Wafi–Golpu is a complex, multiphase mineralised system, comprising:
- Golpu porphyry copper–gold deposit;
- Wafi epithermal gold deposit;
- Nambonga porphyry gold–copper deposit.

The upper portions of the porphyry systems were overprinted by the high-sulphidation epithermal mineralisation at Wafi.

Golpu
The Golpu deposit extends over about 800 m north–south by 500 m west–east, and was drill tested to more than 2,000 m depth.

Porphyry-style veins are preserved within the clay alteration at the top of the Golpu deposit. These veins have had the copper–iron sulphides removed, leaving only a skeleton of quartz. Irregular molybdenite veins are preserved stable remnants of the porphyry mineralising event.

The dominant copper–gold-bearing sulphide species vary laterally and vertically within the deposit from an inner bornite (plus chalcopyrite) core, to chalcopyrite as the dominant copper sulphide, and grading out to a pyrite-only shell on the mineralisation margin.

The proportion, by volume, of disseminated copper–iron sulphides varies from trace to as much as 10%. Pyrite increases from near absent in the core to 10% on the margin in a reverse relationship to chalcopyrite. Disseminated sulphides are typically located at the site of relict iron-bearing phases including primary phenocrystic hornblende and hydrothermal alteration-derived biotite– magnetite.

The Hornblende Porphyry (Livana Porphyr ........

An evaluation of potential mining methods included consideration of block caving, sub-level caving (SLC), sub-level open stoping (SLOS), and open pit methods. Block caving was selected for the following reasons:
-Orebody geometry and geotechnical conditions;
-High productivity, low operating cost mining method;
-Higher-value material located at depth can be accessed earlier in the mine plan.

The proposed mine plan uses technology conventional to block cave operations, including mine design and equipment. Due to high surface ambient temperatures and humidity, and the depth of the mine, considerable ventilation and cooling capacity will be required to be installed to ensure the health and safety of mine workers.

The proposed mining method is block caving at three distinct elevations:

- The BC44 extraction level is planned at 4400 mRL, to extract a total of approximately 67 Mt of material over a seven-year period at a peak annualised 16.84 Mt/a production rate. During caving operations, ore from the block cave drawpoints will be delivered by diesel load–haul–dump vehicles (LHDs) to either of two underground gyratory crushers then conveyed to the Watut process plant on surface by an inclined conveyor system;
- The BC42 extraction level is planned at 4200 mRL, to extract a total of approximately 93 Mt of material over a nine-year period at a peak annualised 16.84 Mt/a production rate. Materials handling from drawpoint to the Wa ........

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