The property hosts a typical Upper Archean to lower Proterozoic style of metallogeny, characteristic of greenstone-hosted lode gold mineralisation, where deposits are often referred to as orogenic, and characterised by the presence of gold-quartz veins and disseminated mineralisation. Gold mineralisation is hosted in moderate to steeply dipping quartz-dominated shear zones with associated extensional vein systems. This model is consistent with Archean orogenic gold deposits described by Hagemann and Cassidy (2000), Richards and Tosdal (2001), Goldfarb et al. (2001) and Roberts et al. (1989).

New Liberty
Within the ultramafic unit, silicification is found proximal to the mineralisation, within the immediate hangingwall and rarely in the footwall gneisses. Other alteration styles associated with the mineralisation include the presence of phlogopite as well as chlorite within the mineralised zone, and an associated sulphidic bleaching of the rocks linked with the destruction of magnetite.

These features point to a pathway for the mineralising fluids which was active over a long period of time. The deposit shows the classic signs of sulphidation, with iron sulphides (mainly pyrrhotite) replacing the magnetite and it has a low sulphide content with sulphides forming between 0.1% and 1% of the mineralised zones.

Multi element analyses of cores have highlighted a clear association between gold and arsenic, sulphur, nickel and t ........

Mining activity for the combined project will include:

- open pit mining of the New Liberty deposit until the breakeven cut-off for underground mining is reached, which corresponds to pitshell 33;

- a transition to underground mining by long- hole open stoping methods (LHOS) and mining of reserves by underground methods;

- open pit mining of the reserves at the Ndablama deposit and direct shipping of Ndblama ore to the New Liberty mill later in the life of the project.

Metallurgical testwork results and industry norms were used to define the process design criteria for the New Liberty Plant. The original process plant was designed, built and commissioned in July 2015 by DRA, an international engineering company, to treat 1.1 Mt/a of ore, corresponding to a mill feed of 146 t/hr.

Since start-up there have been a number of operational issues that have affected plant performance. In late 2016 following the change of project ownership, the operational issues were evaluated and measures identified to improve performance. The planned modifications to the plant, some already implemented, and some planned for late 2017, have been designed to increase the throughput in stages up to 200 t/hr (1.8 Mt/a), while achieving the original design gold recovery of 91–93%.

The process flowsheet is an industry-standard arrangement consisting of crushing, ore stockpiling, grinding and classification, gravity gold recovery, thickening and gold extrac ........