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The texture and composition of tourmaline in metasediments of the Sinai, Egypt: Implications for the tectono-metamorphic evolution of the Pan-African basement

Published online by Cambridge University Press:  05 July 2018

M. M. Abu El-Enen*
Affiliation:
Department of Geology, Faculty of Science, El Mansoura University, El Mansoura 35516, Egypt
M. Okrusch
Affiliation:
Mineralogisches Institut, Universität Würzburg, Am Hubland, D-97074, Würzburg, Germany

Abstract

Accessory tourmaline in metasediments from the Sinai crystalline basement exhibits textural and chemical signatures that relate to the evolution of regional metamorphism and deformation during the Pan-African orogeny and testifies to different P-T path segments. Tourmaline inclusions in various porphyroblasts were formed during the prograde phase of metamorphism; acicular to prismatic crystals in the matrix, oriented sub-parallel to, and enveloped by, the main foliation crystallized syntectonically under prograde and peak metamorphic conditions; tourmaline cross-cutting the main foliation may have formed just after the peak or during the retrograde phase of metamorphism. Some of the cores in tourmaline crystals, showing different colours, are interpreted as former detrital grains. The abundance of tourmaline decreases with increasing peak metamorphic conditions. The tourmaline investigated belongs to the schorl-dravitess group, generally with XMg of 0.42–0.73 and XCa = Ca/(Ca+Na+K+□) of 0.02–0.24, typical of tourmalines in metapelites and metapsammites; whereas detrital cores have been derived from various sources, including former tourmaline-quartz and pre-existing high-metamorphic rocks. Tourmaline of the Sinai metasediments was formed during metamorphism of the sedimentary precursors, essentially in a closed system, where clay minerals and organic matter, together with detrital tourmaline, served as the source of boron. Although a metamorphic facies should be defined by characteristic mineral assemblages present in metamorphic rocks, tourmaline chemistry is a good monitor of P-T conditions in the metapelites and semi-metapelites investigated, showing an increase in XMg with increasing metamorphic grade, where XturMg = 0.60 distinguishes between greenschist and lower-amphibolite facies, while XturMg = 0.65 could distinguish lower- from middle- to upper-amphibolite facies. The results of tourmaline-biotite geothermometry compare well with our former temperature estimates using conventional geothermometry and phase-diagram modelling.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2007

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References

Abd El-Shakour, Z.A. (2005) Metamorphic evolution of migmatites from Sinai, Egypt . Unpublished MSc thesis, University of El Mansoura, Egypt, 135 pp.Google Scholar
Abu El-Enen, M.M. (1995) Geological, geochemical and mineralogical studies on the metamorphic rocks between Wadi Umm-Maghra and Wadi Tweiba, SE Sinai, Egypt . Unpublished PhD thesis, University of El Mansoura, Egypt, 172 pp.Google Scholar
Abu El-Enen, M.M. and Makroum, F.M. (2003) Tectonometamorphic evolution of the northeastern Kid complex, SE Sinai, Egypt. Annals of the Geological Survey of Egypt, 26, 19–37.Google Scholar
Abu El-Enen, M.M., Zalata, A.A., El-Metwally, A.A. and Okrusch, M. (1999) Orthogneisses from the Taba metamorphic complex, SE Sinai, Egypt: Witnesses for granitoid magmatism at an active continental margin. Neues Jahrbuch für Mineralogie Abhandlungen, 175, 53–81.CrossRefGoogle Scholar
Abu El-Enen, M.M., Okrusch, M. and Will, T.M. (2003) Metapelite assemblages in the Umm Zariq schists, central western Kid Complex, Sinai Peninsula, Egypt. Neues Jahrbuch für Mineralogie Abhandlungen, 178, 277–306.CrossRefGoogle Scholar
Abu El-Enen, M.M., Will, T.M. and Okrusch, M. (2004) P-T evolution of the Taba metamorphic complex, Egypt: Constraints from the metapelite assemblages. Journal of African Earth Sciences, 38, 59–78.CrossRefGoogle Scholar
Bhattacharya, A., Mazumdar, A.C. and Sen, S.K. (1988) Fe-Mgmixingin cordierite: Constraints from natural data and implications for cordierite-garnet thermometry in granulites. American Mineralogist, 73, 338–344.Google Scholar
Bröcker, M. and Franz, L. (2000) The contact aureole on Tinos (Cyclades, Greece): tourmaline-biotite geothermometry and Rb-Sr geochronology. Mineralogy and Petrology, 70, 257–283.Google Scholar
Brooijmans, P., Blasband, B., White, S.H., Visser, W.J. and Dirks, P. (2003) Geothermobarometric evidence for a metamorphic core complex in Sinai, Egypt. Precambrian Research, 123, 249–268.CrossRefGoogle Scholar
Colopietro, M.R. and Friberg, L.M. (1987) Tourmaline-biotite as a potential geothermometer for metape-lites; Black Hills, South Dakota. Geological Society of America Abstracts with Programs , 19(7), p. 624.Google Scholar
Cosca, M.A., Shimron, A. and Caby, R. (1999) Late Precambrian metamorphism and coolingin the Arabian-Nubian Shield: Petrology and 40Ar/39Ar geochronology of metamorphic rocks of the Elat area (southern Israel). Precambrian Research, 98, 107–127.CrossRefGoogle Scholar
Dietrich, R.V. (1985) The Tourmaline Group . Van Nostrand Reinhold Co., New York, 300 pp.CrossRefGoogle Scholar
Dixon, T.H. and Golombek, M.P. (1988) Late Precambrian crustal accretion rates in northeast Africa and Arabia. Geology, 16, 991–994.2.3.CO;2>CrossRefGoogle Scholar
Dutrow, B.L. and Henry, D.J. (2000) Complexly zoned fibrous tourmaline, Cruzeiro mine, Minas Gerais, Brazil: A record of evolvingmag matic and hydrothermal fluid. The Canadian Mineralogist, 38, 131–143.CrossRefGoogle Scholar
Dutrow, B.L., Foster Jr, C.T. and Henry, D.J. (1999) Tourmaline-rich pseudomorphs in sillimanite zone metapelites: Demarcation of an infiltration front. American Mineralogist, 84, 794–805.CrossRefGoogle Scholar
Dyar, M.D., Guidotti, C.V., Core, D.P., Wearn, K.M., Wise, M.A., Francis, C.A., Johnson, K., Brady, J.B., Robertson, J.D. and Cross, L.R. (1999) Stable isotopes and crystal chemistry of tourmaline across pegmatite – country rock boundaries at Black Mountain and Mount Mica, southwestern Maine, U.S.A. European Journal of Mineralogy, 11, 281–292.CrossRefGoogle Scholar
El-Gaby, S. and Ahmed, A.A. (1980) The Feiran-Solaf gneiss complex, SW of Sinai. Pp. 95–105 in: Evolution and Mineralization of the Arabian-Nubian Shield (Coory, P.G. and Tahoun, S.A., editors). Institute of Applied Geology (Jeddah, Saudi Arabia), 4.Google Scholar
El-Shafei, M.K. and Kusky, T.M. (2003) Structural and tectonic evolution of the Neoproterozoic Feiran-Solaf metamorphic complex, Sinai Peninsula: Implication for the closure of Mozambique Ocean. Precambrian Research, 123, 269–293.CrossRefGoogle Scholar
El-Tokhi, M. (1990) Petrological, geochemical and experimental studies on migmatite rocks of Feiran area, S. Sinai, Egypt . Unpublished PhD thesis, Karlsruhe, Germany, 98 pp.Google Scholar
Eyal, Y. (1980) The geological history of the Precambrian rocks between Wadi Tweiba and Wadi Um-Mara, NE Sinai. Israel Journal of Earth Science, 29, 53–66.Google Scholar
fürnes, H., Shimron, A.E. and Roberts, D. (1985) Geochemistry of volcanic arc sequences in the southeastern Sinai Peninsula and plate tectonic implication. Precambrian Research, 29, 359–382.CrossRefGoogle Scholar
Gieré, R. (2001) Geochemical and tectonic significance of tourmaline rich metasedimentary rocks in the central Alps. Geological Society of America, Abstracts with Program, 33.Google Scholar
Grew, E.S. (1996) Borosilicates (exclusive tourmaline) and boron in rock-formingminerals in metamorphic environments. Pp. 387–502 in: Boron: Mineralogy, Petrology, and Geochemistry (Grew, E.S. and Anovitz, L.M., editors). Reviews in Mineralogy, 33, Mineralogical Society of America, Washington, D.C. Google Scholar
Grice, J.D. and Ercit, T.S. (1993) Orderingof Fe and Mg in tourmaline crystal structure: The correct formula. Neues Jahrbuch für Mineralogie Abhandlungen, 165, 245–366.Google Scholar
Harraz, H.Z. and El-Sharkawy, M.F. (2001) Origin of tourmaline in metamorphosed Sikait pelitic complex, south Eastern Desert, Egypt. Journal of African Earth Sciences, 33, 391–416.CrossRefGoogle Scholar
Hashad, M.H. (2001) Chemical characteristics and genesis of Wadi Sikait tourmaline. Egyptian Mineralogist, 13, 1–26.Google Scholar
Hawthorne, F.C. and Henry, D.J. (1999) Classification of the minerals of the tourmaline group. European Journal of Mineralogy, 11, 201–215.CrossRefGoogle Scholar
Henry, D.J. (2003) Tourmaline as a geochemical tape recorder in metamorphic rocks. Geological Society of America, Abstracts with Program , 35 (6), p. 397.Google Scholar
Henry, D.J. and Guidotti, C.V. (1985) Tourmaline as a petrogenetic indicator mineral: an example from the staurolite-grade metapelites of NW Maine. American Mineralogist, 70, 1–15.Google Scholar
Henry, D.J. and Dutrow, B.L. (1990) Ca-substitution in Li-poor aluminous tourmaline. The Canadian Mineralogist, 28, 111–124.Google Scholar
Henry, D.J. and Dutrow, B.L. (1992) Tourmaline in a low grade clastic metasedimentary rock: an example of the petrogenetic potential of tourmaline. Contributions to Mineralogy and Petrology, 112, 203–218.CrossRefGoogle Scholar
Henry, D.J. and Dutrow, B.L. (1996) Metamorphic tourmaline and its petrologic application. Pp. 503–557 in Boron: Mineralogy, Petrology, and Geochemistry (Grew, E.S. and Anovitz, L.M., editors). Reviews in Mineralogy, 33, Mineralogical Society of America, Washington, D.C. Google Scholar
Henry, D.J., Dutrow, B.L. and Selverstone, J. (2002) Compositional polarity in replacement tourmaline – an example from the Tauern Window, Eastern Alps. Geological Materials Research, 4, 23 pp.Google Scholar
Hodges, K.V. and Spear, F.S. (1982) Geothermometry, geobarometry and the Al2SiO5 triple point at Mt. Moosilake, New Hampshire. American Mineralogist , 67, 1118–1134.Google Scholar
Hoisch, D.T. (1990) Experimental calibrations of six geobarometers for the mineral assemblage quartz + muscovite + biotite + plagioclase + garnet. Contributions to Mineralogy and Petrology, 104, 225–234.CrossRefGoogle Scholar
Holland, T.J.B. and Powell, R. (1998) An internally consistent thermodynamic data set for phases of petrological interest. Journal of Metamorphic Geology, 16, 309–343.Google Scholar
Kawakami, I. (2001) Tourmaline breakdown in the migmatite zone of the Ryoke metamorphic complex, SW Japan. Journal of Metamorphic Geology, 19, 61–75.CrossRefGoogle Scholar
Kawakami, T. and Ikeda, T. (2003) Boron in metapelites controlled by the breakdown of tourmaline and retrograde formation of borosilicates in the Yanai area, Ryoke metamorphic complex, SW Japan. Contributions to Mineralogy and Petrology, 145, 131–150.CrossRefGoogle Scholar
Kleemann, U. and Reinhardt, J. (1994) Garnet-biotite thermometry revisited: The effect of AlVI and Ti in biotite. European Journal of Mineralogy, 6, 925–941.CrossRefGoogle Scholar
Kretz, R. (1883) Symbols for rock formingminerals. American Mineralogist, 68, 277–279.Google Scholar
Kröner, A., Greiling, R., Reischmann, T., Hussein, I.M., Stern, R.J., Dürr, S. and Zimmer, M. (1987) Pan African crustal evolution in the segment of northern Africa. Pp. 235–257 in: Proterozoic Lithosphere Evolution (Kröner, A., editor). International Lithosphere Program Publication, 130. American Geophysical Union, Geodynamic Series 17. Washington, D.C. CrossRefGoogle Scholar
Krynine, P.D. (1946) The tourmaline group in sediments. Journal of Geology, 54, 65–87.CrossRefGoogle Scholar
Michailidis, K., Kassoli-Fournaraki, A. and Dietrich, R.V. (1996) Origin of zoned tourmalines in graphite-rich metasedimentary rocks from Macedonia, northern Greece. European Journal of Mineralogy, 8, 393–404.CrossRefGoogle Scholar
Moran, A.E., Sisson, V.B. and Leeman, W.P. (1992) Boron in subducted oceanic crust and sediments: Effects of metamorphism and implications for arc magma compositions. Earth and Planetary Science Letters, 111, 331–349.Google Scholar
Morgan VI, G.B. and London, D. (1999) Crystallization of the Little Three layered pegmatite-aplite dike, Ramona District, California. Contributions to Mineralogy and Petrology, 136, 310–330.CrossRefGoogle Scholar
Navon, O. and Reymer, A.P.S. (1984) Stratigraphy, structures and metamorphism of Pan-African age in central Kid, southeastern Sinai. Israel Journal of Earth Science, 33, 135–149.Google Scholar
Novák, M., Selway, J.B., Černý, P., Hawthorne, C. and Ottolini, L. (1999) Tourmaline of the elbaite-dravite series from an elbaite-subtype pegmatite at Blizˇna, southern Bohemia, Czech Republic. European Journal of Mineralogy, 11, 557–568.CrossRefGoogle Scholar
Pesquera, A. and Velasco, F. (1997) Mineralogy, geochemistry and geological significance of tourmaline-rich rocks from the Paleozoic Cino Villas massif (western Pyrenees, Spain). Contributions to Mineralogy and Petrology, 129, 53–74.CrossRefGoogle Scholar
Reymer, A.P.S., Matthews, A. and Navon, O. (1984) Pressure-temperature conditions in the Wadi Kid metamorphic complex: implications for the Pan-African event in SE Sinai. Contributions to Mineralogy and Petrology, 85, 336–345.CrossRefGoogle Scholar
Rog ers, J.J.W., Unrug, R. and Sultan, M. (1995) Tectonic assembly of Gondwana. Journal of Geodynamics, 19, 1–34.Google Scholar
Selway, J.B., Novák, M., Černý, P. and Hawthorne, F.C. (1999) Compositional evolution of tourmaline in lepidolite-subtype pegmatites. European Journal of Mineralogy, 11, 569–584.CrossRefGoogle Scholar
Shackleton, R.M. (1986) Precambrian collision tectonics in Africa. Pp. 329–349 in: Collision Tectonics (Coward, M.P. and Reis, A.C., editors). Special Publication 19, Geological Society, London.Google Scholar
Shackleton, R.M. (1996) The final collision zone between East and West Gondwana: where is it? Journal of African Earth Sciences , 23, 271–287.CrossRefGoogle Scholar
Shimron, A.E and Zwart, H.J (1970) The occurrence of low-pressure metamorphism in the Precambrian of the middle-east and northeast Africa. Geologie en Mijnbouw, 45, 369–374.Google Scholar
Shimron, A.E. (1980) Proterozoic island arc volcanism and sedimentation in Sinai. Precambrian Research, 12, 437–458.CrossRefGoogle Scholar
Shimron, A.E. (1984) Evolution of the Kid Group, southeast Sinai Peninsula: thrusts, mélanges and implication for accretionary tectonics duringthe Late Proterozoic of the Arabian-Nubian Shield. Geology, 12, 242–247.2.0.CO;2>CrossRefGoogle Scholar
Slack, J.F. and Coad, P.R. (1989) Multiple hydrothermal and metamorphic events in the Kidd Creek volcanogenic massive sulfide deposits, Timmins, Ontario: Evidence from tourmaline and chlorites. Canadian Journal of Earth Sciences, 26, 694–715.CrossRefGoogle Scholar
Sperlich, R. (1990) Zoning and crystal chemistry of tourmalines in prograde metamorphic sequences of the Central Alps . Unpublished PhD thesis, University of Basel, Switzerland (not seen).Google Scholar
Sperlich, R., Gieré, R. and Frey, M. (1996) Evolution of compositional polarity and zoningin tourmaline duringprog rade metamorphism of sedimentary rocks in the Swiss Central Alps. American Mineralogist, 81, 1223–1236.CrossRefGoogle Scholar
Stern, R.J. (1994) Arc assembly and continental collision in the Neoproterozoic East African Orogen: implications for consolidation of Gondwanaland. Annual Reviews in Earth and Planetary Sciences , 23, 319–351.Google Scholar
Stern, R.J. (2002) Crustal evolution in the East African Orogen: a neodymium isotopic perspective. Journal of African Earth Sciences, 34, 109–117.CrossRefGoogle Scholar
Teklay, M., Kröner, A., Mezger, K. and Oberhänsli, R. (1998) Geochemistry, Pb-Pb single zircon ages and Nd-Sr isotope composition of Precambrian rocks from southern and eastern Ethiopia: implications for crustal evolution in East Africa. Journal of African Earth Sciences, 26, 207–227.CrossRefGoogle Scholar
Van den Bleeken, G., Corteel, C. and Van den Haute, P. (2007) Epigenetic to low-grade tourmaline in the Gdoumont metaconglomerates (Belgium): A sensitive probe of its chemical environment of formation. Lithos, 95, 165–176.CrossRefGoogle Scholar
Weaver, C.E. and Broekstra, B.R. (1984) Illite-mica. Pp. 67–199 in: Shale Slate Metamorphism in Southern Appalachians (Weaver, C.E. et al., editors). Elsevier, Amsterdam.Google Scholar
Yu, J.M. and Jiang, S.Y. (2003) Chemical composition of tourmaline from the Yunlongtin deposits, Yunnan, China: Implication for ore genesis and mineral exploration. Mineralogy and Petrology, 77, 67–84.CrossRefGoogle Scholar
Zen, E.-An. (1981) Metamorphic mineral assemblages of slightly calcic pelitic rocks in and around the Taconic Allochthon, southwestern Massachusetts and adjacent Connecticut and New York. US Geological, Survey , Professional Paper, 1113, 1–128.Google Scholar