Zelená slída s podílem chromu v balinských slepencích rosicko-oslavanského souvrství (svrchní karbon) u OslavanČlánek v PDF
Green chromium-bearing mica in Balinka Conglomerates of Rosice-Oslavany Formation (Upper Carboniferous) at Oslavany
Clasts of light-green mica containing chromium were recorded in the Upper Carboniferous conglomerates at Oslavany (Rosice-Oslavany Coalfield, Boskovice Graben). It is a potassium-deficient muscovite to illite (0.514–0.912 apfu K) with 0.88–2.29 wt. % Cr2O3 (0.046–0.119 apfu Cr). Slightly increased both Mg (0.180–0.440 apfu Mg) and Fe (0.151–0.169 apfu Fe) contents also were detected. Mica is very low in Ti (< 0.003 apfu), V (< 0.002 apfu), Mn (< 0.002 apfu) and F (<0.052 apfu); Ba lies below detection. The origin of the clastic material of the Balinka conglomerates can be found in the crystalline complexes in the vicinity. Chromium-bearing mica could originate from hydrothermally altered spinel peridotites or other ultramafics of adjacent Moldanubicum (Gföhl Unit) or Moravian unit.
Stanislav Houzar, Department of Mineralogy and Petrography, Moravian Museum, Zelný trh 6, 659 37 Brno, Czech Republic
Petra Kopečná, Department of Geological Sciences, Faculty of Science. Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
Jindřich Štelcl, Václav Vávra, Department of Geological Sciences, Faculty of Science. Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic; Department of Biology, Faculty of Education, Poříčí 7, 603 00 Brno, Czech Republic