The burial of soils in the widespread layers of the ice complex basically occurs by activating natural exogenous processes: landslides, landslips, mudflows. These processes, in their turn, can be caused by a certain combination of circumstances of natural or anthropogenic character, or in their combination. The article is provided morphological, physical and chemical characteristics of the properties and composition of pedocomplexes in slope sediments of the basin of alás Oner in Ust-Aldansky district, floodplain terraces of the right bank of the lower reaches of the Aldan river, opposite the mouth of the Buoya river, and a high terrace of the left bank of the Lena river in the Sinsk village. Buried profile of the investigated soils is clearly shown by the morphology and number of features, such as granulometric composition, pH value, hygroscopic moisture, humus and exchangeable cations. Pyrogenic origin of the coals in the upper horizons of surface and buried soils should be noted. Fires in Central Yakutia, capturing large areas with dissected relief, serve as a trigger for the activation of slope and thermoerosion processes, which in their turn may cause burial of soils. Alas′s soil formation has a synlithogenic character as a result of abrasion during formation of alas′s depression, which is filled by a lake. Burial of soil horizons on the sides of mature alas may be improved by increasing the water availability in lake, strengthening of thermoerosion, proluvial-deluvial and other exogenous processes in the adjacent landscapes.