Is the Caspian Sea saltwater?
Caspian Sea
The Caspian Sea, like the Black Sea, Namak Lake, and Lake Urmia, is a remnant of the ancient Paratethys Sea. It became landlocked about 5.5 million years ago due to tectonic uplift and a fall in sea level. During warm and dry climatic periods, the landlocked sea almost dried up, depositing evaporitic sediments like halite that were covered by wind-blown deposits and were sealed off as an evaporite sink when cool, wet climates refilled the basin. (Comparable evaporite beds underlie the Mediterranean.) Due to the current inflow of fresh water, the Caspian Sea is a freshwater lake in its northern portions, and is most saline on the Iranian shore, where the catchment basin contributes little flow. Currently, the mean salinity of the Caspian is one third that of Earth's oceans. The Garabogazköl embayment, which dried up when water flow from the main body of the Caspian was blocked in the 1980s but has since been restored, routinely exceeds oceanic salinity by a factor of 10.
Kashagan Field
Interest in the Caspian Sea first began in 1992 when an exploration program was announced by the Kazakh government. They sought the interest of over 30 companies to partake in the exploration. In 1993 the Kazakhstancaspiishelf was formed which consisted of Eni, BG Group, BP/Statoil, Mobil, Royal Dutch Shell and Total S.A., along with the Kazakh government. This consortium lasted 4 years until 1997, when seismic exploration of the Caspian Sea was undertaken.