Genetic Mechanism of Geothermal System In Niutuozhen Uplift,jizhong Depression

Xiong County has abundant medium and low temperature geothermal resources. With the intensification of mining activities, it is more and more important to study the recharge and runoff conditions of geothermal fluids. In order to study groundwater recharge mechanism, it is necessary to determine recharge source, location of recharge area, recharge cycle, recharge channel and recharge velocity. In this paper, the sources and ages of geothermal fluids in various geothermal reservoirs are determined by environmental isotope techniques. Based on the hydrochemistry characteristics of thermal fluids, the connectivity and flow relationship of each reservoir are analyzed. This research shows that,the geothermal fluid in Xiong County mainly comes from atmospheric precipitation, and most of them are formed by geothermal warming in the long runoff process. Its overall migration direction is from south to north. The age of the geothermal fluid in Xiong County is 32~44 ka. The hydraulic connection between the Neogene geothermal fluid and the upper aquifer is weak under natural conditions, and the hydraulic connection between the geothermal fluid of thermal storage in different times is weak. In the same tectonic unit, there is a positive correlation between groundwater age and sedimentation age, that is, the older the geothermal reservoir, the older the geothermal fluid.