Geochemical and petrographic characteristics of the Miocene rocks of the Shamakhi-Gobustan trough (South Caspian basin) and the North Absheron uplift zone (Middle Caspian basin) indicate that these sediments contain products of erosion of the magmatic rocks of the Eurasian continent’s active margin - the volcanic arc of the Lesser Caucasus, as well as granitic basement of the Garabogaz High and Mesozoic-Eocene sedimentary strata of the Middle Caspian basin and the Greater Caucasus. The uplift of the Greater Caucasus, which began in the Middle Eocene as a result of the collision of the Afro-Arabian and Eurasian plates, brought to the exposure of the Mesozoic-Eocene sedimentary rocks of the Tethys Ocean that were deposited from the detrital material of the disintegrated igneous rocks of the Lesser Caucasus and the granitic basement of the Russian platform. The clastic material of these eroded Cretaceous-Eocene sedimentary rocks was accumulated in the Miocene basin that caused the geochemical characteristics of the Miocene sediments demonstrating the occurrence of igneous rocks of active margins or products of their erosion in the sources area. The accumulation of thick quartz-containing sand beds in the Chokrakian time (analogous to the Langhian stage) in a number of fields of the Shamakhi-Gobustan trough was the result of the exposure removal to the surface of quartz-rich Cretaceous rocks of the Greater Caucasus because of collisional processes, and their intensive erosion due to humidization of the climate during the Middle Miocene climatic optimum. Judging by the geochemical characteristics, during deposition of shale mudrocks the arid conditions prevailed. Keywords: Miocene; South Caspian and Middle Caspian basins; geochemistry; provenance; climate; geodynamic setting.