| Abstract |
The western Yunnan region (Dianxi district) located in the eastern Himalayan syntaxis, with well-developed faults and abundant high-temperature geothermal resources. Taking the geothermal water from the Dianxi geothermal fields as the research object, the hydrochemical and isotopic characteristics of geothermal fluids are studied and analyzed, elucidating the genetic model of magmatic high-temperature geothermal systems, and revealing the hydrochemical processes and genesis of geothermal water during the circulation process. The Rehai geothermal water type is mainly HCO3 Cl-Na. High Cl content of geothermal water comes from the supply of magmatic water, while Na, K, and HCO3 mainly come from the leaching of feldspar minerals by mantle derived CO2. Water hydrogen and oxygen isotopes indicate the source of atmospheric precipitation, while Rehai hot spring water shows "18O shift". It is related to the mixing of magmatic water and the interaction between water and rock. According to the Na-K cation thermometer, among numerous Dianxi geothermal fields, the deep reservoir temperature of the Rehai geothermal field is the highest, reaching 260 ℃. The Rehai geothermal water undergoes deep circulation and obtains deep heat after being recharged by atmospheric precipitation infiltration in the metamorphic rock area of the Gaoligongshan group located in the northeastern mountainous area; Rising along the fault, exposed as a hot spring at the surface. |