干旱区生态环境知识资源中心(Arid): Zinc-bearing ferromanganese mineralization in a rift-marginal carbonate platform, Red Sea, Egypt: Reconstruction of an epigenetic-supergenetic system

Arid

DOI	10.1016/j.oregeorev.2020.103837
	Zinc-bearing ferromanganese mineralization in a rift-marginal carbonate platform, Red Sea, Egypt: Reconstruction of an epigenetic-supergenetic system
	Afify, A. M.; Sanz-Montero, M. E.; Osman, R. A.
通讯作者	Afify, AM (corresponding author), Benha Univ, Dept Geol, Fac Sci, Banha 13518, Egypt.
来源期刊	ORE GEOLOGY REVIEWS
ISSN	0169-1368
EISSN	1872-7360
出版年	2020
卷号	127
英文摘要	Polymetallic mineralization hosted by rift marginal carbonate preserves a comprehensive archive that enables reconstruction of the initiation and evolution of rifting. The present study focuses on a Miocene shallow marine succession and related polymetallic (Fe-Mn-Zn) ores at the Um Greifat area along the Red Sea coast in the Central Eastern Desert of Egypt. The study area represents a unique Early-Middle Miocene syntectonic marginal carbonate platform of shallow marine and coastal plain facies. The carbonate-clastic succession comprises two units, lower and upper, that are separated by a magnesite bed. Dolomitization, karstification, fracturing and brecciation are the main diagenetic features, which allow reconstructing fluctuations of sea level induced by tectonic uplift and rifting. The polymetallic nonsulfide mineralization comprises mainly Fe-Mn-Zn oxides, forming a stratiform and strata-bound ore bodies in the lower unit of the succession and/or lenticular and cavernous masses in the upper unit. The mineralogy is dominated by chalcophanite, hetaerolite, goethite, hematite and smithsonite besides zincite, pyrolusite, cryptomelane, franklinite, coronadite, quartz and alunite-natroalunite. Less common siderite, pyrite and chalcopyrite are observed. Crystal morphologies, texture and distribution of the ferromanganese minerals were modified depending on the textures, porosity, open-spaces and discontinuities of their host carbonate. The mode of occurrence, texture, mineralogy and geochemistry of the polymetallic ores suggest a two epigenetic-supergene origin. The early stage encompassed precipitation of sulfides, silica and/or circulation of highly acidic metal-rich hydrothermal solutions through faulted carbonate blocks. Dissolution and intensive oxidation of primary sulfides, Fe+2 and Mn+2 in oxic and supergenetic conditions resulted in the formation of polymetallic oxides that represent the late stage. Major uplifting and exhumation by the Red Sea extension, along with circulation of low-temperature hydrothermal fluids through faulted areas, initiated ore mineral precipitation under near-neutral to mildly acidic conditions. The interplay of diagenesis, deformation, tectonism and hydrothermalism was likely enhanced by rift-induced geothermal activity in the Red Sea basin and adjacent areas.
英文关键词	Marginal carbonate platform Ferromanganese minerals Polymetallic deposits Dolomite-magnesite Red Sea rifting
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000598324600001
WOS类目	Geology ; Mineralogy ; Mining & Mineral Processing
WOS研究方向	Geology ; Mineralogy ; Mining & Mineral Processing
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/349096
作者单位	[Afify, A. M.; Osman, R. A.] Benha Univ, Dept Geol, Fac Sci, Banha 13518, Egypt; [Afify, A. M.; Sanz-Montero, M. E.] Univ Complutense Madrid, Fac Geol Sci, Dept Mineral & Petr, C Jose Antonio Novais 12, Madrid 28040, Spain
推荐引用方式 GB/T 7714	Afify, A. M.,Sanz-Montero, M. E.,Osman, R. A.. Zinc-bearing ferromanganese mineralization in a rift-marginal carbonate platform, Red Sea, Egypt: Reconstruction of an epigenetic-supergenetic system[J],2020,127.
APA	Afify, A. M.,Sanz-Montero, M. E.,&Osman, R. A..(2020).Zinc-bearing ferromanganese mineralization in a rift-marginal carbonate platform, Red Sea, Egypt: Reconstruction of an epigenetic-supergenetic system.ORE GEOLOGY REVIEWS,127.
MLA	Afify, A. M.,et al."Zinc-bearing ferromanganese mineralization in a rift-marginal carbonate platform, Red Sea, Egypt: Reconstruction of an epigenetic-supergenetic system".ORE GEOLOGY REVIEWS 127(2020).