Hostname: page-component-848d4c4894-r5zm4 Total loading time: 0 Render date: 2024-07-03T12:13:20.219Z Has data issue: false hasContentIssue false
  • English
  • Français

Restite-melt and mafic-felsic magma mixing and mingling in an S-type dacite, Cerro del Hoyazo, southeastern Spain

Published online by Cambridge University Press:  03 November 2011

H. P. Zeck
H. P. Zeck
Affiliation:
H.P. Zeck, Geological Institute, Øster Voldgade 10, 1350 K Copenhagen, Denmark
Get access Rights & Permissions [Opens in a new window]

Abstract

Approximately 10-15 vol% of the Neogene Hoyazo dacite consists of Al-rich restite rock inclusions (A12O3 = 20–45%) and monocrystal inclusions derived therefrom. Restite material and dacitic melt were formed syngenetically from a (semi-)pelitic rock sequence by means of anatexis. Restite rock fragments and dacite show similar high δ18O values (13–16‰) corresponding to those found for sedimentary material. Striking monocrystal restite inclusions in the dacite rock are graphite crystals measuring a few hundred μm, 0.5–10 mm blue cordierite crystals and 2–10 mm ruby red crystals of almandine-rich garnet (1.1 ± 0.2 vol%). Although the almandine crystals are perfectly euhedral, they are identical in every respect to the crystals found in the Al-rich restite rock inclusions and cannot be crystallisation products of the magmatic melt. The dacite also contains many inclusions of quartz gabbroic and basaltoid material which contains inclusions identical to the restite material found in the dacitic glass base. Many basaltoid inclusions show well-developed chilled borders. These inclusions may represent a more mafic magma of deeper origin which mixed with some dacite magma before mingling into it.

Keywords

almandine-bearing volcanicsAlpine beltBetic Cordillerascordierite-bearing volcanicsNeogene volcanism in southeastern Spain
Type
Research Article
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 83 , Issue 1-2: Second Hutton Symposium: The Origin of Granites and Related Rocks , 1992 , pp. 139 - 144
Copyright
Copyright © Royal Society of Edinburgh 1992

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bacon, C. R. 1986. Magmatic inclusions in silicic and intermediate volcanic rocks. J GEOPHYS RES 91, 6091–112.CrossRefGoogle Scholar
Barbarin, B. & Didier, J. 1992. Genesis and evolution of mafic magmatic enclaves through various types of interactions between coeval felsic and mafic magmas. TRANS R SOC EDINBURGH EARTH SCI 83, 145–53.Google Scholar
Chappell, B. W., White, A. J. R. & Wyborn, D. 1987. The importance of residual source material (restite) in granite petrogenesis. J PETROL 28, 1111–38.CrossRefGoogle Scholar
Dabrio, C. J., Esteban, M. & Martin, J. M. 1981. The coral reef of Níjar, Messinian (uppermost Miocene), Almería province, SE Spain. J SEDIMENT PETROL 51, 521–39.Google Scholar
Battistini, G.DiToscani, , Laccarino, S. & Villa, I. M. 1987. K/Ar ages and the geological setting of calc-alkaline volcanic rocks from Sierra de Gata, SE Spain. NEUES JAHRB MINERAL, MONATSH, 1987, 369–83.Google Scholar
López-Ruiz, J., Badiola, E. R. & Cacho, L.García 1977. Origine des grenats des roches calco-alcalines du Sud-Est de I'Espagne. BULL VOLCANOL 40, 141–52.CrossRefGoogle Scholar
López-Ruiz, J. & Badiola, R. E. 1980. La región volcánica neogena del sureste de España. ESTUD GEOL 36, 5–63.Google Scholar
Magaritz, M., Whitford, D. J. & James, D. E. 1978. Oxygen isotopes and the origin of high 87Sr/86Sr andesites. EARTH PLANET SCI LETT 40, 220–30.CrossRefGoogle Scholar
Munksgaard, N. C. 1984. High δ18O and possible pre-eruptional Rb-Sr isochrons in cordierite-bearing Neogene volcanics from SE Spain. CONTRIB MINERAL PETROL 87, 3651–8.CrossRefGoogle Scholar
Munksgaard, N. C. 1985. A non-magmatic origin for compositionally zoned euhedral garnets in silicic Neogene volcanics from SE Spain. NEUES JAHRB MINERAL MONATSH, 1985, 73–82.Google Scholar
Poli, G. & Tommasim, S. 1991. Model for the origin and significance of microgranular enclaves in calc-alkaline granitoids. J PETROL 32, 657–66.CrossRefGoogle Scholar
Scambos, T. A., Loiselle, M. C. & Wones, D. R. 1986. The Centre Pond pluton: the restite part of the story (phase separation and melt evolution in granitoid genesis). AM J SCI 286, 241–80.CrossRefGoogle Scholar
White, A. J. R. & Chappell, B. W. 1977. Ultrametamorphism and granitoid genesis. TECTONOPHYSICS 43, 7–22.CrossRefGoogle Scholar
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 del Hoyazo, SE Spain. Thesis, Amsterdam University.Google Scholar
Zeck, H. P. 1970. An erupted migmatite from Cerro del Hoyazo, SE Spain. CONTRIB MINERAL PETROL 26, 225–46.CrossRefGoogle Scholar
Zeck, H. P. 1972. Transformation trillings in cordierite. J PETROL 13, 367–80.CrossRefGoogle Scholar