The Big Ledge mine located in northeastern Nevada, USA is a former barite mine site that now hosts an acidic pit lake and highly concentrated waste rock seepage, which flows into an intermittent stream. In an effort to identify the source(s) of the seepage, stable isotopic analyses were conducted (δ²H, δ¹⁸O_H2O, δ¹⁸O_SO4, and δ³⁴S) in the pit lake, seepage, and groundwater. Additionally, inverse geochemical modeling was utilized to evaluate mixing relationships and mineral equilibria. Mass-balance calculations were also performed on the seepage/stream system to quantify discrete and diffuse solute inputs to surface waters. The stable isotopic composition of the pit lake and seepage display evaporative enrichment with the seeps being intermediate between the pit lake and groundwater, indicating that water in the seeps is partially sourced in the upgradient pit lake. Inverse modeling corroborates the isotopic mixing relationships, suggests that sulfide minerals could be dissolving along the flow path in the waste rock, and predicts the precipitation of sulfate salts from the concentrated seepage waters. Mineralogical analysis of efflorescent salts at the site, including epsomite (MgSO₄·7H₂O), pickeringite (MgAl₂[SO₄]₄·22H₂O), and melanterite (FeSO₄·7H₂O), corroborates the inverse modeling. Mass-balance calculations indicate the presence of diffuse acid mine drainage inflows along the creek, which, along with discrete inflows from waste rock seepage, contribute to sustained dissolved-metal transport in the perennial Tabor Creek downgradient from the mine.

位于美国内华达州东北部的Big Ledge矿山以前是重晶石矿山，现在拥有一个酸性矿坑湖和高浓度的rock石渗漏，并断断续续地流入。在努力确定渗水的源极（S），稳定同位素分析进行了（δ ² H，δ ¹⁸ ö _H2O，δ ¹⁸ ö _SO4，和δ ³⁴S）在坑湖，渗流和地下水中。另外，逆地球化学模型被用来评估混合关系和矿物平衡。还对渗流/水流系统进行了质量平衡计算，以量化向地表水的离散和扩散溶质输入。坑湖和渗流的稳定同位素组成显示出蒸发富集，渗流介于坑湖和地下水之间，表明渗漏中的水部分来自上游的坑湖。反演模型证实了同位素的混合关系，表明硫化物矿物可能沿着废石流道溶解，并预测了来自浓渗水的硫酸盐的沉淀。现场的风化盐的矿物学分析，₄ ·7H ₂ O），堇青石（MgAl ₂ [SO ₄ ] ₄ ·22H ₂ O）和黑铁矿（FeSO ₄ ·7H ₂ O）证实了逆建模。质量平衡计算表明，沿着小溪存在着分散的酸性矿山排水流，再加上废石渗流引起的离散流，导致矿山多年生的塔博尔河下降坡中的溶解金属持续运移。