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dc.contributor.authorChannell, J. E. T.
dc.contributor.authorHarrison, R. J.
dc.contributor.authorLascu, I.
dc.contributor.authorMcCave, I. N.
dc.contributor.authorHibbert, F. D.
dc.contributor.authorAustin, W. E. N.
dc.identifier.citationChannell , J E T , Harrison , R J , Lascu , I , McCave , I N , Hibbert , F D & Austin , W E N 2016 , ' Magnetic record of deglaciation using FORC-PCA, sortable-silt grain size, and magnetic excursion at 26 ka, from the Rockall Trough (NE Atlantic) ' , Geochemistry, Geophysics, Geosystems , vol. 17 , no. 5 , pp. 1823-1841 .
dc.identifier.otherBibtex: urn:bfcdaf53eb8b1e940ef74cb465366ba3
dc.descriptionResearch supported by US NSF grants 0850413 and 1014506, and the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013) / ERC Grant Agreement No. 320750. The UK NERC and BGS funded the recovery of Core MD04-2822.en
dc.description.abstractCore MD04-2822 from the Rockall Trough has apparent sedimentation rates of ∼ 1 m/kyr during the last deglaciation (Termination I). Component magnetization directions indicate a magnetic excursion at 16.3 m depth in the core, corresponding to an age of 26.5 ka, implying an excursion duration of ∼350 years. Across Termination I, the mean grain size of sortable silt implies reduced bottom-current velocity in the Younger Dryas and Heinrich Stadial (HS)-1A, and increased velocities during the Bølling-Allerød warm period. Standard bulk magnetic parameters imply fining of magnetic grain size from the mid-Younger Dryas (∼12 ka) until ∼ 8 ka. First-order reversal curves (FORCs) were analyzed using ridge extraction to differentiate single domain (SD) from background (detrital) components. Principal component analysis (FORC-PCA) was then used to discriminate three end members corresponding to SD, pseudo-single domain (PSD) and multidomain (MD) magnetite. The fining of bulk magnetic grain size from 12 to 8 ka is due to reduction in concentration of detrital (PSD+MD) magnetite, superimposed on a relatively uniform concentration of SD magnetite produced by magnetotactic bacteria. The decrease in PSD+MD magnetite concentration from 12 to 8 ka is synchronized with increase in benthic δ13C, and with major (∼70 m) regional sea-level rise, and may therefore be related to detrital sources on the shelf that had reduced influence as sea level rose, and to bottom-water reorganization as Northern Source Water (NSW) replaced Southern Source Water (SSW).
dc.relation.ispartofGeochemistry, Geophysics, Geosystemsen
dc.subjectMagnetic granulometryen
dc.subjectFORC-PCA analysisen
dc.subjectSortable silten
dc.subjectMagnetic excursionen
dc.subjectTermination Ien
dc.subjectRockall Troughen
dc.subjectGE Environmental Sciencesen
dc.titleMagnetic record of deglaciation using FORC-PCA, sortable-silt grain size, and magnetic excursion at 26 ka, from the Rockall Trough (NE Atlantic)en
dc.typeJournal articleen
dc.contributor.institutionUniversity of St Andrews. Geography & Sustainable Developmenten
dc.contributor.institutionUniversity of St Andrews. Marine Alliance for Science & Technology Scotlanden
dc.contributor.institutionUniversity of St Andrews. Scottish Oceans Instituteen
dc.contributor.institutionUniversity of St Andrews. St Andrews Sustainability Instituteen
dc.description.statusPeer revieweden

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