Continental intraplate volcanism in the Sinai subplate: The Oligo-Miocene basalts of the Gulf of Suez rift

El-Bialy, Mohammed Z.; Khalifa, Ibrahim H.; Omar, Mohamed M. M.

doi:10.1016/j.jafrearsci.2017.03.004

Cited by 11 publications

(14 citation statements)

References 82 publications

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“…The Rigenco gabbros are characterized by extremely low Ce/Pb and Nb/U values close to crustal values (Figure 6a,b), indicating that gabbroic magma incorporated crustal components (El‐Bialy et al, 2018; Zhong et al, 2011). Commonly, two processes may result in such a composition.…”

Section: Discussionmentioning

confidence: 99%

“…Discriminated diagrams for the source characteristics of Rigenco gabbros. (a) Nb/U versus Nb diagram (after El‐Bialy, Khalifa, & Omar, 2018). (b) Ce/Pb versus Ce diagram (after El‐Bialy et al, 2018).…”

Section: Discussionmentioning

confidence: 99%

“…(a) Nb/U versus Nb diagram (after El‐Bialy, Khalifa, & Omar, 2018). (b) Ce/Pb versus Ce diagram (after El‐Bialy et al, 2018). (c) Zircon ε Hf ( t ) values versus ages.…”

Section: Discussionmentioning

confidence: 99%

“…Chondrite and primitive mantle normalizing values are from Sun and McDonough (). Literature data source from Li, He, et al (2016); Li, Zhu, et al (2016), Hao et al (2016a), Wu et al (2016), and Fan et al (2016) [Colour figure can be viewed at wileyonlinelibrary.com]gabbroic magma incorporated crustal components(El-Bialy et al, 2018;Zhong et al, 2011). Commonly, two processes may result…”

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confidence: 99%

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Magmatic gap associated with stepwise arc‐continent collision during the subduction of Banggong‐Nujiang Tethys Ocean: Evidence from Late Jurassic bimodal magmas

et al. 2020

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The magmatic suites in the southern margin of South Qiangtang Terrane (SQT) provide important clues to the process of northward subduction of the Banggong‐Nujiang Tethys Ocean (BNTO) and its geodynamic evolution. Previous studies identified a magmatic gap from Late Jurassic to Early Cretaceous (ca. 150–130 Ma) in the southern margin of SQT. Although the gap is generally correlated with the process related to BNTO subduction, the previous models on this remain equivocal. In this study, we investigated a suite of bimodal magmatic rocks newly recognized in the Rigenco area of SQT, including gabbros and granodiorites which were dated at 151.7 ± 3.8 Ma and 150.0 ± 2.0 Ma respectively. Based on geochemical and isotopic analyses, it is inferred that the gabbroic magmas were derived from a sub‐arc mantle source enriched by metasomatism of voluminous slab‐derived and crustal compositions, and that the granodiorites were derived from sub‐arc juvenile lower crust. Combining the petrogenesis of gabbros and granodiorites, it is proposed that the bimodal magmas were produced under a tectonic setting of general compression with local extension. A detailed evaluation of the tectonic setting of the magmatic bimodal suite suggests crustal thickening at ca. 150 Ma and that the BNTO involved multiple arcs and sub‐basins. A new model of arc‐SQT collision is proposed to account for the magmatic gap which commenced at ca. 150 Ma. The model of arc–continent collision in this case can well explain the present distribution and occurrence of magmatic rocks of late Jurassic age in the southern margin of the SQT, especially the magmatic gap. Our discovery of Late Jurassic bimodal rocks provides a critical evidence for step‐wise arc–continent collision during BNTO subduction, and contributes to the understanding of the magmatic gap in SQT and the evolution of BNTO.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

“…(a) Nb/U versus Nb diagram (after El‐Bialy, Khalifa, & Omar, 2018). (b) Ce/Pb versus Ce diagram (after El‐Bialy et al, 2018). (c) Zircon ε Hf ( t ) values versus ages.…”

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

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Magmatic gap associated with stepwise arc‐continent collision during the subduction of Banggong‐Nujiang Tethys Ocean: Evidence from Late Jurassic bimodal magmas

et al. 2020

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“…In the Red Sea district, studies have mainly focused on the younger volcanic rocks (<13 Ma) erupted on the eastern coast of the Red Sea in the Arabian Plate (Bertrand, Chazot, Blichert-Toft, & Thoral, 2003;Krienitz et al, 2009;Shaw, Baker, Menzies, Thirlwall, & Ibrahim, 2003), and to lesser extent on basaltic dykes that crop out on Sinai (Baldridge, Eyal, Bartov, Steinitz, & Eyal, 1991;El-Bialy, Khalifa, & Omar, 2018). Conversely, the Egyptian basaltic rocks are less frequently studied (Endress, 2010).…”

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confidence: 99%

Origin and geotectonic evolution of Mir Tertiary basaltic andesite dykes, Western Desert, Egypt: Constraints from mineral and bulk‐rock chemistry

Farahat

Ali

2018

Geological Journal

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Compared with widespread Egyptian Tertiary basaltic rocks, Mir Tertiary basaltic dykes from the Western Desert of Egypt show distinct mineralogical and geochemical characteristics that provide insights into the nature of their mantle source and geotectonic evolution as well as melting and crystallization conditions. Their mineralogical features (i.e., presence of orthopyroxene and lack of olivine) distinguish them from the other Egyptian Tertiary basalts. They have basaltic andesite compositions (SiO2 = 53.55–55 wt.%, Na2O + K2O = 4.64–4.8 wt.%, MgO = 2.66–3.02 wt.%) with tholeiitic character. Temperature of crystallization ranges from 1,112°C to 1,140°C for plagioclase; from 1,085°C to 1,123°C for clinopyroxene; and from 1,034°C to 1,090°C for orthopyroxene. These results are in harmony with petrographic observations which suggest early crystallization of plagioclase, followed by simultaneous crystallization of plagioclase and clinopyroxene, and soon thereafter by orthopyroxene crystallization. Titanomagnetite–ilmenite intergrowths indicate oxygen fugacity (ƒO2) of −12.09 and −9.4 log units, suggesting crystallization at relatively oxidized conditions. Their temperature ranges from 959°C to 1,125°C, suggesting that the titanomagnetite joins the crystallized phases at early stages and continued until later stages. Mir basaltic andesite (MBA) has low Ni (15–27.9 ppm), Cr (19.8–48.5 ppm), and Sc (20–25 ppm) concentrations together with high FeOt/MgO ratios (3.18–3.58) relative to primitive basalts, arguing for their evolved nature. They have sub‐chondritic Nb/Ta ratios (15.5–17) similar to ocean–island basalts and higher than those of continental crust, ruling out a significant effect of crustal contamination. The high La/Nb (>1.4) with the negative Nb, Ta, and Ti anomalies on the primitive mantle‐normalized patterns most likely indicates that their primary magma was derived from partial melting of a mantle source previously metasomatized by influx of subduction‐related slab fluids/melts. Moreover, the super‐chondritic Zr/Hf ratios (39.55–55.21) and the negative K and Ti anomalies point to carbonate metasomatism of their mantle source. This inference is further supported by their high (K2O + Na2O)/TiO2 ratios (>1) which are comparable with experimentally produced carbonated peridotite melts. The high Zr/Y (average 9.75) and La/Yb ratios (8.6–10) of the MBA suggest that they were generated via low degrees of partial melting. Indeed, modelling calculations indicate generation by lower melting degrees (<10%) of a garnet‐bearing lherzolite mantle source. The melting region was at the garnet stability field suggesting a deeper origin (exceeds ~85 km) for MBA. Field and geochemical characteristics of the Egyptian Tertiary volcanism proved that it is spatially and temporally related to extension that has occurred during Red Sea rifting. Extension most likely due to the NE–SW tensional stresses which reactivated the old fractures and triggered mafic magma generation through passive upwelling of the asthenospheric mantle.

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Phanerozoic Minor Volcanics and Intrusives of the Arabian-Nubian Shield

Saleh

Kamar

Mira

2021

Regional Geology Reviews

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Continental intraplate volcanism in the Sinai subplate: The Oligo-Miocene basalts of the Gulf of Suez rift

Cited by 11 publications

References 82 publications

Magmatic gap associated with stepwise arc‐continent collision during the subduction of Banggong‐Nujiang Tethys Ocean: Evidence from Late Jurassic bimodal magmas

Magmatic gap associated with stepwise arc‐continent collision during the subduction of Banggong‐Nujiang Tethys Ocean: Evidence from Late Jurassic bimodal magmas

Origin and geotectonic evolution of Mir Tertiary basaltic andesite dykes, Western Desert, Egypt: Constraints from mineral and bulk‐rock chemistry

Phanerozoic Minor Volcanics and Intrusives of the Arabian-Nubian Shield

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