The Arabian–Nubian Shield, an Introduction: Historic Overview, Concepts, Interpretations, and Future Issues

2021 ◽  
pp. 1-38
Author(s):  
Peter R. Johnson
Keyword(s):  
Nubian Shield ◽  
Arabian Nubian Shield

Genesis of gabbroic intrusions in the Arabian Shield, Saudi Arabia: mineralogical, geochemical and tectonic fingerprints of the Neoproterozoic arc magmatism

2021 ◽  
pp. 1-18
Author(s):  
Shehata Ali ◽  
Abdullah S. Alshammari
Keyword(s):  
Saudi Arabia ◽  
Fault System ◽  
Geochemical Data ◽  
Stability Field ◽  
Arabian Shield ◽  
Red Sea Rift ◽  
Nubian Shield ◽  
Najd Fault System ◽  
Garnet Stability Field ◽  
Arabian Nubian Shield

Abstract 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 ∼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.

Geochemistry and P–T–t evolution of the Abu-Barqa Metamorphic Suite, SW Jordan, and implications for the tectonics of the northern Arabian–Nubian Shield

2013 ◽  
Vol 239 ◽  
pp. 56-78 ◽  
Author(s):  
Ghaleb H. Jarrar ◽  
Thomas Theye ◽  
Najel Yaseen ◽  
Martin Whitehouse ◽  
Victoria Pease ◽  
...  
Keyword(s):  
Nubian Shield ◽  
Arabian Nubian Shield

scholarly journals Multiple Stages of Carbonation and Element Redistribution during Formation of Ultramafic-Hosted Magnesite in Neoproterozoic Ophiolites of the Arabian-Nubian Shield, Egypt

2019 ◽  
Vol 127 (1) ◽  
pp. 81-107 ◽  
Author(s):  
Mokhles K. Azer ◽  
Hisham A. Gahlan ◽  
Paul D. Asimow ◽  
Heba S. Mubarak ◽  
Khaled M. Al-Kahtany
Keyword(s):  
Nubian Shield ◽  
Element Redistribution ◽  
Arabian Nubian Shield ◽  
Multiple Stages

The evolution of the Neoproterozoic Elat Metamorphic Complex, northernmost Arabian-Nubian Shield: Island arc to syncollisional stage and post-collisional magmatism

2019 ◽  
Vol 320 ◽  
pp. 137-170 ◽  
Author(s):  
Yehuda Eyal ◽  
Moshe Eyal ◽  
Boris Litvinovsky ◽  
Bor–ming Jahn ◽  
Rani Calvo ◽  
...  
Keyword(s):  
Island Arc ◽  
Metamorphic Complex ◽  
Nubian Shield ◽  
Arabian Nubian Shield
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