Tectono-metamorphic evolution of the Wadi Hafafit Culmination (central Eastern Desert, Egypt). Implication for Neoproterozoic core complex exhumation in NE Africa
DOI:
https://doi.org/10.1344/105.000000258Keywords:
Precambrian, Subduction, Metamorphism, Thermobarometry, Radiometric age datingAbstract
The Neoproterozoic rock assemblages in the Wadi Hafafit Culmination (WHC) can be subdivided into two main units which are separated by the Nugrus Thrust. The structurally higher Nugrus unit is mainly composed of low grade micaschists, metavolcanic, serpentinites, and metagabbros. The overthrusted Hafafit unit forms the Hafafit domes and is composed of ortho- and para-gneisses associated with amphibolite and ultramafic rocks. Mineral chemistry and thermobarometry indicate that the WHC was affected by two main metamorphic phases. The first metamorphic phase (M1), observed in the micaschists of the Nugrus unit, is characterized by greenschist- facies conditions. Garnet-biotite and garnet-muscovite geothermometry, as well as temperatures calculated by means of the TWEEQU program yield temperatures of 400°–550°C, whereas the white mica geobarometer reveals pressure of 3.7-4.9 kbar for this metamorphic phase (M1). The second metamorphic phase (M2), observed in gneisses and amphibolites of the Hafafit unit, is characterized by amphibolite-facies conditions. Garnet-biotite, garnet-amphibole and amphibole-plagioclase geothermometry yield temperatures of 600°–750°C, whereas the garnet-hornblende-plagioclase-quartz geobarometer indicates pressures of 6-8 kbar for the second metamorphic phase (M2). Sm-Nd and Rb-Sr whole rock-mineral isochron ages around 590 Ma for gneisses and amphibolites probably represent cooling from the metamorphic thermal peak which was attained around 600 Ma or slightly earlier. A 3-stage geologic evolution model is proposed for the tectonic evolution of the WHC. The first stage started earlier than 680 Ma ago with rifting and ocean floor spreading at a time which is as yet unspecified. It was followed by a second stage of subduction and emplacement of subduction-related granitoids around 620-640 Ma. At this time, the Hafafit region has become an active margin with the production of large amounts of calc-alkaline subduction-related volcanic and plutonic sequences. Subduction was terminated by collision and NW-ward Nugrus Nappe thrusting under greenschist-facies conditions (M1) around 620-640 Ma. At this stage, rocks of Hafafit unit were subjected to intense deformation and metamorphism in amphibolite facies (M2). Next came the third stage of late-orogenic extension and crustal thinning that was controlled by the Najd transform faults (620-580 my) and that resulted in exhumation of the Hafafit domes through a combination of transpression and lateral extrusion.
References
Abd El-Naby, H., Frisch, W., 2002. Origin of Wadi Haimur-Abu Swayel gneiss belt, south Eastern Desert, Egypt: petrological and geochronological constraints. Precambrian Research, 113, 307-332.
Abd El-Naby, H., Frisch, W., 2006. Geochemical constraints from the Hafafit Metamorphic Complex (HMC): evidence of Neoproterozoic back-arc basin development in the central Eastern Desert of Egypt. Journal of African Earth Science, 45, 173-186.
Abd El-Naby, H., Frisch, W., Hegner, E., 2000. Evolution of PanAfrican Wadi Haimur metamorphic sole, Eastern Desert, Egypt. Jounal of Metamorphic Geology, 18, 639-651.
Abdelsalam, M.G., Stern, R.J., 1993. Structure of the late Proterozoic Suture, Sudan. Journal of Geological Society of London, 150, 1065-1074.
Beaumont, C., Jamieson, R.A., Nguyen, M.H., Lee, B., 2001. Mid-crustal channel flow in large hot orogens: results from coupled thermal-mechanical models, in Slave - Northern Cordillera Lithospheric Evolution (SNORCLE) and Cordilleran Tectonics Workshop; Report of 2001 Combined Meeting, Lithoprobe Report, compiled by F. Cook and P. Erdmer, 112-170.
Bennett, J.D., Mosley, P.N., 1987. Tiered-tectonics and evolution, Eastern Desert and Sinai, Egypt. In: Matheis, G., Schandelmeier, H. (eds.). Current research in African earth sciences. Rotterdam, Balkema, 79-82.
Berhe, S.M., 1990. Ophiolites in northeast and east Africa: implications for Proterozoic crustal growth. Journal of Geological Society of London, 147, 41–51.
Berman, R.G., 1991. Thermobarometry using multi-equilibrium calculations: a new technique with petrological applications. Canadian Mineralogists, 29, 833-855.
Bhattacharya, A., Mohanty, L., Maji, A., Sen, S.K., Raith, M., 1992. Non-ideal mixing in the phlogopite-annite binary: constraints from experimental data on Mg-Fe partitioning and a reformulation of the biotite-garnet geothermometer. Contributions to Mineralogy and Petrology, 111, 87-93.
Blasband, B., Brooijmans, P., Dirks, P., Visser, W., White, S., 1997. A Pan-African core complex in the Sinai, Egypt. Geologie en Mijnbouw, 76, 247-266.
Blasband, B., White, S., Brooijmans, P., De Boorder, H., Visser, W., 2000. Late Proterozoic extensional collapse in the Arabian-Nubian Shield. Journal of Geological Society of London, 157, 615–628.
Bucher, K., Frey, M., 1994. Petrogenesis of metamorphic rocks. 6th Edition, Berlin, Springer, 341pp.
Burchfiel, B.C., Royden, L.H., 1985. North-south extension within the convergent Himalayan region. Geology (Boulder), 13(10), 679-682.
Camp, V.E., 1984. Island arcs and their role in the evolution of the western Arabian Shield. Geological Society of America Bulletin, 95, 913-921.
Davidson, C., Grujic, D.E., Hollister, L.S., Schmid, S.M., 1997. Metamorphic reactions related to decompression and synkinematic intrusion of leucogranite, High Himalayan Crystalline, Bhutan. Journal of Metamorphic Geology, 15, 593-612.
Edwards, M.A., Kidd, W.S.F., Li, J., Yue,Y., Clark, M., 1996. Multi-stage development of the southern Tibet detachment system near Khula Kangri. New data from Gonto La. Tectonophysics, 260, 1-19.
El Gaby, S., El Nady, O., and Khudeir, A., 1984. Tectonic evolution of the basement complex in the central Eastern Desert of Egypt. Geologische Rundschau, 73, 1019-1036.
El Gaby, S., List, F. K., and Tehrani, R., 1988. Geology, evolution and metallogenesis of the Pan-African belt in Egypt. In: El Gaby, S., Greiling, R. O. (eds.) The Pan-African belt of northern Africa and adjacent areas. Vieweg, Braunschweig, 17-68.
El Ramly, M. F., Greiling, R., Kröner, A., Rashwan, A. A., 1984. On the tectonic evolution of the Wadi Hafafit area and environs, Eastern Desert of Egypt. Journal of King Abdulaziz University, Earth Sciences, 6, 113-126.
El Ramly, M.F., Greiling, R.O., Rashwan, A.A., Rasmy, A.H., 1993. Explanatory note to accompany the geological and structural maps of Wadi Hafafit area, Eastern Desert of Egypt. Geological Survey of Egypt, Paper No. 68.
Ernst, W.G., 1988. Tectonic history of subduction zones inferred from retrograde blueschist P-T paths. Geology, 16, 1081-1084.
Ferry, J.M., Spear, F.S., 1978. Experimental calibration of the partitioning of Fe and Mg between biotite and garnet. Contributions to Mineralogy and Petrology, 66, 113-117.
Fowler, A., El Kalioubi, B., 2002. The Migif-Hafafit gneissic complex of the Egyptian Eastern Desert: fold interference patterns involving multiply deformed sheath folds. Tectonophysics, 346, 247-275.
Fritz, H., Wallbrecher, E., Khudeir, A.A., Abu El Ela, F., Dallmeyer, R.D., 1996. Formation of Neoproterozoic metamorphic core complexes during oblique convergence (Eastern Desert, Egypt). Journal of African Earth Science, 23, 311–329.
Fritz, H., Dallmeyer, R.D., Wallbrecher, E., Loizenbauer, J., Hoinkes, G., Neumayr, P., Khudeir, A.A., 2002. Neoproterozoic tectonothermal evolution of the central Eastern Desert of Egypt: a slow velocity tectonic process of core complex exhumation. Journal of African Earth Science, 34, 137–155.
Gans, P.B., Mahood, G.A., Schermer, E., 1989. Synextensional magmatism in the Basin and Range Province:A case study from the eastern Great Basin: Geological Society of America, Special Paper 233, 53 pp.
Graham, C.M., Powell, R., 1984. A garnet-hornblende geothermometer: calibration, testing and application to the Pelona Schist, Southern California. Journal of Metamorphic Geology, 2, 13-31.
Greiling, R.O., Kröner, A., El Ramly, M.F., 1984. Structural interference patterns and their origin in the Pan-African basement of the southeastern Desert of Egypt. In: Kröner, A., Greiling, R.O. (eds.). Precambrian tectonics illustrated. Schweizerbart, Stuttgart, Germany, 401-412.
Greiling, R.O., Kröner, A., El Ramly M.F., Rashwan, A.A., 1988. Structural relationships between the southern and central parts of the Eastern Desert of Egypt: details of a fold and thrust belt. In: El-Gaby, S., Greiling, R.O. (eds.). The Pan-African belt of Northeast Africa and adjacent areas. Germany, Vieweg publisher, Wiesbaden-Braunschweig, 121-146.
Greiling, R.O., Abdeen, M.M., Dardir, A.A., El Akhal, H., El Ramly, M.F., Kamal El Din, G.M., Osman, A.F., Rashwan, A.A., Rice, A.H.N., Sadek, M.F., 1994. A structural synthesis of the proterozoic Arabian –Nubian shield in Egypt. Geologisches Rundschau, 83, 484-501.
Guidotti, C.V., Sassi, F.P., 1976. Muscovite as a petrogenetic indicator mineral in pelitic schists. Neues Jahrbuch für Mineralogie, 127, 97-142.
Hashad, A.H., Sayyah, T.A., El Manharawy, M.S., 1981. Isotopic composition of strontium and origin of Wadi Kareim volcanics, Eastern Desert. Egyptian Journal of Geology, 25, 141-147.
Hey, M.A., 1954. A review of the chlorites. Mineralogical Magazine, 30, 277-292.
Hodges, K.V., Spear, F.S., 1982. Geothermometry, geobarometry and the Al2SiO5 triple point at Mt. Moosilauke, New Hampshire. American Mineralogist, 67, 1118-1134.
Holland, T.J.B., Blundy, J., 1994. Non-ideal interactions in calcic amphiboles and their bearing on amphibole-plagioclase thermometry. Contributions to Mineralogy and Petrology, 116, 433–447.
Hynes, A., Forest, R.C., 1988. Empirical garnet-muscovite geothermometry in low-grade metapelites, Selwyn range (Canadian Rockies). Journal of Metamorphic Geology, 6, 297-309.
Johnson, P.R., Vranas, G.J., 1984. The origin and development of Late Proterozoic rocks of the Arabian Shield. DGMR. Jeddah Open-File Report, 4-32.
Kleemann, J., Reinhardt, J., 1994. Garnet-biotite thermometry revisited: The effect of Al(VI) and Ti in biotite. European Journal of Mineralogy, 6, 925-941.
Kohn, M.J., Spear, F.S., 1990. Two new geobarometers for garnet amphibolites, with applications to southern Vermont. American Mineralogist, 75, 89-96.
Kretz, R., 1983. Symbols for rock-forming minerals. American Mineralogist, 68, 277–279.
Kröner, A., Todt, W., Hussein, I.M., Mansour, M., Rashwan, A.A., 1992. Dating of late Proterozoic ophiolites in Egypt and Sudan using the single grain zircon evaporation technique, Precambrian Research, 59, 15-32.
Leake, B.E., Woolley, A.R., Arps, C.E.S., Birch, W.D., Gilbert, M.C., Grice, J.D., Hawthorne, F.C., Kato, A., Kisch, H.J., Krivovichev, V.G., Linthout, K., Laird, J., Mandarino, J.A., Maresch, W.V., Nickel, E.H., Rock, N.M.S., Schumacher, J.C., Smith, D.C., Stephenson, N.C.N., Ungaretti, L., Whittaker, E.J.W., Youzhi, G., 1997. Nomenclature of amphiboles: Report of the Subcommittee on Amphiboles of the International Mineralogical Association, Commission on New Minerals and Mineral Names. Mineralogical Magazine, 61, 295–321.
Liew, T.C. Hofmann, A.W., 1988. Precambrian crustal components, plutonic associations, plate environment of the Hercynian fold belt of central Europe: Indications from an Nd and Sr isotopic study. Contrib. Mineral. Petrol., 98, 129-138.
Lister, G.S., Baldwin S.L., 1993. Plutonism and the origin of metamorphic core complexes. Geology, 21, 607-610.
Loizenbauer, J., Wallbrecher, E., Fritz, H., 1999. The Deformation History of the Meatiq Metamorphic Core Complex, Eastern Desert, Egypt: Constraints on Geochronology, Structural Analyses and Fluid Inclusion Studies. Journal of Conference Abstracts, 4(1), Session A05:5A, p. 1.
Loizenbauer, L., Wallbrecher, E., Fritz, H., Neumayr, P., Khudeir, A.A., Kloetzli, U., 2001. Structural Geology, single zircon ages and fluid inclusion studies of the Meatiq metamorphic core complex: Implications for Neoproterozoic tectonics in the Eastern Desert of Egypt. Precambrian Research, 110, 357-383.
Mancktelow, N.S., 1995. Nonlithostatic pressure during sediment subduction and the development and exhumation of high pressure metamorphic rocks. Journal of Geophysical Research, 100, 571-583.
Massonne, H.J., Schreyer, W., 1987. Phengite geobarometry based on the limiting assemblage with K-feldspar, phlogopite and quartz. Contributions to Mineralogy and Petrology, 96, 212-224.
Mezger, K., Essene, E.J., Halliday, A.N., 1992. Closure temperature of the Sm/Nd system in metamorphic garnets. Earth Planetary Science Letter, 113, 397-409.
Moghazi, A.M., Hassanen, M.A., Mohamed, F.H., Ali, S., 2004. Late Neoproterozoic strongly peraluminous leucogranites, South Eastern desert, Egypt: petrogenesis and geodynamic significance. Mineralogy and Petrology, 81, 19-41.
Neumayr, P., Mogessie, A., Hoinkes, G., Puhl, J., 1996. Geological setting of the Meatiq metamorphic core complex in the Eastern Desert of Egypt based on amphibolite geochemistry. Journal of African Earth Science, 23, 331-345.
Neumayr, P., Hoinkes, G., Puhl, J., Mogessie, A., Khudier, A.A., 1998. The Meatiq dome (Eastern Desert, Egypt) a Precambrian metamorphic core complex: petrological and geological evidence. Journal of Metamorphic Geology, 16, 259-279.
Stern, R.J., Hedge, C.E., 1985. Geochronologic and isotopic constraints on Late Precambrian crustal evolution in the Eastern Desert of Egypt. American Journal of Sciences, 285, 97-127.
Stern, R.J., 1985. The Najd Fault System, Saudi Arabia and Egypt: a late Precambrian rift related transform system? Tectonics, 4, 497-511.
Stoeser, D.B., Camp, V.E., 1985. Pan-African microplate accretion of the Arabian Shield. Geological Society of America Bulletin, 96, 817-826
Velde, B., 1967. Si4+ content of natural phengites. Contributions to Mineralogy and Petrology, 17, 250-258.
Wendt, I., 1986. Radiometrische Methoden in der Geochronologie. Clausthaler Tektonische Hefte 23, Pilger, Clausthal Zellerfeld, 170 pp.
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