Hydrogeological characteristics and lithofacies paleogeography of the Northwestern Subei Faulted Basin, China

The northwestern part of the northern faulted basin develops five aquifer-bearing strata ranging from the Pre-Sinian to the Late Cenozoic. Among these, the Late Cenozoic unconsolidated porous aquifer system can be subdivided into four major aquifer groups. The third aquifer group (rich in sand layers) serves as the primary exploitation zone for deep groundwater, while the second and fourth aquifer groups (dominated by clayey silt) function as semi-permeable layers. The entire deep groundwater system conforms to a semi-confined "Type II leakage system" model. Groundwater environmental dynamics are predominantly controlled by sedimentary settings and lithofacies-paleogeography.