Geophysical processes and biosphere: article

Аnnotation: The work is devoted to the study of paleocryogenic formations and lithogenic dislocations that arose both during and after the formation of deposits in the Dmitrov quarry, Moscow region (56°19ʹ07ʹʹ N, 37°33ʹ16ʹʹ E). In the top of the Mikulinski-Early Valdai lacustrine-swamp complex, subaerial initially ground veins filled with mantle loams, which formed into the cold final stage of the Early Valdai (MIS 4), in its lower layer there are subaqueous pseudomorphoses along polygonal wedge ice (PWI) in the form of enveloping structure, were identified. At the boundary of deposits of the Moscow and Mikulinski age, ground veins with a vertical orientation of coarse clastic host layers are described, which, in our opinion, may have a convective nature. In the middle part of the section of the marginal zone of the Mikulinsky complex, in sandy-silty sediments with clay interbeds displaced along the consedimentary normal fault, pseudoseismogenic diagenetic disturbances were found in the form of convolute folds at the sand/clay boundary and pseudonodules of sand in peat sand and sand in silt. These structures could be the result of the development of gravitational instability of sediments with contrasting density, which is consistent with the lower dispersion and higher density of sediments in the upper layer of convolutions or inside pseudonodules. The results obtained significantly refine the conditions for the formation of ground disturbances in Quaternary deposits of tectonically stable periglacial regions.