THE LATE WEICHSELIAN BARENTS-KARA ICE SHEET: IN DEFENSE OF A MAXIMUM RECONSTRUCTION

Abstract

Extent of the Late Weichselian glaciation in western Arctic Russia is considered uncertain. Grosswald''s model suggesting a continuous and long-lived Barents-Kara Ice Sheet centered on the Kara Sea is questioned by advocates of "restricted'''' models, including the QUEEN Program members. Based on sets of radiocarbon dates, they argue for a smaller and "diachronous'''' glaciation. However, the QUEEN reconstruction is inconsistent with the record of ice flow across the Kara-Barents divide, as well as with glacial geology of Kola Peninsula, Late Weichselian climate of the Arctic, Eurasian continental paleohydrology, and the entire paleogeographic context of northern Eurasia. As for the sets of radiocarbon dates, they appear erroneous (too old), these dating errors having been due to impeded ventilation of the Pleistocene Arctic Ocean and to recycling and contamination of the sampled materials. Destructive impacts of late-glacial ice-sheet surges and Eurasian megafloods upon the glacial sequences would also aggravate the situation. Thus we [Grosswald and Hughes, 1995\link44, 2002\link45] choose to ignore the dates until these problems are addressed. The rest of evidence supports extensive and continuous glaciation of the Barents-Kara continental margin at the last glacial maximum (LGM). Our reconstructions depict the Barents-Kara Ice Sheet before and after massive thawing of its bed that allows partial gravitational collapse of the overlying ice.