The Caspian Sea through time: a mysterious sea

Despite decades of investigations, the Caspian remains a mysterious sea. Located at the border between Europe and Asia, this endorheic and brackish water body receives influences from high and low latitudes, thus temperate and subtropical climates. Geologically, it is both a sea and a lake, although recent international agreements provide it with an intermediate status. Its water levels have widely fluctuated over the Quaternary. They are typically reconstructed from coastal regions, which suffer hiatus at low stand. Only few deep cores are available for science despite its intense and competitive study for petroleum exploration. The usual proxy methods encounter shortcomings, either they do not apply (rare diatoms and no foraminifera below ۵۰ m), or they lack calibration (dinoflagellate cysts). Radiocarbon dating is complex and suffers from poorly constrained reservoir effects. This communication will explore the extent of our knowledge and its limitations.