MODERN VIEWS OF CASPIAN SEA LEVEL CHANGE IN HOLOCENE

Fluctuations of Caspian Sea level is one of the topical paleogeographical and geomorphological problem. Despite long and intense research history and significant assembled material, there are a lot of discussion and unsolved questions in the history of the Caspian Sea. Caspian paleogeography most fully reflects changes of geographical conditions not only in its water area but also in its vast basin during Pleistocene and Holocene. Evolution of Caspian region cannot be understood separately from Black and Azov Sea (that were isolated from World Ocean on some periods) and undrained Aral Sea.

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 [2013] and A.A. Svitoch [1997] prefer stratigraphy based on fauna of Caspian endemic Didacna Eichwald and radiocarbon dating. G.I. Rychagov [1993] 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.