The property is centered around the large, 1.4-kilometre-diameter Cerro Hermoso diatreme which hosts extensive mineralization. Miramont has identified three priority targets for further exploration and initial drilling.
Central Breccia Zone
This zone is found within the heart of the diatreme. The formation of gold-bearing hydrothermal breccia, the potential host-rock for mineralization, is extensive. Three separate phases of breccia have been identified all of which host gold. Historic channel sampling in the central breccia resulted in 43 meters averaging 1.8 g/t. Selective sampling by Miramont has confirmed the channel sample results and expanded the Central Breccia zone. The high value for gold is 18.4 g/t while 87 of 178 samples collected were greater than 0.1 g/t.
Other outcrops of mineralized breccias have been found up to 800 meters away. This indicates the widespread presence of gold and the extensive tonnage potential of this receptive host rock.
The Stockwork Zone
The stockwork zone lies just outside the northern rim of the diatreme. It is a 500 by 400 meter area of extensive stockwork veining developed within the Tacaza andesite unit. It is also adjacent to an outcropping hornblende diorite intrusion. Finally all of this appears to be contained within a separate fault-block concentric to the diatreme margin.
Stockwork veining here consists of a patchy to pervasive, crisscrossing network of quartz veinlets. Mineralization at surface is mostly oxidized metal sulfides although occasional fresher sulfide grains can be seen.
The Stockwork Zone has significant silver, copper, and gold mineralization throughout the area (see geochem maps). Values as high as 500 g/t Ag, 3.9% Cu and 10 g/t Au have been found here. Of a total 79 samples collected in this area 67 had more than 10 g/t Ag, 29 had more than 0.1% copper and 13 had greater than 0.5 g/t Au.
The combination of intrusive activity, structural setting and widespread mineralization makes this an excellent target.
Carbonate Replacement Zone
This zone is known from a review of investigations carried out by previous operators of the Santa Barbara mine. Development on lower levels (approx. 200 meters below surface) encountered carbonate replacement deposits (CRD’s) within the underlying Ayavaca limestone unit. Values up to 6.9% Zn, 6.6% Pb and 6.2 oz/t Ag have been found in multiple horizons.
Examination of old mine dump material has identified massive sulfide in limestone as well as some possible marble/skarn. This latter is an indication of skarn formation where limestone comes into contact with intrusive rock. Skarn deposits, such as the nearby Tintaya and Las Bambas Mines, can be major precious and base-metal producers.
Other Targets
Miramont geologists have identified other target areas within the concessions. These are currently defined as secondary but may be upgraded to priority as new mapping, geochemical sampling and geophysical information become available.
Geochemical anomalies in all target areas for gold, silver and copper are shown in these maps.