The Ballarat goldfield is positioned in the hanging-wall of the crustal-scale north-south striking, west-dipping Williamson Creek reverse fault. Three north-trending mineralised zones are identified in the Ballarat goldfields: Ballarat East, Ballarat West (including Ballarat South) and Little Bendigo. Gold mineralisation is hosted by Ordovician turbidites of the Castlemaine Supergroup.

The Ballarat Goldmine is located in the Ballarat East goldfield and lies on the eastern limb of the Ballarat Anticline. The turbidites were folded into a series of north-south trending, tight, upright chevron-style anticlines with wavelengths ranging from 50 m to 300 m. Numerous parasitic folds occur around the hinge zones of the larger folds. The three major fold lines of the Ballarat East goldfield are the Sulieman, Scandinavian and First Chance Anticlines.

The Ballarat goldfields are divided into multiple ‘compartments’ by a series of major faults referred to as cross courses. Cross-course faults are sub-vertical, brittle faults that are un mineralised yet play an important role in the distribution of mineralisation, and gold tenors are relatively consistent within individual compartments. Cross courses typically trend northeast or northwest and have displacements ranging from centimetres to several hundreds of metres.

The Ballarat goldfield is an orogenic gold deposit. Vein mineral assemblages include several generations of quartz with chlorite, sericite, a ........

The current mine covers a relatively narrow area approximately 400 metres in width and five kilometres in length, extending to a depth of approximately 760 m below the surface.

Primary access underground is via the Woolshed Gully decline, nominal dimensions of 4.6 metres high and 4.6 metres wide at a gradient of 1:6.5 down to a depth of approximately 130 metres below the surface. The mine entrance (portal) is located at the southern end of the mine.

The decline system below the Woolshed Gully decline has been developed at nominal dimensions of 5.3 metres high by 5.0 metres wide at a gradient of 15%. At approximately 1,200 m from the portal, twin declines split into the Suleiman decline (approximately 1,900 m long) and the Woah Hawp decline (approximately 3,700 m long).

Underground mining includes development drilling, ground support, blasting, loading and hauling. All works are carried out by GPG as an “owner-operator”. Production drilling and mechanised cable bolting are carried out by a separate contractor (MacMahon).

Underground development is carried out using conventional drill and blast techniques with twin boom 1000V electric hydraulic jumbos. Jumbos drill blast holes in development faces, blast holes are then charged with explosives and fired breaking the rock. Jumbos are also utilised for the installation of ground support in the walls and backs of the excavation.

The ground support design for mine development co ........

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