铜是一个中等不兼容的 chalcophile 元素。它的行为被硫化物强烈控制。硫的种形成被氧易逃逸控制。因此,斑岩 Cu 存款通常被氧化(与氧易逃逸 ?>? FMQ +2 )(Mungall 2002;阳光等。2015 ) 。问题是当大多数在会聚的边缘的岩浆高度被氧化时,斑岩 Cu 存款是很稀罕的,建议高氧易逃逸独自不是足够的。甚至在很高的氧易逃逸的披风橄榄岩的部分融化与太低而无法直接形成斑岩 Cu 存款的起始的 Cu 内容形成弧岩浆(李等。2012;Wilkinson 2013 ) 。这里,我们显示出 subducted 的那部分融化在高氧易逃逸的年轻海洋的平板(> FMQ +2 ) 可以与起始的 Cu 内容形成岩浆直到 ?> 500 ? ppm,为斑岩矿化作用有利。通过硫化物浸透和累积的 Cu 的丰富前对斑岩 Cu 矿化作用未必有益。相反,与氧化铁联系的斑状的热水的硫化物的 re-melting 可以有主要贡献到斑岩存款。厚制服大陆人外壳减少热水的液体的漏,从而支持斑岩矿化作用。不过,它对形成液体渗透厚大陆人外壳到达 2-4 的深度的矿石也更困难 ? 斑岩存款形成的 km。
Copper is a moderately incompatible chalcophile element. Its behavior is strongly controlled by sulfides. The speciation of sulfur is controlled by oxygen fugacity. Therefore, porphyry Cu deposits are usually oxidized (with oxygen fugacities 〉 AFMQ +2) (Mungall 2002; Sun et al. 2015). The problem is that while most of the magmas at convergent margins are highly oxidized, porphyry Cu deposits are very rare, suggesting that high oxygen fugacity alone is not sufficient. Partial melting of mantle peridotite even at very high oxygen fugacities forms arc magmas with initial Cu contents too low to form porphyry Cu deposits directly (Lee et al. 2012; Wilkinson 2013). Here we show that partial melting of subducted young oceanic slabs at high oxygen fugacity (〉AFMQ +2) may form magmas with initial Cu contents up to 〉500 ppm, favorable for porphyry mineralization. Pre-enrichment of Cu through sulfide saturation and accumulation is not necessarily beneficial to porphyry Cu mineralization. In contrast, re- melting of porphyritic hydrothermal sulfide associated with iron oxides may have major contributions to porphyry deposits. Thick overriding continental crust reduces the "leakage" of hydrothermal fluids, thereby promoting porphyry mineralization. Nevertheless, it is also more difficult for ore forming fluids to penetrate the thick continental crust to reach the depths of 2-4 km where porphyry deposits form.