Filo del Sol is a composite porphyry-epithermal deposit, straddling the frontier between Argentina and Chile at latitude 28°29′ S, that has attracted a great deal of recent attention because of several drill intersections in excess of 1 km long with unusually high Cu, Au, and Ag grades. The deposit is part of the 8.5-km-long, N- to NE-trending Filo del Sol alignment of porphyry and high-sulfidation epithermal centers, which, in turn, is located in the newly defined Vicuña metallogenic belt that unites the well-known late Oligocene to middle Miocene Maricunga and El Indio belts. The deposit is hosted by Permian felsic volcanic rocks intruded by Triassic monzogranite and, nearer the surface, by shallowly dipping Late Cretaceous volcano-sedimentary rocks. These lithologic units were intruded by several generations of mafic dikes and high-level sills and, in the middle Miocene, by a parallel swarm of composite diorite porphyry dikes. An intermineral magmatic-hydrothermal breccia body is closely associated with the porphyry dikes and subsequently cut at shallow levels by a smaller, finer-grained breccia of phreatic and, possibly, phreatomagmatic origin. Early Cu-Au mineralization, mainly as chalcopyrite, is associated with K-feldspar- and biotite-bearing potassic alteration and accompanying A-type quartz-veinlet stockworks. The potassic zone was massively overprinted and extensively reconstituted by a zone of vuggy residual quartz and silicification in the core of the deposit, flanked by quartz-alunite as part of a more extensive lithocap. These alteration types host high-sulfidation Cu-Au-Ag mineralization as pyrite with early enargite and later bornite, chalcocite, covellite, and numerous Ag-bearing sulfosalts, with the highest grades typically confined to vuggy residual quartz. Largely barren, steam-heated alteration is preserved above and overprinted on the lithocap. The results of radiometric dating (six U-Pb and 22 Re-Os ages) show that porphyry intrusion and potassic alteration began at ~15 Ma and lasted for nearly 1 m.y., although most of the molybdenite samples reported ages from 14.7 to 14.4 ± 0.06 Ma. This short interval coincided with a pulse of regional compressive tectonism accommodated by high-angle, thick-skinned, reverse faulting of basement-cored blocks, and concomitant uplift and exhumation. This uplift gave rise to ~1 km of erosion during formation of the Filo del Sol deposit, thereby accounting for the extreme telescoping of high-sulfidation over porphyry mineralization. Spatial association of these middle Miocene intrusion centers with dated middle Permian and Eocene mineralization suggests deep-seated structural control of the Filo del Sol alignment. Ongoing supergene processes under low-pH conditions produced a near-surface resource dominated by chalcanthite, with minor underlying chalcocite enrichment, as well as partially oxidizing a shallow zone of high-grade Ag mineralization.

中文翻译：

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阿根廷-智利 Filo del Sol 斑岩铜金矿和浅成热液铜金银矿化地质：安第斯隆升期间的极端伸缩

Filo del Sol 是一个复合斑岩-浅成热液矿床，横跨南纬 28°29′ 的阿根廷和智利边境，由于多个钻探交叉点长度超过 1 公里，铜含量异常高，因此最近引起了广泛关注。 、Au 和 Ag 牌号。该矿床是 8.5 公里长、北东至北东走向的斑岩和高硫化浅成热液中心 Filo del Sol 排列的一部分，而该排列又位于新定义的 Vicuña 成矿带中，该带将良好的已知渐新世晚期到中新世中期的马里昆加和埃尔印第奥带。该矿床由三叠纪二长花岗岩侵入的二叠纪长英质火山岩以及靠近地表的浅倾晚白垩世火山沉积岩构成。这些岩性单元被几代镁铁质岩脉和高位岩脉侵入，并在中新世中期被平行群的复合闪长斑岩岩脉侵入。矿间岩浆-热液角砾岩体与斑岩岩脉密切相关，随后在浅层被更小、更细粒的潜水角砾岩（可能是水岩浆来源）切割。早期的铜金矿化主要为黄铜矿，与含钾长石和黑云母的钾蚀变以及伴随的 A 型石英脉网状结构有关。钾质带被矿床核心的一个孔洞残留石英和硅化带大量覆盖和广泛重建，两侧是石英明矾石，作为更广泛的岩盖的一部分。这些蚀变类型以黄铁矿形式存在高硫化铜金银矿化，其中包括早期的硫铜矿和后来的斑铜矿、辉铜矿、蓝铜矿和大量含银硫盐，最高品位通常局限于孔隙状残余石英。大部分贫瘠的、蒸汽加热的蚀变被保留在上面，并叠印在石盖上。放射性测年结果（6 个 U-Pb 年龄和 22 个 Re-Os 年龄）表明，斑岩侵入和钾蚀作用开始于约 15 Ma，并持续了近 1 my，尽管大多数辉钼矿样本报告的年龄为 14.7 至 14.4 ± 0.06嘛。这一短暂的时间间隔与区域挤压构造运动的脉冲相一致，该脉冲由基底岩心块的高角度、厚皮、反向断层以及伴随的隆起和折返所适应。在 Filo del Sol 矿床形成过程中，这种隆升引起了约 1 公里的侵蚀，从而解释了斑岩矿化上高硫化作用的极端伸缩。这些中新世中期侵入中心与已确定的中二叠纪和始新世矿化的空间关联表明，Filo del Sol 排列受到深层结构控制。低 pH 条件下持续进行的表生过程产生了以辉铜矿为主的近地表资源，下方有少量辉铜矿富集，并部分氧化了浅层高品位银矿化带。这些中新世中期侵入中心与已确定的中二叠纪和始新世矿化的空间关联表明，Filo del Sol 排列受到深层结构控制。低 pH 条件下持续进行的表生过程产生了以辉铜矿为主的近地表资源，下方有少量辉铜矿富集，并部分氧化了浅层高品位银矿化带。这些中新世中期侵入中心与已确定的中二叠纪和始新世矿化的空间关联表明，Filo del Sol 排列受到深层结构控制。低 pH 条件下持续进行的表生过程产生了以辉铜矿为主的近地表资源，下方有少量辉铜矿富集，并部分氧化了浅层高品位银矿化带。