Geochemical Genesis of Arsenic in the Geothermal Waters from the Rehai Hydrothermal System, Southwestern China
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- 作者：Qinghai Guo ; qhguo2006@gmail.com ; Mingliang Liu ; Jiexiang Li ; Chao Zhou
- 关键词：arsenic ; hot spring ; steam-heated acidic water ; water-rock interaction ; magmatic fluid input
- 刊名：Procedia Earth and Planetary Science
- 出版年：2017
- 出版时间：2017
- 年：2017
- 卷：17
- 期：Complete
- 页码：49-52
- 全文大小：139 K
- 卷排序：17
文摘
The geothermal waters from the Rehai magmatic hydrothermal system, located in the Tengchong volcanic region, south-western China, are characterized by diversified hydrochemical types and a wide range of pH values. The neutral hot springs in Rehai generally have much higher arsenic concentrations than the acid hot springs. Further inspection shows that the acid, sulfate-rich springs are essentially locally-perched groundwaters heated by H2S-rich steam separated from deep geothermal fluid. Hence, the dissolution of near-surface rocks at moderate temperatures is the sole source of arsenic in the steam-heated acid springs. In comparison, the arsenic in the neutral hot springs, which represent the deep-circulating geothermal fluids, comes from long-term water-rock interactions at much higher reservoir temperatures. Moreover, the possibility that magmatic fluid is a potential arsenic source for the neutral springs in Rehai cannot be ruled out.