Zircon geochronology and Sr, Nd, Pb isotope geochemistry of granitoids from Bayuda Desert and Sabaloka (Sudan): Evidence for a Bayudian event (920–900Ma) preceding the Pan-African orogenic cycle (860–590Ma) at the eastern boundary of the Saharan Metacraton

Küster, D.; Liégeois, Jean-Paul; Matukov, D. I.; Сергеев, С. А.; Lucassen, Friedrich

doi:10.1016/j.precamres.2008.03.003

Cited by 142 publications

(89 citation statements)

References 44 publications

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“…In the Darfur area, measured compositions of whole rock and leached feldspars of the Kas granite are very similar and not distinguished in the diagram (our unpublished data, 2006, eTable 3; one data point of the granites from D&W: Davidson and Wilson 1989). Measured and initial ratios are shown for granites from the Bayuda area (whole rock; Küster et al 2008). Four metamorphic rocks of the Darfur area represent measured ratios (no initial ratios given, one sample plots outside the panel with 207 Pb/ 204 Pb=16.01; Davidson and Wilson 1989).…”

Section: Discussionmentioning

confidence: 86%

“…Data sources: Davidson and Wilson (1989), Harms et al (1990), Zimmer et al (1995), Küster and Liégois (1998), Stern and Abdelsalam (1998), Teklay et al (2001), Bailo et al (2003), Küster et al (2008) and our unpublished data (2006). Mesozoic to Cenozoic intra-plate magmatic rocks of the studied area include crust-contaminated samples.…”

Section: Discussionmentioning

confidence: 99%

“…1; e.g. Black and Liégois 1993;Abdelsalam et al 2002;Küster et al 2008). The second reservoir is dominant east of the suture and on the Arabian Peninsula.…”

Section: Isotope Signature Of the Pan-african Basementmentioning

confidence: 99%

“…Davidson and Wilson 1989;Harms et al 1990;Stern 2002;our unpublished data 2006). Pb isotope signatures are unconstrained in many areas except in the Bayuda area (Küster et al 2008) and for a few samples from the Darfur (Davidson and Wilson 1989). Therefore, Pb isotope data were supplemented for Pan-African post-orogenic granites in the Darfur region ( Fig.…”

Section: Isotope Signature Of the Pan-african Basementmentioning

confidence: 99%

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Nd, Pb, and Sr isotope composition of Late Mesozoic to Quaternary intra-plate magmatism in NE-Africa (Sudan, Egypt): high-μ signatures from the mantle lithosphere

Lucassen

Franz

Romer

et al. 2008

Contrib Mineral Petrol

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The isotopic composition of mafic small-volume intra-plate magmatism constrains the compositions of the sub-continental mantle sources. The Nd, Pb, and Sr isotope signatures of widespread late Mesozoic to Quaternary intra-plate magmatism in NE Africa (Sudan, South Egypt) are surprisingly uniform and indicate the presence of a high-µ (µ= 238 U/ 204 Pb) source in the mantle. The rocks are characterized by small ranges in the initial isotopic composition of Nd, Pb, and Sr and most samples fall within ε Nd ca 3 to 6, 206 Sr/ 86 Sr ca. 0.7028 to 0.7034. We interpret this reservoir as lithospheric mantle that formed beneath the Pan-African orogens and magmatic arcs from asthenospheric mantle, which was enriched in trace elements (U, Th, and light REE). Combining our new data set with published data of intra-plate magmatic rocks from the Arabian plate indicates two compositionally different domains of lithospheric mantle in NE-Africa -Arabia. The two domains are spatially related to the subdivision of the Pan-African orogen into a western section dominated by reworked cratonic basement (NEAfrica; high-µ lithospheric mantle) and an eastern section dominated by juvenile Pan-African basement (easternmost NE-Africa and Arabia; moderate µ lithospheric mantle). The compositions of the Pan-African lithospheric mantle and the MORB-type mantle of the Red Sea and Gulf of Aden spreading centers could explain the Nd-Pb-Sr isotopic compositions of the most pristine Afar flood basalts in Yemen and Ethiopia by mixtures of the isotopic composition of regional lithospheric and asthenospheric sources.

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Section: Discussionmentioning

confidence: 86%

Section: Discussionmentioning

confidence: 99%

“…1; e.g. Black and Liégois 1993;Abdelsalam et al 2002;Küster et al 2008). The second reservoir is dominant east of the suture and on the Arabian Peninsula.…”

Section: Isotope Signature Of the Pan-african Basementmentioning

confidence: 99%

Section: Isotope Signature Of the Pan-african Basementmentioning

confidence: 99%

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Nd, Pb, and Sr isotope composition of Late Mesozoic to Quaternary intra-plate magmatism in NE-Africa (Sudan, Egypt): high-μ signatures from the mantle lithosphere

Lucassen

Franz

Romer

et al. 2008

Contrib Mineral Petrol

Self Cite

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“…The Paleoproterozoic and Archean grains were possibly sourced from the Saharan Metacraton or crust similar to the Khida terrane [67]. Late Mesoproterozoic-early Neoproterozoic crust is known in the Bayuda Desert [71,72] and, as mentioned, suspected in Sinai [58,73].…”

Section: Detrital Zircon Spectramentioning

confidence: 82%

An Expanding Arabian-Nubian Shield Geochronologic and Isotopic Dataset: Defining Limits and Confirming the Tectonic Setting of a Neoproterozoic Accretionary Orogen

Johnson¹

2014

TOGEOJ

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Geologic investigations of the Arabian-Nubian Shield (ANS) are supported by a valuable, expanding dataset of geochronologic ages and isotopic analyses. U-Pb zircon SIMS, TIMS, and evaporation data provide robust temporal control on depositional, volcanic, and intrusive events. Nd, Sr, O and, increasingly, Hf isotopic studies provide insights into magma sources and constraints on crustal recycling. Apart from well-established exceptions where Paleoproterozoic and Archean rocks intercalated in the ANS underwent Neoproterozoic reworking, the data elegantly confirm the Neoproterozoic age and juvenile character of the bulk of the ANS. The geochronologic and isotopic data reveal that some ANS sedimentary, volcanic, and igneous rocks contain pre-Neoproterozoic material as xenocrysts and possible glaciogenic clasts, but give no evidence that the ANS is otherwise underlain by any extensive tracts of older crust. Together with structural mapping, the expanding dataset confirms ANS boundaries where long-inferred in the west and suggests the placement of hitherto uncertain boundaries elsewhere. The suggested boundaries imply that the ANS is of a somewhat smaller size than considered in published discussions, which in turn impacts assessment of Neoproterozoic crustal growth rate. The Arabian-Nubian Shield (ANS) is an accretionary orogen at the northern end (present-day coordinates) of the East African Orogen. It is one of the largest expanses of mantle-derived, juvenile Neoproterozoic crust on Earth, underlying an area of ~2.7 x 10 6 km 2 . Its western boundary is a contact with pre-Neoproterozoic crust belonging to the Saharan Metacraton and Congo-Tanzania Craton. Farther south, the ANS is in contact with the Congo-Tanzania Craton and Mozambique Belt. A southeastern ANS margin is recognized as a contact with pre-Neoproterozoic gneiss belonging to a crustal block referred to as Azania. An eastern ANS margin, long a topic of debate, is suspected beneath Phanerozoic cover in central Arabia, and a northwestern margin with late Mesoproterozoic crust is suspected in Sinai.

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Neoproterozoic calc‐alkaline peraluminous granitoids of the Deleihimmi pluton, Central Eastern Desert, Egypt: implications for transition from late‐ to post‐collisional tectonomagmatic evolution in the northern Arabian–Nubian Shield

et al. 2011

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The widely distributed late-collisional calc-alkaline granitoids in the northern Arabian-Nubian Shield (ANS) have a geodynamic interest as they represent significant addition of material into the ANS juvenile crust in a short time interval . The Deleihimmi granitoids in the Egyptian Central Eastern Desert are, therefore, particularly interesting since they form a multiphase pluton composed largely of latecollisional biotite granitoids enclosing granodiorite microgranular enclaves and intruded by leuco-and muscovite granites. Geochemically, different granitoid phases share some features and distinctly vary in others. They display slightly peraluminous (ASI ¼ 1-1.16), non-alkaline (calc-alkaline and highly fractionated calc-alkaline), I-type affinities. Both biotite granitoids and leucogranites show similar rare earth element (REE) patterns [(La/Lu) N ¼ 3.04-2.92 and 1.9-1.14; Eu/Eu Ã ¼ 0.26-0.19 and 0.11-0.08, respectively) and related most likely by closed system crystal fractionation of a common parent. On the other hand, the late phase muscovite granites have distinctive geochemical features typical of rare-metal granites. They are remarkably depleted in Sr and Ba (4-35 and 13-18 ppm, respectively), and enriched in Rb (381-473 ppm) and many rare metals. Moreover, their REE patterns show a tetrad effect (TE 1,3 ¼ 1.13 and 1.29) and pronounced negative Eu anomalies (Eu/Eu Ã ¼ 0.07 and 0.08), implying extensive open system fractionation via fluid-rock interaction during the magmatic stage. Origin of the calc-alkaline granitoids by high degree of partial melting of mafic lower crust with subsequent crystal fractionation is advocated. The broad distribution of late-collisional calc-alkaline granitoids in the northern ANS is related most likely to large areal and intensive lithospheric delamination subsequent to slab break-off and crustal/mantle thickening. Such delamination caused both crustal uplift and partial melting of the remaining mantle lithosphere in response to asthenospheric uprise. The melts produced underplate the lower crust to promote its melting. The presence of microgranular enclaves, resulting from mingling of mantle-derived mafic magma with felsic crustalderived liquid, favours this process. The derivation of the late-phase rare-metal granites by open system fractionation via fluid interaction is almost related to the onset of extension above the rising asthenosphere that results in mantle degassing during the switch to post-collisional stage. Consequently, the switch from late-to post-collisional stage of crustal evolution in the northern ANS could be potentially significant not only geodynamically but also economically.

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Zircon geochronology and Sr, Nd, Pb isotope geochemistry of granitoids from Bayuda Desert and Sabaloka (Sudan): Evidence for a Bayudian event (920–900Ma) preceding the Pan-African orogenic cycle (860–590Ma) at the eastern boundary of the Saharan Metacraton

Cited by 142 publications

References 44 publications

Nd, Pb, and Sr isotope composition of Late Mesozoic to Quaternary intra-plate magmatism in NE-Africa (Sudan, Egypt): high-μ signatures from the mantle lithosphere

Nd, Pb, and Sr isotope composition of Late Mesozoic to Quaternary intra-plate magmatism in NE-Africa (Sudan, Egypt): high-μ signatures from the mantle lithosphere

An Expanding Arabian-Nubian Shield Geochronologic and Isotopic Dataset: Defining Limits and Confirming the Tectonic Setting of a Neoproterozoic Accretionary Orogen

Neoproterozoic calc‐alkaline peraluminous granitoids of the Deleihimmi pluton, Central Eastern Desert, Egypt: implications for transition from late‐ to post‐collisional tectonomagmatic evolution in the northern Arabian–Nubian Shield

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