Institute of Oil and Gas, Ministry of Science and Education of the Azerbaijan Republic, Baku, Azerbaijan¹ ; Sergo Ordzhonikidze Russian State University for Geological Prospecting, Moscow, Russia²
V. Yu. Kerimov, Chief Researcher¹, Head of Department², Doctor of Geological and Mineralogical Sciences, Professor, vagif.kerimov@mail.ru

Sergo Ordzhonikidze Russian State University for Geological Prospecting, Moscow, Russia
R. A. Mamedov, Candidate of Geological and Mineralogical Sciences, Associate Professor

Institute of Oil and Gas, Ministry of Science and Education of the Azerbaijan Republic, Baku, Azerbaijan
V. Sh. Gurbanov, Executive Director, Doctor of Geological and Mineralogical Sciences, Professor
N. G. Shikhiev, Head of Education Department, Candidate of Chemical Sciences

In the South Caspian Basin, the Pliocene complex stands out among the sedimentary complexes with the greatest thickness and rhythmic alternation of sandy and clay deposits. During the formation of the productive red-colored stratum, a huge mass of coarsegrained material with a maximum thickness of 7.0–8.5 km has accumulated, which is 25–30% of the total thickness of the sedimentary cover in the basin. The sedimentation rate at that time was 2.5–3.0 km/million years. This is an order of magnitude higher than the avalanche sedimentation rate. Paleogeographic reconstructions showed that fluvialdelta complexes played a significant role in the formation of sedimentary complexes in the South Caspian Basin. During lowering of sea level, sediments were washed away from the continental shelves and slopes by underwater currents and density flows and formed giant cones of outflow. Large rivers (Paleo-Volga, Paleo-Kura, Paleo-Uzboy) and dozens of small rivers formed at the end of the Miocene in the surrounding land rushed into the narrow Pliocene sea in the center of the modern basin, delivering a huge amount of detrital material. To study the reservoirs of the South Caspian Basin, the models of distribution of natural reservoirs, paleogeographic settings of sedimentation, lithological and facies schemes, thickness maps, sedimentation velocity maps, and a scheme for determining the boundaries of sedimentation depocenters were developed.

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