MIGRATION OF SUBSIDENCE CENTERS IN THE BOHAI BAY BASIN, EAST CHINA SEA SHELF BASIN AND THE PHILIPPINE SEA BASIN IN PALEOGENE AND THEIR GEODYNAMIC IMPLICATIONS

The Bohai Bay Basin is a Mesozoic and Cenozoic intracontinental rift basin. As a Mesozoic and Cenozoic superposed basin on a cratonic basement, the East China Sea Shelf Basin has passed three periods of tectonic evolution:rifting, depression and regional subsidence. The paper studied in details the transition of subsidence centers in Paleogene of the East China Sea Shelf Basin, and comparison was made with the migration of deposition or subsidence centers in the Bohai Bay Basin and the Philippine Sea Basin in middle-late Eocence. Our data reveal that the evolution of the three basins was dominated by the collision of India-Eurasia plate together with the retrogressive subduction of the Pacific Plate. The W-E direction creep of mantle flow together with mantle upwelling caused by the India-Eurasia plate collision made lithosphere stretching, thinning and rupturing, led to the development of NE faults of right-lateral strike-slip in the eastern China Basins, and then further controlled the tectonic evolution of the Bohai Bay Basin and the East China Sea Shelf Basin. The retrogressive subduction of the Pacific Plate provided the strain spaces for lithosphere extension to the east and creep in eastern Asia, and the change in subduction direction during late Eocence has important influence on the tectonic evolution of Eastern China Basins.