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.

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).

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.

New 1500 tpd agitation leach and Merrill-Crowe processing plant commenced commissioning tests in Q1 of 2017, and expected to commence full operation during Q2 2017.