Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-22T18:04:47.315Z Has data issue: false hasContentIssue false

Composition of trioctahedral micas in the Karlovy Vary pluton, Czech Republic and a comparison with those in the Coruubian batholith, SW England

Published online by Cambridge University Press:  05 July 2018

M. Stone
Affiliation:
Earth Resources Centre, University of Exeter, Exeter EX4 4QE, UK
J. Klomínský
Affiliation:
Czech Geological Survey, Klárov 3, 118 21 Prague 1, Czech Republic
G. S. Rajpoot
Affiliation:
Konevova 110, 13000 Prague 3, Czech Republic

Abstract

Trioctahedral micas in the Karlovy Vary pluton range in composition from Fe-biotites in the granites of the Older Intrusive Complex (OIC) through siderophyllite and lithian siderophyllite to zinnwaldite in the granites of the Younger Intrusive Complex (YIC). Li + AlVI + Si would appear to substitute for Fe2+ + AlIV in biotite with a formula similar to that given in Henderson et al. (1989), but Li + Si appears to substitute for Fe2+ + AlIV in the Li-micas. In mica vs. host rock plots, Rb and F show positive linear covariation except for the Li-mica granites, but femic constituents and tFeO/(tFeO + MgO) have separate trends for OIC and YIC granites and micas. Further differences between OIC and YIC granite micas are seen in their Ti and Mg contents and in plots like V vs. SiO2, AlIVvs. Fe/(Fe+Mg) and Li vs. total iron as Fe2+ and in the results of discriminant analysis. These reveal a geochemical hiatus between OIC and YIC granite micas that coincides with a major temporal hiatus.

Biotite compositions in the YIC granites are similar to those in the granites of the Cornubian batholith and reveal a similar magmatic evolution and genesis in which later biotites evolve to lithian siderophyllites with some enrichment in trace alkalis and F. It is suggested that the biotite granites in the YIC were derived from the products of partial fusion of the OIC granites. A less well-marked geochemical hiatus exists between YIC biotites and zinnwaldites. In some plots (e.g. Si vs. Li, Li vs. tFe) apparent continuity between biotite and the Li-micas suggests continuous evolution, but in others (e.g. Rb vs. TiO2, Rb(biotite) vs. Rb(rock)), Li-mica data points stand apart from the biotites suggesting, like the whole rock data, a separate evolution. Comparison with the more abundant data for Li-micas of the Cornubian batholith suggests derivation of the Li-mica granites by partial fusion of the OIC/YIC granite residues.

Type
Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1997

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

Bauer, V.H. (1967) Geochemische gliedering grani-tischer gesteine des Thuringer Waldes und Erzgebirges ihre lagerstatten genetische bedeutung. Freiberger Forschungshefie 209.Google Scholar
Cerný, P. and Burt, D.M. (1984) Paragenesis, crystal-lochemical characteristics and geochemical evolution of micas in granite pegrnatites. In Micas (Bailey, S. W., ed.) Reviews in Mineralogy, 13, 257-97. Mineralogical Society of America, Washington.CrossRefGoogle Scholar
Chaudhry, M.N. and Howie, R.A. (1973) Lithium-aluminium micas from the Meldon aplite, Devonshire, England. Mineral. Mag., 39, 289-96.CrossRefGoogle Scholar
Dangerfield, J. and Hawkes, J.R. (1981) The Variscan granites of south-west England: additional information. Proc. Ussher Soc., 5, 116-20.Google Scholar
Exley, C.S. and Stone, M. (1982) Hercynian intrusive rocks. In: Igneous Rocks of the British Isles, (Sutherland, D. S., ed.) Wiley, Chichester, 287320.Google Scholar
Foster, M.D. (1960) Interpretation of the composition of lithium micas. U.S. Geol. Surv. Prof. Paper, 354-E, 115-47.Google Scholar
Gerstenberger, H. (1989) Autometasomatic Rb enrichment in highly evolved granites causing lowered Rb-Sr isochron intercepts. Earth Planet. Sci. Lett., 93, 65-75.CrossRefGoogle Scholar
Gottesmann, B. and Tischendorf, G. (1978) Klassifikation, chemismus und Optik trioktae-drischer Glimmer. Z. geo. Wiss., Berlin, 6, 681708.Google Scholar
Haslam, H.W. (1968) The crystallization of intermediate and acid magmas at Ben Nevis, Scotland. J. Petrol., 9, 84-104.CrossRefGoogle Scholar
Heeht, L. (1994) The chemical composition of biotite as an indicator of magmatic fractionation and metaso-matism in Sn-specialised granites of the Fichtelgebirge (NW Bohemian Massif, Germany). In Metallogeny of Collisional Orogens, (Seltmarm, Kämpf and Möller, eds). Czech Geol. Survey, Prague, 295-300.Google Scholar
Henderson, C.M.B., Martin, J.S. and Mason, R.A. (1989) Compositional relations in Li-micas from S.W. England and France: an ion- and electron-microprobe study. Mineral. Mag., 53, 427—49.CrossRefGoogle Scholar
Klomínský, J. and Absolonová, E. (1974) Geochemistry of the Karlovy Vary granite massif (Czechoslovakia). In Metallization Associated with Acid Magmatism, Vol. 1 (Stemprok, M., ed.). Geological Survey, Prague, 189-96.Google Scholar
Lange, H., Tischendorf, G., Pälchen, W., Klemm, I. and Ossenkopf, W. (1972) Fortschritte der Metallogenie im Erzgebirge - B, Zur Petrographic und Geoehemie der nite des Erzgebirges. Geologie, 21, 457—93.Google Scholar
Leake, B.E. (1974) The crystallization history and mechanism of emplacement of the western part of the Galway granite, Connemara, western Ireland. Mineral. Mag., 39, 498-513.CrossRefGoogle Scholar
Leat, P.T., Thompson, R.N., Morrison, M.A., Hendry, G.L. and Trayhorn, S.C. (1987). Geodynamic significance of post-Variscan intrusive and extrusive potassic magmatism in SW England. Trans. R. Soc. Edinb.: Earth Sci., 77, 349-60.CrossRefGoogle Scholar
Müller, G. (1966) Die Beziehungen zwischen der chemischen Zusammensetztmg, Lichtbrechung und Dichte einiger Koexistiezender Biotite, Muskovite und Chlorite aus granitischen Tiefergesteinen. Contrib. Mineral. Petrol., 12, 173-91.CrossRefGoogle Scholar
Neiva, A.M.R. (1976) The geochemistry of biotites from granites of northern Portugal with special reference to their tin content. Mineral. Mag., 40, 453—66.CrossRefGoogle Scholar
Puziewicz, J. (1994) Titanium content in biotite from granitic rocks as an indicator of magma crystal-lization conditions. Archiwum Mineralogiczne, Tom L, zeslyt 1, 135-6.Google Scholar
Puziewicz, J. and Johannes, W. (1990) Experimental study of a biotite-bearing granitic system under water-saturated and water-undersaturated conditions. Contrib. Mineral. Petrol., 104, 397-406.CrossRefGoogle Scholar
Rajpoot, G.S. (1992) Granites in tin metallogenic provinces of Hercynian fold belt (SW England and NW Bohemia) and their comparison with granites in the Himalayas. Unpubl. PhD thesis, CGU.Google Scholar
Rajpoot, G.S. and Klomínský, J. (1993) Granite in tin fields of Europe and in the Himalayas - a comparative study. Czech Geol. Surv. Spec. Papers, 1, 1-64.Google Scholar
Rajpoot, G.S. and Klomínský, J. (1994) Typology and origin of granite in the Comubian and Kršné hory Smrčiny batholiths. Bull. Czech Geol. Surv., 92, 6374.Google Scholar
Rieder, M. (1970) Chemical composition and physical properties of lithium-iron micas from the Krušné hory Mts (Erzgebirge). Part A. Chemical composi-tion. Contrib. Mineral. Petrol., 27, 131-58.CrossRefGoogle Scholar
Speer, J.A (1984) Micas in igneous rocks. In Micas, (Bailey, S. W., ed.), Mineralogical Society of America. Reviews in Mineralogy, 13, 299—356.Google Scholar
Speer, J.A. and Becker, S.W. (1992) Evolution of magmatic and subsolidus AFM mineral assemblages in granitoid rocks: biotite, muscovite and garnet in the Cuffytown Creek pluton, South Carolina. Amer. Mineral., 77, 821-33.Google Scholar
Štemprok, M. (1986) Petrology and geochemistry of the Czechoslovak part of the Krušé hory Mts granite pluton. Sbor. Geol. Vèd. Prague, LG, 27, 111-56.Google Scholar
Štemprok, M. (1992) Geochemical development of the Krušé hory/Erzgebirge granite pluton exemplified on its Czechoslovak part. Geophys. Veriöff. Univ. Leipzig, Bd. IV, 5163.Google Scholar
Stone, M. (1979) Textures of some Cornish granites. Proc. Ussher Soc., 4, 370-9.Google Scholar
Stone, M. (1984) Textural evolution of lithium mica granites in the Cornubian batholith. Proc. Geol. Assoc., 95, 2941.CrossRefGoogle Scholar
Stone, M. (1992) The Tregonning granite: petrogenesis of Li-mica granites in the Comubian batholith. Mineral. Mag., 56, 141-55.CrossRefGoogle Scholar
Stone, M., Exley, C.S. and George, M.C (1988) Compositions of trioctahedral micas in the Cornubian batholith. Mineral. Mag., 52, 175-92.CrossRefGoogle Scholar
Thorpe, R.S. (1987) Permian K-rich volcanic rocks of Devon: petrogenesis, tectonic setting and Geological significance. Trans. R. Soc. Edinb.: Earth Sci., 77, 361-6.CrossRefGoogle Scholar
Tischendorf, G. (1989) Silicic magmtttism and metallo-genesis of the Erzgebirge. Manuscript, Potsdam, 316 pp.Google Scholar
Tischendorf, G., Frise, G. and Schindler, R. (1969) Die Dunkelglimmer der westerzgebirgisch — vogtlän-dischen Granite und ihre Bedeutung als petrogen-etische und metallogenetische Kriterien. Geologie, 18, 1024-44.Google Scholar
Weiss, S. and Troll, G. (1989) The Ballachulish igneous complex, Scotland: petrography, mineral chemistry, and order of crystallization in the monzodiorite — quartz diorite suite and in the granites. J. Petrol., 30, 1069-115.CrossRefGoogle Scholar