DOI: 10.1038/ngeo2351
论文题名: Generation of porphyry copper deposits by gas-brine reaction in volcanic arcs
作者: Blundy J. ; Mavrogenes J. ; Tattitch B. ; Sparks S. ; Gilmer A.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2015
卷: 8, 期: 3 起始页码: 235
结束页码: 240
语种: 英语
Scopus关键词: copper
; hydrothermal fluid
; island arc
; magma chamber
; magmatism
; ore deposit
; porphyry
; subduction zone
; volcanism
英文摘要: Porphyry copper deposits, that is, copper ore associated with hydrothermal fluids rising from a magma chamber, supply 75% of the world's copper. They are typically associated with intrusions of magma in the crust above subduction zones, indicating a primary role for magmatism in driving mineralization. However, it is not clear that a single, copper-rich magmatic fluid could trigger both copper enrichment and the subsequent precipitation of sulphide ore minerals within a zone of hydrothermally altered rock. Here we draw on observations of modern subduction zone volcanism to propose an alternative process for porphyry copper formation. We suggest that copper enrichment initially involves metalliferous, magmatic hyper-saline liquids, or brines, that exsolve from large, magmatic intrusions assembled in the shallow crust over tens to hundreds of thousands of years. In a subsequent step, sulphide ore precipitation is triggered by the interaction of the accumulated brines with sulphur-rich gases, liberated in short-lived bursts from the underlying mafic magmas. We use high-temperature and high-pressure laboratory experiments to simulate such gas-brine interactions. The experiments yield copper-iron sulphide minerals and hydrogen chloride gas at magmatic temperatures of 700-800 °C, with textural and chemical characteristics that resemble those in porphyry copper deposits. We therefore conclude that porphyry copper ore forms in a two-stage process of brine enrichment followed by gas-induced precipitation. © 2015 Macmillan Publishers Limited. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106259
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: School of Earth Sciences, University of Bristol, Bristol, United Kingdom; Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia
Recommended Citation:
Blundy J.,Mavrogenes J.,Tattitch B.,et al. Generation of porphyry copper deposits by gas-brine reaction in volcanic arcs[J]. Nature Geoscience,2015-01-01,8(3)