Special features of slope deposits structureo in the Sikhote-Alin uplands

Abstract

Some horizons (1 to 3) with increased density and clay content (up to 50%) are well pronounced in coarse slope deposits in various regions of the Sikhote-Alin uplands. Their mean depth of occurence ranges from 1 to 2,5 m. Their formation is related to a number of factors and processes, such as 1) elastic material outwash from upper layers of the slope cover and its accumulation on the contact with more compact rocks, 2) interchanging saturation - drying up of surface stratum (0,4-0,6 m) which goes along with swelling and shrinkage of the ground, 3) «cryogenic packing» of sediments at the contact of the active layer with frozen ground or with solid rocks. Sequences of slope deposits demonstrate superimposed results of all processes varied in space and time or having acted simultaneously. The second group seems to be most important, with most distinct lithogenetic effect on the western macroslore of Sikhote-Alin. A great number of these formations appear to be inherited of relict, their origin being related to former permafrost or cryogenesis.