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Graphite occurrences in the low-pressure/high-temperature metamorphic belt of the Sierra de Aracena (southern Iberian Massif)

Published online by Cambridge University Press:  05 July 2018

M. Rodas ,
F. J. Luque ,
J. F. Barrenechea ,
J. C. Fernández-Caliani ,
A. Miras  and
C. Fernández-Rodríguez
M. Rodas
Affiliation:
Departamento de Cristalografía y Mineralogía, Facultad de Geología, Universidad Complutense de Madrid, 28040 Madrid, Spain
F. J. Luque*
Affiliation:
Departamento de Cristalografía y Mineralogía, Facultad de Geología, Universidad Complutense de Madrid, 28040 Madrid, Spain
J. F. Barrenechea
Affiliation:
Departamento de Cristalografía y Mineralogía, Facultad de Geología, Universidad Complutense de Madrid, 28040 Madrid, Spain
J. C. Fernández-Caliani
Affiliation:
Departamento de Geología, Facultad de Ciencias Experimentales, Universidad de Huelva, 21819 Palos de la Frontera, Huelva, Spain
A. Miras
Affiliation:
Departamento de Cristalografía y Mineralogía, Facultad de Química, Universidad de Sevilla, 41071 Sevilla, Spain
C. Fernández-Rodríguez
Affiliation:
Departamento de Geología, Facultad de Ciencias Experimentales, Universidad de Huelva, 21819 Palos de la Frontera, Huelva, Spain
*
*E-mail: jluque@eucmax.sim.ucm.es
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Abstract

Four distinct associations of graphite have been identified in the low-pressure, high-temperature belt of the Sierra de Aracena (SW Spain). Syngenetic occurrences include: (1) stratiform graphite mineralization within a calc-silicate series; (2) disseminated graphite within a terrigenous sequence; and (3) ‘restitic’ graphite within anatectic tonalites and their enclaves. Epigenetic graphite occurs as (4) veins cross-cutting mafic granulites.

Graphite in all types of occurrences is highly crystalline, with the c parameter close to 6.70 Å. Such c values correspond to temperatures of formation of ∼800°C. The thermal properties of graphite are also typical of well-ordered graphite and provide DTA exothermic maxima ranging from 810 to 858°C depending on the mode of occurrence. The differences among the temperatures of formation estimated by graphite geothermometry, the position of the exothermic maximum in the DTA curves, and petrologic geothermometers are discussed in terms of the applicability of graphite geothermometry to granulite-facies rocks. Carbon isotope analysis yields δ13C values in the range from −31.6 to −21.4% for syngenetic graphite of types I, II and III attributable to biogenically-derived carbon. The heavier signatures for graphite in vein occurrences (δ13C= −17.7 to −18.3%) with respect to syngenetic graphites suggest that isotopically heavy carbonic species were incorporated into the metamorphic fluids (probably as a consequence of decarbonation reactions of the calc-silicate rocks) from which graphite precipitated into the veins. These fluids were strongly channelled through structural pathways.

Keywords

graphitecalc-silicate rockslow-P/high-Tmetamorphismsouthern Spain
Type
Research Article
Information
Mineralogical Magazine , Volume 64 , Issue 5 , October 2000 , pp. 801 - 814
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2000

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References

Arneth, J.D., Schidlowski, M., Sarbas, B., Goerg, U. and Amstutz, G.C. (1985) Graphite content and isotopic fractionation between calcite-graphit e pairs in metasediments from the Mgama Hills, Southern Kenya. Geochim. Cosmochim. Acta, 49, 1553–60.CrossRefGoogle Scholar
Bard, J.P. (1969) le métamorphisme régional progressif de Sierra de Aracena en Andalousie occidentale (Espagne).Thèse d’État, Univ. Montpellier.Google Scholar
Bard, J.P. and Moine, B. (1979) Acebuches amphibolites in the Aracena Hercynian metamorphic belt (south-west Spain): geochemical variations and basaltic affinities. Lithos, 12, 271–82.CrossRefGoogle Scholar
Barrenechea, J.F., Luque, F.J., Rodas, M. and Pasteris, J.D. (1997) Vein-type graphite in Jurassic volcanic rocks of the External Zone of the Betic Cordillera, southern Spain. Canad Mineral., 35, 1379–90.Google Scholar
Castro, A, Fernández, C., De la Rosa, J.D., Moreno-Ventas, I., El-Hmidi, H., El-Biad, M., Bergamín, J.F. and Sánchez, N. (1996 a) Triple-junction migration during Paleozoic plate convergence: the Aracena metamorphic belt, Hercynian massif, Spain. Geol. Rundsch., 85, 180–5.CrossRefGoogle Scholar
Castro, A, Fernández, C., De la Rosa, J. D., Moreno-Ventas, I. and Rogers, G. (1996 b) Significance of MORB-derived amphibolites from the Aracena Metamorphic Belt, Southwest Spain. J. Petrol, 37, 235–60.CrossRefGoogle Scholar
Crawford, W.A. and Valley, J.W. (1990) Origin of graphite in the Pickering gneiss and the Franklin marble, Honey Brook Upland, Pennsylvania Piedmont. Geol. Soc. Amer. Bull., 102, 807–11.2.3.CO;2>CrossRefGoogle Scholar
Crespo-Blanc, A. and Orozco, M. (1988) The Southern Iberian Shear Zone: a major boundary in the Hercynian folded belt. Tectonophysics, 148, 221–7.CrossRefGoogle Scholar
Des Marais, D.J., Strauss, H., Summons, R.E. and Hayes, J.M. (1992) Carbon isotope evidence for the stepwise oxidation of the Proterozoic environment. Nature, 359, 605–9.CrossRefGoogle ScholarPubMed
Diessel, C.F.K. and Offler, R., 1975, Change in physical properties of coalified and graphitised phytoclasts with grade of metamorphism. Neues Jahrb. Mineral. Mh., 1, 11–27.Google Scholar
Dissanayake, C.B. (1994) Origin of vein graphite in high-grade metamorphic terranes. Role of organic matter and sediment subduction. Mineral. Deposita, 29, 57–67.CrossRefGoogle Scholar
Farquhar, J. and Chacko, T. (1991) Isotopic evidence for involvement of CO2-bearing magmas in granulite formation. Nature, 354, 60–3.CrossRefGoogle Scholar
Fernández-Rodríguez, C., Fernández Caliani, J.C., Miras, A, Barrenechea, J.F., Luque, F.J. and Rodas, M. (1996) Nuevos datos geológicos sobre las mineralizaciones de grafito de la Banda Metamórfica de Aracena, Huelva (Macizo Ibérico Meridional). Geogaceta, 20 (7), 1576–7.Google Scholar
Glassley, W. (1982) Fluid evolution and graphite genesis in the deep continental crust. Nature, 295, 229–31.CrossRefGoogle Scholar
Grew, E.S. (1974) Carbonaceous material in some metamorphic rocks of New England and other areas. J. Geol., 82, 50–73.CrossRefGoogle Scholar
Hahn-Weinheimer, P. and Hirner, A. (1981) Isotopic evidence for the origin of graphite. Geochem. J., 15, 9–15.CrossRefGoogle Scholar
Hansen, E.C., Janardhan, A.S., Newton, R.C., Prame, W.K.B.N. and Ravindrakumar, G.R. (1987) Arrested charnockite formation in southern India and Sri Lanka. Contrib. Mineral. Petrol., 96, 225–44.CrossRefGoogle Scholar
Hapuarachchi, D.J.A.C. (1977) Decarbonation reactions and the origin of vein-graphite in Sri Lanka. J. Nat. Sci. Council Sri Lanka, 5, 29–32.Google Scholar
Hoefs, J. and Frey, M.J. (1976) The isotopic composition of carbonaceous matter in a metamorphic profile of the Swiss Alps. Geochim. Cosmochim. Acta, 40, 945–51.CrossRefGoogle Scholar
Itaya, T. (1981) Carbonaceous material in pelitic schists of the Sanbagawa metamorphic belt in central Shikoku, Japan. Lithos, 14, 215–24.CrossRefGoogle Scholar
Jackson, D.H., Mattey, D.P. and Harris, N.B.W. (1988) Carbon isotope compositions of fluid inclusions in charnockites from southern India. Nature, 333, 167–70.CrossRefGoogle Scholar
Jubés, E. and Carbonell, A. (1918) Informe sobre los yacimientos de grafito de la zona de Almonaster-Cortegana (Huelva). Bol. Of. Min. Metal. 9, 12, 14, 15, and 16.Google Scholar
Julivert, M., Fontboté, J.M., Ribeiro, A. and Conde, L. (1974) Memoria Explicativa del Mapa Tectónico de la Península Ibérica y Baleares. IGME, Madrid.Google Scholar
Kanaris-Sotiriou, R. (1997) Graphite-bearing peraluminous dacites from the Erlend volcanic complex, Faeroe-Shetland Basin, North Atlantic. Mineral. Mag., 61, 175–84.CrossRefGoogle Scholar
Katz, M.B. (1987) Graphite deposits of Sri Lanka: a consequence of granulite facies metamorphism. Mineral. Deposita, 22, 18–25.CrossRefGoogle Scholar
Kwiecinska, B. (1980) Mineralogy of natural graphites. Polska Akad. Nauk, Prace Mineral., 67, 5–79.Google Scholar
Lamb, W. and Valley, J.W. (1984) Metamorphism of reduced granulites in low-CO2 vapour-free environment. Nature, 312, 56–8.CrossRefGoogle Scholar
Lamb, W. and Valley, J.W. (1985) C-O-H fluid calculations and granulite genesis. Pp. 119–31 in: The Deep Proterozoic Crust in the North Atlantic Provinces (Tobi, A.C. and Touret, J.L.R., editors). D. Reidel Publishing Company, Dordrecht, The Netherlands.CrossRefGoogle Scholar
Luque, F.J. and Rodas, M. (1999) Constraints on graphite crystallinity in some Spanish fluid-deposited occurrences from different geologic settings. Mineral. Deposita, 34, 215–9.CrossRefGoogle Scholar
Luque, F.J., Rodas, M. and Galán, E. (1992) Graphite vein mineralization in the ultramafic rocks of southern Spain: Mineralogy and genetic relationships. Mineral. Deposita, 27, 226–33.CrossRefGoogle Scholar
Luque, F.J., Barrenechea, J.F. and Rodas, M. (1993) Graphite geothermometry in low and high temperature regimes: two case studies. Geol. Mag., 130, 501–11.CrossRefGoogle Scholar
Luque, F.J., Pasteris, J.D., Wopenka, B., Rodas, M. and Barrenechea, J.F. (1998) Natural fluid-deposited graphite: Mineralogical characteristics and mechanisms of formation. Amer. J. Sci., 298, 471–98.CrossRefGoogle Scholar
Luque, F.J., Rodas, M. and Barrenechea, J.F. (1999) Graphite deposits in southern Spain: Role of carbon isotopes in defining genetic models. Pp. 1117–20 in: Mineral Deposits: Processes to Processing, Vol. 7 (Stanley, C.J., editor). A.A. Balkema, Rotterdam.Google Scholar
Mattey, D.P. (1987) Carbon isotopes in the mantle. Terra Cognita, 7, 31–7.Google Scholar
Munhá, J., Oliveira, J.T., Ribeiro, A, Oliveira, V., Quesada, C. and Kerrick, R. (1986) Beja-Acebuches ophiolite: Characterization and geodynamic significance. Maleo, 2, 31.Google Scholar
Naraoka, H., Ohtake, M., Maruyama, S. and Ohmoto, H. (1996) Non-biogenic graphite in 3.8-Ga metamorphic rocks from the Isua district, Greenland. Chem. Geol., 133, 251–60.CrossRefGoogle Scholar
Newton, R.C., Smith, J.V. and Windley, B.F. (1980) Carbonic metamorphism, granulites and crustal growth. Nature, 288, 45–50.CrossRefGoogle Scholar
Pasteris, J.D. and Luque, F.J. (1997) Why is the graphite in large epigenetic deposits of uniformly high crystallinity?. Geol. Soc. Amer., Abst. with Prog., 28, A–91.Google Scholar
Poulson, S.R. (1996) Equilibrium mineral-fluid stable isotope fractionation factors in graphitic metapelites. Chem. Geol, 131, 207–17.CrossRefGoogle Scholar
Quesada, C, Fonseca, P.E., Munhá, J., Oliveira, J.T. and Ribeiro, A. (1994) The Beja-Acebuches ophiolite (Southern Iberia Variscan fold belt). Geological characterization and geodynamic significance. Bol. Geol. Min., 105, 3–49.Google Scholar
Radhika, U. P., Santosh, M. and Wada, H. (1995) Graphite occurrences in Southern Kerala: Characteristics and genesis. J. Geol. Soc. India, 45, 653–66.Google Scholar
Rumble, D., Duke, E.F. and Hoering, T.C. (1986) Hydrothermal graphite in New Hampshire: Evidence of carbon mobility during regional metamorphism. Geology, 14, 452–5.2.0.CO;2>CrossRefGoogle Scholar
Santosh, M. and Wada, H. (1993 a) Microscale zonation in graphite crystals: Evidence for chanelled CO2 influx in granulites. Earth Planet. Sci. Lett., 119, 19–26.CrossRefGoogle Scholar
Santosh, M. and Wada, H. (1993 b) A carbon isotope study of graphites from the Kerala Khondalite Belt, southern India: Evidence for CO2 infiltration in granulites. J. Geol., 101, 643–51.CrossRefGoogle Scholar
Satish-Kumar, M. and Santosh, M. (1998) A petrological and fluid inclusion study of calc-silicate-charnockite associations from southern Kerala, India: implications for CO2 influx. Geol. Mag., 135, 27–45.CrossRefGoogle Scholar
Schidlowski, M., Appel, P.W.U., Eichmann, R. and Junge, C.E. (1979) Carbon isotope geochemistry of the 3.7×109-yr-old Isua sediments, West Greenland: implications for the Archean carbon and oxygen cycles. Geochim. Cosmochim. Acta, 43, 189–99.CrossRefGoogle Scholar
Schoell, M. and Wellmer, F.-W. (1981) Anomalous 13C depletion in early Precambrian graphites from Superior Province, Canada. Nature, 290, 696–9.CrossRefGoogle Scholar
Shengelia, D.M., Akhvlediani, R.A. and Ketskhoveli, D.N. (1979) The graphite geothermometer. Dokl. Acad. Nauk SSSR, 235, 132–4.Google Scholar
Silva, K.K.M.W. (1987) Mineralization and wall-rock alteration at the Bogala graphite deposit, Bulathkohupitiya, Sri Lanka. Econ. Geol., 82, 1710–22.CrossRefGoogle Scholar
Tagiri, M. (1981) A measurement of the graphitizing degree by the X-ray powder diffractometer. J. Japan. Assoc. Min. Petr. Econ. Geol., 76, 345–52.CrossRefGoogle Scholar
Touret, J.R.L. (1971) Le facies granulite en Norvege meridionale. II: Les inclusions fluids. Lithos, 4, 423–6.CrossRefGoogle Scholar
Vry, J., Brown, P.E., Valley, J.W. and Morrison, J. (1988) Constraints on granulite genesis from carbon isotope compositions of cordierite and graphite. Nature, 332, 66–8.CrossRefGoogle Scholar
Wada, H. and Santosh, M. (1995) Stable isotopic characterization of metamorphic fluid processes in the Kerala Khondalite Belt, south India. Mem. Geol. Soc. India, 34, 161–72.Google Scholar
Wada, H., Tomita, T., Matsuura, K., Iuchi, K., Ito, M. and Morikiyo, T. (1994) Graphitization of carbonaceous matter during metamorphism with references to carbonate and pelitic rocks of contact and regional metamorphisms, Japan. Contrib. Mineral. Petrol., 118, 217–28.CrossRefGoogle Scholar
Weis, P.L., Friedman, I. and Gleason, J.P. (1981) The origin of epigenetic graphite: evidence from isotopes. Geochim. Cosmochim. Acta, 45, 2325–32.CrossRefGoogle Scholar
Yardley, B.W.D. and Valley, J.W. (1997) The petrologic case for a dry lower crust. J. Geophys. Res., 102(B6), 12173–85.CrossRefGoogle Scholar