Mesozoic tectonic evolution and dynamic mechanisms of the northern Bozhong depression of the Bohai Bay Basin, eastern China

Abstract

The northern Bozhong depression of the Bohai Bay Basin in eastern China is an important area for oil and gas exploration in buried hills, which has complex structural styles and evolutionary processes. Based on 3D seismic and drilling data, the features of the Mesozoic structural deformation of the northern Bozhong depression are analyzed, and the tectonic evolution and dynamic mechanisms are also discussed. The complex Mesozoic structural styles of the northern Bozhong depression are composed of compression, strike-slip, and extension structures, which mainly trend in the near E-W, NW, NE, and NNE directions. Triggered by the collision and subduction between the North China, South China and Izanagi plates and associated stress fields of different periods, natures and directions, the northern Bozhong depression has experienced five stages of deformation at the end of the Middle Triassic, the Late Triassic, the Early-Middle Jurassic, the Late Jurassic-Early Cretaceous and the Late Cretaceous. Cyclical tectonic evolution has controlled the development of structural styles of different strikes and natures and the spatial distribution of strata in the northern Bozhong depression, providing an important foundation for hydrocarbon accumulation in buried hills.