桂林地区岩溶水87Sr/86Sr特征

锶是岩石圈上部含量最大的微量元素，其元素及其同位素化学性质都比较稳定。不同水岩作用条件下，锶元素含量及其同位素值都不一样。本文通过对桂林地区的两个典型岩溶地下河系统不同类型地下水样87Sr/86Sr值和Sr含量的分析，得出；流经不同岩层的地下水其87Sr/86Sr值和Sr含量不同，同一地下河系统中不同类型地下水的87Sr/86Sr值Sr含量不同，其值的差异由岩性和水岩作用决定。说明87Sr/86Sr值能反映地下水的形成、径流和混合作用，是较理想的示踪剂，在岩溶水研究中具有很广阔的应用前景。

87Sr/86Sr Characteristics of Karst Water in Guilin Area

Strontium is the richest trace element in upper lithosphere. Due to its stable chemical characteristics, it is inactive to most substances under natural conditions. The Sr concentrations and 87Sr/86Sr ratios are obviously different in different water-rock interac-tion settings. Based on analyzing Sr2+ and 87Sr/86Sr of different groundwater samples in two underground river systems, this paper has drawn some conclusions. Underground waters passing through different strata have different 87Sr/86Sr ratios and Sr concentra-trations. These differences depend on the strata and the water rock interaction. Therefore, the 87Sr/86Sr ratio can reflect the forma-tion, runoff and mixing of underground water and hence is an ideal tracer with a wide application vista in karst water research.