Geology, geochemistry and sulfur isotope composition of the Late;Proterozoic Jingtieshan (Superior-type) hematite-jasper-barite iron ore;deposits associated with stratabound Cu mineralization in the Gansu;Province, China

doi:10.1007/s001260050188

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	Geology, geochemistry and sulfur isotope composition of the Late;Proterozoic Jingtieshan (Superior-type) hematite-jasper-barite iron ore;deposits associated with stratabound Cu mineralization in the Gansu;Province, China
	Sun, H 3; Wu, J ; Yu, P ; Li, J
刊名	MINERALIUM DEPOSITA
	1998
卷号	34 期号:1 页码:102-112
ISSN号	0026-4598
DOI	10.1007/s001260050188
英文摘要	The Jingtieshan deposit occurs in a Precambrian tectonic-stratigraphic terrane within the Northern Qilian Caledonian Orogen, and is generally considered as a Superior-type iron formation. The deposit is characterized by Fe-Si-Ba and Cu mineralization and consists of two types of orebodies, an upper jasper-barite-iron deposit and a lower copper sulfide deposit. The iron orebodies occur as independent stratigraphic layers concordant within a thick argillaceous succession, and exhibit line-grained textures and well-developed sedimentary layering;. The ores are predominantly composed of specularite and jasper with lesser amounts of magnetite, hematite, siderite, and barite. The presence of barite, hematite: and jasper as major components shows that the iron ores were precipitated in a relatively oxidized ocean floor environment. The Cu orebody directly underlies the iron ore and is hosted by chlorite-sericite-quartz phyllite. The Cu mineralization is composed of pyrite and chalcopyrite and is characterized by stockwork. The disseminated and stockwork Cu mineralization is metamorphosed and concordant with respect to foliation, indicating pre-fabric development, i.e. pre-metamorphism. and was probably originally formed by reduced fluids reacting at the base of and within the oxide iron formation. Geochemical data show that the jasper-barite-iron ores, which resemble Superior-type iron formations. have a high input of hydrothermal-hydrogeneous elements (SiO2, av.=56%; Fe2O3t, av. = 30%: Mn. av. = 0.45%: BaO, av. = 16.7%) with minimal terrigeneous input (<15% combined Al2O3, TiO2, K2O MgO, etc.). The delta(34)S of exhalative barite Varies from 28 to 34 parts per thousand, which is very heavy with respect to other Late Proterozoic sulfate-bearing deposits, except those of circa 600 Ma in which the sulfides range from 8 to 20 parts per thousand. The sulfur isotope data indicate that the barite was formed by the mixing of a Be-rich hydrothermal fluid with sulfate-rich ambient seawater and that the sulfides ores were most probably derived from the reduction of seawater sulfate during subsurface reaction with ferrous iron-bearing minerals. These data are consistent with the jasper-barite-iron deposit forming by hydrothermal exhalative and chemical sedimentary processes on the floor of an ocean basin, and with the Cu mineralization forming by hydrothermal filling and replacement in base of and within the iron formation.
学科主题	地层学与地史学
WOS关键词	SULFATE
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
语种	英语
出版者	SPRINGER VERLAG
WOS记录号	WOS:000077375200009
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/37288]
专题	中国地质调查局
作者单位	1.Chinese Acad Geol Sci, Inst Mineral Deposits, Beijing 100037, Peoples R China. 2.Chinese Acad Geol Sci, Inst Geol & Mineral Resources, Xian 710054, Peoples R China. 3.中国地质科学院矿产资源研究所
推荐引用方式 GB/T 7714	Sun, H,Wu, J,Yu, P,et al. Geology, geochemistry and sulfur isotope composition of the Late;Proterozoic Jingtieshan (Superior-type) hematite-jasper-barite iron ore;deposits associated with stratabound Cu mineralization in the Gansu;Province, China[J]. MINERALIUM DEPOSITA,1998,34(1):102-112.
APA	Sun, H,Wu, J,Yu, P,&Li, J.(1998).Geology, geochemistry and sulfur isotope composition of the Late;Proterozoic Jingtieshan (Superior-type) hematite-jasper-barite iron ore;deposits associated with stratabound Cu mineralization in the Gansu;Province, China.MINERALIUM DEPOSITA,34(1),102-112.
MLA	Sun, H,et al."Geology, geochemistry and sulfur isotope composition of the Late;Proterozoic Jingtieshan (Superior-type) hematite-jasper-barite iron ore;deposits associated with stratabound Cu mineralization in the Gansu;Province, China".MINERALIUM DEPOSITA 34.1(1998):102-112.