ИСТИНА

Periglacial areas of Weichselian ice sheets are long studied as a source of climatostratigraphic data correlatable with the global paleorecords and to understand the complex landscape response to changes in glacial dynamics. Pronounced loess-paleosol series majorly accumulated along the southern margins of the periglacial zone proved to be a reliable paleoarchive for such reconstructions. However, the closer periphery of past ice sheets still lacks a comparable paleorecord as the thickness of postglacial deposits declines northward against the growing intensity and dynamics of landscape transformations. A specific loamy mantle, which has remained a stumbling block for over a century-long scientific discussion, covers the interfluvial areas of central and northern parts of the East-European Plain. It can be regarded as a northern substitute of loess-paleosol series though of a rather more homogenous and less explicit structure that left its genetic and age interpretations quite inconsistent and controversial. Nevertheless, a detailed investigation of several uplands in the marginal zone of the Late Saalian glaciation allowed us to distinguish the facies architecture of cover loams. We elucidated the principal set and succession of characteristic lithostratigraphic units separated by a series of superimposed cryogenic and paleosol horizons, which eliminate the heterogenous origin and prolonged accumulation of the loamy mantle during the Late Pleistocene. Buried cryogenic deformations and paleosol features can be utilized both as stratigraphic markers and climate indicators when their position and replicability in paleolandscapes are considered. The lithological structure of each unit reflects a specific set of features indicating distinct changes in periglacial paleoenvironments that turn out to be either gradual or abrupt revealing several major erosion episodes during the Weichselian. That elaboration on the morphostratigraphy of cover loams was enabled due to a combined application of macro-, meso- and micromorphologic methods during both field and laboratory examination of 3D-organization of deposits supplemented by geomorphic analysis of modern and paleotopographies of interfluves. That provided a reliable basis for chronostratigraphic correlations throughout the entire Late Pleistocene periglacial zone showing a high potential of the hierarchical morphogenetic approach to unravel the depositional history of such clastic sedimentary covers often lacking a precise numerical age control.