Grain size, mineral and chemical compositions of modern deposits fron the northern Caspian Sea and the Volga River delta

Comparatively better grading of sediments from the northern Caspian Sea is due to additional factors such as bottom currents and storms. When passing from the Volga River delta to the northern Caspian Sea, sediments are enriched in rare earth elements (except Eu), Ca, Au, Ni, Se, Ag, As, and Sr, but depleted in Na, Rb, Cs, K, Ba, Fe, Cr, Co, Sc, Br, Zr, ??, U, and Th. Concentrations of Zn remain almost unchanged.

Sedimentation rates and types of recent deposits in the northern Caspian Sea are governed mainly by abundant runoff of the Volga River.