| Title | Hydrogeochemistry of hot springs in Western Jiangxi Province, SE-China |
|---|---|
| Authors | Zhanxue Sun, Gongxin Chen, lu Li, Xinghua Shi |
| Year | 2023 |
| Conference | World Geothermal Congress |
| Keywords | hot spring, hydrogeochemistry, isotopes, subsurface temperature evaluation of geothermal reservoirs, Jiangxi Province |
| Abstract | In order to assess the potential of geothermal development, hydrogeochemistry of ten selected hot springs from Western Jiangxi Province, SE-China are studied. Based on field investigation and sample analysis, the chemical composition and isotopic characteristics of the hot springs and the evaluation of subsurface temperatures of geothermal reservoirs in this area are discussed. The hydrochemical types of hot springs in the area mainly belong to HCO3-Na and HCO3-Ca types distributed in southern part, and SO4-HCO3-Na type exposed in the northern part. Most hot springs are neutral or weak alkaline nitrogen-containing waters . Isotopic compositions of hydrogen, oxygen and strontium indicated that the hot waters are of meteoric origin. The geothermal water are formed by deep circulation of precipitation through the faults and fractures. The recharge altitudes of the hot springs of HCO3-Na type and SO4-HCO3-Na type are estimated to be about 900-1700m, and the recharge altitude of the hot springs of HCO3-Ca type ranges from 200-700m. The 14C ages of SO4-HCO3-Na hot springs are greater than 6000a, much older than that (about 2000a) of HCO3-Na type hot springs. Using quartz and chalcedony geothermometers, the temperatures of the geothermal reservoirs are calculated as about 80-100℃ for HCO3-Na type hot springs, 40-60℃ for HCO3-Ca type hot springs and 90-120℃for SO4-HCO3-Na type hot springs respectively. The geothermal waters are low-mid geothermal resources and suitable for direct uses. |