Accumulated mine waste in certain locations in the abandoned mining district of Linares-La Carolina (southern Spain) contain high levels of metals. Therefore, in recent years, many of these tailings ponds have been restored and sealed. This study assessed the efficacy of two geophysical techniques, electrical resistivity tomography (ERT) and induced polarisation (IP), combined with hydrochemical studies, as tools to image the effectiveness of the encapsulation. In the bedrock, ERT profiles distinguished a surficial layer of moderate-low resistivity values (below 80 Ω m), associated with alluvial sands or altered granite, and a deeper zone of high resistivity (up to 1000 Ω m) related to unaltered granite basement. Lateral changes in resistivity were identified inside the upper layer and downstream of the tailings pond. The IP profiles detected local anomalies in the chargeability values (up to 8 mV/V), unusual in granitic rocks. The locations with high chargeability also had low resistivity, which typically indicates the percolation of mining leachates in the underlying altered granites. Integration of geological and geochemical information confirmed this interpretation. This work verified that the combined use of ERT and IP methods were effective for monitoring ancient tailings ponds and for assessing tailings encapsulation.

中文翻译：

---

通过结合电气（ERT 和 IP）和水化学技术（利纳雷斯，西班牙南部）对尾矿池进行评估

在 Linares-La Carolina（西班牙南部）废弃矿区的某些地点积累的矿山废物含有高含量的金属。因此，近年来，许多这些尾矿库都得到了修复和封存。本研究评估了两种地球物理技术、电阻率断层扫描 (ERT) 和激发极化 (IP) 的功效，并结合水化学研究，作为对封装有效性进行成像的工具。在基岩中，ERT 剖面区分了与冲积砂或蚀变花岗岩相关的中低电阻率值（低于 80 Ω·m）的表层，以及与未蚀变的花岗岩基底相关的更深的高电阻率区域（高达 1000 Ω·m） . 在尾矿池的上层和下游确定了电阻率的横向变化。IP 剖面检测到带电值的局部异常（高达 8 mV/V），这在花岗岩中是不常见的。具有高充电率的位置也具有低电阻率，这通常表明采矿渗滤液在下面的蚀变花岗岩中渗滤。地质和地球化学信息的整合证实了这一解释。这项工作验证了 ERT 和 IP 方法的结合使用对于监测古尾矿池和评估尾矿包封是有效的。