Contrasting regimes of Cu, Zn and Pb transport in ore-forming   hydrothermal fluids

doi:10.1016/j.chemgeo.2014.12.008

CORC > 北京大学 > 地球与空间科学学院

	Contrasting regimes of Cu, Zn and Pb transport in ore-forming hydrothermal fluids
	Zhong, Richen ; Brugger, Joel ; Chen, Yanjing ; Li, Wenbo
刊名	化工地质
	2015
关键词	Thermodynamic modeling Au-Cu-Pb-Zn Metal transport Chloride complexing Hydrosulfide complexing LA-ICP-MS MOLECULAR-DYNAMICS SIMULATION COPPER-MOLYBDENUM DEPOSIT PORPHYRY MO DEPOSIT OIL-FIELD BRINES IN-SITU XAS THERMODYNAMIC PROPERTIES CHLORIDE COMPLEXES GOLD DEPOSITS HYDROSULFIDE/SULFIDE COMPLEXES
DOI	10.1016/j.chemgeo.2014.12.008
英文摘要	Sulfur and chlorine are the two most important ligands accounting for metal transport in the upper crust. In this study, four metal- and sulfur-saturated model fluids with varying salinities and redox states were simulated in the Fe-Cu-Pb-Zn-Au-S-C-H-O system, over a wide pressure-temperature (P-T) range (50-650 degrees C, 0.8-5.0 kbar), in order to compare the roles of chloride and bisulfide complexing for metal transport at the light of the latest available thermodynamic properties. The range in simulated Zn and Pb concentrations of the model fluids compares well with those of natural hydrothermal fluids, suggesting that the model can be used to evaluate hydrothermal ore-forming processes in Nature. The modeling reveals two different modes of Cu, Pb and Zn complexing in sulfur-saturated hydrothermal solutions. At lower temperature, chloride complexes are the predominant Cu, Pb and Zn species in sulfide-saturated systems, as expected from previous studies. However, hydrosulfide Cu, Pb and Zn complexes predominate at higher temperature. The predominance of bisulfide complexing for base metals at high temperature in sulfur-saturated systems is related to the prograde dissolution of pyrite and/or pyrrhotite, which results in a rapid increase in sulfur solubility. Metals transport as chloride or bisulfide complexes determines the modes of metal enrichment. In chloride-complexing dominated systems (e.g., Mississipi Valley Type deposits), low sulfide solubilities mean that the ore fluids cannot carry both reduced sulfur and metals, and ore precipitation is triggered when the ore fluid encounters reduced sulfur, e.g., via fluid mixing or via sulfate reduction. In contrast, in fluids where bisulfide complexing is predominant, cooling and desulfidation reactions are efficient mechanisms for base metal sulfide precipitation. Since both Au and base metals (Cu, Pb and Zn) are predicted to be transported as hydrosulfide complexes in high-temperature primary magmatic fluids in equilibrium with sulfide minerals, high-salinity is not a necessity for magmatic hydrothermal deposits such as porphyry- and skarn-style deposits. (C) 2014 Elsevier B.V. All rights reserved.; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000349861600014&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701 ; Geochemistry & Geophysics; SCI(E); EI; 10; ARTICLE; joel.brugger@monash.edu; liwenbo@pku.edu.cn; 154-164; 395
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/155332]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Zhong, Richen,Brugger, Joel,Chen, Yanjing,et al. Contrasting regimes of Cu, Zn and Pb transport in ore-forming hydrothermal fluids[J]. 化工地质,2015.
APA	Zhong, Richen,Brugger, Joel,Chen, Yanjing,&Li, Wenbo.(2015).Contrasting regimes of Cu, Zn and Pb transport in ore-forming hydrothermal fluids.化工地质.
MLA	Zhong, Richen,et al."Contrasting regimes of Cu, Zn and Pb transport in ore-forming hydrothermal fluids".化工地质 (2015).