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dc.contributor.advisorCawood, P. A. (Peter Anthony)
dc.contributor.advisorRobinson, Ruth Alison Joyce
dc.contributor.advisorSaka, John
dc.contributor.authorManda, Blackwell Chawala
dc.coverage.spatial213 p.en_US
dc.date.accessioned2018-01-12T16:41:12Z
dc.date.available2018-01-12T16:41:12Z
dc.date.issued2016-06-22
dc.identifier.urihttps://hdl.handle.net/10023/12469
dc.description.abstractGlobal 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.en_US
dc.language.isoenen_US
dc.publisherUniversity of St Andrews
dc.rightsAttribution-NonCommercial-NoDerivatives 4.0 International*
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/*
dc.subjectMalawien_US
dc.subjectMozambiqueen_US
dc.subjectLA-ICP-MSen_US
dc.subjectGondwanaen_US
dc.subjectRodiniaen_US
dc.subjectCrustalen_US
dc.subjectEvolutionen_US
dc.subjectMetamorphismen_US
dc.subjectMagmatismen_US
dc.subjectGeochronologyen_US
dc.subjectGeochemistryen_US
dc.subject.lccQE511.M2
dc.subject.lcshGeology--Malawien
dc.subject.lcshEarth (Planet)--Crusten
dc.titleDecrypting the crustal evolution of the Mozambique Belt in Malawien_US
dc.typeThesisen_US
dc.contributor.sponsorUniversity of Malawien_US
dc.contributor.sponsorNERC Isotope Geosciences Laboratories (NIGL)en_US
dc.contributor.sponsorUniversity of St Andrewsen_US
dc.type.qualificationlevelDoctoralen_US
dc.type.qualificationnamePhD Doctor of Philosophyen_US
dc.publisher.institutionThe University of St Andrewsen_US
dc.publisher.departmentUniversity of Malawien_US


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