Tectonic Features of Oil and Gas Basins in Eastern Part of China

ABSTRACT During the Mesozoic-Cenozoic, eastern China underwent two stages of structural development. Sedimentary basins in eastern China have certain characteristics. Basement faults are well developed in these basins. There was rapid sedimentation during the Mesozoic-Cenozoic. The basins are located on either side of the Songliao depression. The amount of subsidence in these basins is limited, with a maximum depth of sedimentation of 4,000 to 6,000 m (13,000 to 20,000 ft). During the Mesozoic, the most intense tectonic movements occurred in the Songliao basin, where there was much faulting, accompanied by volcanic activity. The Bohai Bay basin was the center of major Tertiary tectonic activity. There are more than 50 major basement faults in this basin. Basin formation was controlled primarily by movement of the Pacific plate and related volcanic activity. These basins are epicontinental basins along the margin of continental crust. Hydrocarbons were generated during the time of basin formation, and much of the oil and gas discovered has been in rocks where it was generated or where migration was over short distances.