Genesis Analysis of Sulfate Thermal Mineral Water In Karst Aquifers At Xiwenzhuang Uplift, Taiyuan Basin

Taiyuan basin is a Cenozoic fault basin. The formation of faults block and horst in the basin are controlled by the north-south and east-west faults. The karst thermal mineral water is mainly distributed in the area between the Sanji horst and the Tianzhuang fault. The main aquifers of karst thermal water are the carbonate of the Ordovician Fengfeng group, the upper and lower Majiagou groups. The hydrochemical type of karst thermal water is SO4-Ca•Mg type. According to the ion concentration relationship and the saturation index of the main mineral in the thermal mineral water, it can be inferred that the hydrochemical type is mainly affected by the gypsum layer. The effect of the dissolution of gypsum on the dissolution of calcite and dolomite has an inhibitory effect. The age of karst thermal mineral water in the Xiwenzhuang uplift is more than 20,000a, which is ancient water. Long-term water-rock interactions provide the time of conduction heating and enriched mineral components for the thermal mineral water. As the high value area of the temperature, TDS and Sr concentration in karst thermal mineral water，Xiwenzhuang uplift is the catchment area of thermal mineral water in the basin, and also the best area of regional thermal mineral water. From the recharge area to the discharge area in the basin, there are occurred such a trend: cold groundwater with low-TDS and hydrochemical type of HCO3-Ca•Mg to karst thermal mineral water with high TDS and hydrochemical type of SO4-Ca•Mg.