The Promesa project is a porphyry copper-gold-silver system, located at an elevation between 3,800 m to 4,400 m asl. It is approximately 360 kms by road from the City of Cusco on paved highway along the Lima-Nazca highway where it turns off to the property for a further 7.2 km of rugged road. The property comprises three concessions covering 3,000 kms with gentle topography to deep valleys.
The Promesa project is located between 35 and 42 km to the west of the northwest corridor with three other projects in advanced exploration: Los Chancas (Southern Peru), Trapiche (Minera Buenaventura) and Antilla (Panoro Minerals). It is located in the north extreme of a 55 km corridor including the silver-gold mines of Inmaculada, Pallancata and Selene owned by Minera Hochschild Mining PLC.
At Promesa, a composite, north-oriented, hornblende and quartz-eye bearing porphyry stock of granodiorite composition intrudes a dominantly clastic sequence of quartz-arenite and pelite of the Early Cretaceous Soraya Formation. Hydrothermal alteration is dominated by biotite and K-feldspar bearing potassic assemblages that affect the intrusive units and certain pelitic horizons of the country rock, whereas quartz-sericitic alteration is locally present in transgressive veins of D-type and more commonly occupies a peripheral position in quartz-arenite country rock. Copper mineralization accompanies moderate to weak quartz-stockworks with chalcopyrite primarily hosted by the composite porphyry stock near its contact with the host sedimentary sequence. Minor supergene chalcocite is present at the redox front in quartz-sericite altered country rock."
Exploration Campaigns
From 2002 to 2012 three exploration campaigns were completed:
Cordillera de la Minas, 2002 to 2003
In 2002, based on a sediment sampling campaign and results of 908 samples, first-order anomalies were defined and then reviewed with mapping at 1:2000 scale.
Cordillera de la Minas, 2003 to 2008
In 2003, a detailed geological survey was carried out at 1:2000 scale, in an area of 1,200 hectares. Geochemical sampling of 706 rock chip samples was completed. Geophysical surveys of 8.2 km IP and 95.3 km magnetometry. Four drill holes were completed and drilled totaling 1,540.4 meters.
The drillholes intercepted mineralized zones as shown in the table below:
Drillhole | From (m) | To (m) | Length (m) | Cu (%) | Au (g/t) | Ag (g/t) | Mo (%) | Trend | Host Rock | Zone |
PRO-01 | 34 | 450 | 416 | 0.21 | 0.05 | 2.07 | 0.01 | - | - | - |
Include | 40 | 290 | 25 | 0.17 | 0.05 | 2.08 | 0.008 | El Cofre | Diorite/QMP | Primary |
Include | 242 | 250 | 8 | 0.39 | 0.09 | 3.30 | 0.01 | El Cofre | Diorite | Primary |
Include | 308 | 450 | 142 | 0.27 | 0.07 | 2.29 | 0.012 | El Cofre | Diorite/QMP | Primary |
Include | 368 | 384 | 16 | 0.49 | 0.14 | 3.10 | 0.01 | El Cofre | QMP | Primary |
PRO-02 | 6 | 385 | 375 | 0.21 | 0.05 | 4.31 | 0.009 | - | - | - |
Include | 6 | 100 | 94 | 0.25 | 0.07 | 10.90 | 0.006 | El Cofre | Diorite/QMP | Seconday/ Primary |
Include | 12 | 28 | 16 | 0.54 | 0.03 | 1.90 | 0.006 | El Cofre | Quartzites/Sandstones | Supergene |
Include | 296 | 385 | 89 | 0.38 | 0.07 | 3.98 | 0.005 | Esperanza | QMP | Primary |
Include | 314 | 376 | 62 | 0.43 | 0.09 | 1.80 | 0.006 | Esperanza | QMP | Primary |
PRO-03 | 6 | 255 | 249 | 0.18 | 0.05 | 2.84 | 0.009 | - | - | - |
Include | 140 | 255 | 115 | 0.25 | 0.08 | 4.03 | 0.1 | Milagros | Andesite/Sandstone | Primary |
Include | 236 | 244 | 8 | 0.40 | 0.07 | 3.10 | 0.1 | Milagros | Andesite/Sandstone | Primary |
Include | 250 | 252 | 2 | 2.15 | 0.42 | 4.10 | 0.013 | Milagros | QMP/Sandstone | Primary |
PRO-04 | 18 | 450 | 432 | 0.18 | 0.04 | 2.26 | 0.005 | - | - | - |
Include | 84 | 286 | 202 | 0.26 | 0.06 | 3.48 | 0.006 | Esperanza | QMP/Sand-Quartzites | Primary |
Include | 164 | 188 | 24 | 0.52 | 0.12 | 1.60 | 0.005 | Esperanza | QMP | Primary |
Include | 234 | 238 | 4 | 0.50 | 0.22 | 2.10 | 0.006 | Esperanza | Hydrothermal Breccia | Primary |
The presence of mineralized intervals grading above 0.4% Cu and up to 0.43 g/t Au indicates that the property has the potential to host a porphyry copper-gold deposit in addition to possibly hosting supergene copper mineralization in the sediments as shown by the presence of incipient chalcocite enrichment in PRO-02. Also it is noted the presence of copper and the high continuity of the mineralization along the length of the four drillholes.
Panoro Minerals, 2008 to 2012
In the 2012 campaign the exploration work was carried out including 44 rock chip samples, 75.85 km of Magnetometry, 75.85 km of self potential, 74.9 km of IP and a 1:2000 geological survey over a total of 2000 hectares. Panoro has identified four exploration targets in the property of which Target 1 shows the level of the mineralized porphyry exposed at surface where four drillholes were completed by CDLM. The magnetometer survey covered a large portion of the area of interest and a main intensive magnetic response is recognized below Target 1 and extends below the sediments to the north, overall surrounded by a high chargeability halo.
Luis Vela, P. Geo., Vice President of Exploration for Panoro and a "qualified person" under National Instrument 43-101, has reviewed and approved the scientific and technical information.