Geodynamic conditions of formation of sedimentary basins of South Kazakhstan (Shu-Sarysu, Pre-Balkhash, Ili)

Abstract

The features of geological and geodynamic formation of promising oil and gas basins of Southern Kazakhstan (Shu-Sarysu, Pre-Balkhash-Ili) are considered and the geological evolution of these basins is described, which is associated with the conditions of stable subsidence throughout the late Paleozoic-Mesozoic-Cainazoic. A model of the deep structure of the main structural units of Southern Kazakhstan (folded paleozoid base) and a cover of sedimentary basins along the profile of “Turkestan“are offered. As a result of interpreting geophysical data in the crustal section along the traverse of the profile, numerous gently sloping reflectors are described at depths from several kilometers to the Mohorovicic boundary. These reflecting planes in the regional section form a system of detachments that are associated with a system of gentle over thrusts and interformational disruptions, forming a system of intermittent packets of tectonic lenses folded by dynamometamorphic and metamorphic rocks. The position in the section of these tectonic lenses is an expression of the tectonic stratification of the earth’s crust. The characteristic of the main tectonic elements of this region (suture, accretion prisms, intraplate complexes, collision thrusts and shifts, etc.) is given. As initial reconstructions, various paleogeographic, paleotectonic and geodynamic constructions were used.