Plate subduction and porphyry Cu-Au mineralization

doi:10.18654/1000-0569/2020.01.12

	Plate subduction and porphyry Cu-Au mineralization
	Zhang LiPeng 1,2,3; Li He 1,2,3; Wang Kun1,4
	2020
发表期刊	ACTA PETROLOGICA SINICA
ISSN	1000-0569
卷号	36 期号:1 页码:113-124
通讯作者	Zhang LiPeng([email protected])
摘要	Most porphyry Cu-Au deposits are distributed in convergence margins. Previous studies show that high oxygen fugacity and partial melting of subducted oceanic crust are two key factors for porphyry Cu-Au mineralization. Copper and Au as chalcophile elements are mainly controlled by reduced sulfur (S2-), while the valence and properties of sulfur are controlled by magma oxygen fugacity. Delta FMQ + 2 as the magic magma oxygen fugacity number for porphyry Cu-Au mineralization had long been discovered. Studies found that the main reason is that the sulfur species change dramatically near this oxygen fugacity. Sulfur mainly exists in the form of sulfide at a low oxygen fugacity, but when the oxygen fugacity is above Delta FMQ + 1. 5, the sulfur mainly exists in the form of sulfate. The solubility of sulfate in magma is usually about 10 times that of sulfide. Therefore, high oxygen fugacity can greatly improve the solubility of sulfur in magma during partial melting, which is beneficial to the sulfide in the magma source being destructed and being melted in the form of sulfide, resulting in significantly improving the Cu(Au) contents in initial magma. At the same time, sulfides can remain unsaturated during magma evolution, which is favor of the further enrichment of Cu(Au) as moderately incompatible elements. When magnetite starts to crystallize as the magma evolution, the oxygen fugacity of magmatic system decreases, sulfate is reduced to sulfide , and reduced sulfur (S2-) extracts and concentrates Cu and Au from the magma into the fluid phase, forming porphyry Cu-Au deposits. The high oxygen fugacities commonly occur in the convergent plate margins. Given that the Cu, Au, S contents in oceanic crust are far higher than in continental crust and mantle, then the oxygen fugacity of subduction zone is about two orders of magnitude higher than that of the mantle and lower continental crust. Thus the magmas derived from partial melting of subducted oceanic crusts have far higher Cu, Au, S contents than that sourced from intraplate, which is beneficial to mineralization. Ridge subduction is the most likely geological process of partial melting of oceanic crust since Phanerozoic, and it has high oxygen fugacity. Therefore, ridge subduction is the optimal process for forming large, super-large scale porphyry Cu-Au deposits. Compiled data show that most super-large porphyry Cu-Au deposits are related to ridge subduction in the world.
关键词	Plate subduction Porphyry Cu-Au deposit Oxygen fugacity Adakite Ridge subduction
DOI	10.18654/1000-0569/2020.01.12
收录类别	SCI
语种	英语
WOS研究方向	Geology
WOS类目	Geology
WOS记录号	WOS:000533247400012
出版者	SCIENCE PRESS
引用统计	被引频次：10[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/167458
专题	深海极端环境与生命过程研究中心
通讯作者	Zhang LiPeng
作者单位	1.Chinese Acad Sci, Ctr Deep Sea Res, Inst Oceanol, Qingdao 266071, Peoples R China 2.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Mineral Resources, Qingdao 266237, Peoples R China 3.Chinese Acad Sci, Ctr Ocean Megasci, Qingdao 266071, Peoples R China 4.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
第一作者单位	中国科学院海洋研究所; 中国科学院海洋大科学研究中心
通讯作者单位	中国科学院海洋研究所; 中国科学院海洋大科学研究中心
推荐引用方式 GB/T 7714	Zhang LiPeng,Li He,Wang Kun. Plate subduction and porphyry Cu-Au mineralization[J]. ACTA PETROLOGICA SINICA,2020,36(1):113-124.
APA	Zhang LiPeng,Li He,&Wang Kun.(2020).Plate subduction and porphyry Cu-Au mineralization.ACTA PETROLOGICA SINICA,36(1),113-124.
MLA	Zhang LiPeng,et al."Plate subduction and porphyry Cu-Au mineralization".ACTA PETROLOGICA SINICA 36.1(2020):113-124.

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