Mafic enclaves in peraluminous Variscan granitoid in the Battonya Unit from Southeast Hungary
Article Sidebar
Main Article Content
Abstract
Variscan granitoids occur in the southeastern part of the Tisza Mega Unit of Hungary. The presence of amphibole, calc-alkaline-type Mg-rich biotite in metaluminous basic enclaves, and muscovite and Fe-Al-biotite in peraluminous granitoids, suggests a mixed I-S-type origin. Two types of muscovite have been identifi ed: a primary euhedral to subhedral, Ti-Na-Al rich variety, crystallized after Fe-rich peraluminous biotite in the two-mica granite and in muscovite granite, and a secondary subhedral Si enriched and Mg-bearing, Ti-poor mica formed as a hydrothermal alteration product of feldspars, and is present in all rock types. Given the compositional continuum of “white micas”, we suggest that magmatic crystallization was followed by autometasomatic and hydrothermal activity, due to a water-rich liquid rapped in the rock during the final stages of magmatic activity. Based on the bulk composition of the prevailing rock-type, the abundance of primary muscovite, the majority of the granitoid magma crystallized from a watersaturated peraluminous melt for which the pressure was 490–600 MPa, the temperatures were 650–685 °C and the depth of the intrusion was a minimum of 15 km.
Downloads
Article Details
Authors have copyright and publishing rights on all published manuscripts.
References
ABDEL-RAHMAN, A.F.M. (1994): Nature of biotites from alkaline, calc-alkaline and peraluminous magmas. – J. Petrology 35, 525–541.
BUDA GY. (1975): Classification of the Hungarian granitoid rocks on the basis of feldspar investigation. – CBGA. Proc. Xth Congress, Sec. III. 67–74.
BUDA GY., KOLLER F., KOVÁCS J. & ULRYCH J. (2004/a): Compositional variation of biotite from Variscan granitoids in Central Europe: a statistical evaluation. – Acta Mineralogica-Petrographica, Szeged. 45/1, 21–37.
BUDA GY., KOLLER F. & ULRYCH J. (2004/b): Petrochemistry of Variscan granitoids of Central Europe: Correlation of Variscan granitoids of Tisia and Pelsonian Terranes with granitoids of the Moldanubicum, Western Carpathian and Southern Alps. A review: Part I. – Acta Geologica Hungarica 47/2–3, 117–138.
CHATTERJEE N.D. & JOHANNES W. (1974): Thermal stability and standard thermodynamic properties of synthetic 2M1-muscovite, KAl2AlSi3O10(OH)2. –Contrib. Mineral. Petrol 48, 89–114.
CLARKE D.B. (1992): Granitoid rocks. – Chapman and Hall 283 p.
CLEMENS J.D. & WALL V.J. (1988): Controls on the mineralogy of S-type volcanic and plutonic rocks. – Lithos 21, 53–66.
DEBON F. & LE FORT P. (1983): A chemical-mineralogical classification of common plutonic rocks and association. – Trans. Royal Soc. Edinburgh: Earth Sciences 73, 135–149.
HOLDAWAY M.J. (1971): Stability of andalusite and the aluminum silicate phase diagram. – Am. J. Sci. 271, 97–131.
JOHANNES W. & HOLTZ F. (1996): Petrogenesis and experimental petrology of granitic rocks. – Minerals and rocks. Springer- Verlag, 335 p.
KERRICK D.M. (1972): Experimental determination of muscovite + quartz stability PH2O< Ptotat. – American Journal of Science 272, 946–958.
KOVÁCS S., SZEDERKÉNYI T., HAAS J., BUDA GY., CSÁSZÁR G. & NAGYMAROSY A. (2000): Tectonostratigraphic terranes in the pre-Neogene basement of the Hungarian part of the Pannonian area. – Acta Geol. Hung. 43/3, 225–328.
KOVÁCS S., BUDA GY., HAAS J., BREZSNYÁNSZKY K. & HARANGI SZ. (2010): Tectonostratigraphic terranes and zones juxtaposed along the Mid-Hungarian line: their contrasting evolution and relationships. – Central European Geology. 53/2-3, 165-180. DOI: 10.1556/CEuGeol.53.2010.2-3.4
MILLER C.V., STODDARD E.F., BRADFISH L.J. & DOLLASE W.A. (1981): Composition of plutonic muscovite: genetic implications. – Canadian Mineralogist 19, 25–34.
MONIER G. & ROBERT J.L. (1989): Titanium in muscovites from two mica granites: Substitutional mechanism and partition with coexisting biotites. – Neues Jahrbuch Miner. Abh. 153/2, 147–161.
MONIER G., MERGOLD-DANIEL J. & LABERNARDIÉRE H. (1984): Générations successives de muscovites et feldspaths potassiques dans leucogranite du massif de Millevaches (Massif Central francais). – Bull. Minéral 107, 55–68
PÁL-MOLNÁR E., KOVÁCS G. & BATKI A. (2001): Petrographical characteristics of Variscan granitoids of Battonya Unit boreholes (SE Hungary). – Acta Mineralogica-Petrographica, Szeged. 42, 21–31.
PITCHER W.S. (1993): The nature and origin of granite. – Blackie Academic and Professional London, Glasgow etc. 321 p.
SPEER J.A. (1984): Micas in igneous rocks. – In Mineralogical Society of America. Reviews in Mineralogy. 13, 299–356.
TUTTLE O.F.& BOWEN N.L. (1958): Origin of granite in the light of experimental studies in the system NaAlSi3O8-KAlSi3O8-H2O. Geol. Soc. Am. Mem. 74, 153.
WHITE A.J.R., CLEMENS J.D., HOLLOWAY J.R., SILVER L.T., CHAPPELL B.W. & WALL V.J. (1986): S-type granites and their probable absence in southwestern North America. – Geology 14, 115–118.
WYLLIE P.J. (1977): Crustal anatexis: an experimental review. Tectonophysics 43, 41–71
ZEN E-AN (1988): Phase relations of peraluminous granitic rocks and their petrogenetic implicatios. – Ann. Rev. Earth Planet. Sci. 16, 21–51.