Neoproterozoic concentric intrusive complex of gabbro-diorite-tonalite-granodiorite association, Rahaba area, southern Eastern Desert of Egypt: Implications for magma mixing of arc intrusive rocks

Abdel‐Karim, Abdel‐Aal M.; Azer, Mokhles K.; Mogahed, Moustafa M.

doi:10.1016/j.lithos.2021.106423

Cited by 10 publications

(18 citation statements)

References 68 publications

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“…In summary, the studied rocks in the ZQTB suggest that an active continental margin setting is responsible for the formation of their magmas. A comparable scenario has also been reported in the Neoproterozoic concentric Rahaba intrusive complex from the south Eastern Desert of Egypt (Abdel‐Karim et al, 2021). Gabbros derived from hydrous partial melting of a depleted‐mantle wedge, metasomatized by aqueous fluids released from the subducting oceanic slab; whilst dioritic MMEs were produced regarding the mixing behaviour between mafic and granodioritic magmas under an active continental margin setting (Abdel‐Karim et al, 2021).…”

Section: Discussionsupporting

confidence: 77%

“…On the trigonal tectonic discrimination diagram of Hf/3‐Th‐Ta by Wood et al (1979) (Figure 17a), they are lying in the range of calc‐alkali basalt (CAB), reflective of the geochemical affinity of arc‐related basalt formed in the continental margin. These characteristics could match with resultant behaviour from subduction‐induced metasomatism and enrichment in the mantle source (Abdel‐Karim et al, 2021). Mineralogically, amphibole compositions from MMEs presented high MgO contents ranging from 11.23% to 12.45%, typical characteristic of magnesiohornblende, and indicated that they were crystallized under a relatively oxidizing condition (Zhang, 2017).…”

Section: Discussionmentioning

confidence: 84%

“…The large‐ion lithophile elements (LILE) Ba, Sr, and Rb show an obvious variation between 77 and 656 ppm, 97.3–396.0 ppm, and 6.25–358.0 ppm, respectively. In addition, the dioritic rocks are silica‐saturated, possess relatively high Mg# (molar ratio 100 × Mg 2+ /[Mg 2+ + tot Fe 2+ ]) between 51 and 64, and are marked by high Al 2 O 3 (16.55–18.30 wt%) and CaO (7.78–9.85 wt%) similar to that of high‐alumina basalts (Abdel‐Karim et al, 2021). On the other hand, granodiorites have a high concentration of SiO 2 (64.91–73.61 wt%) and are characterized by relatively low Na 2 O/K 2 O ratios ranging from 0.5 to 0.9 and low A/CNK (molar ratio Al 2 O 3 /[CaO + Na 2 O + K 2 O]) values between 0.92 and 1.04, suggesting that they exhibit metaluminous affinity.…”

Section: Analytical Resultsmentioning

confidence: 99%

“…Given the inefficiency of magma mixing, whole‐rock compositions are relatively heterogeneous in geochemistry. Thus, it is often easy to discern and has been a hot focus of recent studies (Abdel‐Karim et al, 2021; Dong et al, 2020; Fourcade & Allegre, 1981; Sun et al, 2021).…”

Section: Discussionmentioning

confidence: 99%

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Subduction‐related mafic to felsic magmatism in the Xiangpishan concentric calc‐alkaline complex, Northeast Tibetan Plateau

Zou

Deng

et al. 2022

Geological Journal

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The Xiangpishan complex in the Zongwulong‐Qinghainanshan Tectonic Belt, Northeast (NE) Tibetan Plateau, is a composite concentric pluton consisting of a felsic core (granodiorite) surrounded by quartz diorite in the middle to diorite and minor gabbro at the margin with locally less volume of monzogranite. Many dioritic enclaves are unevenly distributed within host granitoids. We evaluate the petrogenesis of the complex by geochemical, geochronological, and Hf isotopic data in tandem with regional data in the belt. The results show that felsic rocks were emplaced during the Late Permian (ca. 262–256 Ma); whilst gabbros yielded a younger age of ca. 249 Ma. As the hybrid phase from mixing between felsic and mafic magmas, enclaves and diorites have analogous ages (ca. 257–254 Ma) to both. Zircons from gabbro and enclaves are marked by higher εHf(t) value up to +1.82; whilst granodiorites have lower εHf(t) value of −5.48, consistent with hybrid diorites possessing intermediate εHf(t) values of −3.14 to 0.34. Furthermore, the quantitative calculation from Mass Balances Modelling suggests that the mass of mafic magma (ca. 67%–79%) is involved to achieve the hybridization. Geochemically, these rocks crystallized from calc‐alkaline magma with different sources, but demonstrated consistent arc‐like signatures, as they are enriched in large‐ion lithophile elements and light rare earth element (LREE), and depleted in high‐ field‐strength elements and heavy rare earth element (HREE). Besides, they present negative Nb–Ta anomalies together with significant P and Ti troughs. Finally, an evolutional model has been proposed that the asthenosphere‐lithosphere interaction played an important role during the emplacement of the complex, where the limited volumes of mantle‐derived melt act as the suppliers of heat and mass (mainly volatile components) to induce partial melting of the juvenile mafic lower crust and mixed (or mingled) with the produced crust‐derived magma during the oceanic subduction, which led to the generation of diorites as well as mafic microgranular enclaves.

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Section: Discussionsupporting

confidence: 77%

Section: Discussionmentioning

confidence: 84%

Section: Analytical Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Subduction‐related mafic to felsic magmatism in the Xiangpishan concentric calc‐alkaline complex, Northeast Tibetan Plateau

Zou

Deng

et al. 2022

Geological Journal

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“…Antigorite serpentinites (Atgserpentinites) constituting Abu Dahr South were transformed to carbonate-rich serpentinites (listvenites) along fractured and sheared zones. The Abu Dahr Nappe is intruded by concentric intrusive complexes of Um Eliega and Rahaba from the north and east, respectively(Zoheir et al., 2008;Abdel-Karim et al, 2021;Azer and Asimow, 2021). These complexes consisting of a mafic core (gabbro and diorite) surrounded by tonalite in the middle to granodiorite at the margin, formed in an active continental margin setting during the subduction of the oceanic slab(Abdel-Karim et al, 2021).10 al.…”

mentioning

confidence: 99%

Hydrothermal alteration of Ni-rich sulfides in peridotites of Abu Dahr, Eastern Desert, Egypt: Relationships among minerals in the Fe-Ni-Co-O-S system,fO2 andfS2

Abdel-Halim

2023

American Mineralogist

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The Neoproterozoic peridotites of Abu Dahr, Eastern Desert of Egypt, consist mainly of highly depleted harzburgites that have experienced multiple stages of serpentinization (lizarditization and antigoritization) and carbonation/listvenitization in a forearc environment.The Abu Dahr forearc harzburgites are more oxidized than oceanic mantle, with the oxygen fugacity (fO 2 ) values ranging from FMQ +0.41 to FMQ +1.20 (average = +0.60 FMQ), and were equilibrated at temperatures of 910-1217°C and pressures of 4.1-7.8 kbar. This study has documented for the first time the presence of a variety of Ni-rich Ni-Fe (-Co) sulfide and metal phases along with Fe-oxides/oxyhydroxides in serpentinized-carbonated peridotites of the Abu Dahr forearc. Here I concentrate on the relationship between redox state and Fe-Ni-Co-O-S minerals with emphasis on the role of hydrothermal processes in upgrading magmatic sulfide tenors, desulfurization (sulfur-loss) of magmatic pentlandite and hydrothermal upgrading of the sulfide phases in Abu Dahr forearc environment. The minerals involved are high-Ni pentlandite (Fe 4 Ni 5 S 8 ), cobaltian pentlandite (Fe 3.47 Ni 4.78 Co 0.75 S 8 ), heazlewoodite (Fe 0.07 Ni 2.93 S 2 ), godlevskite (Fe 0.26 Ni 8.73 Co 0.01 S 8 ), millerite (Fe 0.01 Ni 0.98 Cu 0.01 S), awaruite (Ni 75 Fe 21 ) and native Ni (Ni 93 Fe 5 ), and nickeliferous magnetite and goethite. Chalcopyrite is a rare mineral; other Cuphases, Fe-sulfides and Ni-arsenides/phosphides are not present. Texturally, Ni-sulfide and alloy

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Mixing of magmas from multiple sources in the petrogenesis of multi‐stage Early Cretaceous syenites in the Wulingshan alkaline complex, northern North China Craton: Evidence from enclaves

et al. 2023

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There are several different models for the origin of syenites, but the role of magma mixing in the formation of syenites remains unclear. The Wulingshan alkaline complex in the northern North China Craton consists mainly of porphyritic syenite and syenite with abundant enclaves. These enclaves may provide new insights into the petrogenesis of syenites. We obtained zircon U–Pb age, mineral chemistry, whole‐rock major and trace elements, and Sr–Nd isotopic data for the enclaves and their host rocks to constrain the petrogenesis and identify the role of magma mixing during the formation of the different syenites in the Wulingshan alkaline complex. The results of zircon U–Pb dating indicate that the enclaves and host rocks crystallized contemporaneously at ca. 133 Ma. The enclaves contain abundant clinopyroxene, amphibole, and biotite, and their average Nb/Ta (18.46) and Th/Ce (0.04) ratios are similar to those of the mantle. The enclaves have relatively high Fe2O3T, MgO, and CaO contents, and their SiO2 contents are equivalent to those of intermediate rocks, indicating that they formed by mixing the mafic and felsic magmas to some extent. The different mineral assemblages, major and trace elements and isotopic compositions of the enclaves in the porphyritic syenite and syenite indicate that they are two batches of parental magma with different properties derived from the mantle. The porphyritic syenite and syenite have high SiO2 and low Fe2O3T, MgO, and CaO contents, as well as low V, Cr, Co, and Ni contents. These major and trace element characteristics of the host rocks require the involvement of crustal components. The Sr–Nd isotopic compositions of the enclaves and the host syenitoids plot on a mixing curve between enriched lithospheric mantle and lower crust, indicating that these rocks are the products of magma mixing and crust–mantle interaction. Considering the contact relationships, the geochemistry data, and the mixing model presented in the paper, we propose that the upwelling of the hot asthenosphere heated the overlying enriched lithospheric mantle and triggered low‐degree partial melting. The alkalic mafic magmas derived from enriched mantle sources were mixed with felsic magmas generated by partial melting of the lower (or upper) crust to form the different syenites.

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Neoproterozoic concentric intrusive complex of gabbro-diorite-tonalite-granodiorite association, Rahaba area, southern Eastern Desert of Egypt: Implications for magma mixing of arc intrusive rocks

Cited by 10 publications

References 68 publications

Subduction‐related mafic to felsic magmatism in the Xiangpishan concentric calc‐alkaline complex, Northeast Tibetan Plateau

Subduction‐related mafic to felsic magmatism in the Xiangpishan concentric calc‐alkaline complex, Northeast Tibetan Plateau

Hydrothermal alteration of Ni-rich sulfides in peridotites of Abu Dahr, Eastern Desert, Egypt: Relationships among minerals in the Fe-Ni-Co-O-S system,fO2 andfS2

Mixing of magmas from multiple sources in the petrogenesis of multi‐stage Early Cretaceous syenites in the Wulingshan alkaline complex, northern North China Craton: Evidence from enclaves

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