Estimates of chlorine isotope fractionation factors using density functional theory: Applications to ore-forming systems

doi:10.1016/j.gca.2023.12.026

	Estimates of chlorine isotope fractionation factors using density functional theory: Applications to ore-forming systems
	Zhang, Miao-Miao 12; Wei, Hai-Zhen 1,11,12; Lu, Jian-Jun 12; Williams-Jones, A. E.10; Eastoe, C. J.9; Li, Wei-Qiang 12; Xia, Zhi-Guang 7,8,12; Hohl, S. V.6; Ma, Jing 5; Cai, Yue 3,4
刊名	GEOCHIMICA ET COSMOCHIMICA ACTA
	2024-02-15
卷号	367 页码:1-15
关键词	Chlorine isotopes Density functional theory Metal-chloride complexation Evaporites Phase separation Metallogenic processes
ISSN号	0016-7037
DOI	10.1016/j.gca.2023.12.026
通讯作者	Wei, Hai-Zhen(haizhenwei@nju.edu.cn)
英文摘要	Chloride is the most important anion in ore-forming hydrothermal fluids, and chlorine isotopes are therefore potentially sensitive tracers of the origin and evolution of ore-forming fluids. However, they remain a relatively under-utilized tool in ore deposit geochemistry due to the lack of knowledge of chlorine isotope fractionation during ore-forming processes. Using first-principles density functional theory, this study estimates chlorine isotope fractionation factors for various ore-forming processes. All metal-Cl complexes in hydrothermal fluids are enriched in Cl-37 compared to chloride ions, but the change in delta Cl-37 of the fluid trapped in ore minerals is small after the destabilization of metal-chloride complexes during ore mineral deposition. In the precipitation of evaporite minerals from brine, the sequence of enrichment of the heavy Cl isotope (Cl-37) is halite > carnallite > aqueous chloride > kainite > sylvite > bischofite. The results of this study agree with the experimental observations that progressive precipitation of halite from brine lowers the delta Cl-37 value of the residual fluid until the formation of K-Mg chlorides. In low-temperature deposits, delta Cl-37 values for fluid inclusions and minerals reflect those of the hydrothermal fluid provenance and the mixing of this fluids with saltwater or basinal brines. In high-temperature magmatic-hydrothermal ore deposits that undergo liquid-vapour phase separation, chlorine isotopes fractionate among phases of silicate melt, vapour and chloride-rich liquid. The considerable range in delta Cl-37 in fluid inclusions may also reflect fluid mixing and hydrothermal alteration. At ambient temperature, the delta Cl-37 values may reflect evaporative processes and, in the case of chemical weathering of metallic mineral deposits, may record the supergene enrichment of the metals. This study highlights the use of chlorine isotopes as a new tool for interpreting ore-forming processes.
资助项目	National Natural Science Foundations of China[41830428] ; National Natural Science Foundations of China[41973005] ; Nanjing University Excellence Initiative Scientific drilling for the pegmatitic lithium deposit in western Sichuan ; Research Funds for the Frontiers Science Center for Critical Earth Material Cycling, Nanjing University[2022300193]
WOS关键词	PORPHYRY-COPPER-DEPOSIT ; MOLECULAR-DYNAMICS SIMULATIONS ; MAJOR-ION COMPOSITION ; HYDROTHERMAL FLUIDS ; STABLE CHLORINE ; 1ST-PRINCIPLES CALCULATIONS ; ATACAMA DESERT ; BROOKS RANGE ; HIGH P ; VAPOR
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:001165792200001
资助机构	National Natural Science Foundations of China ; Nanjing University Excellence Initiative Scientific drilling for the pegmatitic lithium deposit in western Sichuan ; Research Funds for the Frontiers Science Center for Critical Earth Material Cycling, Nanjing University
内容类型	期刊论文
源URL	[http://ir.nigpas.ac.cn/handle/332004/43318]
专题	中国科学院南京地质古生物研究所
通讯作者	Wei, Hai-Zhen
作者单位	1.Nanjing Univ, Sch Earth Sci & Engn, 163 Xianlin Ave, Nanjing 210023, Jiangsu, Peoples R China 2.China Univ Geosci, Sch Earth Resources, State Key Lab Geol Proc & Mineral Resources, Wuhan 430074, Peoples R China 3.Chinese Acad Sci, Ctr Excellence Life & Paleoenvironment, Nanjing 210008, Peoples R China 4.Chinese Acad Sci, Nanjing Inst Geol & Palaeontol, State Key Lab Palaeobiol & Stratig, Nanjing 210008, Peoples R China 5.Nanjing Univ, Sch Chem & Chem Engn, Key Lab Mesoscop Chem MOE, Nanjing 210023, Peoples R China 6.Tongji Univ, State Key Lab Marine Geol, Shanghai 200092, Peoples R China 7.Chengdu Univ Technol, Inst Sedimentary Geol, Chengdu 610059, Peoples R China 8.Chengdu Univ Technol, State Key Lab Oil & Gas Reservoir Geol & Exploitat, Chengdu 610059, Peoples R China 9.Univ Arizona, Dept Geosci, Tucson, AZ 85721 USA 10.McGill Univ, Dept Earth & Planetary Sci, Montreal, PQ H3A 0E8, Canada
推荐引用方式 GB/T 7714	Zhang, Miao-Miao,Wei, Hai-Zhen,Lu, Jian-Jun,et al. Estimates of chlorine isotope fractionation factors using density functional theory: Applications to ore-forming systems[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2024,367:1-15.
APA	Zhang, Miao-Miao.,Wei, Hai-Zhen.,Lu, Jian-Jun.,Williams-Jones, A. E..,Eastoe, C. J..,...&Wang, Jun-Lin.(2024).Estimates of chlorine isotope fractionation factors using density functional theory: Applications to ore-forming systems.GEOCHIMICA ET COSMOCHIMICA ACTA,367,1-15.
MLA	Zhang, Miao-Miao,et al."Estimates of chlorine isotope fractionation factors using density functional theory: Applications to ore-forming systems".GEOCHIMICA ET COSMOCHIMICA ACTA 367(2024):1-15.