干旱区生态环境知识资源中心(Arid): Not all Neoproterozoic iron formations are glaciogenic: Sturtian-aged non-Rapitan exhalative iron formations from the Arabian-Nubian Shield

Arid

DOI	10.1007/s00126-019-00898-0
	Not all Neoproterozoic iron formations are glaciogenic: Sturtian-aged non-Rapitan exhalative iron formations from the Arabian-Nubian Shield
	Abd El-Rahman, Yasser 1,2; Gutzmer, Jens 3,4; Li, Xian-Hua 1,5; Seifert, Thomas 3; Li, Chao-Feng 1; Ling, Xiao-Xiao 1; Li, Jiao 1
通讯作者	Abd El-Rahman, Yasser
来源期刊	MINERALIUM DEPOSITA
ISSN	0026-4598
EISSN	1432-1866
出版年	2020
卷号	55 期号:3 页码:577-596
英文摘要	Neoproterozoic iron formations are exposed in the Wadi Hamama area (Egypt) in the northwestern part of the Arabian-Nubian Shield. Mafic and felsic volcanic and volcaniclastic rocks of an intra-oceanic island-arc setting host multiple, thin iron-formation units. Major element compositions of the iron formation confirm a low detrital input, whereas the rare-earth elements and Y data suggest deposition related to an influx of low-temperature hydrothermal fluids. Unlike most Neoproterozoic banded iron formations, but similar to other iron-formation occurrences from the Arabian-Nubian Shield, the Nd isotopic compositions of the Wadi Hamama iron formations are predominantly mantle-like. SIMS U-Pb zircon ages of the host volcaniclastic units indicate that the age of iron-formation deposition is ca. 695 Ma, which is within the Sturtian epoch that is presumed to be a glacial event of global extent. Nevertheless, there is no robust evidence of any influence of Sturtian glaciation in the Arabian-Nubian Shield. Our results rather suggest that the iron formations in the area may have formed as low-temperature exhalites on the floor of an island-arc basin. The iron formations were deposited during periods of volcanic quiescence, with metals having been derived during low-temperature pervasive hydrothermal alteration of volcanic and volcaniclastic rocks exposed at the seafloor-seawater interface. Precipitation took place due to mixing of metal-bearing hydrothermal fluids and cold, oxygenated seawater. There is no need to invoke possible effects of global glaciation to explain the origin of the Sturtian-aged iron formations in the shield. Our study thus suggests that not all Neoproterozoic iron formations are necessarily linked to glacial events as the Hamama deposit represents a non-Rapitan exhalative iron formation.
英文关键词	Cryogenian Exhalite Hydrothermal Iron formations Island arc Sturtian glaciation
类型	Article
语种	英语
国家	Peoples R China ; Egypt ; Germany
收录类别	SCI-E
WOS记录号	WOS:000516969400011
WOS关键词	RARE-EARTH-ELEMENTS ; CENTRAL EASTERN DESERT ; TRACE-ELEMENT ; HYDROTHERMAL FLUIDS ; U-PB ; ATMOSPHERIC OXYGEN ; TECTONIC EVOLUTION ; CRUSTAL EVOLUTION ; GEOCHEMISTRY ; SEAWATER
WOS类目	Geochemistry & Geophysics ; Mineralogy
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
来源机构	中国科学院地质与地球物理研究所
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/315180
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China; 2.Cairo Univ, Fac Sci, Geol Dept, Giza 12613, Egypt; 3.TU Bergakad Freiberg, Dept Mineral, D-09596 Freiberg, Germany; 4.Helmholtz Inst Freiberg Resource Technol, D-09599 Freiberg, Germany; 5.Univ Chinese Acad Sci, Coll Earth & Planetary Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Abd El-Rahman, Yasser,Gutzmer, Jens,Li, Xian-Hua,et al. Not all Neoproterozoic iron formations are glaciogenic: Sturtian-aged non-Rapitan exhalative iron formations from the Arabian-Nubian Shield[J]. 中国科学院地质与地球物理研究所,2020,55(3):577-596.
APA	Abd El-Rahman, Yasser.,Gutzmer, Jens.,Li, Xian-Hua.,Seifert, Thomas.,Li, Chao-Feng.,...&Li, Jiao.(2020).Not all Neoproterozoic iron formations are glaciogenic: Sturtian-aged non-Rapitan exhalative iron formations from the Arabian-Nubian Shield.MINERALIUM DEPOSITA,55(3),577-596.
MLA	Abd El-Rahman, Yasser,et al."Not all Neoproterozoic iron formations are glaciogenic: Sturtian-aged non-Rapitan exhalative iron formations from the Arabian-Nubian Shield".MINERALIUM DEPOSITA 55.3(2020):577-596.