Environmental conditions of the maximum phase of the Last Glaciation: reconstruction based on the studies of sediments of lakes Chukhlomskoye and Galichskoye

Abstract

The paper discusses new palynological data obtained from the bottom sediments of Lake Chukhlomskoye (Kostroma region). The location of the lake beyond the limits of the Late Valdaian ice sheet made it possible to reconstruct the vegetation changes during the maximum phase of the glaciation and compare them with previously obtained data from sediments of Lake Galichskoye. 25-21 thousand calibrated years BP, the region was occupied by open periglacial steppe with limited participation of birch and spruce open forests in the most protected habitats, with continuous spread of permafrost. Climatic reconstructions based on the modern geographical analogue of the fossil pollen flora indicate that mean annual temperature in the region was about ˗4 °C (7 °C below modern), and annual precipitation was at near-present level.