Hydrogeochemical studies of geothermal fluid are widely used to determine the formation mechanism and occurrence environment and predict favourable exploration areas for geothermal resources.[Objective]In order to understand the heat source and causative mechanisms of the geothermal system,the areas of geothermal anomalies are delineated in Yingcheng City,Hubei Province.[Methods]This study examines the geochemical origins of ma-jor components in geothermal fluid and evaluates the thermal reservoir temperatures of geothermal fluid based on the hydrochemical and isotopic characteristics of geothermal water and shallow groundwater.By integrating the tempera-ture and hydrochemical data of shallow groundwater in the area,the geothermal anomaly zones are delineated.[Results]The results show that geothermal water hydrochemistry is mainly SO4-Ca,and the main thermal storage enclosing rock of the geothermal system is marine carbonate rock,with a thermal reservoir temperature of approxi-mately 112.2℃.Atmospheric precipitation infiltration and water-rock interactions in carbonate thermal reservoirs are the main sources of chemical components in geothermal water.The hydrochemical and hydrogen-oxygen isotope characteristics of the geothermal water indicate that the recharge source of the geothermal water is the precipitation from the mountainous areas in the western part of the study area.The atmospheric precipitation infiltrates from the recharge area and then continuously moves to the centre of the southeastern basin with a circulation depth of 3 436.7 m to 5 030.2 m.[Conclusion]Comparisons with the typical magma-heat source type of geothermal sys-tem as well as the results of the data of radioactive elements in the rocks,this study showed that the geothermal sys-tem of Yingcheng is formed by the heating of geothermal temperature gradient.Combined with the temperature and hydrochemistry data of the shallow underground cold water in the area,the final geothermal anomaly area is located in North of Chenhe Town Southwest of Yingchengcity,but the influence of objective constraints such as well depths and anthropogenic contamination on the results of the circle still needs to be considered.
关键词
水文地球化学/地热温标/地热异常/地热资源勘查/地热系统/应城市
Key words
hydrogeochemistry/geothermometer/geothermal anomaly/geothermal resource exploration/geother-mal system/Yingcheng City
维普
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