Groundwaters collected from the undisturbed Picaron Cu–Mo porphyry and exotic prospect (Atacama region, Chile) were analyzed for major and trace elements, along with isotopes of Cu, Mo, S, and ⁸⁷Sr/⁸⁶Sr. Sulfide minerals at Picaron have undergone oxidation by meteoric waters, resulting in the generation of acid and the lateral and downward migration of dissolved trace cations (Cd, Co, Cu, Ni, Pb, and Zn) and (oxy)anions (As, Mo, Sb, and Se). This paper presents a case study utilizing stable metal isotopes in hydrogeochemical mineral exploration to ascertain the possible hydrogeochemical footprints that can be detected around known mineralization. The groundwaters are weakly brackish (TDS < 3500 mg/L), reflected in relatively low trace metal concentrations. Despite this, the groundwaters reflect the dissolution of ore, as well as alteration and wall rock minerals proximal to porphyry mineralization with elevated dissolved concentrations of Ca, Mg, HCO₃⁻, and SO₄²⁻. δ⁶⁵Cu values range from 0.41 to 2.80‰, with values above 1‰ proximal to porphyry mineralization reflecting Cu fractionation during sulfide oxidation and the highest values (up to 2.80‰) proximal to exotic mineralization likely from Cu desorption. Downgradient, δ⁶⁵Cu values decrease; possibility resulting from adsorption of the heavier ⁶⁵Cu onto reactive surfaces or mixing with other sources. δ⁹⁸Mo values proximal to porphyry mineralization (2.41 and 2.42‰) are much higher than the regional average for molybdenite reported in previous studies (0.11‰), suggesting acid neutralization and isotopic fractionation related to adsorption may be occurring close to the source. Much lower δ⁹⁸Mo values downgradient (<1.0‰) are likely indicative of Mo input from surrounding country rocks. The hydrogeochemical trends observed in the Picaron groundwaters highlight the chemical processes of mineral dissolution, precipitation, and recharge pathways and indicate that the leaching of the porphyry mineralization could be the source of exotic mineralization. Ultimately, the results indicate the need for a multiple isotope approach to hydrogeochemical mineral exploration.

分析了未受干扰的Picaron Cu-Mo斑岩和奇异前景（智利阿塔卡马地区）收集的地下水中的主要和痕量元素，以及Cu，Mo，S和⁸⁷ Sr / ^86的同位素皮卡隆的Sr.硫化物矿物已被流域水氧化，导致酸的产生以及溶解的痕量阳离子（Cd，Co，Cu，Ni，Pb和Zn）和（氧）阴离子（As ，Mo，Sb和Se）。本文介绍了一个案例研究，该案例利用稳定的金属同位素进行水文地球化学矿物勘探，以确定可能在已知成矿作用附近探测到的水文地球化学足迹。地下水微咸（TDS <3500 mg / L），反映在相对较低的痕量金属浓度中。尽管这样，地下水反映矿的溶解，以及改变和围岩矿物质近端斑岩矿化与升高的钙，镁，HCO的溶解浓度₃ ^-和SO ₄ ^2-。δ ^65个的Cu值的范围从0.41至2.80‰，上述1‰近端斑岩矿化值反映硫化物氧化过程中的Cu分馏和最高值（最大为2.80‰）近端异国矿化可能由Cu解吸。下坡，δ ^65个的Cu值下降; 可能是由于较重的⁶⁵ Cu吸附到反应性表面上或与其他来源混合。δ ⁹⁸沫值接近斑岩矿化（2.41和2.42‰）是在以前的研究（0.11‰），表明酸中和与吸附可能发生接近源同位素分馏比辉钼矿区域平均高得多的报道。低得多δ ⁹⁸Mo值下降（<1.0‰）很可能表明周围乡村岩石中有Mo输入。在皮卡龙（Picaron）地下水中观察到的水文地球化学趋势突显了矿物溶解，沉淀和补给途径的化学过程，并表明斑岩矿化的浸出可能是外来矿化的来源。最终，结果表明需要采用多种同位素方法进行水文地球化学矿物勘探。