The Guanaco deposits are considered examples of high-sulphidation epithermal systems.

Quillota
The Quillota deposit consists of a vein system that has an area of approximately 200 m long (north–south) by 500 m wide (east–west). The deepest drill hole reached approximately 210 m depth. The main mineralization at Quillota was open pit mined to a depth of approximately 40 m.

Defensa
The Defensa vein system occupied an area of 300 m north–south by 600 m east–west. The deepest drill hole reached 160 m depth. Mineralization was exploited using open pit methods.

Perseverancia
The deepest drill hole reached 270 m at Perseverancia, with the vein system encountered to approximately 160 m vertical depth. Mineralization was defined over an area of 300 m (north–south) by 600 m (east–west). Mining was by open pit methods.

Dumbo
The Dumbo vein system occupies an area of approximately 250 m north–south by 500 m east–west. The deepest drill hole reached 300 m; the vein system reaches approximately 250 vertical metres depth. Dumbo has been mined by an open pit operation.

Cachinalito
As a result of the 2014-2015 drilling campaign, a clear continuity has been established between nearly all previously known sectors in Cachinalito, so that it is now recognized as a single, 1,100 m long, east–west-oriented system.

Cachinalito Central extends for approximately 150 vertical metres from surface, and the deepest drill hole is 300 m. The mineralization has been defined over an area of 100 m north–south by 700 m east-west. Cachinalito Central is currently being mined by underground methods. Aurora is a new vein, discovered during the 2014-2015 drilling campaign between Cachinalito Central and the Soledad property.

Cachinalito West covers an area of approximately 70 m north–south by 400 m east–west. Veins do not crop out at surface. Drilling encountered the veins from approximately 40 m to a maximum of 130 m vertically. The deepest drill hole is currently 340 m.

Natalia
Natalia is a northwest-oriented vein system. The central part covers an area of 200 m north– south by 450 m east–west.

Guanaco mine
The mining methodology used at Guanaco consists of sub-level open stoping (SLOS) and mining is carried out by following the veins with drifts on two levels, separated by 16 m (20 m floor to floor). The main production at Guanaco comes from the Cachinalito West vein, with additional production coming from the Dumbo and Perseverancia veins.

Stopes are designed at a minimum mining thickness of 1.5 m with planned dilution of 0.5 m on either side resulting in final stope widths of 2.5 m. Drifts are designed at 3.5 m with 0.25 m of dilution on either side resulting in a final width of 4 m. Sill pillars of four metres in height are left every 40 m (vertical) and ten metre wide rib pillars are left every 70 m (horizontal).

Amancaya mine
The open pit mine will be carried out as a conventional operation using 30 t trucks and a combination of excavators and front-end loaders. Waste and ore will be blasted and mined separately using a “trenching” method to reduce the amount of dilution. A three metre wide trench will be blasted resulting in a 4.5 m wide trench after overbreak is taken into account. This waste material will be mined out from the trench using the excavator. Once the trench has been cleaned out, the vein will be blasted into the open slot and subsequently mined out using an excavator. The remaining waste on the mining bench will be blasted and mined out using front-end loaders.

The Amancaya Mine underground Mineral Reserves were estimated based on stope designs applied against the Mineral Resource block models for the Central Vein deposit. Planned and unplanned dilution are included in the stope shapes which have been designed for a sub-level stoping mining method.

The existing operation includes:
• Three stage crushing to produce a product size that is 80% passing (P80) 5.3 mm
• Trucking of ore to the leach pad
• Permanent leach pads
• Intermediate and pregnant solution ponds and pregnant solution pumps
• Carbon-in-column (CIC) precious metal adsorption circuit
• Acid wash column
• Anglo American Research Laboratory (AARL) carbon elution circuit
• Electro-winning (EW)
• Barren solution tank and barren pumps
• Drying oven
• Induction furnace.

The new construction includes:
• Reversing conveyor to feed either the heap leach operation or the milling circuit
• Covered stockpile
• Single stage ball milling circuit operated in closed circuit with hydro-cyclones
• Pre-leach thickener
• Three-stage agitated leach circuit
• Three-stage counter-current-decantation (CCD) wash circuit
• Filter feed tank and plate and frame pressure filters to recover solution and produce filtered tailings
• Loading with front end loader and truck haulage to dry tailings deposit
• Dry tailings deposit
• Refurbished Merrill-Crowe circuit for precious metal recovery including:
- Clarifying filters
- De-aeration tower
- Zinc cementation (i.e., precipitation)
- Precipitate filters.

2018 - First full year operating the new agitation leaching in plant.