Huanghua depression,in the middle of Bohai Bay basin,is a major secondary sedimentary and petroliferous unit.Although this basin has been explored for nearly 50 years,the discovery of new reservoirs increased quickly in recent years.The subduction of the Pacific Plate to the Eurasia Plate caused the transtensional deformation of the whole basin.During the Paleogene,the depocenters and subsidence centers of