关键词: 坳陷, 演化, 地幔, 油气资源, 渤海

Abstract: The offshore area is an important part of Bohai Bay Basin.It is the extensions of three depressions,Jiyang,Huanghua,and Lisohe depressions,in the offshore area.Evolution histories of offshore sags are similar to those of the onshore ones.The rising of mantle and the framework of the three surrounding mountains have controlled the formation of the sags,which are controlled by extension faults,instead of strike-slip faults.Tanlu fault does not have great influence on the sedimentary processes in sags.Bozhong sag is different from others,the Dongying formation in which is much thicker and possesses great hydrocarbon generation potential.In the offshore area of Bohai Bay Basin,there are four sags with great hydrocarbon generation potential (Lisozhong,Bozhong,Qikou,and Huanghekou sags) and five exploration fields (uplifts and their plunging ends,shallow structures,buried hills and faulted pre-Tertiary structural plays and slopes of sags).The offshore resources potential is the same large as the three onshore depressions.The offshore area of Bahai Bay Basin has good future in exploration and will become a followup exploration area in East China.

Key words: depression, evolution, earth mantle, oil and gas resources, Bohai Sea