The deposit is part of a larger Tertiary porphyry complex within the large West Fissure structural system. South of the Main Zone, copper mineralisation has been encountered within or near the southern extension of the Portezuelo fault. The orebody contains both sulphide and oxide copper mineralisation. The majority of the copper occurs in a supergene enrichment zone overlying deeper primary sulphide mineralisation. The main minerals are chalcocite, brochantite and chrysocolla and mixed sulphide and oxide copper minerals.
Primary sulphides are pyrite, chalcopyrite and molybdenite.
Exploration during 1999 increased the project s reserve base to 2.86 Mt of contained copper. A sequence of six open pit stages is planned with a remaining life of 11 years. Open-pit ore is hauled to the primary gyratory crusher and the discharge fed to two secondary cone crushers. Due to the dry, dusty nature of the ore and the fine crush required to optimise leach recoveries, waterflush crushers are used to perform the tertiary crushing reduction of the ore to minus-12mm. Ore is stacked in 6 m lifts and leaching solution percolates through from the top of the heap.