This contribution discusses the discovery of PbZn mineralization in hydrocarbon exploration drill holes hosted in siliciclastic Jurassic rocks below the Cretaceous sediment hosted Cu mineralization located north of the Huincul High. In the Early Cretaceous, hydrocarbon and basinal water expulsion took place from the oil source rocks (Los Molles Formation) into the reservoir rocks Lajas Formation (Middle Jurassic), after the formation of diagenetic quartz overgrowths. Marcasite, pyrite and illite + illite-smectite mixed layer minerals then formed together with hydrocarbons. Marcasite (δ³⁴S −3.5 and −2.2‰) and pyrite (δ³⁴S −11.6 to 18.1‰) precipitated via bacterial sulfate reduction from fluids showing temperatures <80 °C and fluctuating pH conditions. During the Paleogene, Andean tectonism triggered migration of oxidized basinal brine containing dissolved leached Zn and Pb from the Los Molles Formation source rocks and S from the evaporites of the basin. This brine entered in the hydrocarbon reservoir of the Lajas Formation, resulting in the precipitation of sphalerite (δ³⁴S +10.4 to +10.8‰) and galena (δ³⁴S +5.2‰) by TSR at temperatures of 119–123 °C together with siderite. The Andean orogeny may also have triggered the migration of hydrocarbons + brines from the shallowest source rocks (Vaca Muerta Formation) and reservoir rocks (Mulichinco, Lajas and Lotena formations) into the red beds of the upper Cretaceous Neuquén Group, which became bleached as a result. Marcasite (δ³⁴S −36.4 to 18.2‰) and pyrite (δ³⁴S −60.2 to −24‰) precipitated by BSR, while calcite (δ¹³C −12.3 to −5.6‰) formed due to redox reactions accompanying formation of quartz overgrowths, clay mineral coatings (δD −92.4‰ to −82.8‰ and δ¹⁸O 16.2‰ to 18.40‰), and barite (δ³⁴S −5.9‰). Quartz overgrowths and barite precipitated from brines (1.5–10 wt% NaCl equiv.) at temperatures of 91–120 °C, with barite precipitating close to the feeder zones. Calcite cements are more widespread and generated from several pulses of brine and hydrocarbons up flow, evidenced by the wide range of homogenization temperatures (100–185 °C) and diversity of UV fluorescence colors of hydrocarbon-rich fluid inclusions. In subsequent Miocene tectonic events, basinal brines were able to leach Cu from the underlying thick red beds of the basin, entering the Neuquén Group oil reservoir traps or carrier beds where they became reduced. Chalcopyrite and bornite precipitated at temperatures >100 °C close to the feeder zones at the expense of barite as a local sulfur source. Chalcocite group minerals (δ³⁴S −21.3‰ to −7.3‰) precipitated outwards in pore spaces of the sandstones at lower temperatures (<100 °C) through BSR of sulfate in the mineralizing brines. Final exhumation of the Neuquén Group (Upper Miocene-Pliocene) promoted the infiltration of the meteoric water, the oxidation of the sulfides and formation of supergene FeCu, V and U minerals. Isotope geochemistry and fluid inclusion results combined with alteration and ore mineralogy document the processes controlling the distribution of base metals in the Huincul High region that can be applied to evaluate the metal potential in other areas of the Neuquén Basin and further extrapolated to similar geological systems elsewhere.

该贡献讨论了在Huincul高地以北的白垩纪沉积的Cu矿化作用之下的硅质碎屑侏罗纪岩石中的烃类勘探钻孔中发现Pb Zn矿化的发现。在白垩纪早期，成岩石英超长形成后，油气和盆地水从油源岩（Los Molles组）排入储层岩Lajas组（中侏罗统）。然后与碳氢化合物一起形成了镁铁矿，黄铁矿和伊利石+伊利石-蒙脱石混合层矿物。白铁矿（δ ^34个小号-3.5 -2.2和‰）和黄铁矿（δ ³⁴S -11.6至18.1‰）是通过细菌硫酸盐还原而从温度<80°C且pH条件波动的流体中沉淀出来的。在古近纪期间，安第斯构造运动触发了氧化的盆地盐水的迁移，这些盆地的盐水含有从Los Molles地层烃源岩中溶解的浸出的Zn和Pb，而S则来自盆地的蒸发物。此盐水在拉哈斯形成的碳氢化合物储层进入，导致闪锌矿的沉淀（δ ³⁴ š10.4到10.8 +‰），方铅矿（δ ³⁴在119–123°C的温度下用TSR测得S + 5.2‰，以及菱铁矿。安第斯造山运动也可能触发了碳氢化合物和盐水从最浅的烃源岩（瓦卡穆尔塔组）和储集层岩石（穆利钦科，拉哈斯和洛特纳组）的迁移到白垩纪内乌肯群上部的红层中，并被漂白。结果。白铁矿（δ ³⁴小号-36.4〜18.2‰）和黄铁矿（δ ³⁴小号-60.2至-24‰）由BSR沉淀，而方解石（δ ¹³由于C形成-12.3 -5.6‰）氧化还原伴随形成石英的反应过度生长，粘土矿物的涂层（δD-92.4‰至-82.8‰和δ ¹⁸ ö16.2‰至18.40‰），和重晶石（δ ³⁴S -5.9‰）。在91-120°C的温度下，盐水（1.5-10 wt％NaCl当量）中的石英过度生长和重晶石沉淀，重晶石沉淀在进料区附近。方解石水泥的分布范围更广，它是由数个盐水和碳氢化合物向上流动的脉冲产生的，均质温度范围很广（100–185°C）和富含碳氢化合物的流体包裹体的UV荧光色的多样性证明了这一点。在随后的中新世构造事件中，盆地盐水能够从盆地下面厚厚的红色层中浸出铜，进入NeuquénGroup油藏圈闭或载体层，并在那里被还原。黄铜矿和堇青石在> 100°C的温度下靠近进料区析出，以重晶石作为当地的硫源为代价。辉铜矿族矿物（δ ³⁴S -21.3‰至-7.3‰）在较低温度（<100°C）下通过矿化盐水中的硫酸盐BSR在砂岩孔隙空间中向外沉淀。Neuquén组（中新世-上新世）的最终发掘促进了陨石水的渗透，硫化物的氧化以及超晶铁，铜，钒和铀矿物的形成。同位素地球化学和流体包裹体结果与蚀变和矿石矿物学相结合，记录了控制汉因库尔高地区基本金属分布的过程，这些过程可用于评估内乌肯盆地其他地区的金属潜力，并进一步推论至其他地方的类似地质系统。