The Eastern Gabbro, Coldwell Complex, hosts several geochemically and mineralogically distinct Cu-platinum group element (PGE) deposits, including the high-grade W Horizon (>100 ppm Pd-Pt-Au over 2 m). Several magmatic and/or hydrothermal models have previously been proposed to explain the range of enrichment in PGEs observed in the Marathon deposit, but no work has integrated textural and compositional variations in sulfides to elucidate which of these models is most suitable. Additionally, comparatively little work has been done to characterize the genesis of Cu-PGE mineralization that occurs to the northwest of the Marathon deposit in the Eastern Gabbro. Through integration of base metal sulfide (BMS) mineralogy, texture, and trace element chemistry, a wide range of magmatic and postmagmatic processes have been characterized that contributed to the formation of these deposits. In all zones of mineralization in the Eastern Gabbro, chalcophile elements were remobilized from primary chalcopyrite by hydrothermal fluids and precipitated as secondary chalcopyrite, which occurs as a replacement of pyrrhotite and as intergrowths with hydrous silicates. BMSs in the mineralized zones in the Marathon deposit (Footwall zone, Main zone, and W Horizon) experienced higher R factors than those deposits located northwest of the Marathon deposit (Four Dams, Area 41, and Redstone), with BMSs in the W Horizon having experienced the highest R factors. The silicate melts from which the Footwall zone crystallized likely experienced some degree of sulfide segregation at depth, albeit to a much lesser degree than the northern deposits. Additionally, the melts from which the mineralized zones in the Marathon deposit crystallized were likely contaminated by high-S/Se Archean sedimentary rocks, whereas the northern deposits were likely contaminated by low-S/Se igneous and/or metamorphic rocks. BMSs in a chalcopyrite-rich pod located within the vicinity of the Coldwell Complex experienced both high R factors and high degrees of contamination (cf. W Horizon and Footwall zone, respectively). This study illustrates the complexity of processes that generate and modify mineralization in conduit-type Ni-Cu-PGE systems.

中文翻译：

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加拿大加德布罗东部的低硫化物，高铂族元素和高硫化物，低铂族元素矿化的机理：来自纹理协会，S / Se值和铂族元素浓度的证据贱金属硫化物

East Gabbro的Coldwell Complex拥有几个地球化学和矿物学上不同的Cu-Pt族元素（PGE）矿床，包括高品位的W Horizo​​n（2 m范围内Pd-Pt-Au> 100 ppm）。先前已经提出了几种岩浆和/或热液模型来解释在马拉松矿床中观察到的PGEs富集范围，但是没有工作整合硫化物的质地和成分变化来阐明哪种模型最合适。此外，在描述东加布罗马拉松矿床西北部发生的Cu-PGE矿化成因方面，所做的工作很少。通过整合贱金属硫化物（BMS）的矿物学，织构和微量元素化学，大量的岩浆作用和后岩浆作用已被表征，这有助于这些矿床的形成。在东部Gabbro的所有矿化区中，嗜热元素通过热液从初级黄铜矿中迁移出来，并沉淀为次级黄铜矿，这是次黄铁矿的替代品以及与含水硅酸盐的共生。与位于马拉松矿床西北部（四个大坝，41区和雷德斯通）的矿床（四个大坝，41区和红石矿床）相比，马拉松矿床（人行壁区，主区和W Horizo​​ns）矿化区中的BMS具有更高的R因子。经历了最高的R因子。底盘区结晶的硅酸盐熔体可能在深处经历了一定程度的硫化物偏析，尽管程度要比北部的矿床小得多。此外，马拉松矿床中矿化带结晶的熔体可能被高S / Se太古代沉积岩污染，而北部矿床可能被低S / Se火成岩和/或变质岩污染。位于Coldwell Complex附近的富含黄铜矿的豆荚中的BMS经历了高R因子和高污染程度（分别参见W Horizo​​n和Footwall区）。这项研究说明了在导管型Ni-Cu-PGE系统中产生和改变矿化过程的复杂性。而北部沉积物很可能被低S / Se火成岩和/或变质岩污染。位于Coldwell Complex附近的富含黄铜矿的豆荚中的BMS经历了高R因子和高污染程度（分别参见W Horizo​​n和Footwall区）。这项研究说明了在导管型Ni-Cu-PGE系统中产生和改变矿化过程的复杂性。而北部沉积物很可能被低S / Se火成岩和/或变质岩污染。位于Coldwell Complex附近的富含黄铜矿的豆荚中的BMS经历了高R因子和高污染程度（分别参见W Horizo​​n和Footwall区）。这项研究说明了在导管型Ni-Cu-PGE系统中产生和改变矿化过程的复杂性。