Synchronous Changes in the Diatom Complexes and Hydrological Conditions in the Middle and Southern Caspian Paleobasins

The content of the diatom complexes of dominating ecological groups in the columns of bottom sediments in the middle and southern Caspian was found to correlate well with the changes in the ion–salt composition of aqueous extracts from these sediments. It was established that the joint interpretation of the two indices increases the reliability of detecting time variations in the hydrological regimes of these basins.