PLEISTOCENE GLACIATIONS IN THE EAST TRANSBAIKALIA AND THE SOUTHEAST OF MIDDLE SIBERIA

Abstract

The maps of four Pleistocene glaciations were compiled: Samarovo (Q II sm), Taz (Q II tz), Muruktin (Q III mr), and Sartan (Q III sr). The maps show distribution of glaciers, ice sheets, and ice-dammed lakes, which occupied vast areas in the river basins of Lena, Vitim, and Olekma. The absolute heights of paleo lakes in the Lena basin are 400 m (tz), 560 m (sm); in the Vitim basin: 860 m (sr), 880 (mr) 900 m (tz); in the Olekma basin: 680 m (mr), 760 m (tz). Well drilling fulfilled to 1180 m depth revealed four glacial layers of Middle and Upper Pleistocene in the interval 0-450 m. Sand sediments were formed due to coastal accumulation of abraded granitic material in the Transbaikaline periglacial lake of the Samarovo age with short-term maximum level of 1020 m and stabile long-term one of 900 m.