Geological and Tectonic Setting of the Kamoreib Metavolcanics, Southern Hamisana Area, Red Sea Hills, NE Sudan
Musab A. Eljah, Faculty of Petroleum and Minerals, Al Neelain University, Khartoum, Sudan.
Esamaldeen Ali, Faculty of Petroleum and Minerals, Al Neelain University, Khartoum, Sudan.
Abdalla E. M. Elsheikh, Faculty of Petroleum and Minerals, Al Neelain University, Khartoum, Sudan.
Khalid A. Elsayed Zeinelabdein, Faculty of Petroleum and Minerals, Al Neelain University, Khartoum, Sudan.
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 acid 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 calc-alkaline geochemical affinity. The rocks were generated above a belt of subduction zone that is later affected by the HSZ. The geographic distribution of the metavolcanics supported by the geochemical analysis present a perspective for constraining subduction polarity of the Kamoreib volcanic arc. The outcome of the present investigation revealed that the Kamoreib volcanics were formed over a northwesterly-dipping subduction zone.
Tectonic Setting, Petrography, Geochemistry, Metavolcanics, Hamisana, Red Sea Hills, Sudan
Kröner, A., Greiling, R. O., Reischmann, T., Hussein, I. M., Stern, R. J., Durr, St., Kruger, J. and Zimmer, M., 1987. Pan-African crustal evolution in north-east Africa. In: Proterozoic Lithospheric Evolution. American Geophysical Union, Geodynamic Series 17 (Edited by Kroner, A,) 235-257.
Stern, R.J., 1994. Arc assembly and continental collision in the Neoproterozoic East African Orogeny: implication for the consolidation of Gondwanaland. Annual Review, Earth Planetary Science. 22/ 319-351.
Stern, R.J., Kroner, A., Manton, W.I., Reischmann, T., Mansour, M. and Hussein, I.M., 1989.Geochronology of the late Precambrian Hamisana shear zone, Red SeaHills, Sudan and Egypt.Journal geological society London 146, 1017-1030.
Abdelrahman E.M., 1993. Geochemical and geotectonic controls of the metallogenic evolution of selected ophiolite complexes from the Sudan: Berliner Geowissenschaftliche Abhandlungen, Reihe A, v. 145,175.
Vail, J. R., 1985. Pan-African (late Precambrian) tectonic terrains and the reconstruction of the Arabian-Nubian Shield.-Geology, 13, 839-842, Boulder.
Fitches, W.R., Graham, R.H., Hussein, I.M., Ries, A.C., Shackelton, R.M.and Price, R.C., 1983. The late ophiolite of Sol Hamed, NE Sudan. Precambrian Res., 19, 385-411.
Hussein, I. M., Kröner, A. and Durr, St., 1984. Wadi Onib-a dismembered Pan- African ophiolite in the Red Sea Hills of Sudan. Bull. Fac. Earth Sci., King Abdulaziz Univ., Jeddah, 6, 319-327.
Almond, D. C., Ahmed, F. and Dawoud, A. S., 1984. Tectonic, metamorphic and magmatic styles in the north Red Sea Hills of Sudan. Faculty Earth Science Bulletin, King Abdulaziz University Jeddah 6, 449-548.
Vail, J. R., 1982. Distribution and tectonic setting of post-kinematic igneous complexes in the Red Sea Hills of Sudan and the Arabian –Nubian Shield. Precamb. Res. Abs., 16, 4, A41.
El Nadi, A. H., 1984. The geology of the late Precambrian metavolcanics, Red Sea Hills, northeast Sudan. Ph. D. Thesis, University of Nottingham.
Richard, L.R., 1995. Mineralogical and petrological data processing system. Minpet Software (C), 1988-1985, Version 2.02.
Garcia, M.O., 1978. Criteria for the identification of ancient volcanic areas.Earth Sci. Rev., 14, 147-165.
Irvine, T.N. and Baragar, W.R.A., 1971. A guide to the chemical classification of the common volcanic rocks. Its impilication for the geodynamic evolution of the eastern Alps. Can. J. Earth Sci., 8, 523–548. Geol. Res, 77, 641-670.
Saunders, A.D. and Tarney, J., 1984. Geochemical characteristic of basaltic volcanism within back-arc basins. In: Kokelaar, B.P and Howells, M.F.(eds.). Marginal basin geology, Spec. Publ. Geol. Soc. London, 16, 59-76.
Pearce, J.A. and Gale, G.H., 1977. Identification of ore-depositionenvironment from trace element geochemistry of associated igneoushost rocks. Geol. Soc. Spec. Publ., 7, 14-24.
Müller, D., Franz, L., Herzig, P. M. and Hunt, S., 2001. Potassic igneous rocks from the vicinity of epithermal gold mineralization, Lihir Island, Papua New Guinea. Lithos 75: 163-186
Pearce, J.A., 1980. Geochemical evidence for the genesis and the eruptivesetting of lavas from Tethyan ophiolites. Proc.Int. Ophiolite Symp, Cyprus, 261-72.
Tatsumi, Y., Sakuyama, M., Fukuyama, H., Kushiro, I., 1983. Generation of arc basalt magmas and thermal structure of mantle wedge in subduction zones (Japan arc). Journal of Geophysical Research, 88, 5815-5825.
Miyashiro, A. and Shido, F., 1980. Differentiation of gabbros in the Mid-Atlantic ridgenear 24" N.-Geochem. J., 14, 145- 154, Amsterdam
Abdelsalam, M.G. and Stern, R.J., 1993. Tectonic evolution of the Nakasib suture, Red Sea Hills, Sudan: evidence for a late Precambrian Wilson Cycle. Journal of the Geological Society, London, Vol. 1150, pp. 393-404.
Schandelmeier, H., Abdelrahman, E.M., Wipfler, E., Kuster, D., Utke, A. and Matheis, G., 1994. Late Proterozoic magmatism in the Nakasib suture, Red Sea Hills, Sudan. Journal ofthe Geological Society, London, Vol. 151, pp. 485-497.
Bevins, R.E., Kokelaar, B.P. and Dunkley, P.N., 1984. Petrology andgeochemistry of lower to middle Ordovician igneous rocks in Wales: avolcanic arc to marginal basin transition. Proc. Geol. Ass., 95, 337-347.