Аннотация:The Caspian Sea and its adjacent areas form the Caspian oil/gas-bearing megabasin, one of the largest in the world, that make up part of the Barents-Caspian oil and gas belt. The N-S-trending megabasin consists of three sedimentary basins, separated by latitudinal sills: North Caspian, Middle Caspian, and South Caspian basins. The granite-metamorphic basement of the basins becomes younger from north to south, from Early Precambrian in the north to Early Cimmerian in the south. It was formed in the transitional zone from the southern edge of the East European Craton (Paleozoic continent Baltica) towards the Tethys oceanic basin. Accordingly, the Caspian megabasin is superimposed on the East European ancient platform, Scythian-Turanian young platform, and Alpine-Himalayan mobile belt. Each tectonic province comprises structural zones of a subordinate character: the North Caspian depression within the first province; Karpinsky Ridge, Kuma zone, North Ustyurt block, Buzachi uplift, Mangyshlak-Central Ustyurt and South Mangyshlak zones, as well as Karabogaz arch, and Middle Caspian basin within the second province; the Greater Caucasus, Kopeh Dag, Kura and South Caspian Depression, West Turkmenian Trough, and Alborz Range within the third province. The age of the sedimentary cover embraces the entire Phanerozoic and, probably, upper parts of the Proterozoic in the North Caspian region; the Jurassic, Cretaceous, and the Cenozoic in the Middle Caspian; and the Oligocene-Holocene in the South Caspian. The Permian and Triassic deposits in the Middle Caspian; the Jurassic, Cretaceous, and lower Paleogene deposits in the South Caspian occupy partly both the folded basement of the basin and its sedimentary cover. The stratigraphic range of oil and gas occurrence varies accordingly: from the Devonian to Paleogene in the North Caspian, from the Triassic to Miocene in the Middle Caspian, and from the Cretaceous to Eopleistocene in the South Caspian. The Explanatory Notes describe oil source rocks and assess oil and gas occurrence prospects. Seismicity of the region is characterized.
