Control of the Jinci fault on karst water in the Jinci spring basin revealed by integrated geophysical surveys

Research on characteristics of the Jinci fault and its controlling effect on karst groundwater in the Jinci spring watershed can facilitate analysis of the migration regularity of karst groundwater in the Jinci spring region. This work conducted such research by surveys using geophysical methods including Controlled Source Audio Frequency Magnetotelluric（CSAMT)，Audio Frequency Magnetotelluric（AMT）and Magnetotelluric（MT). Results show that the southwest section of the Jinci fault strikes in NE-SW direction，dipping SE at angles becoming smaller from shallow to deep subsurface. Its width is about 250 m with influence depth over 1km. In the southeast side of the Jinci fault,relatively water-resistent strata makes most karst water failed to migrate into the Taiyuan basin,inferring the fault is a tensional water conducting fault. There are two karst water strong runoff zones parallel to the Jinci fault in Xishan mountains,the width of which is between 150 m and 300 m. Karst water supplies downstream area through the Jinci fault and strong runoff zones.