Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-13T07:05:20.520Z Has data issue: false hasContentIssue false
  • English
  • Français

Chemical zoning of muscovite from the Ervedosa granite, northern Portugal

Published online by Cambridge University Press:  05 July 2018

M. E. P. Gomes  and
A. M. R. Neiva
M. E. P. Gomes*
Affiliation:
Department of Geology, University of Trás-os-Montes and Alto Douro, 5000 Vila Real, Portugal
A. M. R. Neiva
Affiliation:
Department of Earth Sciences, University of Coimbra, 3000 Coimbra, Portugal
*
*E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

The tin-bearing muscovite granite from Ervedosa contains unzoned primary muscovite. This Hercynian S-type granite was hydrothermally altered at the stanniferous quartz vein walls and contains three types of muscovite: (1) very small unzoned muscovite replacing albite; (2) small unzoned hydrothermal muscovite replacing K-feldspar and quartz; and (3) zoned subhedral muscovite.

In the zoned muscovite, the core has a composition similar to that of magmatic muscovite from the unaltered granite, while the rim has a composition similar to that of hydrothermal muscovite replacing K-feldspar and quartz in the altered granite. The rim corresponds to a late overgrowth richer in the celadonitic component than the core. Infiltrated mineralizing fluids reacted with biotite and K-feldspar of the unaltered granite. We interpret the rim of muscovite to have precipitated from these solutions.

Keywords

chemically zoned muscovitemagmatic muscovitehydrothermal muscoviteS-type granite
Type
Research Article
Information
Mineralogical Magazine , Volume 64 , Issue 2 , April 2000 , pp. 347 - 358
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2000

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

Bau, M. (1991) Rare-earth element mobility during hydrothermal and metamorphic fluid-rock interaction and the significance of the oxidation state of europium. Chem. Geol., 93, 219–30.CrossRefGoogle Scholar
Bea, F. (1996) Residence of REE, Y, Th and U in granites and crustal protoliths; implications for the chemistry of crustal melts. J. Petrol., 37, 521–2.CrossRefGoogle Scholar
Candela, P.A. (1997) A review of shallow, ore-related granites: textures, volatiles and ore metals. J. Petrol., 38, 1619–33.CrossRefGoogle Scholar
Dempster, T.J. (1992) Zoning and recrystallization of phengitic micas: implications for metamorphic equilibration. Contrib. Mineral. Petrol., 109, 526–37.CrossRefGoogle Scholar
Dempster, T.J., Tanner, P.W.G., and Ainsworth, P. (1994) Chemical zoning of white micas: A record of fluid infiltration in the Ougterard granite, Western Ireland. Amer. Mineral., 79, 536–44.Google Scholar
Gomes, M.E.P. (1996) Mineralogy, petrology and geochemistry of granitoid rocks and their minerals from Rebordelo-Bouça-Torre de D.Chama-Agrochaão area and associated mineralizations. Unpubl. Ph.D. Thesis University of Trás-os-Montes e Alto Douro, Portugal.Google Scholar
Grant, J.A. (1986) The isocon diagram – A simple solution to Gresens’ equation for metasomatic alteration. Econ. Geol., 81, 1976–82.CrossRefGoogle Scholar
Le Bas, M.J. and Streckeisen, A. (1991) The IUGS systematics of igneous rocks. J. Geol. Soc., 148, 825–33.CrossRefGoogle Scholar
Lehmann, B. (1990) Metallogeny of Tin. Lecture Notes in Earth Sciences, 32. Springer-Verlag, Berlin.Google Scholar
Miller, C.F., Stoddard, E.F., Bradfish, L.J. and Dollase, W.A. (1981) Composition of plutonic muscovite: genetic implications. Canad. Mineral., 19, 25–34.Google Scholar
Monier, G. and Robert, J.L. (1986) Muscovite solid solutions in the system K2O-MgO-FeO-Al2O3-SiO2-H2O: An experimental study at 2 kbar P H2O and comparison with natural Li-free white micas. Mineral. Mag., 50, 257–66.CrossRefGoogle Scholar
Monier, G., Merggoil-Daniel, J. and Labernardière, H. (1984) Générations successives de muscovites et feldspaths potassiques dans les leucogranites du massif de Millevaches (Massif Central Français). Bull. Mineral., 107, 55–68.Google Scholar
Neiva, A.M.R. (1992) Chemical distinction between three postmagmatic types of white mica from hydrothermally altered granites of Jales and Penamacor-Monsanto, Portugal. Memórias e Notícias, Publ. Mus. Lab. Mineral. Geol. Univ. Coimbra, 113, 75–91.Google Scholar
Rieder, M., Cavazzini, G., D’yakonov, Y.S., Frank-Kamenestkii, V.A., Gottardi, G., Guggenheim, S., Koval, P.V., Muller, G., Neiva, A.M.R., Radoslovich, E.W., Robert, J-L., Sassi, F.P., Takeda, H., Weiss, Z. and Wones, D.R. (1999) Nomenclature of the micas. Mineral. Mag., 63, 267–79.CrossRefGoogle Scholar
Roycroft, P.D. (1989) Zoned muscovite from the Leinster Granite, S.E. Ireland. Mineral. Mag., 53, 663–5.CrossRefGoogle Scholar
Roycroft, P.D. (1991) Magmatically zoned muscovite from the peraluminous two-mica granites of the Leinster batholith, Southeast Ireland. Geology, 19, 437–40.2.3.CO;2>CrossRefGoogle Scholar
Roycroft, P.D. (1992) Muscovite zoning rediscovered. Geology Today, 8, 202– 4.Google Scholar
Speer, J.A. (1984) Micas in igneous rocks. Pp. 299–356 in: Micas (Bailey, S.W., editor). Reviews in Mineralogy, 13, Mineralogical Society of America, Washington D.C.CrossRefGoogle Scholar