Vatukoula is a low-sulphidation epithermal gold vein deposit associated with alkaline type igneous rocks in a volcanic setting, typical of several other major gold mines in the southwest Pacific region including Grasberg, Porgera and Lihir. Post caldera collapsing (a critical genetic feature) was the formation of a north-westerly shear system transecting the caldera, with flatly dipping structures within the peripheral basalts resulting from tectonic resettling. Gold mineralisation is thought to have been set downbetween 3 and 7 million years ago, post-dating magmatism by around 400,000 years. As currently understood, the vast majority of the gold at Vatukoula is located within a two square kilometre fractured block, largely in the form of gold in arsenopyrite. However between 10 and 50% of the gold is in the form of precious metal tellurides. In terms of exploration it is known highlevel epithermal mineralisation and alteration occur up to 4km from the Emperor gold mine, in an area which has a demonstrable present day hydraulic connection with the mine.

Typically, gold mineralization occurs within steeply dipping dykes and shears, flat-dipping structures (sub 45°), known locally as “flatmakes”, and the intersection of two or more structures, referred to as “shatter zones”. An estimated 7Moz (8.5Moz pre mined resources assuming an 80% extraction rate) of gold has been extracted since mining operations commenced.

Gold bearing veins range from 1cm to 1.2 ........

The Mine is a long established underground gold mine. There are a total of nine shafts in the Mine, but only four are being used other than for ventilation; the Smith & Phillip Shaft for hoisting ore, the Cayzer Shaft for men and materials and a Decline Shaft for access for the rubber tyred mine fleet.

The mining operations use conventional labour intensive stopping methods together with trackless ground handling and haulage followed by skip hoisting via the vertical shafts. Stopping will be a mixture of Long Wall Breast, Shrinkage and Cut and Fill.

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