PRELIMINARY INFORMATION ON THE CHEMICAL AND ISOTOPIC COMPOSITIONS OF WATERS FROM THE CASPIAN SEA AND ITS TRIBUTARIES IN THE MAKACHKALA REGION (RUSSIA)

The delta 18O and Sr-87/Sr-86 values of thermal waters from the wester n coast of the Caspian sea, which contribute to its total budget, resu lt from interactions with host rocks; they even suggest a supply by 'd eep' waters. In fact, the Sr contents and the Sr-87/Sr-86 values of th e river and thermal waters are not sufficient for the calculation of a n equilibrated budget, implying that other sources contribute to the b udget of the Caspian waters. The Pb-206/Pb-207 ratio of the waters fro m the Sulak river also suggests local anthropogenic pollution. ((C) Ac ademie des sciences / Elsevier, Paris.)