Sfalerit různých genetických typů sulfidického zrudnění na uranovém ložisku Rožná
Článek v PDFSphalerite of different genetic types of sulphide ore mineralization in the uranium deposit Rožná
Sphalerites from an uranium mine near Rožná in the Czech Republic are identified and studied with respect to their origin. Three genetic types were recognized: stratidependent disseminated sulphide mineralization in marbles, early siderite-sulphide veins together with sphalerites of metasomatites in vicinity of these veins, and latest veins with barite-fluorite-sulphides assemblage. Microprobe analyses and stable isotopic study has proved that the sphalerites of early siderite-sulphide veins differ from those of disseminated ores in marbles. The origin of sulphides in marbles is connected to the protolith of these rocks. On the other hand, the sphalerites of the sulphide-siderite veins are remarkably close to those from the metasomatites in vicinity of these veins. Isotopic study of sulphide sulphur has shown that hydrothermal fluids are derived from the deep sources. Sphalerites precipitated between 260-330 °C. Youngest sphalerites of the barite-fluorite-sulphide stage were probably formed solely from fluids of the local circulation.
Hana Doležalová, Department of Mineralogy and Petrology, Moravian Museum, Zelný trh 6, 659 37 Brno, Czech Republic, e-mail: hdolezalova@mzm.cz
Zdeněk Losos, Institute of Geological Sciences, Fac. of Sci., Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic, e-mail: losos@sci.muni.cz