ISOTOPIC COMPOSITION OF BIOGENIC CARBONATES AND HOLOCENE PALEOGEOGRAPHIC RECONSTRUCTIONS OF THE WESTERN CASPIAN SEASHORE

Abstract

Paleo-reconstruction of one new-Caspian transgression stage was carried out on the base of analysis of oxygen and carbon stable isotopes' content as well as of some metals in bivalve mollusk shells. Dynamics of δ18C values in mollusk shells upon their growth provides information on the temperature conditions and salinity of paleo-basins. The δ13C value characterizes intensity of organic substance accumulation in seawater. Cyclic changes of Sr and Ba concentration in mollusk shells imply the possibility of using these elements as indicators of basin paleoconditions.