Characteristics of the new tectonic movement and its control of groundwater in the Linqu Basin in Shandong

Geological structures, especially the neotectonics, play a controlling role in the occurrence of groundwater in bedrocks, and they are also the key factors for determination of well location and groundwater exploration. The north China anti-drought hydrogeology survey and drilling were carried out in the Linqu Basin in Shandong. Combined with the neotectonic movement in the parsed area and its expression form, some typical examples were select to examine the spatial distribution characteristics of groundwater types, lateral recharge of groundwater runoff conditions and characteristics of groundwater in space, etc. Control of the neotectonic movement of groundwater in the basin was analyzed, and the typical storage structures of groundwater under the control of the new tectonic movement were summarized. The research results show that (1) the Linqu basin is characterized by complex geological background, strong neotectonic activities, multi-phase and multi-directional activities, which has formed modern geomorphic pattern and stratigraphic structure of the basin and controlled the spatial distribution of different types of groundwater. (2) Under the control of the neotectonic movement, the western and southern parts of the basin were uplifted and karst was developed. The direct recharge areas of groundwater are located in the western and southern parts and the lateral runoff recharge constitutes the main source of groundwater recharge in the basin. (3) Under the influence of the tectonic activity intensity, lithological structure and groundwater runoff conditions, the outcropping carbonate rocks on both sides of the Wujing fault are strong runoff zones with underground karst, and the rocks are permeable but not water-rich. The Wujing-Yeyuan section is an underground karst water-rich area. The north of the Yeyuan reservoir and east of Shifotang-Linqu fault to the eastern boundary of the basin are the weakly water-rich areas of insoluble stratified rocks. In the eastern boundary of the basin, the fractures along the Shuangshan-Lijiazhuang fault are the relatively water-rich areas of the Cenozoic basalt with pore and fissures and ancient weathering fissured crust. (4) There are four typical types of groundwater storage structures in the Linqu basin, namely, fault belt type, contact belt type, horizontal layer type and complex type, etc. The belt type groundwater storage structure is the main type of storage structures in the basin, and it has also become the main target of groundwater exploration and well location in the study area.