Geology

The Mocoa deposit is situated in the Eastern Cordillera of Colombia, a 30km wide tectonic belt underlain by volcano-sedimentary, sedimentary and intrusive rocks that range in age from Triassic-Jurassic to Quaternary, and by remnants of Paleozoic metasediments and metamorphic rocks of Precambrian age. This belt hosts several other porphyry-copper deposits, such as Mirador (438 million tonnes measured and indicated at 0.61% copper and 235 million tonnes inferred at 0.52% copper), San Carlos (600 million tonnes inferred at 0.59% copper) and Panantza (463 million tonnes inferred at 0.66% copper), located in Ecuador.

Copper-molybdenum mineralization is associated with a dacite porphyry intrusion of Middle Jurassic age emplaced into andesitic and dacitic volcanics.  The Mocoa porphyry system exhibits a classical zonal pattern of hydrothermal alteration and mineralization, with a deeper central core of potassic alteration overlain by sericitization and surrounded by propylitization.  Mineralization consists of disseminated chalcopyrite, molybdenite and local bornite associated with multiphase veins, stockworks and hydrothermal breccias.  The Mocoa deposit is roughly cylindrical, with a 600m diameter and thicknesses that range from 250m to 350m.  High-grade copper-molybdenum mineralization continues to depths in excess of 1,000m.