结合地下水化学资料,应用含水介质和地下水Sr含量及87Sr/86Sr比值,对鄂尔多斯沙漠高原白垩系含水层中水-岩作用机制进行了研究。结果表明:含水介质中钾长石、斜长石和碳酸盐矿物的87Sr/86Sr比值具有差异,地下水87Sr/86Sr比值介于0.709 871~0.711 792。地下水Sr来源主要为碳酸盐矿物、硫酸盐矿物和硅酸盐矿物中斜长石;白垩系环河组地下水-介质间主要发生碳酸盐矿物溶解、硫酸盐矿物溶解和斜长石溶解等作用,而洛河组地下水-介质间主要发生硫酸盐矿物溶解作用和钾长石溶解作用。碳酸盐矿物、硫酸盐矿物和硅酸盐矿物溶解作用是鄂尔多斯沙漠高原白垩系含水层中发生的主要水-岩作用。
Combined with groundwater chemistry data and using Sr content and 87Sr/86Sr ratios of hydrous media and groundwater,this paper studies the mechanism of water-rock interaction in the Cretaceous aquifer of Ordos Desert Plateau.The result indicates that K-feldspar,plagioclase and carbonate minerals in hydrous media have different 87Sr/86Sr ratios and the 87Sr/86Sr ratios of groundwater are between 0.709871 and 0.711792.Sr in groundwater is primarily derived from carbonate minerals,sulfate minerals and plagioclase of silicate minerals.The water-rock interactions in the groundwater of Huan River Group in the Cretaceous aquifer are mainly carbonate mineral dissolution,sulfate mineral dissolution and plagioclase dissolution,and the interactions of Luo River Group are sulfate mineral dissolution and K-feldspar dissolution.The main water-rock interactions include the carbonate mineral dissolution,sulfate mineral dissolution and silicate mineral dissolution in the Cretaceous aquifer of Ordos Desert Plateau.