Rates of river channel change in three contrasting Scottish upland
environments have been studied within the context of Climatic
fluctuation and landuse changes over the last 250 years. The object of
the research was to assess the spatial and temporal variation in channel
types, the main controls on channel pattern and the dominant modes of
channel adjustment. This was undertaken in a hierarchic framework with
sites being investigated at three spatial scales.
At a macro-scale, the spatial and temporal variation in channel
pattern was evaluated through a random sample of river channel segments
for each study area, derived from the first and second editions of the
1:10,560 0.S. maps plus the 1:10,000 third edition. Each channel
segment was classified within a map-based channel system typology,
specifically constructed for upland Scotland. Measures of activity
collected for each sample incorporated sinuosity, braiding and lateral
shift indices. Flood histories were reconstructed for each study area
on the basis of discharge records, long rainfall records and
contemporary accounts, to assess if there was any evidence for climatic
change, fluctuation or periodicities. Estimates of the recurrence
interval of rainfall and runoff events of differing magnitude, frequency
and duration were assessed. Data, mainly of a qualitative nature, were
derived from contemporary sources and estate plans to evaluate whether
any landuse changes could have changed the runoff regime and sediment
mobility within each catchment.
At a meso-scale, 7 to 9 channel segments (already identified as
"active" within the macro-scale study) were subject to a more detailed
process-response analysis, using sequential aerial photographs. Finally
at a micro-scale, the unit stream powers at these sites were studied in
relation to specific runoff rates thereby relating channel process to
channel form.
The strength of the controls on channel planform type varied in
degree with the area studied. The glacial legacy, the positioning of
local baselevels and sediment size were found to be dominant controls.
In terms of channel dynamics, the position of the Channel planform in
relation to process thresholds and the existence of a quasi-equilibrium
condition were both very important. In terms of process-response, the
following general observations hold true. An extreme event of high RI
(>100 years) will have a major disruptive impact if there is room for
expansion of the channel system and providing thresholds for sediment
transport are exceeded. If these thresholds are high, the fact that the
channel has not recently been disrupted may also be important. The
modes of expansion across the active area depend on the type of channel
involved. Different study areas have different types of Channel
pattern present and thus a greater likelihood of certain types of
planform adjustment. The role of more moderate events (10-50 years)
varies principally with sediment size and Channel slope. Small-scale
modification may take place where stream powers associated with more
moderate events exceed competence thresholds.
It was found that process rates were highly variable in both time
and space and that present rates were not necessarily representative of
the past 250 years. Even within this timespan, there have been periods
of increased activity in response to increased discharges of moderate
magnitude (eg. 1870s-1880s within the Dee study area) and random
extreme magnitude floods (eg. between 1948-1956 in the Tweed study
area). The impact of landuse change, especially in relation to sediment
mobilisation (Dee and Spey study areas), and speed of runoff (Tweed study
area) also appeared to be important.
1986-01-01T00:00:00Z
McEwen, Lindsey Jo
Rates of river channel change in three contrasting Scottish upland
environments have been studied within the context of Climatic
fluctuation and landuse changes over the last 250 years. The object of
the research was to assess the spatial and temporal variation in channel
types, the main controls on channel pattern and the dominant modes of
channel adjustment. This was undertaken in a hierarchic framework with
sites being investigated at three spatial scales.
At a macro-scale, the spatial and temporal variation in channel
pattern was evaluated through a random sample of river channel segments
for each study area, derived from the first and second editions of the
1:10,560 0.S. maps plus the 1:10,000 third edition. Each channel
segment was classified within a map-based channel system typology,
specifically constructed for upland Scotland. Measures of activity
collected for each sample incorporated sinuosity, braiding and lateral
shift indices. Flood histories were reconstructed for each study area
on the basis of discharge records, long rainfall records and
contemporary accounts, to assess if there was any evidence for climatic
change, fluctuation or periodicities. Estimates of the recurrence
interval of rainfall and runoff events of differing magnitude, frequency
and duration were assessed. Data, mainly of a qualitative nature, were
derived from contemporary sources and estate plans to evaluate whether
any landuse changes could have changed the runoff regime and sediment
mobility within each catchment.
At a meso-scale, 7 to 9 channel segments (already identified as
"active" within the macro-scale study) were subject to a more detailed
process-response analysis, using sequential aerial photographs. Finally
at a micro-scale, the unit stream powers at these sites were studied in
relation to specific runoff rates thereby relating channel process to
channel form.
The strength of the controls on channel planform type varied in
degree with the area studied. The glacial legacy, the positioning of
local baselevels and sediment size were found to be dominant controls.
In terms of channel dynamics, the position of the Channel planform in
relation to process thresholds and the existence of a quasi-equilibrium
condition were both very important. In terms of process-response, the
following general observations hold true. An extreme event of high RI
(>100 years) will have a major disruptive impact if there is room for
expansion of the channel system and providing thresholds for sediment
transport are exceeded. If these thresholds are high, the fact that the
channel has not recently been disrupted may also be important. The
modes of expansion across the active area depend on the type of channel
involved. Different study areas have different types of Channel
pattern present and thus a greater likelihood of certain types of
planform adjustment. The role of more moderate events (10-50 years)
varies principally with sediment size and Channel slope. Small-scale
modification may take place where stream powers associated with more
moderate events exceed competence thresholds.
It was found that process rates were highly variable in both time
and space and that present rates were not necessarily representative of
the past 250 years. Even within this timespan, there have been periods
of increased activity in response to increased discharges of moderate
magnitude (eg. 1870s-1880s within the Dee study area) and random
extreme magnitude floods (eg. between 1948-1956 in the Tweed study
area). The impact of landuse change, especially in relation to sediment
mobilisation (Dee and Spey study areas), and speed of runoff (Tweed study
area) also appeared to be important.
-
Bedload transport, vertical exchange and sediment storage in two Scottish Highland gravel bed streams
https://hdl.handle.net/10023/2943
High recovery magnetic tracing techniques have been utilised to record the 3-
dimensional downstream transport of individual clasts within two Scottish Highland
gravel-bed streams over a period of 16 months. The results provide the basis for a
conceptual model of bedload transport and storage involving the interaction of multiple
variables.
Above a threshold level of discharge, determined by local morphology and
sedimentology, flow (in terms of magnitude and duration) remains the principal control of
transport parameters (occurrence, vertical exchange, depth of scour, and transport
distance). Three phases of transport based on increasing discharge are identified; discrete
surficial transport, shallow exchange transport and deep exchange transport. Variations in
apparent flow and transport relationships are explored in relation to individual clast
characteristics and contrasts in bed sedimentology between streams.
The results suggest a large degree of equal mobility in terms of clast size. However,
a tendency exists for material approximating the median bed surface grain size to show
maximum mobility, indicating the importance of hiding effects on gravel entrainment. In
terms of clast form, flattened shapes are the least mobile. This reflects a greater stability at
entrainment, and increased occurrence of capping, for clasts with small c/b axial ratios. A
high percentage of angular material leads to bed strengthening through interlock.
Two clast location variables, morphological position (bar, riffle, pool or
undifferentiated channel), and burial state (top, within or buried), are considered in relation
to the occurrence and distance of transport. The importance of temporary bar and subsurface
storage is highlighted. Residence periods for bed material in both such locations are
determined principally by flow conditions, particularly peak discharge. Powerful floods are
associated with increased submergence of high bars, and erosion to great depth. Material
deposited in high bar positions, or at the base of deep scour zones, is effectively locked in
storage until the next flow of equal or greater discharge.
Although the model presented is based on work at just two sites, it is suggested that
the range of morphological and sedimentological conditions encountered make the general
principles applicable across a broad range of similar environments. Given consideration of
the variables discussed, a specific variation of the model should apply in most river
reaches.
1993-01-01T00:00:00Z
Drew, Ian B.
High recovery magnetic tracing techniques have been utilised to record the 3-
dimensional downstream transport of individual clasts within two Scottish Highland
gravel-bed streams over a period of 16 months. The results provide the basis for a
conceptual model of bedload transport and storage involving the interaction of multiple
variables.
Above a threshold level of discharge, determined by local morphology and
sedimentology, flow (in terms of magnitude and duration) remains the principal control of
transport parameters (occurrence, vertical exchange, depth of scour, and transport
distance). Three phases of transport based on increasing discharge are identified; discrete
surficial transport, shallow exchange transport and deep exchange transport. Variations in
apparent flow and transport relationships are explored in relation to individual clast
characteristics and contrasts in bed sedimentology between streams.
The results suggest a large degree of equal mobility in terms of clast size. However,
a tendency exists for material approximating the median bed surface grain size to show
maximum mobility, indicating the importance of hiding effects on gravel entrainment. In
terms of clast form, flattened shapes are the least mobile. This reflects a greater stability at
entrainment, and increased occurrence of capping, for clasts with small c/b axial ratios. A
high percentage of angular material leads to bed strengthening through interlock.
Two clast location variables, morphological position (bar, riffle, pool or
undifferentiated channel), and burial state (top, within or buried), are considered in relation
to the occurrence and distance of transport. The importance of temporary bar and subsurface
storage is highlighted. Residence periods for bed material in both such locations are
determined principally by flow conditions, particularly peak discharge. Powerful floods are
associated with increased submergence of high bars, and erosion to great depth. Material
deposited in high bar positions, or at the base of deep scour zones, is effectively locked in
storage until the next flow of equal or greater discharge.
Although the model presented is based on work at just two sites, it is suggested that
the range of morphological and sedimentological conditions encountered make the general
principles applicable across a broad range of similar environments. Given consideration of
the variables discussed, a specific variation of the model should apply in most river
reaches.
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Late Quaternary alluvial fans, debris cones and talus cones in the Grampian Highlands, Scotland
https://hdl.handle.net/10023/2941
Alluvial fans, debris cones and rockfall talus cones
are widespread in upland Britain, but remarkably little is
known about their characteristics, development and
significance. This research project has three main
objectives:
1. to establish the morphological and surface sedimentary
characteristics of alluvial fans, debris cones and talus
cones in the Grampian Highlands of Scotland;
2. to identify the factors that have controlled their
formation and distribution; and
3. to determine the timing, nature and rate of fan- and
cone-forming processes.
On the basis of previous literature, an Orioni model
that describes a continuum of fan and cone morphological and
surface sedimentary properties was devised. The
applicability of this model was tested using data for six
variables (long profile gradient, slope form, downslope
changes in clast size, roundness and form, and a scale ratio
of maximum clast size to total fan or cone length) obtained
for fans and cones in the Grampian Highlands and the Lyngen
Peninsula in Northern Norway. The results of these tests
were then used to produce a modified model appropriate to
fans and cones in upland Britain.
Using a combination of map, field and aerial photograph
data, several environmental and morphometric controls on the
distribution and type of fan and cone development were
investigated. The dimensions of different types of fan and
cone are shown to be determined by basin morphometry,
lithology and glacial history. Discriminant analysis
identified basin gradient, basin width and basin height as
the principal catchment properties that influence the
dominant type of fan- or cone-forming process.
Stratigraphic and radiocarbon evidence suggests that
many debris cones are essentially paraglacial landforms that
formed in the earlier part of the Flandrian. Many of these
cones have subsequently been modified in the late Flandrian
by fluvial processes, in some cases in response to
anthropogenic interference. However, evidence from one site
has also revealed that substantial debris cone aggradation
has occurred since c 300 BP, implying high rates of
denudation in the recent past at this site. The volumes of
other debris cones imply that as much as 1-3m of surface
lowering has occurred in gullies upslope since deglaciation.
Much lower values of surface lowering are associated with
alluvial fan development, suggesting that, locally at least,
denudation by fluvial processes has been less significant
than denudation resulting from debris flow.
1988-01-01T00:00:00Z
Brazier, Vanessa
Alluvial fans, debris cones and rockfall talus cones
are widespread in upland Britain, but remarkably little is
known about their characteristics, development and
significance. This research project has three main
objectives:
1. to establish the morphological and surface sedimentary
characteristics of alluvial fans, debris cones and talus
cones in the Grampian Highlands of Scotland;
2. to identify the factors that have controlled their
formation and distribution; and
3. to determine the timing, nature and rate of fan- and
cone-forming processes.
On the basis of previous literature, an Orioni model
that describes a continuum of fan and cone morphological and
surface sedimentary properties was devised. The
applicability of this model was tested using data for six
variables (long profile gradient, slope form, downslope
changes in clast size, roundness and form, and a scale ratio
of maximum clast size to total fan or cone length) obtained
for fans and cones in the Grampian Highlands and the Lyngen
Peninsula in Northern Norway. The results of these tests
were then used to produce a modified model appropriate to
fans and cones in upland Britain.
Using a combination of map, field and aerial photograph
data, several environmental and morphometric controls on the
distribution and type of fan and cone development were
investigated. The dimensions of different types of fan and
cone are shown to be determined by basin morphometry,
lithology and glacial history. Discriminant analysis
identified basin gradient, basin width and basin height as
the principal catchment properties that influence the
dominant type of fan- or cone-forming process.
Stratigraphic and radiocarbon evidence suggests that
many debris cones are essentially paraglacial landforms that
formed in the earlier part of the Flandrian. Many of these
cones have subsequently been modified in the late Flandrian
by fluvial processes, in some cases in response to
anthropogenic interference. However, evidence from one site
has also revealed that substantial debris cone aggradation
has occurred since c 300 BP, implying high rates of
denudation in the recent past at this site. The volumes of
other debris cones imply that as much as 1-3m of surface
lowering has occurred in gullies upslope since deglaciation.
Much lower values of surface lowering are associated with
alluvial fan development, suggesting that, locally at least,
denudation by fluvial processes has been less significant
than denudation resulting from debris flow.
-
Estimating flood statistics from basin characteristics in Scotland
https://hdl.handle.net/10023/2888
Estimation of the probability of occurrence of future flood events at
a site is frequently required for the design of bridges, culverts,
dams and other river engineering works. This study considers a method
for estimating the flood frequency distribution from the physical
characteristics of the drainage basin for use in Scotland when
adequate records of river discharge are not available. The data base
collated includes 3071 station years of annual maximum flood peaks for
168 high quality gauging stations and 12 physical characteristics for
each drainage basin. A linear regression model is derived which
explains 91% of the variation in the average magnitude of floods using
five physical characteristics indexing drainage area, rainfall, stream
density, soil type and lake storage. This model appears robust over
the range of basin types and shows no improvement when shrinkage or
ridge regression is employed. Five physically homogeneous subsets of
basins are derived using a clustering algorithm (NORMIX) and the same
five characteristics, with the addition of an index of channel slope.
For each of subsets 1, 3, 4 and 5, the individual dimensionless flood
frequency distributions for each station are not significantly
different from a single GEV distribution derived for that subset.
Consequently these subsets are considered to be hydrologically
homogeneous in addition to their physical homogeneity. Dimensionless
regional flood frequency distributions are produced for each subset
which allow the estimated average flood magnitude to be scaled to
estimate floods of less frequent occurrence. These regional 'growth
curves' imply a larger return period for a given magnitude flood than
those from the Natural Environment Research Council Flood Studies
Report (NERC, 1975). When the floods are described by a lognormal
model which allows for cross-correlation between stations the
respective return periods are smaller.
1985-01-01T00:00:00Z
Acreman, Michael Charles
Estimation of the probability of occurrence of future flood events at
a site is frequently required for the design of bridges, culverts,
dams and other river engineering works. This study considers a method
for estimating the flood frequency distribution from the physical
characteristics of the drainage basin for use in Scotland when
adequate records of river discharge are not available. The data base
collated includes 3071 station years of annual maximum flood peaks for
168 high quality gauging stations and 12 physical characteristics for
each drainage basin. A linear regression model is derived which
explains 91% of the variation in the average magnitude of floods using
five physical characteristics indexing drainage area, rainfall, stream
density, soil type and lake storage. This model appears robust over
the range of basin types and shows no improvement when shrinkage or
ridge regression is employed. Five physically homogeneous subsets of
basins are derived using a clustering algorithm (NORMIX) and the same
five characteristics, with the addition of an index of channel slope.
For each of subsets 1, 3, 4 and 5, the individual dimensionless flood
frequency distributions for each station are not significantly
different from a single GEV distribution derived for that subset.
Consequently these subsets are considered to be hydrologically
homogeneous in addition to their physical homogeneity. Dimensionless
regional flood frequency distributions are produced for each subset
which allow the estimated average flood magnitude to be scaled to
estimate floods of less frequent occurrence. These regional 'growth
curves' imply a larger return period for a given magnitude flood than
those from the Natural Environment Research Council Flood Studies
Report (NERC, 1975). When the floods are described by a lognormal
model which allows for cross-correlation between stations the
respective return periods are smaller.
-
The formation of valley-wall rock glaciers
https://hdl.handle.net/10023/2797
In recent years, the study of rock glaciers has increased remarkably. Substantive
progress has been made, particularly in understanding the formation of rock
glaciers that have developed adjacent to existing or former valley or cirque
glaciers, However, our understanding of valley-wall rock glaciers that are
located at the base of talus slopes remains scant. Published work exhibits little
consensus on the formation of valley-wall rock glaciers and several hypotheses
remain under vigorous debate. The major objective of the research reported in
this thesis has been to test the generality and feasibility of seven major models
of valley-wall rock glacier formation using both empirical and theoretical
evidence. The primary conclusion is that only one of these models, the
segregation ice model, emerges as a general model of valley-wall rock glacier
genesis. The model assumes that a thin layer or several thin layers of
segregated ice are overlain by interstitially frozen sediments and an unfrozen
mantle of coarse debris. A wide range of empirical and theoretical findings are
shown to be consistent with the implications of the segregation ice model.
Detailed observations on the morphology, sedimentology and distribution of
active, inactive and relict valley-wall rock glaciers studied in Switzerland,
northern Norway and Scotland provided a range of findings that support this
model. Theoretical evidence was obtained by modelling a number of different
density models that reflect different distribution of internal ice by applying a
simple laminar flow equation to field measurements. Although only the
segregation ice model appears to be valid at a general level, the possibility
cannot be excluded of alternative modes of valley-wall rock glacier formation
under particular circumstances. Snow avalanching, deformation of snowbank
or matrix ice, and basal sliding under conditions of high hydrostatic pressure all
constitute possible contributing mechanisms of formation and movement in
particular cases.
1991-01-01T00:00:00Z
Maclean, Alison F.
In recent years, the study of rock glaciers has increased remarkably. Substantive
progress has been made, particularly in understanding the formation of rock
glaciers that have developed adjacent to existing or former valley or cirque
glaciers, However, our understanding of valley-wall rock glaciers that are
located at the base of talus slopes remains scant. Published work exhibits little
consensus on the formation of valley-wall rock glaciers and several hypotheses
remain under vigorous debate. The major objective of the research reported in
this thesis has been to test the generality and feasibility of seven major models
of valley-wall rock glacier formation using both empirical and theoretical
evidence. The primary conclusion is that only one of these models, the
segregation ice model, emerges as a general model of valley-wall rock glacier
genesis. The model assumes that a thin layer or several thin layers of
segregated ice are overlain by interstitially frozen sediments and an unfrozen
mantle of coarse debris. A wide range of empirical and theoretical findings are
shown to be consistent with the implications of the segregation ice model.
Detailed observations on the morphology, sedimentology and distribution of
active, inactive and relict valley-wall rock glaciers studied in Switzerland,
northern Norway and Scotland provided a range of findings that support this
model. Theoretical evidence was obtained by modelling a number of different
density models that reflect different distribution of internal ice by applying a
simple laminar flow equation to field measurements. Although only the
segregation ice model appears to be valid at a general level, the possibility
cannot be excluded of alternative modes of valley-wall rock glacier formation
under particular circumstances. Snow avalanching, deformation of snowbank
or matrix ice, and basal sliding under conditions of high hydrostatic pressure all
constitute possible contributing mechanisms of formation and movement in
particular cases.
-
Glacio-limnological interactions at lake-calving glaciers
https://hdl.handle.net/10023/2793
Iceberg calving is an efficient ablation process which introduces mechanical instability to
glacier systems and can cause non-linear climatic response. This thesis uses glaciological and
limnological data to examine the relative contributions of calving and melting to mass loss at
glacier termini, and the interplay between glaciological and limnological processes. Calving
dynamics are investigated at two lake-terminating glaciers; Glaciar Leon in Chile and
Fjallsjokull in Iceland. Glaciar Leon, a temperate, grounded outlet of the North Patagonian
Icefield, terminates at an active but stable calving margin in Lago Leones. The calving rate of
880 m a-1 in a mean water depth of 65 m is high for lake-calving glaciers. Detailed survey of
the physical limnology of Lago Leones, important for considering heat transfer to the
subaqueous ice face, revealed thermocline development towards the terminus between
spring and summer. Melting at the waterline along the glacier terminus facilitates calving by
undercutting the subaerial calving cliff, and accounts for around a quarter of mass loss at the
terminus. Waterline melting is also an important rate-controlling process for calving at
Fjallsjokull. Precise quantification of melt rates (subaerial, waterline and subaqueous) at the
termini of calving glaciers is difficult and hazardous, but this study has demonstrated the
value of two techniques: (1) detailed survey of melt notch growth, and (2) use of a radiocontrolled
boat to record water temperatures at the ice-water interface. Continuous
automated monitoring showed that lake-level fluctuations are integral to calving behaviour,
influencing calving event timing and size over diurnal and hourly timescales. Fjallsjokull is
sensitive to climatic forcing whereas Glaciar Leon, which exhibits larger seasonal than
annual fluctuations, is less sensitive. Additional controls on calving at both sites are (1)
buoyancy, (2) longitudinal stretching, and (3) the force balance at the ice-water interface.
Calving operates along a continuum defined by the relative importance of interacting calving
mechanisms, to which the climatic response of calving glaciers is sensitive.
2004-01-01T00:00:00Z
Haresign, Eleanor C.
Iceberg calving is an efficient ablation process which introduces mechanical instability to
glacier systems and can cause non-linear climatic response. This thesis uses glaciological and
limnological data to examine the relative contributions of calving and melting to mass loss at
glacier termini, and the interplay between glaciological and limnological processes. Calving
dynamics are investigated at two lake-terminating glaciers; Glaciar Leon in Chile and
Fjallsjokull in Iceland. Glaciar Leon, a temperate, grounded outlet of the North Patagonian
Icefield, terminates at an active but stable calving margin in Lago Leones. The calving rate of
880 m a-1 in a mean water depth of 65 m is high for lake-calving glaciers. Detailed survey of
the physical limnology of Lago Leones, important for considering heat transfer to the
subaqueous ice face, revealed thermocline development towards the terminus between
spring and summer. Melting at the waterline along the glacier terminus facilitates calving by
undercutting the subaerial calving cliff, and accounts for around a quarter of mass loss at the
terminus. Waterline melting is also an important rate-controlling process for calving at
Fjallsjokull. Precise quantification of melt rates (subaerial, waterline and subaqueous) at the
termini of calving glaciers is difficult and hazardous, but this study has demonstrated the
value of two techniques: (1) detailed survey of melt notch growth, and (2) use of a radiocontrolled
boat to record water temperatures at the ice-water interface. Continuous
automated monitoring showed that lake-level fluctuations are integral to calving behaviour,
influencing calving event timing and size over diurnal and hourly timescales. Fjallsjokull is
sensitive to climatic forcing whereas Glaciar Leon, which exhibits larger seasonal than
annual fluctuations, is less sensitive. Additional controls on calving at both sites are (1)
buoyancy, (2) longitudinal stretching, and (3) the force balance at the ice-water interface.
Calving operates along a continuum defined by the relative importance of interacting calving
mechanisms, to which the climatic response of calving glaciers is sensitive.
-
The identification and characterisation of the North Atlantic Heinrich Events using environmental magnetic techniques
https://hdl.handle.net/10023/2782
Heinrich Events (HEs) define intervals of major ice rafting from the Laurentide Ice Sheet (LIS) into the North Atlantic during that last glacial period. The discovery of potential European-sourced precursors to HEs suggest that the smaller, but climactically sensitive, European ice sheets (EIS) may have played a role in the triggering of HEs and their impact on global climates. Environmental magnetism has proved itself to be a useful, rapid and non-destructive tool in the identification and quantification of provenance in sediments from various depositional environments. In this work, environmental magnetic analyses are applied to marine sediment records from the European margin of the NE Atlantic and known to contain ice-rafted debris (IRD) from both LIS and EIS sources. The primary aim in the work of this thesis is to evaluate the methodology as a means of distinguishing IRD provenance. From the data obtained here it is possible to identify several magnetic events that correspond to the HEs and other layers of detrital material and which correlate well to previous standard petrological analyses performed on the same core materials. Magnetic signatures differ within the HEs, suggesting a changing balance of input from multiple sources as opposed to a single LIS source. The data suggest a phasing of these compositional differences through individual HEs. The potential of using environmental magnetic techniques in the identification of IRD provenance within marine sediments is discussed, as is the significance of the observed provenance variations within the cores studied.
2006-01-01T00:00:00Z
Wadsworth, Emilie R.
Heinrich Events (HEs) define intervals of major ice rafting from the Laurentide Ice Sheet (LIS) into the North Atlantic during that last glacial period. The discovery of potential European-sourced precursors to HEs suggest that the smaller, but climactically sensitive, European ice sheets (EIS) may have played a role in the triggering of HEs and their impact on global climates. Environmental magnetism has proved itself to be a useful, rapid and non-destructive tool in the identification and quantification of provenance in sediments from various depositional environments. In this work, environmental magnetic analyses are applied to marine sediment records from the European margin of the NE Atlantic and known to contain ice-rafted debris (IRD) from both LIS and EIS sources. The primary aim in the work of this thesis is to evaluate the methodology as a means of distinguishing IRD provenance. From the data obtained here it is possible to identify several magnetic events that correspond to the HEs and other layers of detrital material and which correlate well to previous standard petrological analyses performed on the same core materials. Magnetic signatures differ within the HEs, suggesting a changing balance of input from multiple sources as opposed to a single LIS source. The data suggest a phasing of these compositional differences through individual HEs. The potential of using environmental magnetic techniques in the identification of IRD provenance within marine sediments is discussed, as is the significance of the observed provenance variations within the cores studied.
-
From 'laissez-faire' to 'homes fit for heroes': housing in Dundee 1868-1919
https://hdl.handle.net/10023/2750
The thesis begins by discussing the process of
urbanisation in nineteenth-century Scotland, the nature of
urban social problems and housing as an urban issue. However,
the major concern of the research has been to examine how most
people consumed housing in Dundee between 1868 and 1919, a
period when the dominant form of provision - private
landlordism - underwent crisis.
A major time-slice has been taken for Dundee in 1911,
using the valuation rolls, allowing the tenure pattern to be
mapped and the pattern of ownership and management to be
analysed. Tensions arising from the landlord-tenant
relationship and tenure distinctions are highlighted,
including the missive system, evictions and the rent crises of
1912 and 1915.
Local government activity has been examined, especially
the powers vested in local officials and the actions they
took, particularly in the way this affected landlords, factors
and tenants. The nature and form of slum crusades as a
response to the perceived, failure of the urban environment is
discussed. The changes in policy, which led to the first
state-aided council, housing scheme in Scotland, have been
researched.
Finally the thesis turns to living space and examines the
connections between women, planning and the home.
Overall the thesis is intended to be a major contribution to
the social history and social geography of Dundee.
1991-01-01T00:00:00Z
Young, Jean Kay
The thesis begins by discussing the process of
urbanisation in nineteenth-century Scotland, the nature of
urban social problems and housing as an urban issue. However,
the major concern of the research has been to examine how most
people consumed housing in Dundee between 1868 and 1919, a
period when the dominant form of provision - private
landlordism - underwent crisis.
A major time-slice has been taken for Dundee in 1911,
using the valuation rolls, allowing the tenure pattern to be
mapped and the pattern of ownership and management to be
analysed. Tensions arising from the landlord-tenant
relationship and tenure distinctions are highlighted,
including the missive system, evictions and the rent crises of
1912 and 1915.
Local government activity has been examined, especially
the powers vested in local officials and the actions they
took, particularly in the way this affected landlords, factors
and tenants. The nature and form of slum crusades as a
response to the perceived, failure of the urban environment is
discussed. The changes in policy, which led to the first
state-aided council, housing scheme in Scotland, have been
researched.
Finally the thesis turns to living space and examines the
connections between women, planning and the home.
Overall the thesis is intended to be a major contribution to
the social history and social geography of Dundee.
-
Wheelchair users and housing in Dundee: the social construction and spatiality of disability
https://hdl.handle.net/10023/2722
The thesis examines the experiences and perceptions of wheelchair users living
in different types and tenures of housing in the City of Dundee. The
interrelationships between space, society and the body are examined in the
empirical context of housing, ableism and the disabled body. The voices of
wheelchair users, gleaned from in-depth, semi-structured interviews, are used
throughout the thesis to illustrate how the geographies of people with disabilities
are delineated and constrained by socio-cultural representations of disability.
Conceptually the study has been guided by the social model of disability, but
insights from postmodernism and feminist literature are drawn on to add a further
dimension to the interpretation of the data and the study's methodology. The
social construction of difference, social exclusion and definitions of the normal
and aberrant body emerge as key concepts linking analysis of the data at the
spatial scales of the neighbourhood, home and the body. Spatial metaphors of
'out of place', 'marginalised' or 'socio-spatially excluded' capture the essence of
the impressions people with disabilities hold of their interactions with their living
spaces and service providers. The study suggests that greater reciprocal dialogue
is required between service users and service providers to broaden the knowledge
base from which disability related housing decisions are made.
2002-01-01T00:00:00Z
Levy, Susan L.
The thesis examines the experiences and perceptions of wheelchair users living
in different types and tenures of housing in the City of Dundee. The
interrelationships between space, society and the body are examined in the
empirical context of housing, ableism and the disabled body. The voices of
wheelchair users, gleaned from in-depth, semi-structured interviews, are used
throughout the thesis to illustrate how the geographies of people with disabilities
are delineated and constrained by socio-cultural representations of disability.
Conceptually the study has been guided by the social model of disability, but
insights from postmodernism and feminist literature are drawn on to add a further
dimension to the interpretation of the data and the study's methodology. The
social construction of difference, social exclusion and definitions of the normal
and aberrant body emerge as key concepts linking analysis of the data at the
spatial scales of the neighbourhood, home and the body. Spatial metaphors of
'out of place', 'marginalised' or 'socio-spatially excluded' capture the essence of
the impressions people with disabilities hold of their interactions with their living
spaces and service providers. The study suggests that greater reciprocal dialogue
is required between service users and service providers to broaden the knowledge
base from which disability related housing decisions are made.
-
A detailed chemical and petrological investigation of the rocks of the Shiant Isles
https://hdl.handle.net/10023/2721
1953-01-01T00:00:00Z
Murray, Ransom James
-
Some aspects of the sedimentology of the superficial deposits of the Eden estuary, Fife
https://hdl.handle.net/10023/2692
Little
attention
has
previously
boon
given
to the
sediments of the Eden
estuary,
Fife, Scotland. This research was performed
in
order
to identify, delineate
and account
for the
observed sedimentary
facies in the
superficial sediments of
the intertidal
zone.
1977-01-01T00:00:00Z
Eastwood, Keith Melvyn
Little
attention
has
previously
boon
given
to the
sediments of the Eden
estuary,
Fife, Scotland. This research was performed
in
order
to identify, delineate
and account
for the
observed sedimentary
facies in the
superficial sediments of
the intertidal
zone.
-
Scottish late-glacial moraines: debris supply, genesis and significance
https://hdl.handle.net/10023/2676
A variety of moraine forms were deposited by glaciers during the
Loch Lomond Stadial. Study of such moraines and related landforms
provides a valuable source of data on patterns of landscape evolution
and climatic change. This thesis presents detailed case-studies of
moraines in geologically and topographically contrasting areas on the
Island of Skye, Scotland. Geomorphological mapping,
sedimentological analyses and mathematical modelling techniques
were employed to determine the principal controls on moraine
morphology, composition and distribution. Particular emphasis was
placed on the provenance, transport and deposition of debris, and
their spatial variation. The results were used to construct a summary
model of glacial landform evolution, which relates different
sediment-landform associations to spatial and temporal controls,
particularly basin lithology and structure, topography, position of
deposition and ice-margin activity.
The initial stage of deglaciation in the study area was marked by a
series of readvances and/or stillstands. During this stage, the
lower-lying glaciers were more sensitive to climatic amelioration
than the higher glaciers. The subsequent phase was characterised by
more rapid deglaciation. Evidence for one instance of late-stage in
situ glacier stagnation is described. The results indicate that
landforms hitherto grouped as 'hummocky -moraine' formed by a
variety of processes. Such moraines formed by (a) uneven deposition
of supraglacially and/or -subglacially-derived debris at active ice
margins, (b) deposition at the stagnant margins of otherwise active
glaciers, and (c) deposition during uninterrupted glacier retreat or
areal stagnation. Differentiation and analysis of so-called 'hummocky
moraine' enables glacier behaviour, during the Lateglacial to be
interpreted in great detail.
1991-01-01T00:00:00Z
Benn, Douglas I.
A variety of moraine forms were deposited by glaciers during the
Loch Lomond Stadial. Study of such moraines and related landforms
provides a valuable source of data on patterns of landscape evolution
and climatic change. This thesis presents detailed case-studies of
moraines in geologically and topographically contrasting areas on the
Island of Skye, Scotland. Geomorphological mapping,
sedimentological analyses and mathematical modelling techniques
were employed to determine the principal controls on moraine
morphology, composition and distribution. Particular emphasis was
placed on the provenance, transport and deposition of debris, and
their spatial variation. The results were used to construct a summary
model of glacial landform evolution, which relates different
sediment-landform associations to spatial and temporal controls,
particularly basin lithology and structure, topography, position of
deposition and ice-margin activity.
The initial stage of deglaciation in the study area was marked by a
series of readvances and/or stillstands. During this stage, the
lower-lying glaciers were more sensitive to climatic amelioration
than the higher glaciers. The subsequent phase was characterised by
more rapid deglaciation. Evidence for one instance of late-stage in
situ glacier stagnation is described. The results indicate that
landforms hitherto grouped as 'hummocky -moraine' formed by a
variety of processes. Such moraines formed by (a) uneven deposition
of supraglacially and/or -subglacially-derived debris at active ice
margins, (b) deposition at the stagnant margins of otherwise active
glaciers, and (c) deposition during uninterrupted glacier retreat or
areal stagnation. Differentiation and analysis of so-called 'hummocky
moraine' enables glacier behaviour, during the Lateglacial to be
interpreted in great detail.
-
The development of the Fife road system, 1700-1850
https://hdl.handle.net/10023/2623
During the first half of the eighteenth century the political
and social climate of Scotland was becoming increasingly favourable
for the expansion of agricultural output and mineral exploitation.
These activities generated extra traffic and the growing number of
wheeled vehicles created a demand for soundly constructed roads.
In contrast with the English parish system, responsibility for
road management in Scotland lay with landowners, accountable to
their county meetings. A tax on rent financed a selective programme
of improvement, and when parish labour was converted to a monetary
payment a considerable increase in road works became possible.
In Fife, the influence of farmers and coal owners is seen in
the planning of roads to distribute lime and coal, while leading
landowners were concerned with the national highways which crossed
the peninsula. Although one of these became a toll road in 1753,
the turnpike system was adopted for the county only at the end of
the century. It is the hitherto underestimated activity among
road authorities before the imposition of tolls which forms the
main theme of this study.
The basic pattern of overland connections existing around
1700 is derived from the evidence of settlement distribution and
known physiographic constraints. This pattern is checked against
the earliest available maps and road records to deduce a putative
network. A sequence of maps illustrates the subsequent changes,
including the extent of postal and coach services and control of
roads by the turnpike trusts.
The abandonment of hillside routes, the dominance of the
link between the Forth and Tay ferries, and the influence of
individual landowners on schemes of improvement are illustrated
by more localised studies which emphasise the multiplicity of
factors operating during a crucial phase in the development of
the modern road network.
1985-01-01T00:00:00Z
Silver, Owen Bayliss
During the first half of the eighteenth century the political
and social climate of Scotland was becoming increasingly favourable
for the expansion of agricultural output and mineral exploitation.
These activities generated extra traffic and the growing number of
wheeled vehicles created a demand for soundly constructed roads.
In contrast with the English parish system, responsibility for
road management in Scotland lay with landowners, accountable to
their county meetings. A tax on rent financed a selective programme
of improvement, and when parish labour was converted to a monetary
payment a considerable increase in road works became possible.
In Fife, the influence of farmers and coal owners is seen in
the planning of roads to distribute lime and coal, while leading
landowners were concerned with the national highways which crossed
the peninsula. Although one of these became a toll road in 1753,
the turnpike system was adopted for the county only at the end of
the century. It is the hitherto underestimated activity among
road authorities before the imposition of tolls which forms the
main theme of this study.
The basic pattern of overland connections existing around
1700 is derived from the evidence of settlement distribution and
known physiographic constraints. This pattern is checked against
the earliest available maps and road records to deduce a putative
network. A sequence of maps illustrates the subsequent changes,
including the extent of postal and coach services and control of
roads by the turnpike trusts.
The abandonment of hillside routes, the dominance of the
link between the Forth and Tay ferries, and the influence of
individual landowners on schemes of improvement are illustrated
by more localised studies which emphasise the multiplicity of
factors operating during a crucial phase in the development of
the modern road network.
-
Fundamental and sedimentological controls on luminescence behaviour in quartz and feldspar
https://hdl.handle.net/10023/2586
The optically stimulated luminescence (OSL) characteristics of a suite of quartz and feldspar samples from a range of modern glaciofluvial sediments have been explored to determine the use of OSL as a depositional pathway tracer. Paraglacial and subglacial source material and various glaciofluvial deposits have been analysed from the glacial catchments of Bergsetbreen, Fåbergstølsbreen, and Nigardsbreen as well as the Fåbergstølsgrandane sandur, Jostedalen, Norway.
The OSL distribution signatures have been characterised through exploration of sample skewness, kurtosis and overdispersion, and dose distributions of the different depositional settings and source materials are distinct for both quartz and feldspar. Residual ages are greatest for feldspar, indicating significant potential age overestimation where feldspar is used to date glaciofluvial deposits. Sample dose distributions and overdispersion characteristics are driven by source sediment properties, whereas residual ages are controlled by transport and depositional processes. Those transport and depositional processes which result in significant light exposure, also influence dose distributions, and processes that sort sediments least effectively have the highest residual doses.
Sample OSL characteristics, transport distance and grain size distributions have been investigated using factor analysis, as a means of predicting sediment source, facies, depositional process and deposit type. Although the depositional processes of the quartz samples can be clearly differentiated based upon OSL characteristics, factor analyses of feldspar and grain size characteristics are inconclusive.
The application of quartz OSL to the Norwegian samples was limited by its very poor luminescence sensitivity. Quartz is the preferred mineral for OSL, however, despite the plethora of successful quartz OSL applications, the precise origin of the UV/blue luminescence emission, measured during OSL, remains unclear. The origins of this emission and controls on its intensity were explored using a variety of spectroscopic techniques including photoluminescence, cathodoluminescence, radioluminescence (RL), ionoluminescence (IL) and x-ray excited optical luminescence (XEOL).
Exciting sample luminescence at a range of energies enables exploration of the different donor centres responsible for the luminescence emission. Cathodoluminescence and RL emission spectra are similar, comprising broad emissions at 1.5, 2.0 and 2.7 eV (detection in the UV part of the spectrum was not possible for these experiments). Ionoluminescence emission spectra were dominated by the ~ 3.3 eV emission, which is a component of the signal conventionally monitored during OSL. This emission depleted as a function of dose, to the benefit of the red emission (1.8-2.0 eV) for all samples throughout IL, and similar observations were made for the 3.4 eV emission observed from the XEOL emission spectra. The XEOL spectra are dominated by an emission at ~ 3.8 eV, not widely reported for quartz, which has tentatively been attributed to peroxy linkages. Differences between the IL and XEOL emission spectra are interpreted as evidence for the presence of multiple excited states.
Electronic version excludes material for which permission has not been granted by the rights holder
2012-06-20T00:00:00Z
King, Georgina
The optically stimulated luminescence (OSL) characteristics of a suite of quartz and feldspar samples from a range of modern glaciofluvial sediments have been explored to determine the use of OSL as a depositional pathway tracer. Paraglacial and subglacial source material and various glaciofluvial deposits have been analysed from the glacial catchments of Bergsetbreen, Fåbergstølsbreen, and Nigardsbreen as well as the Fåbergstølsgrandane sandur, Jostedalen, Norway.
The OSL distribution signatures have been characterised through exploration of sample skewness, kurtosis and overdispersion, and dose distributions of the different depositional settings and source materials are distinct for both quartz and feldspar. Residual ages are greatest for feldspar, indicating significant potential age overestimation where feldspar is used to date glaciofluvial deposits. Sample dose distributions and overdispersion characteristics are driven by source sediment properties, whereas residual ages are controlled by transport and depositional processes. Those transport and depositional processes which result in significant light exposure, also influence dose distributions, and processes that sort sediments least effectively have the highest residual doses.
Sample OSL characteristics, transport distance and grain size distributions have been investigated using factor analysis, as a means of predicting sediment source, facies, depositional process and deposit type. Although the depositional processes of the quartz samples can be clearly differentiated based upon OSL characteristics, factor analyses of feldspar and grain size characteristics are inconclusive.
The application of quartz OSL to the Norwegian samples was limited by its very poor luminescence sensitivity. Quartz is the preferred mineral for OSL, however, despite the plethora of successful quartz OSL applications, the precise origin of the UV/blue luminescence emission, measured during OSL, remains unclear. The origins of this emission and controls on its intensity were explored using a variety of spectroscopic techniques including photoluminescence, cathodoluminescence, radioluminescence (RL), ionoluminescence (IL) and x-ray excited optical luminescence (XEOL).
Exciting sample luminescence at a range of energies enables exploration of the different donor centres responsible for the luminescence emission. Cathodoluminescence and RL emission spectra are similar, comprising broad emissions at 1.5, 2.0 and 2.7 eV (detection in the UV part of the spectrum was not possible for these experiments). Ionoluminescence emission spectra were dominated by the ~ 3.3 eV emission, which is a component of the signal conventionally monitored during OSL. This emission depleted as a function of dose, to the benefit of the red emission (1.8-2.0 eV) for all samples throughout IL, and similar observations were made for the 3.4 eV emission observed from the XEOL emission spectra. The XEOL spectra are dominated by an emission at ~ 3.8 eV, not widely reported for quartz, which has tentatively been attributed to peroxy linkages. Differences between the IL and XEOL emission spectra are interpreted as evidence for the presence of multiple excited states.
-
Geographies of hepatitis C : exploring the extent to which geographic accessibility to healthcare influences outcomes amongst individuals infected with Hepatitis C in NHS Tayside, Scotland
https://hdl.handle.net/10023/2135
Millions of people are infected with the Hepatitis C Virus (HCV) worldwide. In the UK, many
individuals continue to live with undiagnosed HCV infection and are increasingly at risk of
developing life-threatening cirrhosis and liver cancer. Of those that are diagnosed, only some
are referred to an HCV specialist centre where vital treatment could cure their infection. Of
those that are referred, only a proportion have actually attended and stayed in follow-up with a
specialist centre. Geographic access to healthcare may be an important factor in these trends,
but has so far received little attention in the context of HCV.
This thesis examines the influence of geographic access to primary and specialist healthcare on
HCV detection, trends of referral, chances of specialist centre utilisation and the odds of staying
in follow-up. It also explores association between geographic access and the type of location in
which diagnoses were made with the risk of mortality from liver-related causes. HCV detection
was lower amongst those with poorer geographic access to primary healthcare, but further
analyses suggest this trend is due to selection, not causation. Individuals with the furthest to
travel were less likely to be referred to an HCV specialist centre, compared to those who lived
closer. Travel-time was not a significant predictor of utilisation of HCV specialist centres, but
with patients in more remote areas less likely to be referred, it is probable that the utilisation
result is biased due to selection. Liver-related mortality was higher for patients diagnosed in
hospitals, but the risk of death was not associated with a lack of geographic access to healthcare.
2010-06-01T00:00:00Z
Astell-Burt, Thomas
Millions of people are infected with the Hepatitis C Virus (HCV) worldwide. In the UK, many
individuals continue to live with undiagnosed HCV infection and are increasingly at risk of
developing life-threatening cirrhosis and liver cancer. Of those that are diagnosed, only some
are referred to an HCV specialist centre where vital treatment could cure their infection. Of
those that are referred, only a proportion have actually attended and stayed in follow-up with a
specialist centre. Geographic access to healthcare may be an important factor in these trends,
but has so far received little attention in the context of HCV.
This thesis examines the influence of geographic access to primary and specialist healthcare on
HCV detection, trends of referral, chances of specialist centre utilisation and the odds of staying
in follow-up. It also explores association between geographic access and the type of location in
which diagnoses were made with the risk of mortality from liver-related causes. HCV detection
was lower amongst those with poorer geographic access to primary healthcare, but further
analyses suggest this trend is due to selection, not causation. Individuals with the furthest to
travel were less likely to be referred to an HCV specialist centre, compared to those who lived
closer. Travel-time was not a significant predictor of utilisation of HCV specialist centres, but
with patients in more remote areas less likely to be referred, it is probable that the utilisation
result is biased due to selection. Liver-related mortality was higher for patients diagnosed in
hospitals, but the risk of death was not associated with a lack of geographic access to healthcare.
-
Lost in translation - the nexus of multi-layered housing policy gaps : the case of Ghana
https://hdl.handle.net/10023/1697
Paradigms of housing policies in developing countries have undergone significant changes since the 1940s in the post-colonial era. The involvement of international development agencies such as the World Bank and the United Nations with their substantial financial and technical resources have engendered a conventional narrative of the hegemony of paradigms sponsored by these agencies. It is in this light that the “enabling principles” of housing policy emerged as the dominant policy discourse from the 1980s. This housing paradigm -“enabling shelter policies” –was actively promoted by the World Bank and the United Nations, acting through its housing agency the UN-Habitat, for adoption by developing countries to reform their housing sectors from the 1980s. One of the main instruments of the enabling principles was the withdrawal or contraction of the state from direct housing development in preference for private sector-led and community initiatives in housing development. Government involvement in direct development of housing was conceived to be an ineffective policy choice which had little geographic impact and therefore had to give way to a systematised approach to housing delivery. Ghana was one of the first African countries to adopt these principles for the reform of the housing sector in the country. Two decades later, it has been observed that the government was making housing policy choices that contradicted the ethos of the enabling principles. In particular it was observed that the state was re-engaging in direct housing development. In the light of the past conception of these activities as being defective policies, their re-emergence was characteristic of policy “reversionism”. This concept of policy reversionism is adopted from theories of theology and criminal justice (where it is known as recidivism) in which processes of reform or progression are reversed. The question explored by the thesis is why housing policy reversionism was emerging and what were the generating factors.
The thesis draws on a critical realist perspective to deconstruct the conventional narratives about the homogenous state and the hegemony of international agencies such as the World Bank and the UN in the advancement of “unproblematic” enabling principles through which the housing sector reforms were designed and implemented. In doing so the thesis established the heterogeneity of the state driven by competition for domination by sectoral, intra-state as well as supra-state interests. In this process, hegemony becomes vulnerable to manipulation as these principles were translated or “indigenised”. Furthermore it is established that this nuanced perspective is further complicated by a dialectical relationship between the contexts of events and prevailing material conditions and the actions taken by policy agents. These complexities layered the housing policy sphere in ways that masked the primary motivations of class interests and political legitimisation underpinning the incidence of reversionism.
2010-11-30T00:00:00Z
Sarfoh, Kwadwo Ohene
Paradigms of housing policies in developing countries have undergone significant changes since the 1940s in the post-colonial era. The involvement of international development agencies such as the World Bank and the United Nations with their substantial financial and technical resources have engendered a conventional narrative of the hegemony of paradigms sponsored by these agencies. It is in this light that the “enabling principles” of housing policy emerged as the dominant policy discourse from the 1980s. This housing paradigm -“enabling shelter policies” –was actively promoted by the World Bank and the United Nations, acting through its housing agency the UN-Habitat, for adoption by developing countries to reform their housing sectors from the 1980s. One of the main instruments of the enabling principles was the withdrawal or contraction of the state from direct housing development in preference for private sector-led and community initiatives in housing development. Government involvement in direct development of housing was conceived to be an ineffective policy choice which had little geographic impact and therefore had to give way to a systematised approach to housing delivery. Ghana was one of the first African countries to adopt these principles for the reform of the housing sector in the country. Two decades later, it has been observed that the government was making housing policy choices that contradicted the ethos of the enabling principles. In particular it was observed that the state was re-engaging in direct housing development. In the light of the past conception of these activities as being defective policies, their re-emergence was characteristic of policy “reversionism”. This concept of policy reversionism is adopted from theories of theology and criminal justice (where it is known as recidivism) in which processes of reform or progression are reversed. The question explored by the thesis is why housing policy reversionism was emerging and what were the generating factors.
The thesis draws on a critical realist perspective to deconstruct the conventional narratives about the homogenous state and the hegemony of international agencies such as the World Bank and the UN in the advancement of “unproblematic” enabling principles through which the housing sector reforms were designed and implemented. In doing so the thesis established the heterogeneity of the state driven by competition for domination by sectoral, intra-state as well as supra-state interests. In this process, hegemony becomes vulnerable to manipulation as these principles were translated or “indigenised”. Furthermore it is established that this nuanced perspective is further complicated by a dialectical relationship between the contexts of events and prevailing material conditions and the actions taken by policy agents. These complexities layered the housing policy sphere in ways that masked the primary motivations of class interests and political legitimisation underpinning the incidence of reversionism.
-
International medical travel and the politics of therapeutic place-making in Malaysia
https://hdl.handle.net/10023/1681
This thesis examines the shifting relationship between the state and its subjects with regard to responsibility for and entitlement to care. Using Malaysia as a case study the research engages with international medical travel (IMT) as an outcome of the neoliberal retrenchment of the welfare state. I offer a critical reading of postcolonial development strategies that negotiate the benefits and challenges of extending care to non-national subjects. The research draws from relevant media, private-sector and governmental documents and 49 semi-structured, in-depth interviews with IMT proponents and critics representing federal, state and urban governmental authorities, professional associations, civil society, private medical facilities and medical travel agencies in Malaysia’s principal IMT regions (Klang Valley, Penang and Malacca). Across four empirical chapters, the thesis demonstrates how ‘Malaysia’ gets positioned as a destination within a range of imagined geographies of care through a strategic-relational logic of care and hospitality. I argue that this positioning places ‘Malaysian’ subjects and spaces into lucrative global networks in ways that underscore particular narratives of postcolonial hybridity that draw from Malaysia’s ‘developing country’, ‘progressive, moderate Islamic’ and ‘multiethnic’ credentials. In considering the political logics of care-giving, I explore how the extension of care can serve as a place-making technology to re-imagine the state as a provider and protector within a globalising marketplace in which care, increasingly commodified, is tied to the production of new political, social, cultural and economic geographies.
Electronic version excludes material for which permission has not been granted by the rights holder
2011-06-24T00:00:00Z
Ormond, Meghann E.
This thesis examines the shifting relationship between the state and its subjects with regard to responsibility for and entitlement to care. Using Malaysia as a case study the research engages with international medical travel (IMT) as an outcome of the neoliberal retrenchment of the welfare state. I offer a critical reading of postcolonial development strategies that negotiate the benefits and challenges of extending care to non-national subjects. The research draws from relevant media, private-sector and governmental documents and 49 semi-structured, in-depth interviews with IMT proponents and critics representing federal, state and urban governmental authorities, professional associations, civil society, private medical facilities and medical travel agencies in Malaysia’s principal IMT regions (Klang Valley, Penang and Malacca). Across four empirical chapters, the thesis demonstrates how ‘Malaysia’ gets positioned as a destination within a range of imagined geographies of care through a strategic-relational logic of care and hospitality. I argue that this positioning places ‘Malaysian’ subjects and spaces into lucrative global networks in ways that underscore particular narratives of postcolonial hybridity that draw from Malaysia’s ‘developing country’, ‘progressive, moderate Islamic’ and ‘multiethnic’ credentials. In considering the political logics of care-giving, I explore how the extension of care can serve as a place-making technology to re-imagine the state as a provider and protector within a globalising marketplace in which care, increasingly commodified, is tied to the production of new political, social, cultural and economic geographies.
-
Empowering Glasgow’s tenants through community ownership?
https://hdl.handle.net/10023/1362
Post 1997, stock transfer has been pivotal to the housing and regeneration agenda of the New Labour government, both at the UK and devolved level. Although a heavily researched policy area, stock transfer research has tended to focus quite narrowly on the perspectives of policymakers, practitioners or members of the transfer association's governing body. To address this research gap and focus more explicitly on the voices of local residents, this paper draws on the case study of the unique two-stage Glasgow housing stock transfer in order to explore 'community ownership' and 'tenant empowerment' from the perspective of 'lay' tenants. Political ambitions for direct democracy and communitarian endeavour have been central to stock transfer agendas in Scotland, where the policy has developed quite distinctly compared with the rest of the UK. Focus group research with tenants in Glasgow, however, highlights that empowerment was not an important priority for tenants at the point of transfer; that the transfer has delivered mixed outcomes in terms of local tenant control; and on the key issue of support for 'full' community ownership tenants were unconvinced, and expressed a need for more information.
2009-06-01T00:00:00Z
McKee, Kim
Post 1997, stock transfer has been pivotal to the housing and regeneration agenda of the New Labour government, both at the UK and devolved level. Although a heavily researched policy area, stock transfer research has tended to focus quite narrowly on the perspectives of policymakers, practitioners or members of the transfer association's governing body. To address this research gap and focus more explicitly on the voices of local residents, this paper draws on the case study of the unique two-stage Glasgow housing stock transfer in order to explore 'community ownership' and 'tenant empowerment' from the perspective of 'lay' tenants. Political ambitions for direct democracy and communitarian endeavour have been central to stock transfer agendas in Scotland, where the policy has developed quite distinctly compared with the rest of the UK. Focus group research with tenants in Glasgow, however, highlights that empowerment was not an important priority for tenants at the point of transfer; that the transfer has delivered mixed outcomes in terms of local tenant control; and on the key issue of support for 'full' community ownership tenants were unconvinced, and expressed a need for more information.
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The end of the Right to Buy and the future of social housing in Scotland
https://hdl.handle.net/10023/1083
Thirty-years after the introduction of the Right to Buy - the most successful example of housing privatisation policy in the UK - the current Housing (Scotland) Bill proposes to end the scheme for both new social housing tenants and new social housing. This paper considers the implications of these modernising reforms, in the context of housing policy divergence post-devolution. It concludes that these proposals are likely to have a significant, but mixed, impact on the future of the social rented sector in Scotland.
This is the author version of an article whose final and definitive form has been published in Local Economy (c)2010 Taylor & Francis. Local Economy is available online at http://www.informaworld.com/openurl?genre=article&issn=0269-0942&volume=25&issue=4&spage=319.
2010-06-01T00:00:00Z
McKee, Kim
Thirty-years after the introduction of the Right to Buy - the most successful example of housing privatisation policy in the UK - the current Housing (Scotland) Bill proposes to end the scheme for both new social housing tenants and new social housing. This paper considers the implications of these modernising reforms, in the context of housing policy divergence post-devolution. It concludes that these proposals are likely to have a significant, but mixed, impact on the future of the social rented sector in Scotland.
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Christian Palestinians in Britain
https://hdl.handle.net/10023/999
This study seeks to address a gap in the literature with regard to the Christian Palestinians. As members of a very small minority, they are often overlooked by the media and the academic community. While this is changing to some extent for Christian Palestinians in the Middle East, there is scant literature that considers their lives in the ‘West’ and almost none on their experiences in Britain. This thesis considers how Christian Palestinians have adapted to life in London, including an analysis of the individual experiences of both Christian Palestinians and Muslim Palestinians. Interviews with respondents focused on their English language abilities, educational achievements, attitudes to intermarriage, and their sense of belonging. These aspects were chosen because they offer an insight into respondents’ private and public lives, a distinction that is particularly important in the study of integration and assimilation. Through the assessment of these attributes, this research seeks to redefine the way that assimilation has been viewed and argues that a more comprehensive study of assimilation must include not only an analysis of whether migrants have adopted a characteristic of the host nation’s population, but also an analysis of whether they have adopted the sentiments their native born counterparts have attached to them.
2010-06-26T00:00:00Z
Shakkour, Suha
This study seeks to address a gap in the literature with regard to the Christian Palestinians. As members of a very small minority, they are often overlooked by the media and the academic community. While this is changing to some extent for Christian Palestinians in the Middle East, there is scant literature that considers their lives in the ‘West’ and almost none on their experiences in Britain. This thesis considers how Christian Palestinians have adapted to life in London, including an analysis of the individual experiences of both Christian Palestinians and Muslim Palestinians. Interviews with respondents focused on their English language abilities, educational achievements, attitudes to intermarriage, and their sense of belonging. These aspects were chosen because they offer an insight into respondents’ private and public lives, a distinction that is particularly important in the study of integration and assimilation. Through the assessment of these attributes, this research seeks to redefine the way that assimilation has been viewed and argues that a more comprehensive study of assimilation must include not only an analysis of whether migrants have adopted a characteristic of the host nation’s population, but also an analysis of whether they have adopted the sentiments their native born counterparts have attached to them.
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Petrology and petrogenesis of the Motzfeldt Ta-mineralisation, Gardar Province, South Greenland
https://hdl.handle.net/10023/845
The Motzfeldt centre is one of four major alkaline centres belonging to the Igaliko complex of South Greenland. The melts parental to the Motzfeldt centre are interpreted from Hf isotopes to be derived form a common mantle source which experienced subsequent isotopic contamination from older crustal components during the interval between segregation and emplacement. Magmatism within the centre commenced with the emplacement of the Motzfeldt Sø Formation at 1273 ± 8 Ma. This unit is unique within the Motzfeldt intrusion as it is characterised by a high degree of textural and mineralogical variability and hosts localised Nb, Ta, U, Th, Zr and REE mineralisation associated with pyrochlore and late-stage REE bearing carbonate phases. Biotite halogen contents show that in addition to enrichment of incompatible elements the MSF and Motzfeldt centre in general is particularly rich in F. The elevated F content is inferred to have extended the crystallisation interval of the melt and facilitated fractionation down to relatively low temperatures. The unusual enrichment of F and incompatible elements in the MSF is suggested to represent the first and most evolved melts extracted from the top of a stratified storage chamber at depth.
The MSF is also characterised by pervasive subsolidus alteration, giving the rock and region a striking brick red colour. Pb-Pb pyrochlore studies indicate that alteration in the formation was effectively synchronous (1267 ± 6 Ma), with the magmatic age of emplacement. Fluid inclusion studies suggest that contemporaneous to the exsolution of juvenile, high salinity, F-rich fluids was the wholesale influx of hydrothermally convected low salinity groundwaters through the formation. The presence of pervasive late-stage hematite and calcite throughout the MSF suggests that the oxidation potential of the bulk fluid increased above the hematite-magnetite buffer during the waning stages of the hydrothermal phase. Mineralisation was promoted by this shift in fluid composition, reducing the complexing potential of fluid ligands and facilitating mineralisation within the high-levels units of the intrusion where alteration is most intense. Economic mineralisation associated with the centre is inferred to be largely sourced from the parental melts, however the role the hydrothermal phase played was particularly important in locally mobilising and concentrating incompatible elements within the high-level units of the formation.
2009-06-25T00:00:00Z
McCreath, Jamie Alan
The Motzfeldt centre is one of four major alkaline centres belonging to the Igaliko complex of South Greenland. The melts parental to the Motzfeldt centre are interpreted from Hf isotopes to be derived form a common mantle source which experienced subsequent isotopic contamination from older crustal components during the interval between segregation and emplacement. Magmatism within the centre commenced with the emplacement of the Motzfeldt Sø Formation at 1273 ± 8 Ma. This unit is unique within the Motzfeldt intrusion as it is characterised by a high degree of textural and mineralogical variability and hosts localised Nb, Ta, U, Th, Zr and REE mineralisation associated with pyrochlore and late-stage REE bearing carbonate phases. Biotite halogen contents show that in addition to enrichment of incompatible elements the MSF and Motzfeldt centre in general is particularly rich in F. The elevated F content is inferred to have extended the crystallisation interval of the melt and facilitated fractionation down to relatively low temperatures. The unusual enrichment of F and incompatible elements in the MSF is suggested to represent the first and most evolved melts extracted from the top of a stratified storage chamber at depth.
The MSF is also characterised by pervasive subsolidus alteration, giving the rock and region a striking brick red colour. Pb-Pb pyrochlore studies indicate that alteration in the formation was effectively synchronous (1267 ± 6 Ma), with the magmatic age of emplacement. Fluid inclusion studies suggest that contemporaneous to the exsolution of juvenile, high salinity, F-rich fluids was the wholesale influx of hydrothermally convected low salinity groundwaters through the formation. The presence of pervasive late-stage hematite and calcite throughout the MSF suggests that the oxidation potential of the bulk fluid increased above the hematite-magnetite buffer during the waning stages of the hydrothermal phase. Mineralisation was promoted by this shift in fluid composition, reducing the complexing potential of fluid ligands and facilitating mineralisation within the high-levels units of the intrusion where alteration is most intense. Economic mineralisation associated with the centre is inferred to be largely sourced from the parental melts, however the role the hydrothermal phase played was particularly important in locally mobilising and concentrating incompatible elements within the high-level units of the formation.
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NHS resource allocation 1997 to 2003 with particular reference to the impact on rural areas
https://hdl.handle.net/10023/825
The central hypothesis of this study was that the allocation system for NHS hospital and community health services between 1997 and 2003 was not meeting key principles of compensating for differences in the need for services and unavoidable costs.
The review and analyses in this study indicate that the underpinning assumptions used when formulating the need adjustment were not robust and that this led to the selection of inappropriate proxies for need. In addition it is concluded that the age adjustment underestimated the costs of elderly care.
This study has concluded that the pay adjustment, which was the largest in the formula, did not reflect actual unavoidable differences in cost because the Warwick studies that were used to set the adjustment ignored the monopsonistic nature of the NHS. As a consequence the pay adjustment was based on the assumption that NHS salaries should be related to local salaries.
This study identified unavoidable additional costs of providing healthcare in rural areas. These findings were consistent with other comprehensive studies on healthcare costs in Scotland, Wales and Northern Ireland. This study concludes that the exclusion of a market forces adjustment for rurality was inconsistent with all other comparable allocation formulae in the Home Countries. The absence of a rurality adjustment resulted in rural areas receiving a lower proportion of NHS funding than was justified and this is referred to as the Inverse Share Law.
This study concludes that the central hypothesis was correct and that a rurality adjustment was justified, but that the principal determinant of service quality was an adequate focus on efficiency.
2009-11-30T00:00:00Z
White, Christopher P.
The central hypothesis of this study was that the allocation system for NHS hospital and community health services between 1997 and 2003 was not meeting key principles of compensating for differences in the need for services and unavoidable costs.
The review and analyses in this study indicate that the underpinning assumptions used when formulating the need adjustment were not robust and that this led to the selection of inappropriate proxies for need. In addition it is concluded that the age adjustment underestimated the costs of elderly care.
This study has concluded that the pay adjustment, which was the largest in the formula, did not reflect actual unavoidable differences in cost because the Warwick studies that were used to set the adjustment ignored the monopsonistic nature of the NHS. As a consequence the pay adjustment was based on the assumption that NHS salaries should be related to local salaries.
This study identified unavoidable additional costs of providing healthcare in rural areas. These findings were consistent with other comprehensive studies on healthcare costs in Scotland, Wales and Northern Ireland. This study concludes that the exclusion of a market forces adjustment for rurality was inconsistent with all other comparable allocation formulae in the Home Countries. The absence of a rurality adjustment resulted in rural areas receiving a lower proportion of NHS funding than was justified and this is referred to as the Inverse Share Law.
This study concludes that the central hypothesis was correct and that a rurality adjustment was justified, but that the principal determinant of service quality was an adequate focus on efficiency.
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Exploring ethnic inequalities in cardiovascular disease using Hospital Episode Statistics
https://hdl.handle.net/10023/819
This thesis is based on a population study conducted to explore ethnic inequalities in cardiovascular disease using Hospital Episode Statistics (HES). The Hospital Episode Statistics have significant potential for health studies for ethnic groups, due to the large number of events from minority ethnic groups, comprehensive clinical information, full England coverage and fine geographical scale. However, the percentage of Finished Consultant Episodes (FCEs) with invalid ethnicity codes is at a high level. This thesis starts by developing a record linkage method and a coding rate method to improve the data quality of ethnicity codes in the HES.
This thesis then further examines ethnic inequalities in cardiovascular disease incidence in England at both national and local geographical scales. The patterns of ethnic inequalities in cardiovascular disease appear to have changed little in the last ten years. However, large variations of geographical relative risk of cardiovascular disease were observed for ethnicity-sex groups. The relationships between areal socioeconomic status measured at different geographical scales and ethnic inequalities in different types of cardiovascular disease were also explored.
As there are very limited data on the mortality of minority ethnic groups in the UK, few studies have compared the incidence and outcome of cardiovascular disease from the same population. This thesis came up with some novel findings, for example, that people from minority ethnic groups, who generally have increased risk of cardiovascular disease incidence, have better cardiovascular disease survival than white people. The contribution of areal socioeconomic status, distance to treatment sites and cardiovascular disease severity and treatment to the ethnic inequalities in cardiovascular survival was examined. The relationships between socioeconomic status measured at different geographical scales and ethnic inequalities in cardiovascular disease severity and treatment were investigated in this thesis as well.
2009-06-11T00:00:00Z
Liu, Lixun
This thesis is based on a population study conducted to explore ethnic inequalities in cardiovascular disease using Hospital Episode Statistics (HES). The Hospital Episode Statistics have significant potential for health studies for ethnic groups, due to the large number of events from minority ethnic groups, comprehensive clinical information, full England coverage and fine geographical scale. However, the percentage of Finished Consultant Episodes (FCEs) with invalid ethnicity codes is at a high level. This thesis starts by developing a record linkage method and a coding rate method to improve the data quality of ethnicity codes in the HES.
This thesis then further examines ethnic inequalities in cardiovascular disease incidence in England at both national and local geographical scales. The patterns of ethnic inequalities in cardiovascular disease appear to have changed little in the last ten years. However, large variations of geographical relative risk of cardiovascular disease were observed for ethnicity-sex groups. The relationships between areal socioeconomic status measured at different geographical scales and ethnic inequalities in different types of cardiovascular disease were also explored.
As there are very limited data on the mortality of minority ethnic groups in the UK, few studies have compared the incidence and outcome of cardiovascular disease from the same population. This thesis came up with some novel findings, for example, that people from minority ethnic groups, who generally have increased risk of cardiovascular disease incidence, have better cardiovascular disease survival than white people. The contribution of areal socioeconomic status, distance to treatment sites and cardiovascular disease severity and treatment to the ethnic inequalities in cardiovascular survival was examined. The relationships between socioeconomic status measured at different geographical scales and ethnic inequalities in cardiovascular disease severity and treatment were investigated in this thesis as well.
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Processes of crevasse formation and the dynamics of calving glaciers : a study at Breiđamerkurjökull
https://hdl.handle.net/10023/775
A new model proposed by Benn et al. (2006, 2007) explains the dynamics of calving glaciers
based on a new sliding law and a calving criterion modified from a crevasse depth model. In
this thesis three key elements of this model are tested:
1) the role of longitudinal stretching as a result of velocity gradients, which pre-conditions
ice at the glacier terminus for calving failure;
2) the accurate prediction of crevasse depths from strain rates, for inclusion within a
calving model as a calving criterion;
3) the role of dynamically induced thinning (as a result of longitudinal stretching at an
accelerating glacier) in causing further acceleration and calving retreat and the onset of
a dynamic thinning feedback through reduced basal pressure.
Field results show that longitudinal strain rates are important controls on calving glaciers,
controlling both dynamic thinning and crevasse depths. Crevasse-depth models proposed by
Van der Veen (1998a, 1998b) and Nye (1957) work well in predicting crevasse depths based on
measured strain rates. The latter in particular is suitable for inclusion as a calving criterion when
modified with a yield criterion. The importance of water in enhancing propagation of crevasses
is demonstrated through modelling studies, and is implicitly included in the calving model.
Measured rates of dynamic thinning at Breiðamerkurjökull, a glacier in South East Iceland,
confirm the importance of this process within a calving model and results from a simple 1-D
model show that the new sliding law not only predicts velocities effectively, but can also predict
the position of a calving terminus based on strain rates and the calving criterion. Suggestions are
made for further more detailed modelling, including time evolution and longitudinal stress
gradients, to apply the model to a range of glaciers and to predict the response of calving
glaciers to climatic and environmental changes.
2008-01-01T00:00:00Z
Mottram, Ruth
A new model proposed by Benn et al. (2006, 2007) explains the dynamics of calving glaciers
based on a new sliding law and a calving criterion modified from a crevasse depth model. In
this thesis three key elements of this model are tested:
1) the role of longitudinal stretching as a result of velocity gradients, which pre-conditions
ice at the glacier terminus for calving failure;
2) the accurate prediction of crevasse depths from strain rates, for inclusion within a
calving model as a calving criterion;
3) the role of dynamically induced thinning (as a result of longitudinal stretching at an
accelerating glacier) in causing further acceleration and calving retreat and the onset of
a dynamic thinning feedback through reduced basal pressure.
Field results show that longitudinal strain rates are important controls on calving glaciers,
controlling both dynamic thinning and crevasse depths. Crevasse-depth models proposed by
Van der Veen (1998a, 1998b) and Nye (1957) work well in predicting crevasse depths based on
measured strain rates. The latter in particular is suitable for inclusion as a calving criterion when
modified with a yield criterion. The importance of water in enhancing propagation of crevasses
is demonstrated through modelling studies, and is implicitly included in the calving model.
Measured rates of dynamic thinning at Breiðamerkurjökull, a glacier in South East Iceland,
confirm the importance of this process within a calving model and results from a simple 1-D
model show that the new sliding law not only predicts velocities effectively, but can also predict
the position of a calving terminus based on strain rates and the calving criterion. Suggestions are
made for further more detailed modelling, including time evolution and longitudinal stress
gradients, to apply the model to a range of glaciers and to predict the response of calving
glaciers to climatic and environmental changes.
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Luminescence spectroscopy of natural and synthetic REE-bearing minerals
https://hdl.handle.net/10023/756
This study investigates the photoluminescence (PL), cathodoluminescence (CL), radioluminescence (RL) and ionoluminescence (IL) of natural and synthetic minerals. The natural minerals (fluorapatite, leucophanite, meliphanite and zircon) are mostly from Ilímaussaq Alkaline Complex in South Greenland, Langesundsfjord in Norway and from different localities within Scotland. Synthetic fluorapatite (manufactured as part of the present study) and zircon doped with rare earth elements (REE) were used to compare single and multidoped materials.
This study has shown that many of the generally accepted applications of luminescence are not as straightforward as often suggested by the current literature. For example, the study demonstrates how site distribution of REE, based on luminescence, is greatly affected by the dopant level and structural changes, and that different conclusions can be drawn on the same sample depending on method applied. Furthermore, it is clearly demonstrated that using luminescence as a tool for quantitative trace element determination is not going to be a standard technique in the near future if ever. The two main findings supporting this conclusion are the non-linear intensity decrease between different REE activators in the same sample and a large variation between activators at the concentration at which self-quenching starts.
In contrast to the general perception that luminescence related to REE is mostly independent of the host, this study has shown a strong interaction between host and REE activators. This conclusion is supported by the change in the activator’s coordination polyhedron observed with single-crystal and powder X-ray diffraction combined with full chemical characterisation. When combining the weak interaction between some REE with the strong host interaction this study has shown the potential for designing new types of colour tuneable and “white light” LEDs based on natural minerals. This study also reveals that zircon doped with Gd³⁺ and Eu³⁺ can potentially have quantum-cutting properties.
2009-06-25T00:00:00Z
Friis, Henrik
This study investigates the photoluminescence (PL), cathodoluminescence (CL), radioluminescence (RL) and ionoluminescence (IL) of natural and synthetic minerals. The natural minerals (fluorapatite, leucophanite, meliphanite and zircon) are mostly from Ilímaussaq Alkaline Complex in South Greenland, Langesundsfjord in Norway and from different localities within Scotland. Synthetic fluorapatite (manufactured as part of the present study) and zircon doped with rare earth elements (REE) were used to compare single and multidoped materials.
This study has shown that many of the generally accepted applications of luminescence are not as straightforward as often suggested by the current literature. For example, the study demonstrates how site distribution of REE, based on luminescence, is greatly affected by the dopant level and structural changes, and that different conclusions can be drawn on the same sample depending on method applied. Furthermore, it is clearly demonstrated that using luminescence as a tool for quantitative trace element determination is not going to be a standard technique in the near future if ever. The two main findings supporting this conclusion are the non-linear intensity decrease between different REE activators in the same sample and a large variation between activators at the concentration at which self-quenching starts.
In contrast to the general perception that luminescence related to REE is mostly independent of the host, this study has shown a strong interaction between host and REE activators. This conclusion is supported by the change in the activator’s coordination polyhedron observed with single-crystal and powder X-ray diffraction combined with full chemical characterisation. When combining the weak interaction between some REE with the strong host interaction this study has shown the potential for designing new types of colour tuneable and “white light” LEDs based on natural minerals. This study also reveals that zircon doped with Gd³⁺ and Eu³⁺ can potentially have quantum-cutting properties.
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Benthic habitats of the extended Faial Island shelf and their relationship to geologic, oceanographic and infralittoral biologic features
https://hdl.handle.net/10023/726
This thesis presents a new template for multidisciplinary habitat mapping that combines the analyses of seafloor geomorphology, oceanographic proxies and modelling of associated biologic features.
High resolution swath bathymetry of the Faial and western Pico shelves is used to present the first state-of-the-art geomorphologic assessment of submerged island shelves in the Azores. Solid seafloor structures are described in previously unreported detail together with associated volcanic, tectonic and erosion processes.
The large sedimentary expanses identified in the area are also investigated and the large bedforms identified are discussed in view of new data on the local hydrodynamic conditions. Coarse-sediment zones of types hitherto unreported for volcanic island shelves are described using swath data and in situ imagery together with sub-bottom profiles and grainsize information. The hydrodynamic and geological processes producing these features are discussed.
New oceanographic information extracted from satellite imagery is presented including yearly and seasonal sea surface temperature and chlorophyll-a concentration fields. These are used as proxies to understand the spatio-temporal variability of water temperature and primary productivity in the immediate island vicinity. The patterns observed are discussed, including onshore-offshore gradients and the prevalence of colder/more productive waters in the Faial-Pico passage and shelf areas in general. Furthermore, oceanographic proxies for swell exposure and tidal currents are derived from GIS analyses and shallow-water hydrographic modelling.
Finally, environmental variables that potentially regulate the distribution of benthic organisms (seafloor nature, depth, slope, sea surface temperature, chlorophyll-a concentration, swell exposure and maximum tidal currents) are brought together and used to develop innovative statistical models of the distribution of six macroalgae taxa dominant in the infralittoral (articulated Corallinaceae, Codium elisabethae, Dictyota spp., Halopteris filicina, Padina pavonica and Zonaria tournefortii). Predictive distributions of these macroalgae are spatialized around Faial island using ordered logistic regression equations and raster fields of the explanatory variables found to be statistically significant.
This new approach represents a potentially highly significant step forward in modelling benthic communities not only in the Azores but also in other oceanic island shelves where the management of benthic species and biotopes is critical to preserve ecosystem health.
2009-06-23T00:00:00Z
Tempera, Fernando
This thesis presents a new template for multidisciplinary habitat mapping that combines the analyses of seafloor geomorphology, oceanographic proxies and modelling of associated biologic features.
High resolution swath bathymetry of the Faial and western Pico shelves is used to present the first state-of-the-art geomorphologic assessment of submerged island shelves in the Azores. Solid seafloor structures are described in previously unreported detail together with associated volcanic, tectonic and erosion processes.
The large sedimentary expanses identified in the area are also investigated and the large bedforms identified are discussed in view of new data on the local hydrodynamic conditions. Coarse-sediment zones of types hitherto unreported for volcanic island shelves are described using swath data and in situ imagery together with sub-bottom profiles and grainsize information. The hydrodynamic and geological processes producing these features are discussed.
New oceanographic information extracted from satellite imagery is presented including yearly and seasonal sea surface temperature and chlorophyll-a concentration fields. These are used as proxies to understand the spatio-temporal variability of water temperature and primary productivity in the immediate island vicinity. The patterns observed are discussed, including onshore-offshore gradients and the prevalence of colder/more productive waters in the Faial-Pico passage and shelf areas in general. Furthermore, oceanographic proxies for swell exposure and tidal currents are derived from GIS analyses and shallow-water hydrographic modelling.
Finally, environmental variables that potentially regulate the distribution of benthic organisms (seafloor nature, depth, slope, sea surface temperature, chlorophyll-a concentration, swell exposure and maximum tidal currents) are brought together and used to develop innovative statistical models of the distribution of six macroalgae taxa dominant in the infralittoral (articulated Corallinaceae, Codium elisabethae, Dictyota spp., Halopteris filicina, Padina pavonica and Zonaria tournefortii). Predictive distributions of these macroalgae are spatialized around Faial island using ordered logistic regression equations and raster fields of the explanatory variables found to be statistically significant.
This new approach represents a potentially highly significant step forward in modelling benthic communities not only in the Azores but also in other oceanic island shelves where the management of benthic species and biotopes is critical to preserve ecosystem health.
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School engagement, self-esteem and wellbeing during transfer from primary to secondary school
https://hdl.handle.net/10023/693
For many years, educators, psychologists and parents have expressed concern about the apparent deterioration of pupil motivation and performance after children move to secondary school. This study used a longitudinal design to examine the transfer process from the perspective of a group of 393 children (195 boys, 198 girls) as they moved from 19 primary schools to four secondary schools in Fife. Children’s self-perceptions of school commitment, school belonging, school participation, self-esteem and global wellbeing were evaluated four times over a 13 month period, twice before transfer in the final year of primary school and twice after transfer in the first year of secondary school. Information was also collected about family and home life, emotions, lifestyle and school on each occasion. The data was analysed using multilevel modelling in order to examine how each of the five outcome variables changed over the time of the study, and how they related to a series of independent variables.
It was anticipated that changes in these outcomes may have occurred immediately after the move to secondary school, perhaps followed by an improvement six months later after they had adapted to changes and settled in to their new schools. The results showed that, contrary to expectations, all outcomes except school participation recorded an improvement at wave 3, immediately after the transfer to secondary school. However, there was some evidence that after an initial ‘honeymoon period’, children perceived certain aspects of school in a less positive light and by wave 4 there was a decline in all outcomes except for the perception of self-esteem, which continued to improve. Since wave 4 was only a few months after transition, a significant change in children’s views is seen quite quickly after transfer. It is not clear whether this represents a return to a more realistic level or if this signals the beginning of a more prolonged negative attitude towards school and education in general. The general conclusion is that the process of transfer to secondary schools is well managed, but it might be helpful for induction programmes to prepare children for the changes in teaching and learning methods that might be encountered, and perhaps other types of programme might be beneficial during the first year.
2009-06-25T00:00:00Z
Horobin, M. Vivienne
For many years, educators, psychologists and parents have expressed concern about the apparent deterioration of pupil motivation and performance after children move to secondary school. This study used a longitudinal design to examine the transfer process from the perspective of a group of 393 children (195 boys, 198 girls) as they moved from 19 primary schools to four secondary schools in Fife. Children’s self-perceptions of school commitment, school belonging, school participation, self-esteem and global wellbeing were evaluated four times over a 13 month period, twice before transfer in the final year of primary school and twice after transfer in the first year of secondary school. Information was also collected about family and home life, emotions, lifestyle and school on each occasion. The data was analysed using multilevel modelling in order to examine how each of the five outcome variables changed over the time of the study, and how they related to a series of independent variables.
It was anticipated that changes in these outcomes may have occurred immediately after the move to secondary school, perhaps followed by an improvement six months later after they had adapted to changes and settled in to their new schools. The results showed that, contrary to expectations, all outcomes except school participation recorded an improvement at wave 3, immediately after the transfer to secondary school. However, there was some evidence that after an initial ‘honeymoon period’, children perceived certain aspects of school in a less positive light and by wave 4 there was a decline in all outcomes except for the perception of self-esteem, which continued to improve. Since wave 4 was only a few months after transition, a significant change in children’s views is seen quite quickly after transfer. It is not clear whether this represents a return to a more realistic level or if this signals the beginning of a more prolonged negative attitude towards school and education in general. The general conclusion is that the process of transfer to secondary schools is well managed, but it might be helpful for induction programmes to prepare children for the changes in teaching and learning methods that might be encountered, and perhaps other types of programme might be beneficial during the first year.
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Primary health care delivery in rural India : examining the efficacy of a policy for recruiting junior doctors in Karnataka.
https://hdl.handle.net/10023/630
This thesis examines the role of primary health care delivery in rural India but specifically focuses on aspects from Karnataka state. It broadly reflects on the differences that exist between urban and rural populations' access to healthcare. The concept of primary health care appears to have lost its lustre at present, it was once enthusiastically promoted in the late 1970s and 1980s but as chronic problems appeared to affect the smooth delivery of healthcare and nowadays major global bodies like the WHO and IMF have relegated primary health concept to a lower level. However in countries like India, which adopted this concept although its implementation has been riddled with complex ongoing problems, there are not sufficient grounds to abandon it completely. These problems are mainly due to the slow implementation, which has left a vast rural population with little or no access to healthcare. Primary health care strongly promotes equity of access hence is vital in many developing nations.
Recruiting highly skilled personnel to work in rural health centres has been an ongoing problem, which hinders the effective delivery of healthcare. A policy followed by Karnataka state tries to rectify this problem by offering postgraduate positions to junior doctors who are willing to work in rural areas. The efficacy of this policy is closely examined from two perspectives. Those who consume healthcare in rural areas are given an opportunity to voice their concerns and also the doctors who work there represent the views of the providers of healthcare. This study was conducted in Bidar district, which lies in the north of Karnataka. Bidar is identified comparatively as a less developed district that has many problems associated with poverty and poor health status. In the process of conducting research a variety of interesting aspects have been highlighted. My hope is that relevant authorities identify with the problems and take measures that could benefit many people's lives.
Interestingly it transpires from the views expressed by the rural population that they have a good grasp of what they think they will need to access a better form of healthcare from the existing system. However it appears that there is almost a universal fatalistic acceptance of them being helpless and voiceless about making any to change by their suggestions nor did most of them have a hope of influencing future prospects. The studies also indicated that where there is a better level of provision there the people tend to access healthcare from authentic sources as opposed to unregistered and unqualified personnel.
The doctors suggested that the policy is very useful provide certain intrinsic changes are made. On the one hand they did accept that their cost benefit and academic value of this policy is great. On the other hand they suggested the hurdles put in the course of achieving the postgraduate position are arduous and often vague sets of guidelines are imposed, making it very hard to make a straightforward transition from working in rural areas to getting a postgraduate position of choice. The doctors working on temporary contracts appeared to suffer genuine discrimination especially due to number of years they spent trying to get permanent position, years which were not counted towards their ambition of further education. Where it appears there is very little difference in the roles and responsibility between permanent and temporary contract doctors the question of why it does not occur to the authorities to redress this issue is discussed.
2008-11-15T00:00:00Z
Salins, Swarthick E
This thesis examines the role of primary health care delivery in rural India but specifically focuses on aspects from Karnataka state. It broadly reflects on the differences that exist between urban and rural populations' access to healthcare. The concept of primary health care appears to have lost its lustre at present, it was once enthusiastically promoted in the late 1970s and 1980s but as chronic problems appeared to affect the smooth delivery of healthcare and nowadays major global bodies like the WHO and IMF have relegated primary health concept to a lower level. However in countries like India, which adopted this concept although its implementation has been riddled with complex ongoing problems, there are not sufficient grounds to abandon it completely. These problems are mainly due to the slow implementation, which has left a vast rural population with little or no access to healthcare. Primary health care strongly promotes equity of access hence is vital in many developing nations.
Recruiting highly skilled personnel to work in rural health centres has been an ongoing problem, which hinders the effective delivery of healthcare. A policy followed by Karnataka state tries to rectify this problem by offering postgraduate positions to junior doctors who are willing to work in rural areas. The efficacy of this policy is closely examined from two perspectives. Those who consume healthcare in rural areas are given an opportunity to voice their concerns and also the doctors who work there represent the views of the providers of healthcare. This study was conducted in Bidar district, which lies in the north of Karnataka. Bidar is identified comparatively as a less developed district that has many problems associated with poverty and poor health status. In the process of conducting research a variety of interesting aspects have been highlighted. My hope is that relevant authorities identify with the problems and take measures that could benefit many people's lives.
Interestingly it transpires from the views expressed by the rural population that they have a good grasp of what they think they will need to access a better form of healthcare from the existing system. However it appears that there is almost a universal fatalistic acceptance of them being helpless and voiceless about making any to change by their suggestions nor did most of them have a hope of influencing future prospects. The studies also indicated that where there is a better level of provision there the people tend to access healthcare from authentic sources as opposed to unregistered and unqualified personnel.
The doctors suggested that the policy is very useful provide certain intrinsic changes are made. On the one hand they did accept that their cost benefit and academic value of this policy is great. On the other hand they suggested the hurdles put in the course of achieving the postgraduate position are arduous and often vague sets of guidelines are imposed, making it very hard to make a straightforward transition from working in rural areas to getting a postgraduate position of choice. The doctors working on temporary contracts appeared to suffer genuine discrimination especially due to number of years they spent trying to get permanent position, years which were not counted towards their ambition of further education. Where it appears there is very little difference in the roles and responsibility between permanent and temporary contract doctors the question of why it does not occur to the authorities to redress this issue is discussed.
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A study of the dynamics of the British Ice Sheet during Marine Isotope Stages 2 and 3, focusing on Heinrich Events 2 and 4 and their relationship to the North Atlantic glaciological and climatological conditions
https://hdl.handle.net/10023/525
A high-resolution investigation into the stratigraphy of core MD95-2006 from the Barra fan, NW Scottish continental slope has been carried out. The study focuses on key palaeoceanographic proxies (percentage Neogloboquadrina pachyderma (s), planktonic foraminiferal stable isotopes, planktonic foraminiferal and ice-rafted debris concentrations) throughout the interval between and including Heinrich Event 4 and Heinrich Event 2. A newly constructed age model produced through ties to the GRIP Greenland ice core record places this interval at approximately 20-48 ka BP. The interval covers the end of Marine Isotope Stage 3 and the start of Marine Isotope Stage 2, dating the MIS3/2 transition at 25.34-26.57 ka BP. Results reveal novel information on the dynamics of the British Ice Sheet (BIS) through this period and their relationship with other circum-North Atlantic ice sheets through a particular focus on the structure and provenance of Heinrich Events 2 and 4 within MD95-2006.
The study reveals that at the time of Heinrich Event 4, placed at 36.2-36.7 ka BP, the BIS was of limited extent and significant ice sheet expansion only occurred after ca. 26.5 ka BP, coinciding with the MIS3/2 transition in the MD95-2006 record. It appears that the margin of the BIS reached the continental slope around 25 ka BP and it is likely that the period between 21.5 and 25 ka BP, represents the maximum extent of the NW Scottish ice sheet. At the time of H4, the BIS was of limited extent whereas the Laurentide Ice Sheet (LIS) was already significantly expanded, thus the dominant radioisotopic signal seen in H4 sediment in MD95-2006 is that of LIS icebergs, overcoming the BIS contribution. In contrast, H2 (21.56-21.72 ka BP) occurs at a time of increased delivery of icebergs from all North Atlantic ice sheets however the MD95-2006 record dominated by the influence of the proximal BIS. This is revealed in both the increased background level of IRD delivery and the correspondence of background and peak IRD radioisotopic ratios tending towards British provenance.
2007-01-01T00:00:00Z
Leigh, Sasha Naomi Bharier
A high-resolution investigation into the stratigraphy of core MD95-2006 from the Barra fan, NW Scottish continental slope has been carried out. The study focuses on key palaeoceanographic proxies (percentage Neogloboquadrina pachyderma (s), planktonic foraminiferal stable isotopes, planktonic foraminiferal and ice-rafted debris concentrations) throughout the interval between and including Heinrich Event 4 and Heinrich Event 2. A newly constructed age model produced through ties to the GRIP Greenland ice core record places this interval at approximately 20-48 ka BP. The interval covers the end of Marine Isotope Stage 3 and the start of Marine Isotope Stage 2, dating the MIS3/2 transition at 25.34-26.57 ka BP. Results reveal novel information on the dynamics of the British Ice Sheet (BIS) through this period and their relationship with other circum-North Atlantic ice sheets through a particular focus on the structure and provenance of Heinrich Events 2 and 4 within MD95-2006.
The study reveals that at the time of Heinrich Event 4, placed at 36.2-36.7 ka BP, the BIS was of limited extent and significant ice sheet expansion only occurred after ca. 26.5 ka BP, coinciding with the MIS3/2 transition in the MD95-2006 record. It appears that the margin of the BIS reached the continental slope around 25 ka BP and it is likely that the period between 21.5 and 25 ka BP, represents the maximum extent of the NW Scottish ice sheet. At the time of H4, the BIS was of limited extent whereas the Laurentide Ice Sheet (LIS) was already significantly expanded, thus the dominant radioisotopic signal seen in H4 sediment in MD95-2006 is that of LIS icebergs, overcoming the BIS contribution. In contrast, H2 (21.56-21.72 ka BP) occurs at a time of increased delivery of icebergs from all North Atlantic ice sheets however the MD95-2006 record dominated by the influence of the proximal BIS. This is revealed in both the increased background level of IRD delivery and the correspondence of background and peak IRD radioisotopic ratios tending towards British provenance.
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The modifiable areal unit phenomenon: an investigation into the scale effect using UK census data
https://hdl.handle.net/10023/465
The Modifiable Areal Unit Phenomenon (MAUP) has traditionally been regarded as a problem in the analysis of spatial data organised in areal units. However, the approach adopted here is that the MAUP provides an opportunity to gain information about the data under investigation. Crucially, attempts to remove the MAUP from spatial data are regarded as an attempt to remove the geography. Therefore, the work seeks to provide an insight to the causes of, and information behind, the MAUP.
The data used is from the 1991 Census of Great Britain. This was chosen over 2001 data due to the availability of individual level data. These data are of key importance to the methods employed. The methods seek to provide evidence of the magnitude of the MAUP, and more specifically the scale effect in the GB Census. This evidence is built on using correlation analysis to demonstrate the statistical significance of the MAUP. Having established the relevance of the MAUP in the context of current geographical research, the factors that contribute to the incidence of the MAUP are considered, and it is noted that a wide range of influences are important. These include the population size and density of an area, along with proportion of a variable. This discussion also recognises the importance of homogeneity as an influential factor, something that is referenced throughout the work. Finally, a search is made for spatial processes. This uses spatial autocorrelation and multilevel modelling to investigate the impact spatial processes have in a range of SAR Districts, like Glasgow, Reigate and Huntingdonshire, on the scale effect.
The research is brought together, not to solve the MAUP but to provide an insight into the factors that cause the MAUP, and demonstrate the usefulness of the MAUP as a concept rather than a problem.
2006-06-20T00:00:00Z
Manley, D. J. (David John)
The Modifiable Areal Unit Phenomenon (MAUP) has traditionally been regarded as a problem in the analysis of spatial data organised in areal units. However, the approach adopted here is that the MAUP provides an opportunity to gain information about the data under investigation. Crucially, attempts to remove the MAUP from spatial data are regarded as an attempt to remove the geography. Therefore, the work seeks to provide an insight to the causes of, and information behind, the MAUP.
The data used is from the 1991 Census of Great Britain. This was chosen over 2001 data due to the availability of individual level data. These data are of key importance to the methods employed. The methods seek to provide evidence of the magnitude of the MAUP, and more specifically the scale effect in the GB Census. This evidence is built on using correlation analysis to demonstrate the statistical significance of the MAUP. Having established the relevance of the MAUP in the context of current geographical research, the factors that contribute to the incidence of the MAUP are considered, and it is noted that a wide range of influences are important. These include the population size and density of an area, along with proportion of a variable. This discussion also recognises the importance of homogeneity as an influential factor, something that is referenced throughout the work. Finally, a search is made for spatial processes. This uses spatial autocorrelation and multilevel modelling to investigate the impact spatial processes have in a range of SAR Districts, like Glasgow, Reigate and Huntingdonshire, on the scale effect.
The research is brought together, not to solve the MAUP but to provide an insight into the factors that cause the MAUP, and demonstrate the usefulness of the MAUP as a concept rather than a problem.
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The formation, constitution and social dynamics of orphaned child headed households in rural Zimbabwe in the era of HIV/AIDS pandemic
https://hdl.handle.net/10023/454
This thesis focuses on children who have lost both parents and are currently living on their own as child headed households (CHHs) in a rural community in Zimbabwe. Children heading households and taking care of siblings is a very “un-childlike” behaviour yet these are growing phenomena. Through an exploration of how CHHs are constituted and evolve the thesis aims to examine whether local constructions of childhood are being (re) conceptualised as a result of Zimbabwe’s escalating HIV/AIDS crisis. In particular it examines whether the socialisation of children within ‘child only’ units is leading to social transformation and/or whether children are in some way attempting to mimic ‘normal’ family/gender relations. It also looks at CHH’s interactions with adults and explores how these affect survival strategies, socialisation and conceptualisations of childhood.
This thesis draws on an intensive ethnographic research project with five CHHs and their siblings in a rural community in Zimbabwe. Participant observation, narratives, drama, essays, focus groups, conversations and participatory techniques were employed to gain an in-depth insight into household evolution, the socialisation of family members, gender roles and survival strategies.
The thesis shows that while children living in CHHs are vulnerable, they exhibited considerable competence and capabilities to sustain themselves. However, state and non-governmental organisations’ definition of childhood and orphanhood on the other hand, and cultural and local understanding of childhood and orphanhood produce new conceptual struggles of childhood that impacts negatively on the CHHs’ integration into society and their capacity to function fully.
The ambivalent position of orphaned children in CHHs needs to be addressed if CHHs are to be recognised as an alternative orphan care arrangement.
2008-06-24T00:00:00Z
Francis-Chizororo, Monica
This thesis focuses on children who have lost both parents and are currently living on their own as child headed households (CHHs) in a rural community in Zimbabwe. Children heading households and taking care of siblings is a very “un-childlike” behaviour yet these are growing phenomena. Through an exploration of how CHHs are constituted and evolve the thesis aims to examine whether local constructions of childhood are being (re) conceptualised as a result of Zimbabwe’s escalating HIV/AIDS crisis. In particular it examines whether the socialisation of children within ‘child only’ units is leading to social transformation and/or whether children are in some way attempting to mimic ‘normal’ family/gender relations. It also looks at CHH’s interactions with adults and explores how these affect survival strategies, socialisation and conceptualisations of childhood.
This thesis draws on an intensive ethnographic research project with five CHHs and their siblings in a rural community in Zimbabwe. Participant observation, narratives, drama, essays, focus groups, conversations and participatory techniques were employed to gain an in-depth insight into household evolution, the socialisation of family members, gender roles and survival strategies.
The thesis shows that while children living in CHHs are vulnerable, they exhibited considerable competence and capabilities to sustain themselves. However, state and non-governmental organisations’ definition of childhood and orphanhood on the other hand, and cultural and local understanding of childhood and orphanhood produce new conceptual struggles of childhood that impacts negatively on the CHHs’ integration into society and their capacity to function fully.
The ambivalent position of orphaned children in CHHs needs to be addressed if CHHs are to be recognised as an alternative orphan care arrangement.
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The potential of high resolution palaeoclimate reconstruction from Arctica islandica
https://hdl.handle.net/10023/411
The potential of Arctica islandica, a long lived marine bivalve with a lifespan of over
300 years, to reconstruct a high resolution (sub-annual) climate record is explored in
this thesis. Fluctuations in trace element and isotopic data from live-collected specimens from Irvine Bay, NW Scotland are compared to instrumental (particularly temperature) data.
X-ray absorption spectroscopy data demonstrate the coordination state of Sr and Mg within the shell. These are consistent with models in which Sr substitutes ideally for Ca in aragonite, and Mg is bound predominantly to organic molecules.
Sr/Ca incorporation may be influenced by changes in the crystal nucleation, propagation and growth rate as well as vital effects. However any effect of seawater temperature on Sr/Ca incorporation was obscured by these other factors. Mg concentration is not a linear function of a single environmental variable or organic content within the shell, indicating that Mg uptake is biologically mediated.
Ba variation shows sporadic increases (of >500% above baseline) in both shells, the timing of which is similar between the prismatic layer and umbo region.
The maxima are, however, not synchronous between the two shells analysed. The controls on Ba uptake require further research, but low Ba/Ca may reflect Ba/Ca
concentrations within the seawater.
Aliquots taken from cod otoliths show that micromilling has negligible effect on δ¹⁸O. The range of reconstructed temperature from δ¹⁸O profiles Arctica islandica shows good agreement with the sea surface temperature data from the nearby Millport marine station to within 2.1 °C. However, both the interannual and intra-annual variation appears to be sensitive to changes in temporal resolution resulting from changes in growth rates. Modelling of δ¹⁸O highlights dependence on changes in temporal resolution of the sampling, in addition to temperature and salinity. Results from the radiocarbon pilot study show that Arctica islandica is a suitable archive for changes in radiocarbon associated with anthropogenic ¹⁴C fluxes.
2007-01-01T00:00:00Z
Foster, Laura
The potential of Arctica islandica, a long lived marine bivalve with a lifespan of over
300 years, to reconstruct a high resolution (sub-annual) climate record is explored in
this thesis. Fluctuations in trace element and isotopic data from live-collected specimens from Irvine Bay, NW Scotland are compared to instrumental (particularly temperature) data.
X-ray absorption spectroscopy data demonstrate the coordination state of Sr and Mg within the shell. These are consistent with models in which Sr substitutes ideally for Ca in aragonite, and Mg is bound predominantly to organic molecules.
Sr/Ca incorporation may be influenced by changes in the crystal nucleation, propagation and growth rate as well as vital effects. However any effect of seawater temperature on Sr/Ca incorporation was obscured by these other factors. Mg concentration is not a linear function of a single environmental variable or organic content within the shell, indicating that Mg uptake is biologically mediated.
Ba variation shows sporadic increases (of >500% above baseline) in both shells, the timing of which is similar between the prismatic layer and umbo region.
The maxima are, however, not synchronous between the two shells analysed. The controls on Ba uptake require further research, but low Ba/Ca may reflect Ba/Ca
concentrations within the seawater.
Aliquots taken from cod otoliths show that micromilling has negligible effect on δ¹⁸O. The range of reconstructed temperature from δ¹⁸O profiles Arctica islandica shows good agreement with the sea surface temperature data from the nearby Millport marine station to within 2.1 °C. However, both the interannual and intra-annual variation appears to be sensitive to changes in temporal resolution resulting from changes in growth rates. Modelling of δ¹⁸O highlights dependence on changes in temporal resolution of the sampling, in addition to temperature and salinity. Results from the radiocarbon pilot study show that Arctica islandica is a suitable archive for changes in radiocarbon associated with anthropogenic ¹⁴C fluxes.
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Migration and the informal support networks of older people in Scotland
https://hdl.handle.net/10023/161
This thesis investigates the effects of national patterns of migration on informal support for older adults in contemporary Scotland. It argues that geography matters, and develops a multi-scale conceptual framework to analyse the relationships among population mobility, contrasting local contexts in which older people live, and care and support from the intergenerational family and the community. 130 older persons from three locales with different migration patterns are recruited to the study and a mixed-method approach is adopted, using data from the census, a questionnaire survey and a set of in-depth interviews with both older people and formal service providers.
The findings demonstrate significant differences between the three study locales in terms of the geography of the intergenerational family and the extent and nature of informal support received. Daughters provide more support than sons, suggesting the continuation of traditional gender norms. Local community is important, especially in the rural locale, but friends and neighbours are not providing a substitute for adult children living at a distance. It appears that non-kin respond to need where physical health is compromised but not where the older person suffers from depression. This raises serious questions about the future of family support in an increasingly mobile society with declining fertility and growing numbers of adult daughters in full-time employment. The relationships demonstrated confirm and extend many previous findings, but the discussion concludes that there are some grounds for optimism. The intergenerational family remains important to its members who can and do overcome geographical separation at times of crisis. Further, slowly changing gender norms, combined with contemporary demographic trends, may effect changes in the pattern of intergenerational support, which will, to some extent, offset the worsening older-age dependency ratios predicted for Scotland and other European countries over the next few decades.
2007-01-01T00:00:00Z
Atherton, Iain Maitland
This thesis investigates the effects of national patterns of migration on informal support for older adults in contemporary Scotland. It argues that geography matters, and develops a multi-scale conceptual framework to analyse the relationships among population mobility, contrasting local contexts in which older people live, and care and support from the intergenerational family and the community. 130 older persons from three locales with different migration patterns are recruited to the study and a mixed-method approach is adopted, using data from the census, a questionnaire survey and a set of in-depth interviews with both older people and formal service providers.
The findings demonstrate significant differences between the three study locales in terms of the geography of the intergenerational family and the extent and nature of informal support received. Daughters provide more support than sons, suggesting the continuation of traditional gender norms. Local community is important, especially in the rural locale, but friends and neighbours are not providing a substitute for adult children living at a distance. It appears that non-kin respond to need where physical health is compromised but not where the older person suffers from depression. This raises serious questions about the future of family support in an increasingly mobile society with declining fertility and growing numbers of adult daughters in full-time employment. The relationships demonstrated confirm and extend many previous findings, but the discussion concludes that there are some grounds for optimism. The intergenerational family remains important to its members who can and do overcome geographical separation at times of crisis. Further, slowly changing gender norms, combined with contemporary demographic trends, may effect changes in the pattern of intergenerational support, which will, to some extent, offset the worsening older-age dependency ratios predicted for Scotland and other European countries over the next few decades.