The characteristics and geodynamic mechanisms of formation of traps in Middle Caspian basin

Abstract

The structures of Middle Caspian basin differ from folded ones of South Caspian. The paper presents the researches of geodynamic processes in Middle Caspian basin and the types of traps formed due to them. Five structural types characteristic for the Middle Caspian basin, which can play a role of traps for hydrocarbons, are described. The significance of concept of formation process of each structure type for the specification of direction of exploration surveys in this region is shown as well. The most interesting of them in the context of geodynamic development are the inversion structures and monocline on the north-east slope of the Great Caucasus. The first structures are the great anticlines occurred due to the inversion of triassic grabens. The combination of lake sediments in the grabens favorable for the formation of parent rocks and giant traps over the last ones reduces the risks of exploration works. The formation of the monocline on the north-east slope of the Great Caucasus may be justified with the salt accumulation in the marginal lakes bordered with barrier reefs in the Upper Jurassic stage. These reef structures may serve as traps for the hydrocarbons.