To meet surging requirements of copper for the green energy revolution, minable resources subequal to all copper production in history must be found in the next two decades. We show that trace elements in zircon and whole-rock samples that are diagnostic of unusually high-pressure magmatic differentiation and high hydration state and oxidation state of their parent silicate melt are effective for discriminating copper sulfide-ore-productive arc magmas from infertile arc magmas. Tests on our database of 5,777 zircons from 80 igneous complexes, including 2,220 zircons from ore-generative intrusions in 37 major porphyry and high-sulfidation epithermal Cu(-Au-Mo) deposits worldwide, demonstrate that our magmatic copper fertility discriminants apparently perform equally well in intraoceanic arcs, continental margin arcs, and continental collision orogens of Ordovician to Quaternary age. That performance consistency means that the tectono-magmatic controls on development of magmatic-hydrothermal copper ore-forming fertility are essentially the same in all those plate-convergence settings. The ratio Ce/√(U × Ti) in zircon is a quantitative indicator of the relative oxygen fugacity of the silicate melt and its sulfur-carrying capacity. The ratio of the europium anomaly to ytterbium in granitoid melts and zircon is an uncalibrated but empirically useful indicator of the melt’s hydration state and ability to provide chloride-complexed metals to exsolving hydrothermal fluids. Plots of (Eu_N/Eu*)/Yb_N vs. Ce/√(U × Ti) in zircon are remarkably effective for discriminating igneous complexes, arc segments, and time intervals within them that can generate and are likely to host magmatic-hydrothermal Cu(-Au-Mo) ore deposits. Arrays of cognate zircons on such plots have slopes that vary with pressure-dependent chlorinity of exsolving fluid and its efficacy in scavenging CuCl from the melt. Our zircon indicators of Cu metallogenic fertility are applicable to detrital as well as in situ zircons and can assist with ore discovery in watersheds upstream from a sediment sampling site. We formulated a composite zircon copper fertility index (ZCFI) that can be applied to each microbeam spot analysis—ZCFI = 10⁴ (Eu_N/Eu_N*)/Yb_N + 5 Ce/√(U_i × Ti)—and substantially decreases the number of zircon analyses needed for reliable prospectivity assessment in a detrital grain population, thereby making this watershed-scale exploration tool cost-competitive with other methods of geochemical exploration.

中文翻译：

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岩浆水合态和氧化态的锆石和全岩微量元素指标判别贫弧岩浆成矿

为了满足绿色能源革命对铜不断增长的需求，必须在未来二十年中找到相当于历史上所有铜产量的可开采资源。我们表明，锆石和全岩样品中的微量元素可诊断异常高压岩浆分异及其母体硅酸盐熔体的高水合状态和氧化状态，可有效区分生产硫化铜矿的弧岩浆和贫瘠的弧岩浆。对来自 80 个火成岩杂岩的 5,777 颗锆石数据库进行的测试，其中包括来自全球 37 个主要斑岩和高硫化浅成热液铜（-Au-Mo）矿床的成矿侵入体的 2,220 颗锆石，表明我们的岩浆铜肥力判别器显然表现同样出色奥陶纪至第四纪的洋内弧、大陆边缘弧和大陆碰撞造山带。这种性能一致性意味着，在所有这些板块汇聚环境中，构造岩浆对岩浆热液铜矿形成肥力发育的控制本质上是相同的。锆石中Ce/√(U×Ti)的比值是硅酸盐熔体相对氧逸度及其载硫能力的定量指标。花岗岩熔体和锆石中铕异常与镱的比率是未经校准但在经验上有用的熔体水合状态和向热液溶解提供氯化物络合金属的能力的指标。锆石中的 (Eu _N /Eu*)/Yb _N与 Ce/√(U × Ti) 绘图对于区分火成岩杂岩、弧段以及其中可产生并可能孕育岩浆的时间间隔非常有效。热液铜（-金-钼）矿床。这些图上的同源锆石阵列的斜率随压力相关的溶出流体的氯度及其从熔体中清除 CuCl 的功效而变化。我们的铜成矿肥力锆石指标适用于碎屑和原位锆石，可以帮助沉积物采样点上游流域中的矿石发现。我们制定了复合锆石铜肥育指数（ZCFI），可应用于每个微束点分析——ZCFI = 10 ⁴ (Eu _N /Eu _N *)/Yb _N + 5 Ce/√(U _i × Ti)——并且基本上减少了碎屑颗粒群中可靠的前景评估所需的锆石分析数量，从而使这种流域规模的勘探工具与其他地球化学勘探方法相比具有成本竞争力。