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Crustal anatexis and melt extraction during deformation in the restitic xenoliths at El Joyazo (SE Spain)

  • B. Cesare (a1), E. Salvioli Mariani (a2) and G. Venturelli (a2)


The dacite of El Joyazo contains abundant metapelitic xenoliths. These can be divided into two main types: garnet-biotite-sillimanite and spinel-cordierite xenoliths. In the xenoliths the widespread occurrence of rhyolitic glass as interstitial films, foliation-parallel layers and primary melt inclusions in all mineral phases indicates that these assemblages developed in the presence of a melt phase, i.e. during anatexis. The composition of the interstitial glass is comparable to that of the melt inclusions, suggesting that melt was locally produced. Phase equilibria indicate that anatexis occurred at P-T conditions of 5–7 kbar and 850±50°C.

Several microstructural lines of evidence show that melt extraction was assisted by deformation during foliation development, and that on the scale of the xenoliths (up to 50 cm) melt escaped mainly by flow along foliation planes. The development of a syn-anatectic foliation also suggests that metapelitic rocks were involved in high-grade metamorphism and partial melting prior to fragmentation and dispersion in the host dacite.

Mass balance calculations, based on the chemical composition of interstitial glass and melt inclusions in minerals, the bulk xenoliths and representative samples of potential pelitic sources support a model wherein the xenoliths represent restites after the extraction of 30 to 55 wt.% melt from graphitic metapelite protoliths similar to the rocks constituting the surrounding Alpujarride metamorphic complex.



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Aranovich, L.Ya. and Podlesskii, K.K. (1983) The cordierite-garnet-sillimanite-quartz equilibrium: experiments and applications. In Kinetics and Equilibrium in Mineral Reactions (Saxena, S.K., ed.) Springer, pp. 173-98.
Bellon, H., Bordet, P. and Montenat, C. (1983) Chronologie du magmatisme Nèogéne des Cordilléres Bètiques (Espagne Mèridionale). Bull. Soc. GéoL France, 25, 205-17.
De Larouzière, F.D., Bolze, J., Bordet, P., Hernandez, J., Montenat, C. and Ott d'Estevou, P. (1988) The Betic segment of the lithospheric Trans-Alboran shear zone during the late Miocene. Tectonophysics, 152, 4152.
Di Battistini, G., Toscani, L., Iaccarino, S. and Villa, I.M. (1987) K/Ar age and the geological setting of calc-alkaline volcanic rocks from Sierra de Gata, SE Spain. Neues Jahrb. Mineral. Mh., 369-83.
Ferry, J.M. and Spear, F.S. (1978) Experimental calibration of the partitioning of Fe and Mg between biotite and garnet. Contrib. Mineral Petrol., 66, 113-7.
Grant, J.A. and Frost, B.R. (1990) Contact metamorphism and partial melting of pelitic rocks in the aureole of the Laramie Anorthosite Complex, Morton Pass, Wyoming. Amer. J. Sci., 290, 425-72.
Hayob, J.L., Essene, E.J., Ruiz, J., Ortega-Gutierrez, F. and Aranda-Gomez, J.J. (1989) Young high-temperature granulites from the base of the crust in central Mexico. Nature, 342, 265-8.
Holtz, F. and Johannes, W. (1991) Genesis of peraluminous granites. I. Experimental investigation of melt compositions at 3 and 5 kb and various H2O activities. J. Petrol., 32, 935-58.
Johnston, A.D. and Wyllie, P.J. (1988) Constraints on the origin of Archaean trondhjemites based on phase relationships of Nûk gneiss with H2O at 15 kbar. Contrib. Mineral. Petrol., 100, 3546.
Lopez-Ruiz, J. and Rodriguez-Badiola, E. (1980) La region volcanica Neogena del sureste de Espana. Estudios Geologicos, 36, 563.
Munskgaard, N.C. (1984) High δ18O and possible preeruptional Rb-Sr isochrons in cordierite-bearing Neogene volcanics from SE Spain. Contrib. Mineral. Petrol., 87, 351-8.
Munskgaard, N.C. (1985) A non-magmatic origin for compositionally zoned euhedral garnet in silicic Neogene volcanics from SE Spain. Neues Jahrb. Mineral. Mh., 7382.
Newton, R.C. and Haselton, H.T. (1981) Thermodynamics of garnet-plagioclase-Al2SiO5 quartz geobarometer. In Thermodynamics of Minerals and Melts (Newton, R.C., Navrotsky, A. and Wood, B.J., eds.) Springer, pp. 131-47.
Nobel, F.A., Andriessen, P.A.M., Hebeda, E.H., Priem, H.N.A. and Rondeel, H.E. (1981) Isotopic dating of the post-Alpine Neogene volcanics in the Betic Cordilleras, Southern Spain. Geol. Mijnbouw, 60, 209-14.
Patiño Douce, A. and Johnston, D.A. (1991) Phase equilibria and melt productivity in the pelitic system: implications for the origin of peraluminous granitoids. Contrib. Mineral. Petrol., 107, 202-18.
Roedder, E. (1984) Fluid inclusions. In Reviews in Mineralogy, 12, 646pp.
Salvioli Mariani, E., Cesare, B. and Venturelli, G. (1995) Petrology of metapelite-derived xenoliths in the Hoyazo dacite (SE Spain). Terra Abstracts, 7, 317.
Srogi, L., Wagner, M.A. and Lutz, T.M. (1993) Dehydration partial melting and disequilibrium in the granulite-facies Wilmington Complex, Pennsylvania-Delaware Piedmont. Amer. J. Sci., 293, 405-62.
Toscani, L., Venturelli, G., Barbieri, M., Capedri, S., Fernandez-Soler, J.M. and Oddone, M. (1990) Geochemistry and petrogenesis of two-pyroxene andesites from Sierra de Gata (SE Spain). Mineral. Petrol., 41, 199213.
Vielzeuf, D. and Holloway, J.R. (1988) Experimental determination of the fluid-absent melting reactions in the pelitic systems, Consequences for crustal differentiation. Contrib. Mineral. Petrol., 98, 257-76.
Vielzeuf, D. and Montel, J.M. (1994) Partial melting of metagreywackes. Part 1. Fluid-absent experiments and phase relationships. Contrib. Mineral. Petrol., 117, 375-93.
Zeck, H.P. (1968) Anatectic origin and further petrogenesis of almandine-bearing biotite-cordierite-labradorite dacite with many inclusions of restite and basaltoid material, Cerro de Hoyazo, SE Spain. PhD Thesis, Amsterdam, 161 pp.
Zeck, H.P. (1970) An erupted migmatite from Cerro de Hoyazo, SE Spain. Contrib. Mineral. Petrol., 26, 225-46.


Crustal anatexis and melt extraction during deformation in the restitic xenoliths at El Joyazo (SE Spain)

  • B. Cesare (a1), E. Salvioli Mariani (a2) and G. Venturelli (a2)


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