ISSN
print 2570-7337
online 2570-7345
Minerals and geochemistry of the Bratislava - Jezuitské Lesy granitic pegmatite (Slovakia)
Keywords
Abstract
The Bratislava - Jezuitské Lesy granitic pegmatite forms a relatively narrow dike (up to 1 - 2 m thick) in parental Hercynian (~350 Ma) S-type granodiorite to granite. The pegmatite internal zoning consists of a coarse-grained quartz-feldspar-muscovite zone, locally with transition into a graphic pegmatite, blocky K-feldspar and massive quartz. An aplitic saccharoidal albite (albite >> quartz + muscovite + garnet) and cleavelandite extensively replace the older pegmatite zones. Beryl, garnet (almandine > spessartine), zircon (£12 wt.% HfO2), monazite to cheralite, Nb-Ta-(Sn) oxide minerals (all columbite-tantalite members, ferrotapiolite, ferrowodginite), and gahnite occur in coarse-grained zone as well as saccharoidal albite. The pegmatite is enriched in Rb, Cs, Be, Nb, Ta, Sn and W and depleted in Li, Sr, Ba, Zr and REE`s. These geochemical features and mineral composition show a relatively highly fractionated pegmatite melt and beryl-columbite subtype of the rare-element class and LCT tendency of the pegmatite. Moreover, anomalously high Y/Ho value (60) and presence of the lanthanide tetrad effect (T1,3 = 1.17), together with presence of fluorapatite (£10 wt.% MnO) and fluorcalciomicrolite, indicate an influence of fluorine-rich fluids during late magmatic to early hydrothermal (high-temperature) evolution stage of the pegmatite. On the contrary, phenakite, bertrandite, quartz II, and muscovite II originated during late hydrothermal (low-temperature) overprint of the pegmatite as a result of post-magmatic Hercynian uplift or Alpine tectono-thermal overprint of the Bratislava granitic massif.
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References
Bau M. (1996) Controls on the fractionation of isovalent trace elements in magmatic and aqueous systems: evidence from Y/Ho, Zr/Hf, and lanthanide tetrad effect. Contrib. Mineral. Petrol. 123, 323-333.
Broska I., Uher P. (2001) Whole-rock chemistry and genetic typology of the West-Carpathian Variscan granites. Geol. Carpath. 52, 79-90.
Cambel B., Vilinovič V. (1987) Geochémia a petrológia granitoidných hornín Malých Karpát. 1-248, Veda, Bratislava.
Černý P., Ercit T. S. (2005) The classification of granitic pegmatites revisited. Can. Mineral. 43, 2005-2026.
Černý P., Meintzer R. E., Anderson A. J. (1985) Extreme fractionation in rare-element granitic pegmatites: selected examples of data and mechanisms. Can. Mineral. 23, 381-421.
Dávidová Š. (1968) Granáty z pegmatitov Malých Karpát. Acta Geol. Geogr. Univ. Comen. Geol. 13, 117-128.
Dávidová Š. (1970) Charakteristik der Pegmatite der Kleinen Karpaten. Geol. Zbor. Geol. Carpath. 21, 115-137.
Dávidová Š. (1978) Mineralógia a petrografia pegmatitov kryštalinika tatríd. Mineralia Slov. 10, 127-146.
Gargulák M., Vanek J. (1989) Beryl - prvý nález z pegmatitov Malých Karpát. Mineralia Slov. 21, 426.
Gbelský J. (1979) Electron microprobe determination of Zr/Hf ratios in zircons from pegmatites of the Malé Karpaty Mts. (West Carpathians). Geol. Zbor. Geol. Carpath. 30, 463-474.
Gbelský J. (1980) Composition of the main morphological types of garnets from pegmatites of the Malé Karpaty Mts. (West Carpathians). Geol. Zbor. Geol. Carpath. 31, 185-199.
Gbelský J., Krištín J. (1985) Gahnit v pegmatitoch Malých Karpát - príspevok k topografickej mineralógii Slovenska. In: Veselský J., Beňka J., Gbelský J. (eds.): Akcesorické minerály - ich petrogenetický a metalogenetický význam, 65-70. Geologický ústav D. Štúra, Bratislava.
Chudík P., Uher P. (2011) Niobium-tantalum oxide minerals in the Jezuitské Lesy granitic pegmatite, Bratislava massif, Slovakia: Ta to Nb and Fe to Mn evolutionary trends on a narrow Be,Cs-rich and Li,B-poor dike. Miner. Petrol. 102, 15-27.
Irber W. (1999) The lanthanide tetrad effect and its correlation with K/Rb, Eu/Eu*, Sr/Eu, Y/Ho, and Zr/Hf of evolving peraluminous granite suites. Geochim. Cosmochim. Acta 63, 489-508.
Kohút M., Uher P. Putiš M., Ondrejka M., Sergeev S., Larionov A., Paderin A. (2009) SHRIMP U-Th-Pb zircon dating of the granitoid massifs in the Malé Karpaty Mountains (Western Carpathians): evidence of Meso-Hercynian successive S- to I-type granitic magmatism. Geol. Carpath. 60, 345-350.
London D. (2008) Pegmatites. 1-348, The Canadian Mineralogist, Special Publication 10, Mineralogical Association of Canada, Québec.
Maheľ M., Cambel B. (1972) Geologická mapa Malých Karpát. Geologický ústav D. Štúra, Bratislava.
McDonough W. F., Sun S.-s. (1995) The composition of the Earth. Chem. Geol. 120, 223-253.
Ondrejka M., Uher P., Putiš M., Broska I., Bačík P., Konečný P., Schmiedt I. (2012) Two-stage breakdown of monazite by post-magmatic and metamorphic fluids: An example from the Veporic orthogneiss, Western Carpathians, Slovakia. Lithos 142-143, 245-255.
Ozdín D. (2010) Beryl a fenakit z granitových pegmatitov tunela Sitina v Bratislave. Bull. mineral.-petrolog. Odd. Nár. Muz. (Praha), 18, 78-84.
Uher P. (1992) Vzácnoprvková Be-Nb-Ta mineralizácia v granitových pegmatitoch Západných Karpát. MS, kandidátska dizertačná práca, Geologický ústav SAV, Bratislava.
Uher P., Broska I. (1995) Pegmatites in two suites of Variscan orogenic rocks (Western Carpathians, Slovakia). Mineral. Petrol. 55, 27-36.
Uher P., Černý P., Novák M., Siman P. (1994) Niobium-tantalum minerals from granitic pegmatites in the Malé Karpaty, Považský Inovec and Žiar Mountains, Western Carpathians, Slovakia. Mineralia Slov. 26, 157-164.
Uher P., Chudík P., Bačík P., Vaculovič T., Galiová M. (2010) Beryl composition and evolution trends: an example from granitic pegmatites of the beryl-columbite subtype, Western Carpathians, Slovakia. J. Geosci. 55, 69-80.
Uher P., Kohút M., Ondrejka M., Konečný P., Siman P. (in print) Monazite-(Ce) in Hercynian granites and pegmatites of the Bratislava Massif, Western Carpathians: compositional variations and Th-U-Pb electron-microprobe dating. Acta Geol. Slov.
Uher P., Žitňan P., Ozdín D. (2007) Pegmatitic Nb-Ta oxide minerals in alluvial placers from Limbach, Bratislava Massif, Western Carpathians, Slovakia: compositional variations and evolutionary trend. J. Geosci. 52, 133-141.
Valach J. (1954) Žulové pegmatity Malých Karpát. Geol. Sbor. Slov. Akad. Vied 5, 26-58.
Veselský J., Gbelský J. (1978) Výsledky štúdia akcesorických minerálov granitoidov a pegmatitov Malých Karpát. Acta Geol. Geogr. Univ. Comen. Geol. 33, 91-111.