Geochemical characteristics of modern hot springs from northwest Hunan

摘要

The studies of chemical compositions of modern hot spring water and gases,isotopiccompositions of H2O,He,Ar,CH4,CO2 in northwest Hunan show that the chemical characteristics of springwater are markedly different,which indicates the difference of background value of country rocks and the dif-ference of the effect of water-rock reaction.The geothermal systems in the studied regions are middle-hightemperature geothermal systems.The distributions of springs are controlled by the press and press-shearfaults that do not dissect deeply to the mantle.The hot spring water is of meteoric water.The origin of ma-terials in the hot springs is correlated with the sedimentary rocks.