Middle pleistocene glaciations of the Russian north

Geological data on the pre-Eemian glaciations of northern Russia, including the latest results by the Russian-Norwegian PECHORA project, are synthesized in order to present evidence for comparison with other early glaciations around the Arctic. The bulk of evidence indicates that Arctic and Subarctic regions of European Russia, of western and central Siberia during the Middle Pleistocene were at least 4 times covered by large ice sheets, which advanced mainly from the shelf ice domes, partly from Fennoscandia and the Putorana Plateau. Ice accumulations in the Ural Mountains were insignificant and did not form any noticeable ice dispersal centres. Unlike the classical glaciated areas, ice sheets of northern Russia acted mainly on a soft, perennially frozen substrate, which was heavily glacitectonised. The Middle Pleistocene ice sheets were much larger than the Weichselian ones. The Fennoscandian ice dispersal centre was most active in northern European Russia during the penultimate glaciation (OIS 6) when shelf-centred ice domes were relatively weaker. Larger continental ice sheets were formed in preceding ice ages, when Kara Sea ice dispersal centre dominated. The lowland ice sheets reached their maximum extent at different stages, from Cromerian Don glaciation in European Russia to OIS 8 in West Siberia. Therefore, the maximum ice limit is time-transgressive in northern Russia. (C) 2003 Elsevier Ltd. All rights reserved.