Suprapermafrost Horizons of the Accumulation of Raw Organic Matter in Tundra Cryozems of Northern Yakutia

Resumo

In the profiles of cryozems (Oxyaquic Turbic Cryosols) developing in tundra of northern Yakutia under conditions of shallow active layer, suprapermafrost horizons of the accumulation of raw organic matter are formed. Taking into account their genesis, stable and regular position in the soil profile, paragenetic links with the overlying horizons and neighboring soil profiles, and a set of diagnostic features and properties, these horizons can be separated as a new type of genetic soil horizons—the organomineral accumulative suprapermafrost horizon (CRO). Its qualitative composition (the ratio of organic and mineral matter in the material) can be reflected at a lower level. In relation to the separation of the new genetic horizon within the framework of the new Russian soil classification system, a new genetic types of soils—cryozem with suprapermafrost accumulation of raw organic matter (suprapermafrost organo-accumulative cryozem)—can be established. Its diagnostic profile has the following horizonation: (O, AO, T)–CR–CRO–┬C.