Abstract: The object of this research is the permafrost sandy soils of Eastern Siberia. Their age range spans from the Mesozoic through the Holocene. The pre-quaternary permafrost sands are developed within the limits Vilyuy syneclise and Khatanga trough, and fall into the epicryogenic category. The quaternary sands are composed of aqueoglacial, glaciolacustrine, marine alluvial-marine, eolian, lacustrine-alluvial and alluvial genetic units. In the northern districts, the syncryogenic soils usually compose the upper part of the cutoffs of these units, while underlying the epicryogenic soils. In central and southern districts, the epicryogenic sands are often embedded on the surface. The study of archive and published materials allowed revealing and generalizing the peculiarities of composition, structure and characteristics of permafrost sands of the platform and mountain territories of Eastern Siberia. It is noted that their granulometric composition extensively varies – from gravelly to silty types. The higher is the sand dispersion, the higher is their natural moisture and porosity factor, and the lower is the density of soil and soil skeleton. The fine and silty sandy soils often have a schlieren cryogenic structure, significantly settle during thawing and frequently develop into the running sands. The larger sands have a predominantly massive cryogenic structure, and settle insignificantly during thawing.

Abstract: The object of this research is the synchrogenic sands that developed in the Russian territories. They are present in the coastal areas of the young Timan-Pechora basub and Pai-Khoi, north of the young West Siberian and Yano-Kolyma platforms, north and the center of the ancient Siberian platform; young Verkhoyano-Chukotka and ancient Baikal-Patomsk orogens, the upper zone of the ancient Altai-Sayan orogen, present riftogene Baikal as well as on some islands of the Arctic shelf.
A schematic map of the extent of different genesis Quaternary sands within the cryolithozone of Russia is compiled. The main regularities of the spatial distribution syncryogenic sands have been identified on this basis and by analysis and synthesis of existing publications on the topic. Most often syncryogenic sands are part of Upper Pleistocene-Holocene complexes of marine, marine deltaic and alluvial genesis, rarely lacustrine and alluvial, glaciolacustrine, glaciofluvial and eolian. Additionally, more ancient Middle Pleistocene-Holocene formations on the West Siberian and Yano-Kolyma platforms and Early Pleistocene-Holocene on the Siberian platform are exposed. Syncryogenic sands occur in the upper part of the section of different geomorphic elements and often overlain epicryogenic one.