Perseus carried out the geological interpretation for Sissingué. Widenbar and Snowden reviewed the interpretation prior to estimation and considers it to be an accurate reflection of the geology of the orebody. The following section is taken from Widenbar (2013) and summarises the geological interpretation provided by Perseus.

In the central part of the Sissingué prospect ('Sissingué Main'), the major host rock is a medium to coarse grained, veined, altered and sulphidised granite. Chemically identical to the porphyritic dykes, it is formed by several of these dykes that have been attenuated by a structural feature, possibly a fold plane, to flow into each other and to form a pear-shaped, approximately 50 m thick body.

Alteration is most intense and gold grades, on average, are highest in the roof of this intrusive body and in the coarse grained sediments above. Emplacement of the dykes is believed to have occurred in several stages or over an extended period as several dykes cross cut the granitic body, some with fuzzy contacts (interpreted as emplaced during cooling period of the granitic body), others with sharp contacts (emplaced after cooling of granite). Gold mineralisation is relatively homogeneous in the upper portion the granite. At depth, with decreasing intensity of alteration, the tenor of the mineralisation decreases.

Elsewhere, mineralisation is interpreted to be associated with isolated dykes and altered sediments in their respective vicinities. This distribution leads to a bi-directional ore body: Granite and associated altered sediments in north- north-eastern extent and with sub-vertical or steep westerly dips, and north-west striking dykes with associated altered sediments, obliquely cross cutting and steep to moderate easterly dips. The most significant zone of gold mineralisation is the Main Zone with its granitic bodies, various dykes and a pervasive alteration halo due to the larger mass of the intrusives.

Gold mineralisation at Sissingué is associated with the porphyritic dykes of tonalitic composition that cross cut the flysch sediments (turbidites). Subsequent metasomatism of the tonalite has led to:

- a sericite-carbonate alteration within the intrusives and the more permeable horizons (sandstones and conglomerates) of the turbidites
- low to moderate grade disseminated gold mineralisation.

Late stage high grade Au-As-quartz-carbonate veins exploited the altered and brittle portions of the intrusives and sediments with common occurrences of visible gold.

Gold mineralisation is found as three distinct styles as summarised below:

• Disseminated or fracture related mineralisation in the felsic intrusive closely associated sericite-carbonate alteration, silification and a pyrite and arsenopyrite mineralisation. The average gold tenor of this type of mineralisation is usually relatively high (2 g/t Au to 5 g/t Au).

• Significant low grade gold mineralisation (commonly below 2 g/t Au) is encountered within sediments immediately adjacent to the intrusive bodies within their respective alteration halos. The gold tenor are perceived to be closely correlated to alteration intensity and hence with primary porosity of the rocks. Sandstones and conglomerate are usually better mineralised than fine grain mud- and siltstones.

• High grade mineralisation (with grades exceeding 1,000 g/t Au) is associated with quartzveins which are encountered in the upper portion of the intrusive bodies and in the altered and brittle portion of sediments directly above. Visible gold is common.

The mining method planned for the operation is conventional open pit excavation with ex-pit waste dumping. The pit will be accessed by a 20 m wide haul road incorporating a 10 percent gradient and two lane ramps. At the pit floor the final benches will be accessed using single lane ramps.

The ramp exit points for each design were placed on the east to provide the shortest hauls to the ROM pad and waste dump. The waste rock dump was located to the east of the pit and adjacent to the processing plant.

The proposed process plant design for the Sissingué Gold Project is based on a robust metallurgical flowsheet designed for optimum recovery with minimum operating costs. The flowsheet is constructed from unit operations that are well proven in industry.

Perseus has advised that ores will be mined so that predominantly oxide / transitional ore will be processed in two phases; during the first year and then again for a five month period in Year 3. Some blending with primary ores will be required in the final two years. Oxide ore will be processed at a rate of up to 1.2 Mt/y using a two stage crushing and single stage SAG mill circuit. Primary ore will be processed at a rate of 1.0 Mt/y using a three stage crushing and ball mill circuit, where the SAG mill has been re-configured to operate as a ball mill.

The treatment plant design incorporates the following unit process operations:
• Initially two stage crushing of oxide ore with open circuit primary crushing and closed circuit secondary crushing to produce a crushed product size of 100% passing (P100) 50 mm.
• Thereafter three stage crushing of primary ores with open circuit primary crushing and closed circuit secondary and tertiary crushing to produce a crushed product size of 100% passing (P100) 14 mm.
• A crushed ore surge bin with a nominal capacity of 100 t. Surge bin overflow will be conveyed to a dead stockpile. Ore from the dead stockpile will be reclaimed by front end loader (FEL) to feed the mill during periods when the crushing circuit is off-line.
• Initial single stage SAG milling of oxide ore in closed circuit with hydrocyclones to produce a P80 grind size of 106 µm.
• Thereafter, ball milling of primary ore in closed circuit with hydrocyclones to produce a P80 grind size of 106 µm.
• Gravity concentration and removal of coarse gold from the milling circuit recirculating load and treatment of gravity concentrate by intensive cyanidation and electrowinning to recover gold to doré.
• Pre-leach thickener to increase the slurry density to the carbon in leach (CIL) circuit to minimise CIL tankage, improve slurry mixing characteristics and reduce overall reagent consumption.
• Initial leach / CIL circuit for oxide ore incorporating one leach tank and six CIL tanks containing carbon for gold adsorption.
• Thereafter pre-oxidation / CIL circuit incorporating one pre-oxidation tank with oxygen addition to reduce leach oxygen requirements and cyanide consumption and six CIL tanks containing carbon for gold adsorption.
• Four tonne pressure Zadra elution circuit, electrowinning and gold smelting to recover gold from the loaded carbon to produce doré.
• Tailings pumping to the tailings storage facility (TSF).