The Antucoya porphyry copper deposit is situated 120 km northeast of Antofagasta in the Early Cretaceous metallogenic belt of the Coastal Cordillera.

The mineralized system is related to granodioritic porphyry (Antucoya porphyry) and dacite porphyry (Buey Muerto porphyry). Late dacitic dikes intrude the former ore-related intrusions and Jurassic andesitic host rocks in a tectonic environment dominated by splays of the Atacama Fault System.

The principal mineralization constitutes a column 350 m thick, composed of atacamite, brochantite, Fe-Cu sulfates, Cubearing limonite, chrysocolla and black oxides, with rare chalcocite and covellite in a thin supergene enrichment blanket.

In the underlying hypogene zone, the mineralization is dominated by chalcopyrite>pyrite>bornite hosted by A- and Bveins in potassic alteration, and in C-veins on the periphery of the porphyry intrusions. The pyrite/chalcopyrite ratio is greater in D-veins within a shallow phyllic zone. The Mo distribution is erratic and poorly characterized. The total resource is 1204 Mt at 0.31%CuT, using a 0.15%CuT cut-off.

Mined oxide ore is crushed, piled into heaps and then leached with sulphuric acid, producing a copper sulphate solution. This solution is then put through a solvent extraction and electrowinning (“SX-EW”) plant to produce copper cathodes, which are sold to fabricators around the world.