Micromorphological diagnostics of the pedogenic processes in soils of Eravninskaya depression in Transbaikalia

We have investigated the physico-chemical properties and micromorphological structure of the soils of Eravninskaya Depression in Transbaikalia. The Luvic Chernozem (Tonguic) is formed on the ancient lake plains under the steppe meadows. These soils are characterized by redistribution of finely dispersed fractions along the profile, significant accumulation of humus, and a high degree of aggregation. In the middle part of the profile cryogenic ooid aggregates, ferruginous nodules and carbonate neoformations are formed due to an increase in the concentration of the solution above permafrost or during freezing. Cryometamorphic soils are developed under the larch taiga at watersheds. In the surface horizons it is observed active humification and reduction of plant tissues with the formation of complex aggregates. The aggregates are angulate and have cryogenic origin. The aggregates in the whitened horizon are often packed in microlayers with signs of skeleton and plasma separation. In the soil under a birch forest, on the slope of the northern exposure, plant residues are humified with the formation of dark-colored humus. In horizons of the middle part of the profile, the aggregates are glued together by ferruginous-argillaceous or argillaceous-carbonate plasma. According to the data obtained, the features and properties of Skeletic Folic Cryosol (Nechic) soil dominate in the soils of the upper part, and the features of Folic Phaeozem (Colluvic, Tonguic) — in the lower part of the northern exposure slope