DOI: 10.1038/ngeo2367
论文题名: Porphyry copper deposit formation by sub-volcanic sulphur dioxide flux and chemisorption
作者: Henley R.W. ; King P.L. ; Wykes J.L. ; Renggli C.J. ; Brink F.J. ; Clark D.A. ; Troitzsch U.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2015
卷: 8, 期: 3 起始页码: 210
结束页码: 215
语种: 英语
Scopus关键词: anhydrite
; degassing
; fractured medium
; magmatism
; porphyry
; sorption
; subduction zone
; sulfur dioxide
英文摘要: Porphyry copper deposits - the primary source of the world's copper - are a consequence of the degassing of intrusion complexes in magmatic arcs associated with ancient subduction zones. They are characterized by copper and iron sulphides, commonly found with anhydrite (CaSO 4), over scales of several kilometres through intensely altered and fractured rocks. The magmatic source of the metals is broadly understood, but the processes that transport and deposit the metals at the megaton scale are unclear. The hydrogen sulphide necessary for metal deposition is commonly assumed to form by a reaction between sulphur dioxide and water, but this reaction is inefficient and cannot explain the formation of economic-grade deposits. Here we use high-temperature laboratory experiments to show that a very rapid chemisorption reaction occurs between sulphur dioxide gas, a principal component of magmatic gas mixtures, and calcic feldspar, an abundant mineral in the arc crust. The chemisorption reaction generates the mineral anhydrite and hydrogen sulphide gas, and triggers deposition of metal sulphides. We use thermodynamic calculations to show that as magmatic gas cools and expands the concentration of hydrogen sulphide gas increases exponentially to drive efficient deposition of metal sulphides and consequent formation of economic-grade porphyry copper deposits. © 2015 Macmillan Publishers Limited. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106232
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: Research School of Earth Sciences, Australian National University, Actone, ACT, Australia; Centre for Advanced Microscopy, Australian National University, Actone, ACT, Australia
Recommended Citation:
Henley R.W.,King P.L.,Wykes J.L.,et al. Porphyry copper deposit formation by sub-volcanic sulphur dioxide flux and chemisorption[J]. Nature Geoscience,2015-01-01,8(3)