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This is a critical review of disputable chronostratigraphic results in the Upper Pleistocene of glaciated Russia including the West Siberian and Russian Plains. The main goal is to assess the validity of stratigraphic tools used for long-distance correlation of young sedimentary formations. The test is performed by comparison of i) Russian stratigraphic schemes of two last glacial cycles against the West European ones and ii) the traditional stratigraphic scales of Russia against the new chronological results brought up by modern dating tools. The multitude of AMS radiocarbon, optical luminescence, uranium series and electron-spin resonance dates obtained by international research projects allowed to reconsider the age of the main stratigraphic markers of Siberia which proved to be by one glacial cycle older than suggested by the traditional correlation schemes. The correlation wisdom in central European Russia for the time being cannot be satisfactorily revised using the statistical approach because of the limited supply of chronometric data. The palaeoenvironments inferred from palynological data in central European Russia are in discrepancy with the presumably coeval periglacial landscapes of Western and Central Europe. This divergence implies that the traditional chronostratigraphic correlation of the older Middle Valdaian interstadials with their Pleniglacial counterparts of MIS 3 stage is probably erroneous. The correlation errors mainly stem from the age underestimation by conventional radiocarbon dates used as chronological links of the Russian Pleistocene formations. [ABSTRACT FROM AUTHOR]

Abstract: The paper summarizes the results of recent studies of Late Pleistocene postglacial geological events which occurred in the flatlands of northern Russia stretching from the Timan Ridge to the Laptev Sea coast. The available sedimentary record includes thawed and perennially frozen subaerial sediments and in places lacustrine and fluvial formations. Hundreds of geochronometric measurements by radiocarbon and luminescence techniques place this record within the time span of 50–11 ka BP which confirms an Early–Mid-Weichselian age of the underlying glacial complex first established by the QUEEN programme. The spectrum of proxies includes sedimentary facies, pollen data, plant macrofossils, oxygen isotope values, megafauna remains, insect assemblages, traces of DNA, paleosols and permafrost properties. Together they indicate a continental, progressively deteriorating climate with very cold winters and warmer than present summers through the second half of the Late Pleistocene. Minor climatic fluctuations are largely due to slightly changing humidity during MIS 3. These changes are more pronounced in periglacial European Russia in the vicinity of the Barents–Kara ice sheet where the Mid-Weichselian biotic maximum contrasts with conditions in the Late Weichselian polar desert. In Siberia, the periglacial environments were more stable and beneficial for biota inspite of the increased continentality. The recent data accumulated by various researchers are incompatible with the conventional correlation of the Karginsky interglacial strata of Siberia with MIS 3 or any part of the European Pleniglacial. [Copyright &y& Elsevier]