Shestakovo site of Western Siberia (Russia): Pedogenic features, humic substances and paleoenvironment reconstructions for last 20-25Â ka

New data characterizing sediments of the Shestakovo-III section located in the southern part of the West Siberian plain have been obtained. The section reveals 9 m of strata in which a number of paleosols and pedogenic zones are identified on the basis of cumulative features of pedogenesis. Paleosols and pedogenic features reflect the pedogenic transformation of sediments in different environments during the late Karghinsk interval (W2), Sartan Glaciation (W3) and Holocene period. The lower part of the sediments at a depth of 7.5-8.5 m has radiocarbon dates from 25 to 18,000 years. The obtained characteristics of the composition, structure and properties of humic substances, as well as comparison with data obtained earlier by other methods of environmental reconstruction enable recognition of the environment at the southern margin of the West Siberia Plain during the last 20-25 ka in more detail.