Soil formation and the underlying permafrost

The composition and fabric of the upper permafrost layer and its relationships with the permafrost-affected soils developing from the loamy substrates on the interfluves within coastal lowlands of northern Yakutia are considered. The studied area is characterized by the maximum activity of cryogenic processes and a shallow depth of seasonal thawing. The permafrost layer affected by the maximum thawing during the Holocene has a specific morphology attesting to the impact of soil processes on it. In general, the modern soil profile and the underlying permafrost layer can be distinguished as the soil-permafrost complex. It is subdivided into the soil profile, the transient layer, and the intermediate layer. The morphology and properties of the transient layer depend on the character of the soil horizons above the permafrost table. The lateral migration of raw organic substances takes place above the permafrost surface between the particular elements of the cryogenic soil complexes; this material tends to accumulate within the transient layer.