Low sulfidation epithermal
The measured and indicated resources in 2012 were 31.6 Mt at 0.80 g/t Au (25.42 t ) and 1.74 g/t Ag (43.54 t ) at a cutoff of 0.2 g/t Au, plus inferred resources of 3.3 Mt at 0.35 g/t Au (1.16 t) and 1.05 g/t Ag (3.47 t) (Archibald et al., 2012). Proven and probable reserves were 15.3 Mt at 1.31 g/t Au (20.00 t) and 2.1 g/t Ag (31.10 t), at a cut-off of 0.2 g/t Au. The deposit is hosted by a sequence of massive and fragmental andesitic volcanic rocks including flow breccias, lapilli tuffs and lavas which are cut by feldspar-quartz porphyries forming sills and phacoliths. These rocks are cut by several steeply-dipping, NE-striking faults. Gold occurs in multi-phase quartz-carbonate veins and vein breccias with chalcedony and to a lesser extent in altered intrusions or in quartz stockworks. There are two orebodies, the Main and Northwest Zones. The Main Zone, which outcrops on Loma Blanca, is 1,100 m long NE with 450 m dip length and width up to 75 m, and dips at 30° NW becoming sub-horizontal at depth. The Northwest Zone sits above the Main Zone and is sub-horizontal to SE-dipping and joins with the Main Zone.

Other Regions, Features and Areas containing this locality

References