Výskyt mikrogranitu s granofyrickou strukturou na hranici dioritové a metabazitové zóny brněnského masivu východně od Jinačovic
Roč.18,č.2(2011)
Tectonic slices of microgranites are exposed in the Metabazite Zone along its boundary with the Diorite Zone of the Cadomian Brno Massif. Rock with granophyric texture was found SW of the Velká Baba Hill. Granophyre is composed of irregular intergrows of quartz and feldspars arranged around albite lath. Rounded quartz is also presented. The granophyre has a chemical composition of trondhjemite, trace elements geochemistry can be well correlated with composition of rhyolites forming layers in metabazalts. Both rocks have character of within-plate to ocean-ridge granites and granophyres are interpreted as subvolcanic equivalent of rhyolites.
Brno Massif; granophyre; geochemistry; geotectonic position
Al-Shanti, A. M. S. – Abdel-Monem, A. A. – Marzouki, F. H. (1984), Geochemistry, petrology and Rb-Sr dating of trondhjemite and granophyre associated with Jabal Tays Ophiolite, Idsas area, Saudi Arabia. – Precambrian Research, 24 (3–4), 321–334.
Barker, D. S. (1970): Compositions of Granophyre, Myrmekite, and Graphic Granite. – Geol. Soc. Amer. Bull., 81, 3339–3350.
Boynton, W. V. (1984), Cosmochemistry of the rare earth elements: meteorite studies. – In: P. E. Henderson (ed), Rare Earth Element Geochemistry. – Elsevier, Amsterdam, 63–114.
Cox, K. G. – Bell, J. D. – Pankhurst, R. J. (1979): The Interpretation of Igneous Rocks. – George Allen & Unwin., London, pp. 450.
Dudek, A. – Weiss, J. (1963): Západomoravské krystalinikum. – Sbor. XIV. sjezdu Spol. pro min. a geol., 5–18.
Finger, F. – Hanžl, P. – Pin, C. – Von, Q. A. – Steyrer, H. P. (2000a): The Brunovistulian, Avalonian Precambrian sequence at the eastern end of the Central European Variscides? In: Franke, W., Haak, V., Oncken, O., Tanner, D. (eds): Orogenic Processes, Quantification and modelling in the Variscan Belt. – Geological Society, London, Special Publication, 179, 103–112.
Finger, F. – Tichomirowa, M. – Pin, C. – Hanžl, P. (2000b): Relics of an early-Panafrican metabasite-metarhyolite formation in the Brno Massif, Moravia, Czech Republic. – Int. J. Earth Sci, 89, 328–335.
Guidotti, C. V. (1984): Micas in metamorphic rocks. – Reviews in Mineralogy, 357–467.
Hanžl, P. (1997): Structural profil through the Brno Massif. – EGSRE, IV, 1.
Hanžl, P. – Melichar, R. (1997): The Brno Massif: A section through the active continental margin or a composed terrane? – Krystalinikum, 23, 33–58.
Johannsen, V. (1962): A descriptive petrography of the igneous rocks. – Chicago Univ. Press, Chicago. 468 s.
Leichmann, J. – Höck, V. (2008): The Brno Batholith: An insight into the magmatic and metamorphic evolution of the Cadomian Brunovistulian unit, eastern margin of the Bohemian Massif. – Journal of Geosciences, 53 (3–4), 281–305.
Lowenstern, J. B. – Clynne, M. A. – Bullen, T. D. (1997): Comagmatic A-type granophyre and rhyolite from the Alid volcanic center, eritrea, northeast Africa. – Journal of Petrology, 38 (12), 1707–1721.
Malý, J. – Weiss, J. (1987): Nově zjištěná ultrabazitová tělesa u Jinačovic v metabazitové zóně brněnského masívu. – Časopis pro mineralogii a geologii, 32, 2.
O‘Connor, J. T. (1965): A classification for quartz-rich igneous rocks based on feldspar ratios. – In: US Geological Survey Professional Paper B525. – USGS, 79–84.
Pearce, J. A. – Harris, N. B. W. – Tindle, A. G. (1984): Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. – J. Petrology, 25, 956–983.
Peccerillo, A. – Taylor, S. R. (1976): Geochemistry of Eocene calc-alkaline volcanic rocks from the Kastamonu area, northern Turkey – Contrib Mineral Petrol 68, 61–81.
Sedlák, J. (1993): Severní část brněnské aglomerace. Tíhové meření 1 : 25 000. – MS, Geofyzika Brno.
Shelley, D. (1992): Igneous and metamorphic rocks under the microscope. – Chapman & Hall, 445 str.
Shortland, R. A. – Salmon, S. – Rowhotiiam, G. – Regan, P. F. (1996): Coexisting acid and basic magmas of the Elizabeth Castle igneous complex, Jersey, Channel islands. – Geoscience in South-West England, 9 (1), 121–126.
Schandl, E. S. – Gorton, M. P. (2002): Application of high field strength elements to discriminate tectonic settings in VMS environments. – Economic Geology, 97 (3), 629–642.
Tuttle, O. F. – Bowen, N. L. (1958): Origin of granite in the light of experimental studies in the system NaAlSi3O8-KAlSi3O8-SiO2-H2O. – Geol. Soc. Am. Mem., 74, 1–151.
Zapletal, K. (1928): Geologie a petrografie okolí brněnského. – Čas. Mor. Zem. Muz., 25, 67–111.