Late glacial events in the central Russian Arctic

Abstract

Investigation of glacigenic diamictons and landforms in the central Russian Arctic has established that continental glaciation was widespread during late glacial time. Diamictons in West-Central Siberia containing marine foraminifera and mollusca include glacitectonic deformation features, and are associated with glacial landforms. These sediments are interpreted as basal tills, formed by continental glaciation which expanded from the exposed Kara Sea shelf, southwards along the western flank of the Ural Mountains. Piedmont glaciers advancing westward from the Urals were obstructed by the southward-flowing ice and were areally restricted. Simultaneously, piedmont glaciers advancing eastward from the crests of the Urals were able to expand without restriction. Alpine glaciation within the Urals was areally restricted and culminated, simultaneously, with the maximum extent of the southward-flowing shelf-based ice. In West Siberia, rapid disintegration of an Early Weichselian ice sheet by marine calving was followed by slow stagnation of the dissected mass throughout the remainder of the Weichselian. In contrast, glaciation in the Pechora Basin reached its maximum during the Middle-Late Weichselian, at least 30,000 years after the glacial maximum in western Siberia. The transition to Holocene climatic conditions was influenced by the presence of remanent decaying glacial masses.