Composition and formation conditions of sediments in the Doroninskoe soda lake (eastern Transbaikalia)

Abstract

It has been established that the southern and eastern parts of the Doroninskoe soda lake bottom with the depth less than 4–4.5 m are mainly composed of micrograined quartz-feldspar sand. Silty-clayey kaolinite-hydromica particles predominate from the depth more than 4–4.5 m. Low maturity of clastic material and its insignificant role in the formation of soda minerals in the lake have been established. Very high concentrations of Cl and Na, as well as high concentrations of S and P, are specific characteristics of the chemical composition of sediments. Distribution of chemical elements is governed by a complex action of the mechanical, alkaline, sorption, and hydrosulfuric barriers. With increasing depth and distance from the shore, concentrations of Ti, Ce, Na, Mn, La, Ca, Co, and Cu increase by 3–3.5 times; Fe, P, V, and Zn, by 4.5–5 times; Mg, Ni, and Cr, by 6–7.5 times; and Cl and S, by 10–15 times. The sharp increase in the contents of Ti, Fe, Mn, Ce, and La is related to the formation of zircon-ilmenite placer horizons. Concentrations of Si, K, and Ba show negative correlation with the psammite component. The Pb content does not depend on the barrier factor.