Sea ice, ice‐rafting, and ocean climate across Denmark Strait during rapid deglaciation (∼16–12 cal ka BP) of the Iceland and East Greenland shelves

ABSTRACT A suite of cores from the North‐West Iceland and East Greenland shelves sampled fossiliferous or unfossiliferous basal glacial diamictons. Radiocarbon dates above the diamictons are similar on both shelves, but the value of the ocean reservoir correction, Δ R , is unknown. Deglaciation occu...

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Bibliographic Details
Published in:Journal of Quaternary Science
Main Authors: Andrews, J. T., Cabedo‐Sanz, P., Jennings, A. E., Ólafsdóttir, S., Belt, S. T., Geirsdóttir, Á.
Other Authors: National Stroke Foundation, Icelandic Centre for Research
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2017
Subjects:
Greenland
Denmark Strait
East Greenland
Ice Sheet
Iceland
Neogloboquadrina pachyderma
Planktonic foraminifera
Sea ice
Online Access:http://dx.doi.org/10.1002/jqs.3007
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjqs.3007
https://onlinelibrary.wiley.com/doi/pdf/10.1002/jqs.3007
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Summary:ABSTRACT A suite of cores from the North‐West Iceland and East Greenland shelves sampled fossiliferous or unfossiliferous basal glacial diamictons. Radiocarbon dates above the diamictons are similar on both shelves, but the value of the ocean reservoir correction, Δ R , is unknown. Deglaciation occurred either ∼16 or 14 cal ka BP depending on the choice of Δ R . The ice sheets were behind the present coastline by 12.2 cal ka BP. We examine seven cores that record the glacial/deglacial transition and present new data on the sea‐ice biomarkers IP 25 and C 25:2 from four of the cores plus data on ice‐rafted debris counts, grain‐size spectra, δ 18 O on the near‐surface planktonic foraminifera Neogloboquadrina pachyderma (s), foraminifera assemblages, and quartz percentage. IP 25 concentrations are markedly higher for the East Greenland sites, while they are frequently below the limit of quantification off Iceland, observations that parallel the wt% quartz in the sediments. The δ 18 O N. pachyderma (s) data show a strong gradient across Denmark Strait with lighter δ 18 O values towards the East Greenland shelf indicative of a large freshwater flux. The presence of the chilled Atlantic Water benthic foraminifera, Cassidulina neoteretis indicates that rapid ice sheet retreat was associated with ocean forcing, combined with other factors.

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