Hydrogeochemical features of geothermal water resources in Wentang Valley Anticline in SW China

Wentang Valley Anticline is selected as study area and thermal water resources in this area will be discussed in this paper. Because of the same geological backgrounds, the hydrogeochemical features of the thermal water is similar in this study area, and its hydrochemical type is SO4-Ca. In addition, the thermal water contains multiplicate and sanative microelements and gases, such as Sr, F, Li, B, and Rn, so it is superior iatrical thermal water. The thermal water source is atmosphere precipitation. And its aquifer may be the stratum of Jialingjiang formation in Lower Trias (T1j). Na-K-Mg diagram shows that five water samples fall in the region of immature water. So it can be said that it has low tempertures in the fluid-rock processes and the thermal water maybe mixed. Mineral equilibrium diagram (log(Q/K)-T diagram) indicates that the log(Q/K)-T curve of quartz is closest to saturation line, and the equilibrious temperature is 65~77°C. This temperature is within the reservoir temperature (65~82°C) calculated by quartz geothermometer.