The Wassa property lies within the southern portion of the Ashanti Greenstone Belt along the eastern margin within a volcano-sedimentary assemblage located close to the Tarkwaian basin contact. The eastern contact between the Tarkwaian basin and the volcanosedimentary rocks of the Sefwi group is faulted, but the fault is discrete as opposed to the western contact of the Ashanti belt where the Ashanti fault zone can be several hundredmeters wide.

The Wassa lithological sequence is characterized by lithologies belonging to the Sefwi Group and consisting of intercalated meta-mafic volcanic and meta-diorite dykes with altered metamafic volcanic and meta-sediments which are locally characterized as magnetite rich, banded iron formation (“BIF”) like horizons (Bourassa, 2003). The sequence is characterized by the presence of multiple ankerite-quartz veins which are sub parallel to the main penetrative foliation. The lithological sequence is also characterized by Eoeburnean felsic porphyry intrusions on the south-western flank of the Wassa mine fold.

The Wassa mineralization is subdivided into a number of domains, namely: F Shoot, B Shoot, 242, South East, Starter, 419, Mid East, and Dead Man’s Hill. Each of these represents discontinuous segments of the main mineralized system. The SAK deposits are located approximately 2 km to the southwest of the Wassa Main deposit on the northern end of a welldefined mineralized trend parallel to the Wassa Main trend. The mineralization is hosted in highly altered multi-phased greenstone-hosted quartz carbonate veins interlaced with sedimentary pelitic units.

Mineralization within the Wassa Mine is= structurally controlled and related to vein densities and sulphide contents.The mineralization generally consists of broadly tabular zones containing dismembered and folded ribbon-like bodies of narrow quartz vein material. Three vein generations have been distinguished on the basis of structural evidence, vein mineralogy, textures and associated gold grades.

A conventional approach to open pit mining is currently being used at the Wassa mine employing excavators and trucks which are considered typical for this type and style of gold mineralization. Drilling and blasting of rock is conducted over bench heights of 5 or 6 m and explosives are delivered to the hole by the manufacturer. Oxide or weathered material is generally only required to be lightly blasted or in some areas can be excavated without blasting. Hydraulic excavators are used in conjunction with conventional blasting practice, to mine a 2.5 or 3.0 m flitch height.

The underground design utilizes a twin decline access from the base of the open pit which reduces the access to the mineralization from the surface topography. The selected mining method is sub-level open stoping utilizing a cemented rock backfill (“CRF”) where appropriate to maintain support for mining the secondary stopes and increasing the overall extraction ratio. A staged approach to ventilation is taken with raises to surface completed in line with the development and production schedule.

In 2003, the plant was converted into a milling CIL circuit, which started operation in 2005 treating a mixture of primary and oxidized ores and material reclaimed from the heap leach pads.

The Wassa treatment plant is currently processing primary ore feed from the open pit operation and consists of a fine crushing, milling, gravity and CIL gold recovery circuit. Historically, the plant has processed a mixture of open pit primary ore, oxidized ore and spent material from the old heap leach operation at treatment rates of up to 3.5 Mtpa, although with the oxide and spent heap leach feeds now generally depleted, the plant is currently processing around 2.65 Mtpa of primary ore.