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    Geochemistry and Tectonic Setting of Cretaceous Sediments from Al Bauga Area, Bayuda Desert, River Nile State, Sudan
    (2015-02) Elzien, Hamed, B.O S.M.; Farah, Al-Imam, O.A.O A.A; Mohamed, Kheiralla. K.M A. A; Hussein, A.H
    Geochemistry; major and trace elements of Al Bauga sediments have been investigated to understand their provenance and tectonic setting. The tectonic discriminant diagrams placed the majority of Al Bauga sediments within the passive margin setting. These sediments generally, are enrich in SiO2 and depleted in K2O and Na2O. The discriminant function diagram of major elements, the enrichment of Zr, Th, La and lack of V, Co and Ni indicate that the source area of most of Al Bauga sediments are felsic provenance.
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    Hydro-geochemical Signature in the Thermal Waters in Jebel Mara, Darfur Region Western Sudan
    (OMICS Publishing Group, 2013-03-01) SM Elzien, SH Mohamed; KM K Keiralla, OA Attaj; HA Hussein
    Hydrochemical investigations, which are significant for the assessment of water quality, have been carried out to study the sources of dissolved ions in hot springs water of some part of Jebel Mara mountain, Darfur region, Sudan. The temperature of hot springs water was varies from 50°C to 60°C. Samples collected from hot springs near Koronga village at Jebel Mara, were analyzed for major solutes and trace elements as part of larger study to characterize the geochemical signature of these ground waters. In these study, four major cations (Ca++, Mg++, Na+ and K+), three major anions (Cl-, SO4 2- and HCO3) and some trace elements (Mn, Zn, Pb, Fe and P) were analyzed in these ground water samples. This study reveals that most waters taken from hot springs has high values of Hydrogen ion concentration (pH) , high values of electrical conductivity (E.C), and high concentrations of total hardness (T.H), total dissolved solids (T.D.S) , bicarbonates (HCO3), sodium (Na+) and Magnesium (Mg++). All these high values of pH, T.D.S, T.H, Na and HCO3 are mainly due to dissolution of these ions from rock bearing minerals of the study area. Normal values of trace elements like Iron (Fe), Copper (Cu), Lead (Pb), Iodine (I) and Zinc (Zn) whereas, high concentrations of Manganese (Mn). The study classified hot springs waters as Calcium-Magnesium-Sodium Bicarbonate type. Using USDA classification, water has been classified as C2 S1 (medium conductivity-salinity and low sodium content). The discharge values of hot springs measured to be between 1-2 L/S for all hot springs near Koronga village. The thermal waters are associated with Tertiary basalt and heat for these thermal waters is obtained during deep circulation in fracture basalt and is related to volcanic or tectonic activity. This study suggested that the geothermal waters of Jebel Mara area are of meteoric origin. Hot springs waters (thermal water) have also been used for medical therapy.
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    Kamoreib Metavolcanic Rocks: A key to understand the Tectonic Evolution of the Southern Hamisana Shear Zone, Red Sea Hills, NE Sudan
    (Graduate College - Alneelain university, 2017-09-01) Musab A. Eljah, Esamaldeen Ali; Abdalla E. M. Elsheikh, Khalid A. Elsayed Zeinelabdein
    The Kamoreib area lies in the southern part of the Hamisana Shear Zone (HSZ), within the Nubian Shield as a transitional area between Gabeit and Gabgaba terrains. The tectonic setting of this area is relatively poorly understood. Therefore, the present investigation is concerned mainly with the geological and tectonic setting of the metavolcanic group at Kamoreib area as a key to the recognition and understanding of the tectonic setting of the southern Hamisana area through petrographic and geochemical analysis. Detailed geological mapping based on interpretation of enhanced satellite image, field observation and petrographic investigations revealed that the mapped area is built up of metavolcanic assemblage ranging from basic to acidic in composition. The metavolcanics include porphyritic dacite, amygdaloidal andesite, andesite, rhyolite and basalt, intercalated with tuffaceous materials. These rocks are highly sheared, hydrothermally altered and regionally metamorphosed to greenschist facies. Petrographic and geochemical analysis revealed that the metavolcanics represent a mature island arc environment, which is characterized by calcalkaline geochemical affinity. The outcome of the present investigations revealed that the geographic distribution of the metavolcanics supported by the geochemical analysis present a perspective for constraining subduction polarity of the Kamoreib volcanic arc that were formed over a northwesterly-dipping subduction zone which is later affected by the HSZ
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    New ophiolite occurrences in Sudan and constraint on the western boundary of the Nubian Shield: Petrographical and geochemical evidence
    (Elsevier Ltd, 2010-07) E.A. Ali, E.M. Abdel Rahman
    Important mafic–ultramafic masses have been located for the first time in the intersection area between the Keraf Shear Zone and the Nakasib Suture Zone of the Nubian Shield. The masses, comprising most of the members of the ophiolite suite, are Sotrebab and Qurun complexes east of the Nile, and Fadllab complex west of the Nile. The new mafic–ultramafic masses are located on the same trend of the ophiolitic masses decorating the Nakasib Suture. A typical complete ophiolite sequence has not been observed in these complexes, nevertheless, the mafic–ultramafic rocks comprise basal unit of serpentinite and talc chlorite schists overlain by a thick cumulate facies of peridotites, pyroxenites and layered gabbros overlain by basaltic pillow lavas with dolerite dykes and screens of massive gabbros. Associated with pillow lavas are thin layers of carbonates and chert. The best section of cumulate mafic–ultramafic units has been observed in Jebel Qurun and El Fadlab complexes, comprising peridotites, pyroxenites and layered gabbros. Dolerite dykes and screens of massive gabbros have been observed with basaltic pillow lava sections in Wadi Dar Tawaiy. The basal ultramafic units of the complexes have been fully or partly retrograded to chlorite magnetite schist and talc to talc-carbonate rocks (listowenites), especially in the Jebel Qurun and Sotrebab complexes. Petrographically, the gabbros (layered and massive) and the basaltic pillow lavas show mineral assemblages of epidote amphibolite facies. The mafic members from the three complexes show a clear tholeiitic trend and oceanic floor affinity. The pillow lavas plot in the field of oceanic floor basalt, namely in the back arc field. Primitive mantle normalized spider diagram of the pillow lavas reveals a closer correspondence to Enrich-Mid-Oceanic Ridge Basalt (E-MORB) type, which is confirmed by the flat chondrite normalized Rare Earth Elements (REE) pattern. Field, petrographical and geochemical evidence supports ophiolitic origin of the three complexes. The newly discovered ophiolitic complexes mark the western continuation of the Nakasib Suture Zone.