Ice sheet-ocean interactions on the central West Greenland margin during the Last Deglaciation and the early Holocene
Abstract
Hemipelagic sediments from cores collected in 2008 and 2009 from large trough mouth fans formed in front of former active ice-stream margins off central West Greenland provide data to constrain the timing of shelf-edge glaciation, to document the timing of ice retreat and to test the role of the West Greenland Current (WGC) in initiating and/or sustaining ice retreat. Using radiocarbon dates, benthic and planktic foraminiferal assemblages, ice-rafted detritus (IRD), lithofacies analysis and quantitative mineralogical data (qXRD) we begin to test the hypothesis that the central West Greenland ice sheet margin advanced during stadials and retreated during interstadials in response to the absence or presence of ocean warming via the WGC. IRD peaks in the cores result from two distinct processes with climatic significance. IRD-rich intervals with a proximal Greenlandic origin are derived from retreat of the GIS off the shelf edge, whereas detrital carbonate enriched IRD intervals are formed from melting of icebergs calved from Laurentide and Innuitian ice sheet margins in northern Baffin Bay. Detrital carbonate (DC) events dated at 14 cal kyr and 11.5 cal kyr are associated with IRD layers and 'Atlantic' fauna. These layers provide evidence for increased advection of WGC along the West Greenland margin and formation of an IRD belt along the W. Greenland margin during the Bølling-Allerod and early Holocene warm intervals, coincident with MWP1A and MWP1B. The timing of these events is compared to the glacial history documented from the adjacent continental shelf.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFMPP23B2045J
- Keywords:
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- 4901 PALEOCEANOGRAPHY / Abrupt/rapid climate change;
- 9315 GEOGRAPHIC LOCATION / Arctic region