Hydrogeological Features of Sedimentary Cover
of the Southern Caspian Megabasin

V. P. Zverev and I. A. Kostikova

Institute of Environmental Geoscience, Russian Academy of Sciences,
Ulanskii per. 13, Moscow, 101000 Russia

Received September 28, 1998

Abstract—The study of the water balance showed that the sedimentary cover of the Southern Caspian Megabasin
has accumulated 24.9 1020 g of free and physically bound groundwater during 185 million years. Altogether
19.6 1020 g of groundwater was turned back to the Caspian Sea in the course of its evolution, 6.2 1020 g of
which turned back during the last 5 million years (Middle Pliocene–Quaternary). This mass of returned ground-
water could form a 1680-m-thick water layer, which is close to the overall rise in the Caspian Sea level (1800)
during this period.