Carbonate mineralization of the Rudnany ore field

The rocks of the Rudnany ore field contains besides siderite also dolomite, Fe-dolomite, ankerite, calcite and virtually all members of the siderite - magnesite isomorphous series. The authors investigated quantity and mineral species of carbonates in the lithostratigraphic units and they characterised their distribution, mode of occurrence, mutual relationship and isotopic composition. The study showed that there is a direct qualitative dependence of the present carbonate species upon the lithological and petrographic rock type. The dependence is very strict in the case of magnesite - breunnerite and calcite, less pronounced for siderite and loose in the case of ankerite and Fe-dolomite. Isotopic composition of the studied carbonates suggests presence of both typical deep-seated source of carbon as well as sedimentary marine carbon. It indicates a marine source for the studied carbonates and their primary rocks. (authors)