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Quantifying Provenance and Transport Pathways of Holocene Sediments From the Northwestern Greenland Margin

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Caron, Myriam et Montero-Serrano, Jean-Carlos et St-Onge, Guillaume et Rochon, André (2020). Quantifying Provenance and Transport Pathways of Holocene Sediments From the Northwestern Greenland Margin. Paleoceanography and Paleoclimatology, 35 (5).

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Résumé

The mineralogical and geochemical compositions of three sediment cores from the northwestern Greenland continental margin (AMD14‐204 and AMD14‐210) and Kane Basin (AMD14‐Kane2B) were investigated using quantitative X‐ray diffraction and energy‐dispersive X‐ray fluorescence in order to document the impact of ice‐ocean interactions on the sediment provenance and transport pathways during the Holocene. Unmixing of the sediment composition and ratios such as quartz/clays and K/Fe indicate that detrital sediments in cores from the northwest Greenland margin are derived mainly from Prøven granite and reworked Archean gneiss, whereas sediments from Kane Basin are derived mainly from detrital carbonate (Ellesmere Island) and Proterozoic gneiss (Humboldt Glacier). Mineralogical and geochemical signatures also reveal that changes in detrital sediment provenance and transport in the region are strongly interconnected to regional ice stream dynamics, especially during the early Holocene with strong meltwater discharge from the Greenland Ice Sheet associated with the end of deglaciation. With the establishment of milder conditions during the mid‐Holocene and reduced glacial activity once ice sheets retreated inland, sediment inputs via ocean currents became more effective. Thus, detrital proxies in core AMD14‐204, located in the Upernavik cross‐shelf trough, support the hypothesis of an intensification of the West Greenland Current influence after 7.7 cal ka BP, which eventually affected the regional sediment dynamic by a greater contribution from basalt to the sediment supply. Finally, our results suggest that the interactions between climate, glacial dynamics, and surface ocean circulation controlled the paleoenvironmental changes observed in the three cores. -- Keywords : Baffin Bay ; Nares Strait ; Holocene ; quantitative bulk mineralogy (qXRD) ; sedimentary geochemistry (ED‐XRF).

Type de document : Article
Validation par les pairs : Oui
Information complémentaire : Cet article a été publié par AGU. Copyright (2020) American Geophysical Union. This paper was published by AGU. Copyright (2020) American Geophysical Union.
Départements et unités départementales : Institut des sciences de la mer de Rimouski (ISMER)
Déposé par : DIUQAR UQAR
Date de dépôt : 16 oct. 2020 14:52
Dernière modification : 16 oct. 2020 14:52
URI : http://semaphore.uqar.ca/id/eprint/1676

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