【摘要】 鄂尔多斯白垩系自流水盆地北部为沙漠高原区,南部为黄土高原区。区内经济以农业和畜牧业为主,地下水的污染较弱。地下水中Sr来源于含Sr矿物的溶解。因此,可以利用Sr及87Sr/86Sr比值来研究水岩作用和地下水的演化。采自盆地20个Sr及其同位素样品的分析结果表明在区域上87Sr/86Sr比值是不均匀的,西南部87Sr/86Sr比值较大(0.711002~0.711570),其他地区87Sr/86Sr比值较小(0.710378~0.710646);在局域地下水系统中,埋深小于100m的浅层地下水,Sr含量较低,87Sr/86Sr比值较大,而埋深大于100m的深层地下水,Sr含量较高,87Sr/86Sr比值较小,并且沿地下水径流方向,Sr的浓度越来越高。苏贝淖湖是自流水盆地北部局域地下水系统的一个排泻区,湖水Sr含量较低,而87Sr/86Sr比值较大,其Sr同位素组成特征与浅层地下水一致,表明湖水来源于浅层地下水。更多还原

【Abstract】 The north district in the Ordos Cretaceous Artesian Basin is desert plateau. And the south district is loess plateau. Agriculture and stock raising are the main economical forms. The pollution in this area is not very prominent, so the strontium and its isotope can be here used to study the water-rock reaction and the evolution of the groundwater. The analyzing results of 20 strontium samples from this basin show that: the 87Sr/86Sr ratios of the groundwater are not uniform regionally. The 87Sr/86Sr ratios(0.711002～0.711570)in the southwest area are bigger than that of the other area (0.710378～0.710646). In local system, the strontium concentration of the groundwater, which depth is less than 100 m, is relatively smaller, and the 87Sr/86Sr is relatively bigger. However, the strontium concentrations of the groundwater, which depths are more than 100 m, is relatively bigger, and the 87Sr/86Sr ratios are relatively smaller. And following the pathway of the groundwater the strontium concentrations become bigger and bigger. The strontium concentration of Subeinao lake water is relatively smaller and the 87Sr/86Sr ratio is relatively bigger, which are identical with shallow groundwater, so the origin of Subeinao lake water is from shallow groundwater.更多还原