干旱区生态环境知识资源中心(Arid): Stratigraphy, petrology, and geochemistry of a neoproterozoic banded iron sequence in the El-Dabbah Group, central Eastern Desert, Egypt

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DOI	10.1016/j.jafrearsci.2020.103805
	Stratigraphy, petrology, and geochemistry of a neoproterozoic banded iron sequence in the El-Dabbah Group, central Eastern Desert, Egypt
	Kiyokawa, Shoichi; Suzuki, Taishi; El-Dokouny, Hanaa Abdenaby; Dawoud, Maher; Abuelhasan, Mohamed Mahmoud
通讯作者	Kiyokawa, S
来源期刊	JOURNAL OF AFRICAN EARTH SCIENCES
ISSN	1464-343X
EISSN	1879-1956
出版年	2020
卷号	168
英文摘要	The El-Dabbah Group of the Nubian Shield, Central Eastern Desert, Egypt, contains a Neoproterozoic banded iron sequence within volcaniclastic rocks deposited in an island arc setting. The group contains a volcaniclastic sequence of relatively undeformed lower-greenschist-facies rocks that are unconformably overlain by terrestrial sedimentary strata of the Hamamat Group. The group is > 7000 m thick and contains three formations (the Lower, Middle, and Upper El-Dabbah formations), which include massive metavolcanic rocks, pillow lavas, well-bedded volcaniclastic rocks, black and greenish shale and banded iron sequences. There is no evidence of glaciation, such as diamictites or cap-carbonate beds, in the three formations. The Middle El-Dabbah Formation (2000 m thick) contains well-preserved iron sequences within the volcaniclastic rocks. Most of the iron sequences comprise beds that are a few meters thick. The iron sequence rocks have low contents of Al, Ti, K, and Na, and low Al/(Al + Fe + Mn + Na + K + Ca) ratios, which suggest there was no continental input. Heavy rare earth element enrichment and the absence of Eu anomalies indicate these rocks formed from low-temperature hydrothermal fluids or in a distal setting from a hydrothermal vent system. delta C-13 values of the black shales are ca. - 22 parts per thousand, suggesting the organic matter was derived from cyanobacterial activity. Given that several black shale units were precipitated below the iron sequences, the cyanobacterial activity might have produced the oxygen at the ocean surface that led to iron oxidation and deposition. Based on the stratigraphic and geo-chemical characteristics of the El-Dabbah Group, we propose the iron sequences were deposited in a small isolated basin within the central rift zone of an oceanic island arc. The relationship between the El-Dabbah Group and Sturtian glaciation remains unclear.
英文关键词	Central eastern desert of Egypt El-dabbah group Neoproterozoic iron formation Oceanic island arc Black shale Sturtian glaciation
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000540173100001
WOS关键词	RARE-EARTH-ELEMENTS ; COASTAL PILBARA TERRANE ; DIXON ISLAND FORMATION ; ARABIAN-NUBIAN SHIELD ; HYDROTHERMAL FLUIDS ; CRUSTAL EVOLUTION ; YTTRIUM ; SEA ; VOLCANISM ; SEDIMENTS
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/324736
作者单位	[Kiyokawa, Shoichi; Suzuki, Taishi] Kyushu Univ, Dept Earth & Planetary Sci, Nishi Ku, 744 Motooka, Fukuoka 8190395, Japan; [Kiyokawa, Shoichi] Univ Johannesburg, Dept Geol, POB 524,Auckland Pk, ZA-2006 Johannesburg, South Africa; [Kiyokawa, Shoichi] Kochi Univ, Ctr Adv Marine Core Res, Nanko Ku, B200 Monobe, Kochi 7838502, Japan; [El-Dokouny, Hanaa Abdenaby; Dawoud, Maher; Abuelhasan, Mohamed Mahmoud] Menoufiya Univ, Fac Sci, Dept Geol, Gamal Abd El Nasr St, Shebin El Korn, Menoufiya, Egypt
推荐引用方式 GB/T 7714	Kiyokawa, Shoichi,Suzuki, Taishi,El-Dokouny, Hanaa Abdenaby,et al. Stratigraphy, petrology, and geochemistry of a neoproterozoic banded iron sequence in the El-Dabbah Group, central Eastern Desert, Egypt[J],2020,168.
APA	Kiyokawa, Shoichi,Suzuki, Taishi,El-Dokouny, Hanaa Abdenaby,Dawoud, Maher,&Abuelhasan, Mohamed Mahmoud.(2020).Stratigraphy, petrology, and geochemistry of a neoproterozoic banded iron sequence in the El-Dabbah Group, central Eastern Desert, Egypt.JOURNAL OF AFRICAN EARTH SCIENCES,168.
MLA	Kiyokawa, Shoichi,et al."Stratigraphy, petrology, and geochemistry of a neoproterozoic banded iron sequence in the El-Dabbah Group, central Eastern Desert, Egypt".JOURNAL OF AFRICAN EARTH SCIENCES 168(2020).