Identification of the North Jining Basin Fault and its response to the northward expansion of the Shanxi rift system, North China

Abstract

The northward growth and expansion of the Shanxi rift system (SRS) are key to understanding the geodynamic evolution of the northeastern Ordos block. Previous studies have suggested that Shanxi rift activity weakens north of the Daihai–Huangqihai Basin under the influence of the EW-strike Zhangjiakou–Bohai tectonic zone. In this study, remote sensing and field investigations reveal an ∼100 km long prominent linear structure north of the Jining Basin in the northeastern Ordos block. Three high-density electrical resistivity tomography (ERT) profiles across this structure identify this region as the North Jining Basin Fault, NE-striking, SW-dipping normal fault that structurally controls the northern margin of the basin, exhibiting typical fault depression characteristics and latest activity in the Holocene. Geological evidence confirms that the fault offsets mid-Holocene sediments with a vertical displacement of ∼2.7 m. Combined with the spatiotemporal evolution of the Shanxi rift system, these findings suggest that the northeastern boundary of the rift remains active and continues to propagate northward, with the North Jining Basin Fault representing northward expansion of the extensional regime of the Shanxi rift.