Hydrogeochemical Characteristics and Genesis of Medium-High Temperature Geothermal System in Northeast Margin of Pamir Plateau
The northeast margin of Pamir tectonic junction is enriched with medium-high temperature geothermal resources.Most previous studies are limited to a single geothermal field and lack of regional systematic research.Here,it applies geothermal hydro-geochemistry as an effective method to study geothermal resources.Based on the geothermal geological characteristics of the northeast margin of the Pamirs Plateau,the hydrochemical genesis,characteristics and isotope analysis of 8 hot spring water,1 cold spring water,11 hot well water and 6 surface water in the study area were analyzed and revealed the evolution characteristics of regional geothermal fluid thermal reservoir and cooling mechanism in the northeast of Pamir.It provides a certain geochemical basis for the exploration of geothermal resources in the northeast of Pamir.The results show that the major ions in geothermal water are mainly originated from sodium/potassium feldspar,cation exchange and magmatic water.The high correlation of ratio in B/Cl、B/Li、B/Cs、Li/Cs、Na/Cl、K/Cl shows that hot water probably has a common parent geothermal fluid.The characteristics of hydrogen and oxygen isotopes indicate that geothermal water is recharged by atmospheric precipitation,snowmelt water and deep magmatic water.A variety of solute thermometers,silicon-enthalpy model and chlorine-enthalpy model were used to reconstruct the geothermal reservoir temperature,cooling process and evolution mode of geothermal groundwater.It inferred that there may be multiple thermal reservoirs under the study area,which the temperature of the deepest parent geothermal fluid storage is about 358-418 ℃ with the Cl-concentrations about 300-400 mg/L.Combined with regional geology and geothermal geological conditions analysis,it believes the geothermal anomaly in the northeast margin of the Pamir Plateau is a result of uncooling magma in the crust and high radioactive granite.
Pamir plateaumedium-high temperature geothermal systemhydrochemistrygeothermometerhigh radioactive granitehydrogeology
万方数据
维普
