Geological architecture and tectonic evolution of Liaodong-Bodong Uplift tectonic belt, Bohai Bay Basin

To clarify the formation and evolution process of Liaodong-Bodong Uplift tectonic belt and its relationship with oil and gas in Bohai Bay Basin, by combining the latest three-dimensional seismic data in the study area, the tectonic characteristics and the uplift time of the tectonic belt was analyzed in detail, the structural deformation characteristics were compared, and the difference in the uplift time was determined, based on which the formation type and evolution model of the tectonic belt was established. It is considered that the Bodong Low Uplift in the tectonic belt is mainly controlled by the extensional fault, while the Liaodong Uplift is mainly controlled by the early extensional fault and the late strike slip fault. Except for the Liaodong Fault, all the main faults in the tectonic belt started to move in the sedimentary period of the Kongdian Formation and the fourth member of Shahejie Formation, or the Sha-4 Member for short, and the peak period is from the sedimentary period of Sha-3 Member and Dongying Formation, and the fault activity was relatively weak after the deposition of Guantao Formation. The uplift time of the tectonic belt rose gradually from south to north: Bodong Low Uplift rose at the end of the deposition of the Sha-4 Member, the southern section of Liaodong Uplift rose at the end of the deposition of the Sha-3 Member, and the northern section of Liaodong Uplift rose at the end of the deposition of the third member of Dongying Formation (or Dong-3 Member in short). The tectonic evolution could be divided into six stages: sedimentary period the Kongdian Formation to Sha-4 Member , sedimentary period of the Sha-3 Member, sedimentary period of the Sha 1 and 2 Members, sedimentary period of the Dong 3 Member, the end of the Dongying Formation, and the present. The tectonic evolution is closely related to the migration and accumulation of oil and gas. The formation time of the tectonic belt before that of the main hydrocarbon generation and expulsion period of the peripheral hydrocarbon generation depression, which is conducive to the accumulation of oil and gas near the tectonic belt. It was easy for oil and gas to accumulate in the bulge area of Bodong low uplift controlled by extensional fault, and for oil and gas to accumulate in the slope area controlled by strike slip fault.