Abstract The mineralization potential of arc magmas depends, among other factors, on the timing of sulfide melt saturation relative to magma differentiation and to exsolution of a magmatic fluid phase. In fossil mineralized or barren systems, understanding the evolution of metals along the magma differentiation path is often hindered by late magmatic processes and hydrothermal alteration. To better understand the process of metal evolution “caught in the act” in crustal reservoirs, we analyzed magmatic sulfides and melt inclusions found within eruptive products from the active arc volcano, La Fossa (Vulcano Island, Italy), for the basalt to rhyolite compositional spectrum. We found that, in case of sulfide-undersaturated and volatile-rich arc basalts, metals are scarcely subtracted by degassing during ascent to shallow crustal reservoirs and reach the highest abundances in intermediate magmas (250 ppm Cu). At sulfide saturation the sulfide melt has 34–66 wt% Cu, leading to a dramatic decrease in chalcophile metals dissolved in the silicate melt. After fractionation of only 0.2–0.3 wt% of sulfide in the solid assemblage, the exsolved sulfide is a monosulfide solid solution (pyrrhotite) containing

中文翻译：

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跟踪弧形岩浆中的金属演化：来自意大利拉福萨活火山的见解

摘要 弧形岩浆的成矿潜力取决于硫化物熔体饱和相对于岩浆分异和岩浆流体相出溶的时间等因素。在化石矿化或贫瘠系统中，了解金属沿岩浆分异路径的演化往往受到晚期岩浆过程和热液蚀变的阻碍。为了更好地了解地壳储层中金属演化的过程，我们分析了在活动弧形火山 La Fossa（意大利 Vulcano 岛）的喷发产物中发现的岩浆硫化物和熔体包裹体，以了解玄武岩到流纹岩的成分光谱。我们发现，在硫化物欠饱和和富含挥发分的弧形玄武岩的情况下，在上升到浅层地壳储层期间几乎不会通过脱气去除金属，并在中间岩浆中达到最高丰度（250 ppm Cu）。在硫化物饱和时，硫化物熔体含有 34-66 wt% 的铜，导致溶解在硅酸盐熔体中的亲硫金属显着减少。在固体组合物中仅分离 0.2-0.3 wt% 的硫化物后，析出的硫化物是一种单硫化物固溶体（磁黄铁矿），其中含有