Abstract:The early left-lateral and late right-lateral strike-slip shearing of the Red River Fault Zone performes a crucial function in controlling the tectonic evolution and sedimentation processes of the Yinggehai Basin. While the Red River Fault has been identified in the northern and southern parts of the Central Depression of the Yinggehai Basin, it remains unclear how the Red River Fault Zone extends within the Central Depression, impacting the study of the basin's tectonic evolution and sedimentation processes. Current studies on the tectonic evolution of the Yinggehai Basin are based on the No. 1 Fault on the eastern side and the Yingxi Fault on the western side as boundaries. In this paper, utilizing satellite altimetry gravity anomaly data in the Yinggehai Basin and employing the normalized vertical derivative total horizontal derivative edge recognition (NVDR-THDR) method, we determined the distribution of the Central Fault. This recognition is verified by 2D seismic sections in the northern and central parts of the Central Depression. The Central Fault is the extension of the Red River Fault Zone in the Yinggehai Basin, developing as a left-stepping fault system north of the Dongfang Diapir area, forming an eastward dislocation in plan view. In the Changnan Diapir area, it consists of several parallel faults. In the Ledong Diapir area, a left-stepping sinistral strike-slip fault system is developed, leading to the development of the Ledongnan Subsag (pull-apart basin). Seismic profiles reveal that the buried depth of the Central Fault is larger in the Central Depression, with a two-way travel time exceeding 6 s. According to the stratigraphic sequences, the main active period of the Central Fault predates 30 Ma to 15.98 Ma. The Cenozoic sediment thickness of the Yinggehai Basin, calculated using the fast inversion method of the double-interface model of the gravity field, reveals the development of five depocenters with thicknesses exceeding 15 km in the Central Depression. Generally, to the west of the Central Fault are the depocenters, while to the east, there is a gradient zone with smaller sediment thickness. Simultaneously, the five diapir belts in the Central Depression are all distributed to the west of the Central Fault, with the left-stepping sinistral strike-slip fault system in the Ledong diapir area exerting significant control on three parallel diapir belts. The Central Fault holds great significance for the tectonic evolution and oil and gas exploration in the Yinggehai Basin.