Although detailed petrologic studies of veins in the Velardeña property have not been completed, individual deposits within the nearby Santa María dome have been studied in some detail and found to correspond to both shallow epithermal and deeper-seated mesothermal styles of mineralization. Epithermal veins, often displaying banded and open-space-filling quartz, occur at the Industria Mine where they are clearly distal to the main intrusive mass. The higher-level veins at Velardeña appear to be of this type. Many veins, especially at deeper levels in the Santa Juana and Terneras mines, are dominated by high modal percentages of coarse and fine grained, polymetallic sulfides, have little silicate gangue, and occupy a position within and proximal to intrusions and their thermally metamorphosed aureoles.
True epithermal veins occur at Velardeña, but at depth the majority of veins, breccias, and massive sulfide replacements are mesothermal in character, commonly contain arsenopyrite, and may be related to a deeper intrusive source.
Two main vein systems are present on the Velardeña property. The first is the northwest striking system found in the Santa Juana deposit, while the second is the east-west trending vein array which includes the Terneras, San Juanes, Roca Negra and San Mateo deposits.
Mineralization consists primarily of calcite-quartz veins with minor calc-silicate hosted (“skarn”) and massive sulfide replacement bodies. All mineraliza ........
