Problems of the Cryogenic Soils’ Diagnostics in the Recent Russian Soil Classification System

Resumo

The paper is targeted at positioning the cryogenic soils in the recent classification system of Russian soils. An on-line discussion and recent publications demonstrated significant differences in conceptual approaches to cryogenic soils, as well as their unaccounted diversity in the permafrost zone and their dynamics in time (e.g., during the thawing period) that create problems for their classification. In particular, the results depend on the observation time. Diagnostic properties of cryogenic horizon and the depth of the active layer were in the center of the discussion. Possible changes in the list of soil types and subtypes are proposed for the next approximation of the Russian soil classification system. The Cryozem order is proposed for the soils with the cryogenic diagnostic horizon (CR) and the maximum active layer depth of 1 m and less. Soils with other diagnostic horizons and with the active layer depth of more than 1 m should be accounted as permafrost-affected soils within the other orders of the soil classification system. Authors invite colleagues to further discussion with the aim to establish standard classification criteria for cryogenic soils.