Geochemical Investigations of the Geothermal Waters in the Kangding Area, SW China: Constraints from Hydrochemistry and D-O-T Isotopy

Abstract

Geothermal resources, as a representative of clean energy, has been paid significant attention in the world. Due to active neotectonics and widespread magmatic rocks, the abundant geothermal waters in the Kangding area have been investigated. Hydrochemistry and D–O–T isotopy studies were carried out to clarify the genetic mechanism of geothermal waters. The hydrochemical types of geothermal waters are mainly Ca2+–Na+–HCO3− type, Na+–Cl−–HCO3− type, and Na+–HCO3− type. Silicate dissolution and the cation exchange process are the water–rock interactions determining hydrochemical compositions. The recharge elevation of geothermal water was calculated to be 3034–3845 m, with an average of 3416 m. The reservoir temperatures of shallow and deep geothermal reservoirs vary from 50 to 115 °C and from 114 to 219 °C, respectively, and the mixing ratio of cold water is 0.56–0.89. These findings help to reveal the genetic mechanism of geothermal waters in the Kangding area.