Deglaciation history and palaeoceanography of the western Spitsbergen margin since the last glacial maximum

Abstract

Abstract Two high resolution cores from the Spitsbergen margin were studied to increase the understanding of the palaeoceanography and deglaciation of the Spitsbergen continental margin. Planktonic and benthic foraminiferal δ18O records along with foraminiferal abundance counts and dropstone analysis were used to interpret the palaeoceanography of the Spitsbergen margin and to link the marine record with deglaciation of the Barents Sea Ice Sheet. High foraminiferal and dropstone abundances during the Late Weichselian glacial maximum show that this period was characterized by seasonally ice-free conditions. The initial deglaciation recognized along the Spitsbergen margin is dated at 14.1 ka BP and represents the break up of the Barents Sea Ice Sheet, though some input from the Spitsbergen ice dome is likely. This initial deglaciation was produced by glacio-isostatic relative sea-level rise and/or by increased solar insolation after the minimum of the Late Weichselian. The first unequivocal deglaciation of Spitsbergen ice occurred at 13 ka, whereas the oceanographic regime was still dominated by polar waters. The beginning of the Holocene was heralded by a second deglaciation phase of the Spitsbergen ice mass. The first influx of North Atlantic waters causing rapid iceberg calving and melting was recorded at this time. Dropstone input virtually ended at approximately 9 ka BP when most glaciers had retreated beyond their present day positions. A short relatively cool episode produced by the retreat of the North Atlantic waters during the early Holocene was recorded along the Spitsbergen margin.