Geochemistry and iron isotope systematics of coexisting Fe-bearing minerals in magmatic Fe-Ti deposits: A case study of the Damiao titanomagnetite ore deposit, North China Craton

doi:10.1016/j.gr.2019.12.001

CORC > 海洋研究所 > 中国科学院海洋研究所 > 海洋地质与环境重点实验室

	Geochemistry and iron isotope systematics of coexisting Fe-bearing minerals in magmatic Fe-Ti deposits: A case study of the Damiao titanomagnetite ore deposit, North China Craton
	Wei, Youqing 1,3,5; Niu, Yaoling 2,3,4,5; Gong, Hongmei 3,5; Duan, Meng 3,5; Chen, Shuo 3,5; Guo, Pengyuan 3,5; Sun, Pu 3,5
刊名	GONDWANA RESEARCH
	2020-05-01
卷号	81 页码:240-251
关键词	Iron isotopes Titanomagnetite Exsolution Sub-solidus cooling
ISSN号	1342-937X
DOI	10.1016/j.gr.2019.12.001
通讯作者	Wei, Youqing(yqwei49@126.com) ; Niu, Yaoling(yaoling.niu@durham.ac.uk)
英文摘要	Geochemical and iron isotopic compositions of magnetite, ilmenite and pyrite separates from the Fe-Ti oxide ores hosted in the Damiao anorthosite-type Fe-Ti ore deposit were analyzed to investigate sub-solidus cooling history of the titanomagnetite. The Fe-Ti oxides form two series of solid solutions, namely, ulvospinel-magnetite (Usp-Mt(ss)) and hematite-ilmenite (Hem-Ilm(ss)) solid solutions. The magnetite separates have 14-27 mol% ulvospinel, while the ilmenite separates have 5-8 mol% hematite. Major element compositions of the mineral separates suggest that the ilmenites were mainly exsolved from the Usp-Mt(ss) by oxidation of ulvospinel in the temperature range of similar to 820-600 degrees C and experienced inter-oxide re-equilibration with the magnetites. Associated with the exsolution is the substantial inter-mineral iron isotope fractionation. The magnetite separates are characterized by high delta Fe-57 (+0.27 - +0.65 parts per thousand), whereas the ilmenite separates have lower delta Fe-57 (-0.65 to -028 parts per thousand). Two types of pyrite are petrographically observed, each of which has a distinctive iron isotope fingerprint. Type I pyrite (pyrite(I)) with higher delta Fe-57 (delta Fe-57 = +0.63 - +0.95 parts per thousand) is consistent with magmatic origin, and type II pyrite (pyrite(II)) with lower delta Fe-57 (delta Fe-57 = -0.90 to -0.11 parts per thousand) was likely to have precipitated from fluids. Iron isotopic fingerprints of the pyrite(I) probably indicate variations of oxygen fugacity, whereas those of the pyrite(II) may result from fluid activities. The iron isotopic fractionation between the magnetite and ilmenite is the net result of sub-solidus processes (induding ulvospinel oxidation and inter-oxide re-equilibration) without needing varying oxygen fugacity albeit its presence. Although varying composition of magnetite-ilmenite pairs reflects variations of oxygen fugacity, inter-oxide iron isotopic fractionation does not. (C) 2019 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
资助项目	National Natural Science Foundation of China (NSFC)[41806080] ; National Natural Science Foundation of China (NSFC)[41630968] ; National Natural Science Foundation of China (NSFC)[41776067] ; 111 Project of China[B18048] ; Shandong Provincial Key Laboratory of Depositional Mineralization & Sedimentary Mineral of China[DMSM2018059]
WOS研究方向	Geology
语种	英语
出版者	ELSEVIER
WOS记录号	WOS:000523559700006
内容类型	期刊论文
源URL	[http://ir.qdio.ac.cn/handle/337002/167059]
专题	海洋研究所_海洋地质与环境重点实验室
通讯作者	Wei, Youqing; Niu, Yaoling
作者单位	1.Shandong Univ Sci & Technol, Shandong Prov Key Lab Deposit Mineralizat & Sedim, Qingdao 266590, Peoples R China 2.Univ Durham, Dept Earth Sci, Durham HD1 3LE, England 3.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Geol, Qingdao 266061, Peoples R China 4.China Univ Geosci, Sch Earth Sci & Resources, Beijing 100083, Peoples R China 5.Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China
推荐引用方式 GB/T 7714	Wei, Youqing,Niu, Yaoling,Gong, Hongmei,et al. Geochemistry and iron isotope systematics of coexisting Fe-bearing minerals in magmatic Fe-Ti deposits: A case study of the Damiao titanomagnetite ore deposit, North China Craton[J]. GONDWANA RESEARCH,2020,81:240-251.
APA	Wei, Youqing.,Niu, Yaoling.,Gong, Hongmei.,Duan, Meng.,Chen, Shuo.,...&Sun, Pu.(2020).Geochemistry and iron isotope systematics of coexisting Fe-bearing minerals in magmatic Fe-Ti deposits: A case study of the Damiao titanomagnetite ore deposit, North China Craton.GONDWANA RESEARCH,81,240-251.
MLA	Wei, Youqing,et al."Geochemistry and iron isotope systematics of coexisting Fe-bearing minerals in magmatic Fe-Ti deposits: A case study of the Damiao titanomagnetite ore deposit, North China Craton".GONDWANA RESEARCH 81(2020):240-251.