Hematite–Carbonate Gossanites in the Yubileinoe Massive Sulfide Deposit (South Urals): Evidence of the Replacement of Sulfide Clasts and Hyaloclasts

The article considers the textural and structural features of hematite–carbonate rocks associated with carbonate–sulfide clastic ores in the Yubileinoe massive sulfide deposit, South Urals. Some hematite–carbonate rocks exhibit signs of the replacement of sulfide clasts and hyaloclasts by the hematite–carbonate material, classified as carbonate analogs of gossanites. The hematite–carbonate aggregates after sulfide clasts are characterized by the inherited reniform–colloform, radial, and crystalline-granular structures, as well as the inclusions of relict sulfides and tellurides. The hematite–carbonate aggregates after sulfide clasts contain elevated concentrations of chalcophile (Cu, Zn, Pb, As, Sb, Bi, and Te) and lithophile (Ti, Zr, V, and W) trace elements. The hematite–carbonate clasts after hyaloclasts characterized by the presence of aggregates with globular structure and syneresis cracks, and contain relics of chlorite aggregates. The matrix of hematite–carbonate rocks consists of calcite with inclusions and aggregates of dolomite, chlorite, quartz, and apatite. Late sulfide mineralization (pyrite metacrystals, as well as aggregates and veins of chalcopyrite and sphalerite) is characteristic of both hematite–carbonate rocks after sulfide clasts and hyaloclasts.