MODERN VIEWS OF CASPIAN SEA LEVEL CHANGE IN HOLOCENE
Despite importance of this region there are a lot of debatable questions: number of transgression-regression periods (primarily in Late Pleistocene), its age, parameters, connection between Ponto-Caspian water areas and deglaciation of East European plain etc. Differences in author’s points of view are the result of using different paleogeographical methods for reconstruction of Caspian Sea history. For example, T.A. Yanina  and A.A. Svitoch  prefer stratigraphy based on fauna of Caspian endemic Didacna Eichwald and radiocarbon dating. G.I. Rychagov  prefers geomorphological method for upper Late Pleistocene and Holocene reconstructions. And S.I. Varuschenko and R.K. Klige [Varushenko et al, 1987] prefer hydrological models and archeological evidences.
Reviewed most reasonable in our opinion reconstruction of the Caspian sea Holocene history indicate a number of problems, primarily related to the incompleteness of the geological record and deficiency of data from the sections available for study, that reveal transgressive Caspian basins, while each subsequent major sea level rise was destroying evidence of the previous one. Despite a significant results in Caspian Sea paleontology (especially Bivalvia species) there are still a lot of unsolved issues that connects with shortening of variety of Didacna Eichwald, a lot of references for many extinct forms based on several nowadays living species. Evolution of many species and kinship ties are also causes discussion. Keen problem of Caspian research seems insufficient characteristic of regressive periods in Pleistocene and Holocene.