The Kremnica Au-Ag epithermal deposit: an example of laterally outflowing hydrothermal system?

The Neogene Kremnica low-sulphidation deposit is situated on marginal faults of a resurgent horst, associated with rhyolite magmatism. Wallrock alteration includes adularia, illite or I/S and kaolinite. South of the vein system extensive alteration continues with zones dominated by kaolinite, I/S and smectite replacing rhyolite. Fluid inclusion and stable isotope data indicate lateral outflow of fluids from N to S, with major boiling and Au deposition in central part of the vein system. Large areas of steam-heated waters probably accompanied the veins at subsurface level, while their outflow to S could be responsible for the extensive alteration of rhyolites, sporadic low-grade quartz/chalcedony veinlets with stibnite and silicite deposits in local limnic/lacustrine basins.