Precambrian banded iron formations in the North China Craton: Silicon and oxygen isotopes and genetic implications

doi:10.1016/j.oregeorev.2013.09.011

CORC > 中国地质调查局 > 中国地质调查局 > 中国地质科学院矿产资源研究所

	Precambrian banded iron formations in the North China Craton: Silicon and oxygen isotopes and genetic implications
	Li Yanhe 2; Hou Kejun ; Wan Defang ; Zhang Zengjie ; Yue Guoliang
刊名	ORE GEOLOGY REVIEWS
	2014
卷号	57 页码:299-307
关键词	BIFs Formation mechanism Silicon isotope Oxygen isotope North China Craton
ISSN号	0169-1368
DOI	10.1016/j.oregeorev.2013.09.011
英文摘要	Banded iron formations (BIFs) are Precambrian chemical marine sedimentary formations that record major transitions of chemical composition, and oxidation-reduction state of oceans at the time of their deposition. In this paper, we report silicon and oxygen isotope compositions of a variety of BIFs from the North China Craton (NCC) in order to deduce the mechanism of their formation. Quartz in the various types of BIFs from the NCC are generally depleted in Si-30, where delta Si-30(NBS-28) values range from -2.0 parts per thousand to -0.3 parts per thousand. (average, -0.8 parts per thousand), similar to delta Si-30(NBS-28) values measured from modern submarine black chimneys and sinters. The delta O-18(V-SWOW) values of quartz in the BIFs are relatively high (8.1 parts per thousand-21.5 parts per thousand; average, 13.1 parts per thousand), similar to those of siliceous rock formed by hydrothermal activities. The delta Si-30(NBs-28) values of quartz in magnetite bands are commonly lower than those of quartz in adjacent siliceous bands within the same sample, whereas delta O-18(V-SMOW) values are higher in the magnetite bands. A negative correlation is observed between delta Si-30(NBS-28) and delta O-18(V-SMOW) values of quartz from siliceous and magnetite bands in BIF from Fuping, Hebei Province. The isotopic compositions of silicon and oxygen of quartz in BIFs provide insights for the formation mechanisms of silicon-iron cyclothems in BIFs. After the silicon- and iron-rich hydrothermal solution was injected onto the seabed, the abrupt temperature drop caused oversaturation of silicic acid, resulting in rapid precipitation of SiO2 and deposition of siliceous layers. Ferric hydroxide was precipitated later than SiO2 because of low free-oxygen concentration in the ocean bottom. Progressive mixing of hydrothermal solution with seawater caused a continuous drop in temperature and an increase in Eh values, resulting in gradual oxidation of hydrothermal Fe2+ and deposition of iron-rich layers. In summary, each silicon-iron cyclothem marks a large-scale submarine hydrothermal exhalation. The periodic nature of these exhalations resulted in the formation of regular silicon-iron cyclothems. The widespread distribution of BIFs indicates that volcanism and submarine hydrothermal exhalation were extensive; the low delta Si-30(NBS-28) and high delta O-18 (V-SWOW) values of the BIFs indicate that the temperature of seawater was relatively high at the time of BIF formation, and that concentrations of Fe2+ and H4SiO4 in seawater were saturated. (C) 2013 Elsevier B.V. All rights reserved.
学科主题	矿床地质
WOS关键词	SOUTH-AFRICA ; TRANSVAAL SUPERGROUP ; ATMOSPHERIC OXYGEN ; LIAONING-PROVINCE ; SI ; GEOCHEMISTRY ; EVOLUTION ; CHERTS ; TEMPERATURE ; SEAWATER
WOS研究方向	Geology ; Mineralogy ; Mining & Mineral Processing
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000328869100018
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/40437]
专题	中国地质科学院矿产资源研究所
作者单位	1.Chinese Acad Geol Sci, Inst Mineral Resources, MLR Key Lab Metallogeny & Mineral Assessment, Beijing 100037, Peoples R China; Minist Land & Resources, Key Lab Isotope Geol, Beijing 100037, Peoples R China 2.中国地质科学院矿产资源研究所
推荐引用方式 GB/T 7714	Li Yanhe,Hou Kejun,Wan Defang,et al. Precambrian banded iron formations in the North China Craton: Silicon and oxygen isotopes and genetic implications[J]. ORE GEOLOGY REVIEWS,2014,57:299-307.
APA	Li Yanhe,Hou Kejun,Wan Defang,Zhang Zengjie,&Yue Guoliang.(2014).Precambrian banded iron formations in the North China Craton: Silicon and oxygen isotopes and genetic implications.ORE GEOLOGY REVIEWS,57,299-307.
MLA	Li Yanhe,et al."Precambrian banded iron formations in the North China Craton: Silicon and oxygen isotopes and genetic implications".ORE GEOLOGY REVIEWS 57(2014):299-307.