Mineralogy of magnetite-grunerite-siderite ores in Radoškov (Bílý potok Unit, Svratka dome, Moravicum)Article PDF
Mineralogy of magnetite-grunerite-siderite ores in Radoškov (Bílý potok Unit, Svratka dome, Moravicum)
Metamorphic iron mineralization was documented in an abandoned adit east of Radoškov, Czech Republic. Siderite-rich ore with magnetite, amphibole asbestos, chlorite and small amounts of pyrite occur in chlorite-muscovite and muscovite-biotite phyllites (Svratka Dome, Moravicum). Siderite associated with abundant pyrite and accessory (relic?) muscovite but no amphibole was detected in the same lithology at similar locality Javůrek-Stříbrnice. Siderite is (especially at the first locality) texturally complicated, mostly Mg-rich (20–40% Mg-component) with a low contents of Mn (Stříbrnice) and belongs among paragenetically early minerals. White fibrous amphibole and magnetite are younger metamorphic products. Chemical composition of the amphibole corresponds to grunerite with significant cummingtonite component (XMg = 37–38), contents of other elements (e.g. Ca, Al) are very low. Sulphides are represented by pyrite and rare arsenopyrite. Conditions of metamorphic overprint were not precisely defined due to the wide stability of the assemblage siderite-magnetite-grunerite; major mineral assemblage of the surrounding metapelites (quartz+albite+chlorite+biotite+magnetite) indicates greenschist facies.
Eva Víšková, Vladimír Hrazdil, Stanislav Houzar, Department of Mineralogy and Petrography, Moravian Museum, Zelný trh 6, 659 37 Brno, Czech Republic, firstname.lastname@example.org.
Bohuslav Fojt, Institute of Geological Sciences, Masaryk University, Kotlářská 2, Brno, Czech Republic; email@example.com