干旱区生态环境知识资源中心(Arid): Genesis of gabbroic intrusions in the Arabian Shield, Saudi Arabia: mineralogical, geochemical and tectonic fingerprints of the Neoproterozoic arc magmatism

Arid

DOI	10.1017/S0016756821000182
	Genesis of gabbroic intrusions in the Arabian Shield, Saudi Arabia: mineralogical, geochemical and tectonic fingerprints of the Neoproterozoic arc magmatism
	Ali, Shehata; Alshammari, Abdullah S.
通讯作者	Ali, S (corresponding author), Minia Univ, Fac Sci, Geol Dept, El Minia 61519, Egypt.
来源期刊	GEOLOGICAL MAGAZINE
ISSN	0016-7568
EISSN	1469-5081
出版年	2021
卷号	158 期号:9 页码:1639-1656
英文摘要	The Arabian Shield of Saudi Arabia represents part of the Arabian-Nubian Shield and forms an exposure of juvenile continental crust on the eastern side of the Red Sea rift. Gabbroic intrusions in Saudi Arabia constitute a significant part of the mafic magmatism in the Neoproterozoic Arabian Shield. This study records the first detailed geological, mineralogical and geochemical data for gabbroic intrusions located in the Gabal Samra and Gabal Abd areas of the Hail region in the Arabian Shield of Saudi Arabia. Geological field relations and investigations, supported by mineralogical and geochemical data, indicate that the gabbroic intrusions are generally unmetamorphosed and undeformed, and argue for their post-collisional emplacement. Their mineralogical and geochemical features reveal crystallization from hydrous, mainly tholeiitic, mafic magmas with arc-like signatures, which were probably inherited from the previous subduction event in the Arabian-Nubian Shield. The gabbroic rocks exhibit sub-chondritic Nb/U, Nb/Ta and Zr/Hf ratios, revealing depletion of their mantle source. Moreover, the high ratios of (Gd/Yb)(N) and (Dy/Yb)(N) indicate that their parental mafic melts were derived from a garnet-peridotite source with a garnet signature in the mantle residue. This implication suggests that the melting region was at a depth exceeding similar to 70-80 km at the garnet stability field. They have geochemical characteristics similar to other post-collisional gabbros of the Arabian-Nubian Shield. Their origin could be explained by adiabatic decompression melting of depleted asthenosphere that interacted during ascent with metasomatized lithospheric mantle in an extensional regime, likely related to the activity of the Najd Fault System, at the end of the Pan-African Orogeny.
英文关键词	gabbro Neoproterozoic post-collisional magmatism Arabian Shield Saudi Arabia
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000683961700010
WOS关键词	MAFIC-ULTRAMAFIC INTRUSION ; ALKALINE VOLCANIC-ROCKS ; EASTERN DESERT ; NUBIAN SHIELD ; CLINOPYROXENE COMPOSITION ; OCEANIC BASALTS ; SOUTH SINAI ; ISLAND-ARC ; MANTLE ; EGYPT
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/2XILL650/363416
作者单位	[Ali, Shehata] Minia Univ, Fac Sci, Geol Dept, El Minia 61519, Egypt; [Alshammari, Abdullah S.] Hail Univ, Fac Sci, Hail 2440, Saudi Arabia
推荐引用方式 GB/T 7714	Ali, Shehata,Alshammari, Abdullah S.. Genesis of gabbroic intrusions in the Arabian Shield, Saudi Arabia: mineralogical, geochemical and tectonic fingerprints of the Neoproterozoic arc magmatism[J],2021,158(9):1639-1656.
APA	Ali, Shehata,&Alshammari, Abdullah S..(2021).Genesis of gabbroic intrusions in the Arabian Shield, Saudi Arabia: mineralogical, geochemical and tectonic fingerprints of the Neoproterozoic arc magmatism.GEOLOGICAL MAGAZINE,158(9),1639-1656.
MLA	Ali, Shehata,et al."Genesis of gabbroic intrusions in the Arabian Shield, Saudi Arabia: mineralogical, geochemical and tectonic fingerprints of the Neoproterozoic arc magmatism".GEOLOGICAL MAGAZINE 158.9(2021):1639-1656.