| Abstract |
Jiangxi Province is located in the Southeastern China Active Geothermal Zone, and is one of the provinces in which thermal waters distribute most widely in the country. In this area, there are 95 hot springs and more than 42 thermal water bore holes. Of the western part of the area, nitric thermal waters are widely found. In this paper, the chemical and isotopic compositions of the nitric thermal waters in Western Jiangxi Province are analyzed. The origin and formation conditions of the thermal springs are discussed including the recharge elevation, mineral-solution equilibria and residence time of these thermal springs. The nitric thermal waters are ultra-fresh and high alkaline with abundant SiO2, F, Na, Li, B, Sr, Rb, etc. but low concentrations of Ca, Mg, Cl, Ag, V, Pb, Zn, Co, etc. The low TDS of the thermal waters is attributed to the dynamic equilibrium of precipitation-dissolution in geothermal systems. The geothermal reservoir temperature is estimated as ranging from 80℃ to 130℃ and the circulation depth of geothermal waters is calculated to be ranging between 1670m and 2030m for the nitric thermal springs. The genesis models are also discussed. The geothermal waters are suitable for direct uses such as aquaculture, agriculture, sanatoriums and spas. |