LITHOLOGICAL-GEOCHEMICAL DIFFERENTIATION OF BOTTOM DEPOSITS IN THE ANGARA CASCADE RESERVOIRS

Abstract

A long-term complex study of the Angara cascade reservoirs, the largest artificial reservoirs, showed that the bottom deposits were formed at the predominance of terrigenous influx. The compositional-structural and geochemical characteristics of various lithodynamic types of bottom sediments along a generalized transverse profiles testify that they represent a complex system with varying proportions of sandy, silty, and clayey particles and associations of chemical elements. As is indicated by the composition of the abraded rocks, the sedimentation settings, and the type of the lithological-geochemical differentiation of the bottom deposits, the scattering and differentiation of abrasion fluxes occurred simultaneously with the formation of new types of bottom sediments, whose composition was partially inherited from precursor rocks. It was established that the change in the lithodynamic settings in the Angara cascade reservoirs and the trend of the lithological-geochemical differentiation of the bottom sediments are governed by the same laws as in natural basins. © Pleiades Publishing, Ltd. 2007.