Structure and sedimentary characteristics of the Meso-Cenozoic basin group along the Yangtze River in the Lower Yangtze region

The basin group along the Yangtze River is an important part of the Meso-Cenozoic petroliferous basins in the Lower Yangtze region, which is also an important window for the study of the structure and tectono-sedimentary evolution of the Meso-Cenozoic basins in East China. There are nine relatively independent faulted basins from west to east in the Yangtze River's middle and lower reaches, including Poyang, Qianshan, Wanjiang, Quanjiao, Wuwei, Jurong-Nanling, Changzhou-Xuancheng, Liyang and Pinghu basins, which comprise a basin system or group in the plane, named the Lower Yangtze basin group. Sedimentary filling in the basins was divided into two stages including faulting from the Late Cretaceous to the Paleogene, and depression from the Neogene to the Quaternary. The former stage is characterized by the sedimentation of fluviolacustrine and delta facies, while the latter stage is marked by the deposition of fluvial facies. The fault basin system formed in the Late Oligocene, and a unified depression system formed in the Neogene along the Yangtze River. Due to the Neogene differential deformation, the basinal strata were differentially denuded, forming the modern geological setting of the sedimentary basins.