Mineralogical and Fluid Inclusion Evidence for Reworking of Au Mineralization by Ag-Sb-Base Metal-Rich Fluids from the Bytíz Deposit, Příbram Uranium and Base-Metal Ore District, Czech Republic

This mineralogical and fluid inclusion study was conducted on an Au-bearing quartz–sulfide vein encountered in the deep parts of Bytíz deposit Příbram uranium base-metal district, Bohemian Massif, Czech Republic. The samples were taken where is crosscut by common Zn-Pb ore Bt23C. early mineralization composed mainly quartz (Q-1 to Q-3), illite–muscovite, Fe-Mg chlorite, arsenopyrite, Au-Ag alloys, showing a wide range compositions (4–69 at. % Ag) decrease Au/(Au + ratios during evolution. Younger hydrothermal processes led crystallization nests veinlets late (Q-4), carbonates (siderite, dolomite–ankerite calcite), sulfides (galena, sphalerite, chalcopyrite, tetrahedrite), suite Ag Bi-tellurides, acanthite. input Sb manifested partial complete replacement some gold grains aurostibite unnamed (Ag,Au)-Sb oxide with composition close AuSbO3. study, combined chlorite thermometry arsenopyrite thermometry, showed that crystallized from progressively cooled (from 300 400 °C down ca. 180 °C), diluted (1.2–7.0 wt. NaCl eq.) aqueous solutions. portion formed fluids highly variable salinity (0.2–23.4 homogenization temperatures decreasing 250 < 50 °C, which compare well Bt23C other veins area. Our illustrates nature intensity reworking mediated younger Ag,Sb-rich fluids, giving rise Příbram’s typical late-Variscan mineralization.