Based on analyzing the catenary sequence of soils and parent materials down the northern slope of the Klin-Dmitrov Ridge adjacent to the Upper Volga Lowland (formerly the periglacial zone of the Russian Plain), it was revealed that sediments including sandy loams, clay loams and clays, which constituted slope terraces at heights from 130 to 180 m a.s.l. and often accounted for lithic discontinuities in soil profiles, had glacio-lacustrine genesis, i.e., they had accumulated during the existence of a periglacial dammed lake at the final stages of the Late Pleistocene.