色达—松潘断块温泉水文地球化学特征及成因分析

为查明色达—松潘断块地热资源赋存状态及热源来源,以四川黑水县内3处温泉(热水塘、上达古、卡龙沟)为研究对象,采集温泉水样进行水化学分析和同位素测试,研究地热水的补给来源和热储温度。研究结果显示,热水塘温泉的地下水化学类型为HCO₃-Na型,上达古温泉和卡龙沟温泉的地下水化学类型为HCO₃-Ca型,补给水源主要为大气降水,补给高程分别为5 121 m、3 890 m、3 921 m。结合矿物饱和指数,采用SiO₂地热温标计算3处温泉的热储温度,分别为119.036 ℃、49.034 ℃、30.215 ℃。综合分析认为研究区地下热水的成因主要为大气降水经高山补给区入渗至储集层,吸取地下深部向上传导的热量和放射性元素衰变释放的热量,并与围岩发生水-岩作用形成地下热水,在断裂发育部位热水沿断裂带向上运移,最后在地表出露形成温泉。

Geothermal Hydrogeochemical Characteristics and Genetic Analysis of the Seda-Songpan Fault Block

To determine the geothermal resource occurrence and source in the Sedar-Songpan fault block, three hot springs(namely Reshuitang, Shangdagu and Kalonggou) in Heishui County of Sichuan Province were taken sampled, and analyzed for their water chemistry and isotopes, and the recharge source and heat storage temperature of geothermal water were discussed. The results show that the groundwater chemistry types of the Heishui hot springs are HCO₃-Ca or HCO₃-Na, and the replenishing water came mainly from atmospheric precipitation. The replenishment elevation of the Reshuitang, Shangdagu and Kalonggou is 5,121 m, 3,890 m and 3,921 m, respectively. Considering mineral saturation, SiO₂ geothermometer was used to calculate the hot spring thermal storage temperature, yielding 119.036 ℃, 49.034 ℃ and 30.215 ℃, respectively. Based on the genetic analysis of the local geothermal water, we concluded that the underground hot water was formed by: the infiltration of meteoric water into the reservoir through the alpine recharge area, which absorbed heat from deep underground conducts and interacted with the wallrocks, forming the underground hot water. In the better developed parts of faults, cracks and joints, the hot water ascended along fault zones, and finally emerged as hot spring on the surface.