The Cerro Corona copper-gold deposit is typical of porphyry style mineralisation comprising stock work quartz-pyrite-marcasite-chalcopyrite ± bornite ± hematite ± magnetite veining, hosted by intensely altered intrusive lithologies of diorite to dacitic composition.

The Cerro Corona copper-gold deposit is hosted by a 600 to 700 metre diameter sub-vertical, cylindrical-shaped diorite porphyry emplaced in mid-Cretaceous limestone, marls and siliciclastic rocks. Within the porphyry, the copper-gold mineralisation is primarily associated with zones of stock work quartz veining conforming to classic porphyry-type vein definition. The Cerro Corona porphyry is unusual in that it carries a very high gold content compared to other copper-gold deposits.

There are at least two phases of diorite placement, only one of which is mineralised. The non-mineralised diorite is generally regarded as the last event, and is referred to as ‘barren core’. Most recent geological modelling strongly suggests that the Cerro Corona porphyry probably comprises four or five satellite stocks, the last two of which are barren. Early mineralisation was accompanied by moderate to strong potassic alteration, which has been commonly overprinted by late, semi pervasive argillic alteration and locally, by structurally controlled phyllic alteration assemblages (quartz-sericite-pyrite).

There are three distinct mineralised zones within the deposit. These are identified as the annulus zone, the northern zone and the southern zone. Each of these is treated separately in geological and resource modelling.

In addition to the mineralised zones, the deposit is characterised by several domains conforming to the degree of oxidation and weathering. Supergene oxidation and leaching processes at Cerro Corona have led to the development of a weak to moderate copper enrichment blanket. This allows for the subdivision of the deposit from the surface downward, into an oxide zone, a mixed oxide sulphide zone, a secondary enriched (supergene) sulphide zone and a primary (hypogene) sulphide zone.

Cerro Corona Mine operates one open-pit operation and one copper-gold plant at elevations ranging from approximately 3,600 to 4,000 metres above mean sea level. Contract mining is deployed in the open pit, applying conventional drill, blast, load and haul methods. Accelerated mining, based on nine separate pit stages, exceeds processing rates, allowing generated tailings to be placed back in the pit. Ore is stockpiled during the accelerated mining phase at Cerro Corona and is typically managed at net smelter return (NSR) cut-off values of between US$14.99/t and US$26/t. The Cerro Corona deposit is mined by conventional surface open-pit mining methods. The final surface mine area is expected to cover some 900 by 1,000 metres. The mining operation will extend from the crest of the original Cerro Corona hill, which peaked at 3,964mRL, to a final depth at around 3,570mRL. The Cerro Corona pit is mined via open cut methods by conventional drill and blast with a truck and excavator fleet. Load and haul is carried out by 36 tonne dump trucks and excavators with a 9 tonne bucket capacity. Mining benches are all 10m high and haul roads have a maximum gradient of 10%. All the material requires drill and blast with varying powder factors according to rock hardness, using a 200mm blast hole diameter.

The crushing plant comprises two jaw crushers in parallel and two Abon Sizers in each line. Crushed product is conveyed to a two-stage grinding circuit consisting of a Semi Autogenous Grind (SAG) mill and a ball mill, in closed circuit with cyclone cluster for classification. Cyclone overflow represents the final milled product and feeds the flotation plant.

The processing plant consists of a conventional primary crushing, semi-autogenous grind (SAG)/ball milling and flotation circuit to generate a copper-gold concentrate. The final concentrate is thickened and filtered before being stockpiled for road transport (380km) to the Salaverry port for shipment to copper smelters in Japan and Germany. The thickened rougher flotation tails and the cleaner scavenger flotation tails are transferred individually to the TSF.

TSF embankments are constructed in a downstream/centreline manner and located downstream from the process plant over the Las Gordas and Las Águilas gorges. The embankments (Las Gordas, Las Águilas and La Hierba) are being constructed progressively with borrow materials from limestone quarries. The embankments contain a clay core constructed from pit material (oxide material). The TSF has a remaining LoM storage capacity of ~26.4Mt up to 3,803m relative level (mRL).