The Queen’s Birthday Project area includes the town of Moliagul. This area is legendary because it has produced more gold nuggets than any other place in Australia.
The Queen’s Birthday group of mines were noted for their consistent production throughout the 1800’s until their closure in the early 1920’s. The mines are is recorded as responsible for producing ~100,000 ounces of gold. The Queen’s Birthday mine shaft is down to 250 metres below surface and a significant body of quartz along the main fault zone was still present in the drives and stopes.
This area has provided numerous gold discoveries ranging from the “Welcome Stranger” nugget at Moliagul to the Queen’s Birthday area to the south at Goldsborough. Historical records have reported a significant concentration of alluvial nuggets at Whites Patch about 4km north of the Queen’s Birthday mine at Goldsborough. At Burnt Creek, abundant nuggets were mined under 3 to 5 metres of alluvial cover in a series of “patches”.
The Queen’s Birthday prospect lies within the western margin of the Bendigo-Ballarat zone of the Lachlan Fold Belt that covers much of Victoria and New South Wales. Early Devonian granites intruded the sediments and remobilised the gold in the sediments.
The primary geological controls are believed to be the fault planes developed along a significant shear zone known as the Goldborough - Whela Shear. The steeply dipping, folded, faulted and cleaved sediments have undergone deformation that was primarily associated with east-west compression. Regionally the beds are steeply dipping and striking north-south or north north-east. The presence of the widespread quartz reefs tends to follow a similar strike.
Active shear lines trend to dip steeply west (~ 80o) and are characterised by historically rich, sub-horizontal mineralised veining into the tensional features associated with the hanging wall. Spur veins in the reverse fault zone have been reported to occur from the deep shafts of Moliagul Mine. Failure planes and drags against fault planes have also been reported and tensional openings and dilation arras host quartz and mineralising fluid.
Queen’s Birthday is a shear hosted gold mineralised system that lies at the southern end of the Goldsborough – Wehla Shear Zone, a major deep penetrating structure that has provided fluid pathways for large quantities of gold and quartz. An initial mineralisation model has been interpreted from a limited data base (see diagram below).
Ando Minerals N.L. in the 1970’s undertook a significant exploration program along the Queen’s Birthday area with several lines of percussion drilling and indications that at least one diamond drill hole.
A routine grid drilling program by Western Mining Corporation (WMC) in the 1980s, discovered new mineralisation that produced in excess of 60,000 ounces. Reef Mining NL at Tarnagulla Gold Co followed up the WMC work outlining a high grade repeating structure that was hosted in a south plunging zone.
Exploration will target both open pit and underground resources. An initial shallow open pit target over the line of reef (~900 metres of Strike) has been identified. Underground targets are extensions south from the existing mine development (50 to 250 metres below surface) as well as beneath the existing workings (+ 300 metres).