柳林泉域岩溶水化学演化及地球化学模拟

为揭示柳林泉域岩溶水化学演化机理,在对柳林泉域水文地质调查的基础上,从岩溶水阴阳离子组成和矿物饱和指数入手,分析了岩溶水化学特征及其演化过程,通过建立逆向地球化学模型,模拟了岩溶含水层中的水岩作用。结果表明:沿地下水流动路径,柳林泉域岩溶水化学类型由补给区的HCO_3-Ca·Mg型演化为径流区的HCO_3·SO_4-Ca·Mg型,在排泄区演化为HCO_3·SO_4-Ca·Na型。柳林泉域岩溶水化学演化的主要地球化学作用为碳酸盐岩和石膏的溶解作用,且沿地下水流动路径,由补给区的方解石和白云石共同溶解作用,逐渐向径流区的白云石和石膏溶解作用为主演化,排泄区还发生了岩盐溶解作用。去白云岩化作用和Na~+-Ca~(2+)离子交换吸附作用在径流区和排泄区影响岩溶水化学类型。

Hydrochemical evolution and geochemical simulation of karst groundwater in Liulin springs

To reveal the evolution mechanism of groundwater quality in Liulin karst system in northern China, we used the major ions and saturation indices to analyze the hydrochemical characteristics and geochemical processes. Meanwhile, we established a reverse geochemical model to quantitatively simulate the water-rock interactions in karst aquifers. The results showed that the hydrochemical type changed from HCO3-Ca· Mg in the recharge area to HCO3· SO4-Ca· Mg in the runoff area and to HCO3·SO4-Ca· Na in the discharge area. The geochemical processes of hydrochemical evolution in karst water were the dissolution of carbonate minerals and gypsum. Along the flow path, the processes were evolved from the simultaneous dissolution of calcite and dolomite in the recharge area to the dissolution of dolomite and gypsum in the runoff area, and the dissolution of halite was added in the discharge area. Besides, the dedolomitization and cation exchange between Na+ and Ca2+ in the runoff and discharge areas affected the hydrochemical types of karst groundwater in Liulin.