干旱区生态环境知识资源中心(Arid): Subduction to post-collisional volcanism in the Northern Arabian-Nubian Shield: Genesis of Cryogenian/Ediacaran intermediate-felsic magmas and the lifespan of a Neoproterozoic mature island arc

Arid

DOI	10.1016/j.precamres.2021.106148
	Subduction to post-collisional volcanism in the Northern Arabian-Nubian Shield: Genesis of Cryogenian/Ediacaran intermediate-felsic magmas and the lifespan of a Neoproterozoic mature island arc
	Maurice, Ayman E.; Gharib, Moustafa E.; Wilde, Simon A.; Ali, Kamal A.; Osman, Madiha S. M.
通讯作者	Maurice, AE (corresponding author), Helwan Univ, Fac Sci, Geol Dept, Cairo 11795, Egypt.
来源期刊	PRECAMBRIAN RESEARCH
ISSN	0301-9268
EISSN	1872-7433
出版年	2021
卷号	358
英文摘要	The Neoproterozoic intermediate-felsic volcanic rocks in the Wadi Ambagy area, Eastern Desert of Egypt, comprise three units: Dokhan intermediate-felsic volcanics, post-Dokhan felsic volcanics and felsites. The Dokhan lavas are generally porphyritic and composed of andesite and dacite with subordinate basalt, whereas the postDokhan felsic volcanics are represented by phyric and aphyric rhyolites. The medium-K calc-alkaline nature, LILE enrichment, Ta-Nb anomalies and LREE-enriched patterns of the Dokhan volcanic rocks are consistent with development in a subduction setting. Arc crustal thickness estimation using average (La/Yb)n is similar to 32 km, indicating that these rocks were generated in a Neoproterozoic island arc with thick crust. The subduction magmas were generated by hydrous mantle melting and they evolved by fractional crystallization. In contrast, the post-Dokhan felsic volcanics and felsites have medium- to high-K and shoshonitic affinities, respectively. They are highly silicic with weak to absent Ta-Nb anomalies and significant Nb, Zr, Hf and REE enrichment, which increases from the post-Dokhan felsic volcanics to the felsites. These geochemical features suggest generation in a post-collisional to within-plate tectonic setting by partial melting of mafic or intermediate arc crustal sources. SHRIMP U-Pb zircon dating indicates a crystallization age of similar to 660 Ma for the subduction-related Dokhan andesite and dacite, reflecting a magmatic arc lifespan longer than previously considered. The change of setting from subduction to post-collisional was accompanied by an increased role of crustal sources in the generation of the felsic magmas, resulting in differentiation of the accreted arc crust.
英文关键词	Neoproterozoic Subduction Mature island arc Dokhan volcanics Felsites Eastern Desert of Egypt
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000652101500008
WOS关键词	EAST-AFRICAN OROGEN ; GEBEL-UMM-TAWAT ; DOKHAN VOLCANICS ; HAMMAMAT GROUP ; CALC-ALKALINE ; CHEMICAL CLASSIFICATION ; CONTINENTAL GROWTH ; TERMINAL COLLISION ; CRUSTAL EVOLUTION ; DETRITAL ZIRCONS
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/2XILL650/351425
作者单位	[Maurice, Ayman E.; Gharib, Moustafa E.] Helwan Univ, Fac Sci, Geol Dept, Cairo 11795, Egypt; [Wilde, Simon A.] Curtin Univ, Sch Earth & Planetary Sci, POB U1987, Perth, WA 6845, Australia; [Ali, Kamal A.] United Arab Emirates Univ, Coll Sci, Dept Geol, Abu Dhabi, U Arab Emirates; [Osman, Madiha S. M.] Elmergib Univ, Fac Sci, Geol Dept, Elmergib, Libya
推荐引用方式 GB/T 7714	Maurice, Ayman E.,Gharib, Moustafa E.,Wilde, Simon A.,et al. Subduction to post-collisional volcanism in the Northern Arabian-Nubian Shield: Genesis of Cryogenian/Ediacaran intermediate-felsic magmas and the lifespan of a Neoproterozoic mature island arc[J],2021,358.
APA	Maurice, Ayman E.,Gharib, Moustafa E.,Wilde, Simon A.,Ali, Kamal A.,&Osman, Madiha S. M..(2021).Subduction to post-collisional volcanism in the Northern Arabian-Nubian Shield: Genesis of Cryogenian/Ediacaran intermediate-felsic magmas and the lifespan of a Neoproterozoic mature island arc.PRECAMBRIAN RESEARCH,358.
MLA	Maurice, Ayman E.,et al."Subduction to post-collisional volcanism in the Northern Arabian-Nubian Shield: Genesis of Cryogenian/Ediacaran intermediate-felsic magmas and the lifespan of a Neoproterozoic mature island arc".PRECAMBRIAN RESEARCH 358(2021).