Abstract Hydrothermal iron oxide-copper-gold (IOCG) ore deposits are globally important sources of Cu and Au. IOCG systems show many common features, but also considerable diversity in terms of geological setting, mineralization style and ore fluid characteristics. The key factors that control ore formation are controversially debated and no general ore deposit model has been able to explain the diversity of IOCG deposits on the global scale. Building on previous work that characterized four distinct fluid types at the Prominent Hill IOCG deposit, South Australia, we have analyzed the rare earth element (REE) composition of fluorite from the Prominent Hill, Olympic Dam and Ernest Henry IOCG deposits and from two prospects close to Prominent Hill. The REE data of fluorite from Prominent Hill show four distinct chondrite-normalized patterns, which reflect the four fluid types identified as metalliferous volcanic lake water derived fluid, magmatic-hydrothermal fluid, sedimentary basin brine, and wall rock-buffered basement brine. Two strikingly similar REE pattern types were found in fluorite from the Olympic Dam deposit and one in an exploratory data from the Ernest Henry deposit, demonstrating the involvement of the same principal fluid types. We therefore conclude that world-class IOCG deposits can form by interaction of host rocks with different characteristic types of ore fluids and their combinations, thus IOCG deposits do not necessarily form by a single sequence of processes.

中文翻译：

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萤石作为氧化铁-铜-金系统中的指示矿物：解释 IOCG 矿床的多样性

摘要 热液氧化铁-铜-金(IOCG) 矿床是全球重要的Cu 和Au 来源。IOCG 系统显示出许多共同特征，但在地质背景、矿化类型和矿流体特征方面也具有相当大的多样性。控制成矿的关键因素存在争议，没有通用的矿床模型能够解释全球范围内 IOCG 矿床的多样性。在之前对南澳大利亚 Prominent Hill IOCG 矿床的四种不同流体类型特征的研究的基础上，我们分析了来自 Prominent Hill、Olympic Dam 和 Ernest Henry IOCG 矿床的萤石的稀土元素 (REE) 成分，以及两个接近到突出山。Prominent Hill 萤石的 REE 数据显示四种不同的球粒陨石归一化模式，反映了含金属火山湖水衍生流体、岩浆-热液流体、沉积盆地卤水和围岩缓冲基底卤水四种流体类型。在来自 Olympic Dam 矿床的萤石中发现了两种非常相似的 REE 模式类型，在来自 Ernest Henry 矿床的勘探数据中发现了一种，表明涉及相同的主要流体类型。因此，我们得出结论，世界级 IOCG 矿床可以通过母岩与不同特征类型的矿流体及其组合的相互作用形成，因此 IOCG 矿床不一定是由单一过程序列形成的。在来自 Olympic Dam 矿床的萤石中发现了两种非常相似的 REE 模式类型，在来自 Ernest Henry 矿床的勘探数据中发现了一种，表明涉及相同的主要流体类型。因此，我们得出结论，世界级 IOCG 矿床可以通过母岩与不同特征类型的矿流体及其组合的相互作用形成，因此 IOCG 矿床不一定是由单一过程序列形成的。在来自 Olympic Dam 矿床的萤石中发现了两种非常相似的 REE 模式类型，在来自 Ernest Henry 矿床的勘探数据中发现了一种，表明涉及相同的主要流体类型。因此，我们得出结论，世界级 IOCG 矿床可以通过母岩与不同特征类型的矿流体及其组合的相互作用形成，因此 IOCG 矿床不一定是由单一过程序列形成的。