Porphyry deposits occur not only in subduction zones, but also in collisional belts worldwide. The magmatic oxygen fugacity (ƒo₂) is an important element for the formation of porphyry, and influences the processes in source, migration, and precipitation of Cu and other chalcophile elements. Magmatic sulphur exists mainly as sulphate () at higher oxygen fugacity, which combines with chalcophile elements (e.g., Cu, Au) as ion complexes then formed the ore‐bearing magma. In contrast, magmatic sulphur exists mainly as sulphide (S²⁻), sulphide will precipitate easily. A magmatic event usually involves multiple intrusive activities. These porphyries have various ƒo₂ evolutions, implying that they are formed in different formation environments or dynamic mechanisms. In a subduction setting, plates begin to dehydrate and then partial melting occurs in the early stage of subduction. Following the extensive dehydration, partial melting occurs as the plate diving deeper. As a result, the later magma is more oxidative than the earlier one. While under the collisional setting, porphyritic magma is likely related to the previous arc magmatism of subduction or juvenile mantle components in the thickened lower crust. The hydrous and metalliferous fertile magma formed. Then, reduction of water supply is the possible factor that leads to the gradually decrease of ƒo₂. As a result of this study, metallogenic elements are usually developed in later porphyritic magma at a subduction environment, but in the early porphyritic magma at a collisional environment. This can provide guidance for prospecting of porphyry deposits in multi‐phases of porphyritic magma districts.

中文翻译：

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俯冲和碰撞背景下岩浆氧逸度的独特演化历史及其对伴生斑岩铜矿的控制

斑岩沉积不仅发生在俯冲带，而且在全世界的碰撞带中也发生。岩浆氧逸度（ƒo ₂）是用于斑岩的形成的重要元素，并且在源，迁移，和Cu的沉淀和其他亲硫元素影响的处理。岩浆硫主要以较高的氧逸度形式以硫酸盐（）形式存在，它与亲硫元素（例如Cu，Au）结合成离子络合物，然后形成含矿岩浆。相反，岩浆硫主要以硫化物（S ^2-）形式存在，硫化物将易于沉淀。岩浆事件通常涉及多种侵入性活动。这些斑岩具有各种ƒo ₂进化，暗示它们是在不同的形成环境或动力机制中形成的。在俯冲的环境中，板块开始脱水，然后在俯冲的早期发生部分熔化。大量脱水后，随着板的深潜，部分熔化发生。结果，后期的岩浆比早期的岩浆更具氧化性。在碰撞环境下，斑状岩浆很可能与先前的俯冲作用或加厚地壳中的幼年地幔成分的弧岩浆有关。形成了含水和含金属的肥沃岩浆。然后，还原水供应的是通向逐渐减小的ƒo可能因子₂。作为这项研究的结果，成矿元素通常在俯冲环境下的晚斑状岩浆中形成，而在碰撞环境下则在早期的斑状岩浆中形成。这可以为斑岩型岩浆地区多阶段斑岩型矿床的勘探提供指导。