New chronological (14C, OSL), paleontological and geochemical data on developing of ice-dammed lakes in Kurai basin (south-eastern part of the Russian Altai) during the MIS-2

Abstract

One of the highly debatable issue of the Altai Pleistocene paleogeography is the chronology and extension of the last ice-dammed lakes. For the first time paleontological, mineralogical characteristics, and optically stimulated luminescence (OSL) ages for lacustrine deposits confirm accumulation of ice-dammed lake with depth at least 170 m in Kurai basin at the end of the Late Pleistocene - 16-19 ka. New data provide information about the ecology and evolution of this Sartan reservoir. Draining of this lake less affected the topography in comparison with earlier cataclysmic glacier-lakes outburst floods. Nevertheless, the lake controlled human settlement of the basin in the Late Paleolithic. Drying of this reservoir defined formation of the modern hydrological network, including flowing of the Chuya River along the steep gorge between the Maashey and Belgibash mouths. New data evidence for significant difference in evolution of the Kurai-Chuya system of intermountain depressions and Uimon basin at the end of the Late Pleistocene.