Аннотация:In this article we present the materials in respect to the Quaternary paleocryological, paleosols and paleobotanic development in the north of the West Siberian Plain. Data demonstrating wide distribution of polygonal-wedge structures in the region are elucidated. The structures represent polygonal ice wedge pseudomorphs and initially ground wedges. The former developed in the terminal phase of the Pleistocene in the end of marine isotope stage1 2 (MIS-2), and are the successors of the epigenetic polygonal ice wedges which cut the Karginian (MIS-3) alluvial mass, whereas the second formed in the syncryogenetic alluvial deposits in the course of MIS-3. Redeposited material of cryohydromorphic paleosols has been revealed in the filling of the pseudomorphs; fragments of humus horizon are included – they are used for 14C-dating. Spore-pollen spectrum in that filling shows prevalence of boggy tundra and tundra-steppe vegetation. The set of obtained data casts doubt on hypothesis of prevalence of cold deserts and ice sheets in the study area and shows existence of developed vegetable cover at a background of sufficient and, in places, superfluous moistening. It occurs on account of close position of the permafrost roof. Also the inference in respect to non-glaciated development of the region in the cryochrons, which are similar to MIS-2, is concluded.
