Geochemical genesis of geothermal waters from the Longling hydrothermal area, Yunnan, Southwestern China

• 作者: GUO Qing-hai GUO Wei LI Jie-xiang LIU Ming-liang WANG Yan-xin ZHANG Can-hai ZHANG Xiao-bo ZHOU Chao ZHU Ming-cheng
• 来源期刊: 地下水科学与工程：英文版
• 学科: 地球科学
• 年，卷（期）: 2015,（3）
• 页码范围: 213-221
• 页数: 9页
• 分类号: P314

摘要

Longling is characterized by a wide distribution of hydrothermal areas, among which the Banglazhang hydrothermal system is the most geothermally active. Banglazhang is marked by intensive hydrothermal activities including hot springs, geysers, fumaroles and hydrothermal explosions. The geothermal waters from the Longling region are mainly HCO3-Na type with low but comparable SO4 and Cl concentrations. Calculations based on a variety of chemical geothermometers and a K-Ca geobarometer indicate that the Banglazhang hydrothermal system has much higher subsurface temperature and CO2 pressure compared to the other systems such as Daheba, Dazhulin and Huangcaoba. However, geothermal water samples collected from all these alternative hydrothermal areas are either partially equilibrated with reservoir minerals or are immature. The silica-enthalpy relationships of Banglazhang geothermal waters indicate the presence of a deep geothermal fluid with an enthalpy value and silica concentration of 945 J/g（up to around 220 °C） and 339 mg/L. Our work indicates the Banglazhang area is a promising source in terms of long-term utilization of hydrothermal resources.