Based on the results of field research, analysis of high-resolution satellite images, detailed study and dating of sediments and soils of  the Nadeinovo, Nizhniy Bulanka and Kuitun sections in the Western  Transbaikalia, the areas of modern development of cryogenic  processes and horizons with cryoturbations of 14.2–11.7 kyr BP  were revealed. Modern cryogenic processes (frost heaving, cracking) are clearly manifested in wetlands of river valleys. Small (up to 1 m)  tufura drums and thermokarst depressions predominate in the  riverbeds of Kuitunka and Tarbagatayka. The time of formation of  paleocryogenic horizons was established in the Nadeino section,  where three layers were distinguished with cryogenic deformations  dated to ~14.2–14.0, ~12.7–12.5 and 11.9–11.7 cal kyr BP. In the  Nizhniy Bulanka section, a thick cryogenic horizon was found, which  formed ~12.8 kyr BP. In the Kuytun section, a buried thermoerosion- suffosion gully was discovered that formed ~14.5–14.3 kyr BP. There  are syngenetic and epigenetic cryogenic horizons. In the  Kuitunka river basin, polygonal-block morphology is distinguishable  within plowed areas of watersheds and slopes on high-resolution  satellite images. Dimensions of the hillocks range from 4 to 50 m,  height – 0.5–2 m. The hummocks are divided by depressions and  hollows. The time of formation of this paleocryogenic relief is the Early Sartan (29–23 kyr BP). Subsequently, the polygonal-block  relief experienced several stages of formation and destruction and in  the Holocene turned into a hilly-valleys relief with the island  distribution of permafrost. Thawing of permafrost in the warming of  the Late Glacial and early Holocene caused the activation of thermal  erosion, linear erosion, suffosion and changes in the microrelief in  the upper parts of the erosion network. Modern dells, rills, gullies partially inherit paleocryogenic depressions and troughs.