Late Weichselian to Holocene paleoenvironments in the Barents Sea

Paleoceanographic changes since the Late Weichselian have been studied in three sediment cores raised from shelf depressions along a north–south transect across the central Barents Sea. AMS radiocarbon dating offers a resolution of several hundred years for the Holocene. The results of lithological and micropaleontological study reveal the response of the Barents Sea to global climatic changes and Atlantic water inflow. Four evolutionary stages were distinguished. The older sediments are moraine deposits. The destruction of the Barents Sea ice sheet during the beginning of the deglaciation in response to climate warming and sea level rise resulted in proximal glaciomarine sedimentation. Then, the retreat of the glacier front to archipelagoes during the main phase of deglaciation caused meltwater discharge and restricted iceberg calving. Fine-grained distal glaciomarine sediments were deposited from periodic near-bottom nepheloid flows and the area was almost permanently covered with sea ice. The dramatic change in paleoenvironment occurred near the Pleistocene/Holocene boundary when normal marine conditions ultimately established resulting in a sharp increase of biological productivity. This event was diachronous and started prior to 10 14C ka BP in the southern and about 9.2 14C ka in the northern Barents Sea. Variations in sediment supply, paleoproductivity, sea-ice conditions, and Atlantic water inflow controlled paleoenvironmental changes during the Holocene.

[1]  R. Stein,et al.  Late Quaternary growth and decay of the Svalbard/Barents Sea ice sheet and paleoceanographic evolution in the adjacent Arctic Ocean , 1998 .

[2]  L. Polyak,et al.  Post-glacial environments of the southeastern Barents Sea: foraminiferal evidence , 1996, Geological Society, London, Special Publications.

[3]  S. Forman,et al.  Late-glacial and Holocene paleoceanography and sedimentary environments in the St. Anna Trough, Eurasian Arctic Ocean margin , 1999 .

[4]  P. Reimer,et al.  Extended 14C Data Base and Revised CALIB 3.0 14C Age Calibration Program , 1993, Radiocarbon: An International Journal of Cosmogenic Isotope Research.

[5]  J. Dowdeswell,et al.  Maximum extent of the Eurasian ice sheets in the Barents and Kara Sea region during the Weichselian , 1999 .

[6]  T. Dokken,et al.  Rapid climatic shifts during isotope stages 2 4 in the Polar North Atlantic , 1996 .

[7]  J. Duplessy,et al.  Holocene paleoceanography of the northern Barents Sea and variations of the northward heat transport by the Atlantic Ocean , 2001 .

[8]  S. Forman,et al.  Late Weichselian deglacial history of the Svyataya (Saint) Anna Trough, northern Kara Sea, Arctic Russia , 1997 .

[9]  Wolfgang Kuhnt,et al.  Changes in Artic Ocean paleoproductivity and hydrography during the last 145 kyrs: the benthic foraminiferal record , 2001 .

[10]  T. Vinje,et al.  Barents Sea drift ice characteristics , 1991 .

[11]  S. Forman,et al.  Radiocarbon content of pre‐bomb marine mollusks and variations in the 14C Reservoir age for coastal areas of the Barents and Kara Seas, Russia , 1997 .

[12]  A. Solheim,et al.  Late‐and postglacial environments in the northern Barents Sea west of Franz Josef Land , 1994 .

[13]  L. Polyak,et al.  Glacigenic deposits of the Central Deep: a key to the Late Quaternary evolution of the eastern Barents Sea , 1993 .

[14]  J. Andrews.  Late Quaternary Palaeoceanography of the North Atlantic Margins , 1996 .