scholarly journals Geochemistry and mineralogy of the Jebel Aja Igneous Intrusion and the associated exotic pegmatites, Arabian Shield, Saudi Arabia

Lithos ◽  
2021 ◽  
pp. 106395
Author(s):  
Hisham A. Gahlan ◽  
Paul D. Asimow ◽  
Mokhles K. Azer ◽  
Chi Ma ◽  
Khaled M. Al-Kahtany ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Arabian Shield ◽  
Igneous Intrusion

Earliest Phanerozoic or latest Proterozoic fossils from the Arabian Shield, Kingdom of Saudi Arabia

1979 ◽  
Author(s):  
Preston Cloud ◽  
S.M. Awramik ◽  
Karen Morrison ◽  
D.G. Hadley
Keyword(s):  
Saudi Arabia ◽  
Arabian Shield ◽  
Kingdom Of Saudi Arabia

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.

scholarly journals Large-Scale 3D Modeling and Inversion of Multiphysics Airborne Geophysical Data: A Case Study from the Arabian Shield, Saudi Arabia

Minerals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 271 ◽  
Author(s):  
Michael Zhdanov ◽  
Fouzan Alfouzan ◽  
Leif Cox ◽  
Abdulrahman Alotaibi ◽  
Mazen Alyousif ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
3D Modeling ◽  
Large Scale ◽  
Geophysical Data ◽  
Arabian Shield ◽  
Airborne Geophysical Data ◽  
And Inversion

A Discussion on global tectonics in Proterozoic times - Late Proterozoic cratonization in southwest Saudi Arabia

1976 ◽  
Vol 280 (1298) ◽  
pp. 517-527 ◽  
Keyword(s):  
Saudi Arabia ◽  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Granulite Facies ◽  
Greenschist Facies ◽  
Arabian Shield ◽  
Granulite Facies Metamorphism ◽  
Quartz Monzonite ◽  
Facies Metamorphism ◽  
Global Tectonics

Early cratonal development of the Arabian Shield of southwestern Saudi Arabia began with the deposition of calcic to calc-alkalic, basaltic to dacitic volcanic rocks, and immature sedimentary rocks that subsequently were moderately deformed, metamorphosed, and intruded about 960 Ma ago by dioritic batholiths of mantle derivation (87Sr/86Sr = 0.7029). A thick sequence of calc-alkalic andesitic to rhyodacitic volcanic rocks and volcanoclastic wackes was deposited unconformably on this neocraton. Regional greenschistfacies metamorphism, intensive deformation along north-trending structures, and intrusion of mantle-derived (87Sr/86Sr = 0.7028) dioritic to granodioritic batholiths occurred about 800 Ma. Granodiorite was emplaced as injection gneiss about 785 Ma (87Sr/86Sr = 0.7028- 0.7035) in localized areas of gneiss doming and amphibolite to granulite facies metamorphism. Deposition of clastic and volcanic rocks overlapped in time and followed orogeny at 785 Ma. These deposits, together with the older rocks, were deformed, metamorphosed to greenschist facies, and intruded by calc-alkalic plutons (87Sr/86Sr = 0.7035) between 600 and 650 Ma. Late cratonal development between 570 and 550 Ma involved moderate pulses of volcanism, deformation, metamorphism to greenschist facies, and intrusion of quartz monzonite and granite. Cratonization appears to have evolved in an intraoceanic, island-arc environment of comagmatic volcanism and intrusion.

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