Patterns of distribution of eluvia soils in the oil region of Tatarstan

Abstract

The article is devoted to the study of eluvial deposits in the southeastern part of the Republic of Tatarstan. As a result of river erosion, a highly dissected and rugged terrain has formed here. Its characteristic elements are erosion-denudation watersheds separated by narrow river valleys and terraced slopes. According to the results of the research, it was revealed that the differences in the structure of weathering profiles in carbonate and terrigenous soil massifs are due to the structural and mineralogical features of rocks that were formed at the stage of sedimentation and subsequent diagenesis. In the central part, on the site of the upper plateau, the rocks underwent mainly physical weathering processes, on the site of the middle plateau – chemical weathering processes, on the site of the lower plateau – physical and chemical weathering processes. Such selectivity in the manifestation of hypergenic processes is due to the predominant lithotypes of sedimentary rocks composing the surfaces of the upper, middle and lower plateaus of the studied territory. Based on the conducted research, the zoning of the studied territory was performed and an engineering and geological map was built. The results obtained made it possible to understand the mechanism of weathering of carbonate and terrigenous rocks, as well as to assess the potential change in their physical and mechanical properties during the construction and operation of buildings and structures.