Pu Xiangheng, Zhou Li, Chen Zhengshan, Zhou Wenge
School of Geography and Environmental Science, Guizhou Normal University, Guiyang, China.
State Key Laboratory Incubation Base for Karst Mountain Ecology Environment of Guizhou Province, Guiyang, China.
PLoS One. 2025 Jun 18;20(6):e0324054. doi: 10.1371/journal.pone.0324054. eCollection 2025.
Due to the lack of experimental studies, the effect of water-rock interactions on the hydrochemical characteristics of hot springs within belted reservoir remains poorly understood. To solve this issue, we analyzed the hydrochemical characteristics of the hot springs and the geochemical features of the reservoir rocks in the Jianhe hot springs in Guizhou province, SW China. All water sample analyses adhered to the China analytical procedures (GB 8538-2022), then carried out water-rock interacting experiments with representative reservoir rocks (e.g., metamorphosed tuff, metamorphosed quartz sandstone, and slate) under varying reaction time, temperature, and pH conditions. The results indicate that the concentration of dissolved ions in the solution increased with time, then gradually stabilized, reaching dynamic equilibrium around 35 days. Higher temperatures facilitated the leaching of K+, Na+, and H2SiO3, meanwhile reduced the leaching of Ca2+ and Mg2+. However, both Ca2+ and Mg2+ in the solution showed a pronounced response to pH changes from 4 to 10, whereas the K+, Na+, and H2SiO3 concentrations were less sensitive to pH changes. In particular, under experimental conditions corresponding to the reservoir (90°C), the Ca2+, concentrations as leached from metamorphosed tuff agreed well with the hydrochemical data in Jianhe hot springs, which are significantly lower than those in the solutions interacted with quartz sandstone or slate, and indicate that metamorphosed tuff should be the primary sources for K+, Na+, Ca2+, Mg2+ and H2SiO3 in the hot springs.
由于缺乏实验研究，带状储层内热泉水 - 岩相互作用对温泉水化学特征的影响仍知之甚少。为解决这一问题，我们分析了中国西南部贵州省剑河温泉的水化学特征以及储层岩石的地球化学特征。所有水样分析均遵循中国分析程序（GB 8538 - 2022），然后在不同的反应时间、温度和pH条件下，用代表性的储层岩石（如变质凝灰岩、变质石英砂岩和板岩）进行水 - 岩相互作用实验。结果表明，溶液中溶解离子的浓度随时间增加，然后逐渐稳定，在35天左右达到动态平衡。较高的温度促进了K +、Na +和H2SiO3的溶出，同时减少了Ca2 +和Mg2 +的溶出。然而，溶液中的Ca2 +和Mg2 +对pH从4到10的变化均表现出明显的响应，而K +、Na +和H2SiO3的浓度对pH变化不太敏感。特别是，在与储层相对应的实验条件（90°C）下，变质凝灰岩溶出的Ca2 +浓度与剑河温泉的水化学数据吻合良好，明显低于与石英砂岩或板岩相互作用的溶液中的浓度，表明变质凝灰岩应是温泉中K +、Na +、Ca2 +、Mg2 +和H2SiO3的主要来源。
