NÁLEZ NEOBVYKLÉ MLADŠÍ SIDERITOVÉ VÝPLNĚ RUDNÍ ŽÍLY V HRABŮVCE (KULM NÍZKÉHO JESENÍKU)

A fine-grained siderite rock was found to form a younger stage of subvertical NNW-SSE trending polymetallic post-Variscan Zn-Pb vein hosted by the Lower Carboniferous greywackes in the Hrabůvka quarry. The rock is formed mainly by sparitic Fe-rich carbonate (siderite to Mg-siderite) containing small admixture (~15 wt. %) of detritic component composed of clay, and fragments of older hydrothermal minerals and host greywacke. Except of siderite, the authigenic phases are represented also by minor framboidal pyrite and sphalerite. Bulk chemical composition is characterized by high both FeO (40.6 wt. %) and CO2 (32.6 wt. %) contents. Rare earth element abundances and stable isotope data are similar to those of local Tertiary sediments and different from those characterizing the post-Variscan vein dolomite. It is concluded that the studied siderite probably originated during sideritization of carbonate-rich Tertiary sediment, which sink into the reactivated fault that has been already earlier (during the post-Variscan period) cemented by Zn-Pb mineralization