Characteristics of geothermal waters in eastern Wugongshan based on hydrogen, oxygen, and strontium isotopes

It is crucial to investigate the features of the geothermal waters for sustainable exploitation and utilization. It is rich in low-medium temperature geothermal waters in the Wugongshan area in Jiangxi Province, which is urgent to find out the characteristics of the geothermal waters. This study intends to reveal the genetical model of geothermal waters in the eastern Wugongshan area including recharge source, cyclic evolution, and heat source, based on the methodical analysis of hydrogen, oxygen, and strontium isotopic data. Results show that the precipitation at recharge elevations between 1500 and 2200 m is the main recharge source of geothermal waters in the study area. Precipitation infiltrates deep into the area near the crust and is heated into geothermal fluid. Water-rock interactions occur during deep circulation. In the upwelling process, geothermal waters are mixed with shallow groundwaters at different mixing ratios (17%–74%). Finally, a conceptual model of the geothermal waters is proposed. It can provide some guidance for the development of geothermal waters in the eastern Wugongshan area.