This study was aimed at identifying and quantifying mixing proportions in surface waters downstream of historical Cu-W-F skarn mine tailings at Yxsjöberg, Sweden, using ¹⁸O, ²H, and ⁸⁷Sr/⁸⁶Sr isotopes. In addition, a simple mathematical model was developed to evaluate the consistency of the mixing calculations. Hydrochemical and isotopic data from 2 groundwater wells, 6 surface water and 2 rainwater sampling sites, spanning 6 sampling campaigns between May and October were used. Three mixed surface waters downstream of the tailings were identified, namely: C7, C11 and C14. C7 was directly influenced by groundwater from the tailings whereas C11 was also subsequently influenced by C7. C14 on the other hand, had contributions from C11. Sequential mixing calculations indicated that the contribution of the groundwater to C7 ranges from 1 to 17%. The subsequent contribution of C7 to C11 varied from 49 to 91% whereas C14 had contributions of C11 ranging between 16 and 56%. A strong agreement between the model data (MD) and measured raw data (RD) for C11 and C14 indicated the accuracy of the mixing calculations. Variations between the MD and RD at C7, however, was mainly due to sorption and reductive processes underneath the tailings, which tend to attenuate the amount of dissolved ions reaching the surface waters, resulting in a low ionic contribution of the tailings groundwater to the surface water. The low ionic contribution of the groundwater to C7 suggested that although the tailings impoundment is of environmental concern, its impact on the downstream surface waters is small. The results of this study suggest that mixing calculations in surface waters involving a closed system such as groundwater (as an end-member) must be treated with caution. It is recommended that the interpretation of such mixing results must be coupled with detailed knowledge of the potential hydrogeochemical processes along its flow paths.

这项研究的目的是使用¹⁸ O，² H和⁸⁷ Sr / ^86来确定和量化瑞典Yxsjöberg历史Cu-WF矽卡岩型矿山尾矿下游地表水中的混合比例。锶同位素。此外，开发了一个简单的数学模型来评估混合计算的一致性。使用了5月至10月之间的6个采样活动的2个地下水井，6个地表水和2个雨水采样点的水化学和同位素数据。确定了尾矿下游的三个混合地表水，分别为：C7，C11和C14。C7直接受到尾矿中地下水的影响，而C11随后也受到C7的影响。另一方面，C14来自C11。顺序混合计算表明，地下水对C7的贡献为1％至17％。C7对C11的后续贡献从49％到91％不等，而C14对C11的贡献在16％到56％之间。C11和C14的模型数据（MD）与测量的原始数据（RD）之间有很强的一致性，表明混合计算的准确性。但是，C7处的MD和RD之间的变化主要是由于尾矿下面的吸附和还原过程，这往往会削弱到达地表水的溶解离子的量，从而导致尾矿地下水对地表的离子贡献较低。水。地下水对C7的低离子贡献表明，尽管尾矿库有环境问题，但对下游地表水的影响很小。这项研究的结果表明，必须谨慎处理涉及封闭系统（如地下水）（作为最终成员）的地表水的混合计算。