滇东富源古敢水族乡热水塘锶—氟—硅—氡型理疗热矿水的地球化学特征及成因

Geochemical characteristics and genesis of Sr—F—Si—Rn physiotherapy hot mineral water of Reshuitang,in Gugan Town,Fuyuan County,Eastern Yunnan

为支撑滇东富源县古敢水族乡热水塘温泉旅游的开发和可持续利用,笔者等通过采集区内水样进行水化学及环境同位素分析,对温泉的形成机理及其理疗价值进行了研究。结果表明:热水塘温泉温度为37.8~42.2℃,pH值为7.24~7.75,TDS(溶解固态物质总量)的质量浓度为1245~1840 mg/L,属于中低温弱碱性热矿水。温泉水中偏硅酸的质量浓度为48.20~60.57 mg/L,F为2.86~2.94 mg/L,Sr为8.60~14.40 mg/L,均达到了硅水、氟水、锶水的理疗水质标准,此外温泉水中222Rn浓度达到了129.4 Bq/L,接近于氡水的理疗水质标准,具有较大的开发利用价值。热水塘温泉水中阳离子以Ca^(2+)、Mg^(2+)为主,阴离子以SO_(4)^(2-)、HCO_(3)-为主,水化学类型为SO_(4)^(2-)—Ca^(2+)·Mg^(2+)型。石膏和碳酸盐岩矿物的溶解是控制热水塘温泉水化学特征的主要因素,其中石膏的溶解占据了主导地位。参与水岩反应的CO_(2)的δ^(13)CCO_(2)(V-PDB)值为-11.64‰~-14.24‰,具有明显的沉积有机质来源特征。14C测年结果表明热水塘温泉年龄为3291a BP,氢氧同位素特征表明热水塘温泉由大气降水补给,补给高程为2101.9~2138.3 m,补给区温度为5.9~6.2℃。利用硅—焓方程法计算得出热水塘温泉的冷水混合比例为0.84~0.89,综合硅—焓方程计算的热储温度和校正后的SiO2地热温标计算的热储温度,得出热水塘温泉的热储温度为173.1~220.3℃,循环深度为2059.7~2661.1 m。

Objectives:In order to support the development and sustainable utilization of the Reshuitang hot spring tourism in Gugan Shui nationality township,Eastern Yunnan.Methods:The formation mechanism and physiotherapeutic value of the Reshuitang hot spring were studied by collecting water samples for hydrochemistry and environmental isotope analysis.Results:The temperature of the Reshuitang hot spring is 37.8~42.2℃,the pH value is 7.24~7.75,and the TDS is 1245~1840 mg/L.It belongs to medium—low temperature,weak alkaline,hot mineral water.The content of H_(2)SiO_(3)in the hot spring water is 48.20~60.57 mg/L,the content of F is 2.86~2.94 mg/L,and the content of Sr is 8.60~14.40 mg/L,which all meet the water quality standards of physical therapy hot mineral water of silicon water,fluorine water and strontium water.In addition,the concentration of 222Rn in the hot spring water reaches 129.4 Bq/L,which is close to the physical therapy water quality standard of radon water.So the Reshuitang hot spring has great development and utilization value.The cations in the hot spring are mainly Ca^(2+)and Mg2+,and the anions are mainly SO_(4)^(2-)and HCO_(3)-.The hydrochemical type of the Reshuitang hot spring is SO_(4)^(2-)—Ca^(2+)·Mg^(2+)type.The dissolution of gypsum and carbonate minerals is the main factor controlling the hydrochemical characteristics of the Reshuitang hot spring,in which the dissolution of gypsum plays a dominant role.Conclusions:δ^(13)C value of CO_(2)participating in water—rock reaction is-11.64‰~-14.24‰,CO_(2)involved in water—rock reaction in hot spring water comes from sedimentary organic matter.14C dating results show that the age of the Reshuitang hot spring is 3291 a BP.The hydrogen and oxygen isotope characteristics show that the Reshuitang hot spring is recharged by atmospheric precipitation.The recharge elevation is 2101.9~2138.3 m,and the temperature in the recharge area is 5.9~6.2℃.The silicon enthalpy equation method is used to calculate that the cold water mixing ratio of the Reshuitang hot spring is 0.84~0.89.Based on the heat storage temperature calculated by the silicon enthalpy equation and the heat storage temperature calculated by the corrected SiO_(2)geothermal temperature scale,it is considered that the heat storage temperature of the Reshuitang hot spring is 173.1~220.3℃,and the circulation depth is 2059.7~2661.1 m.