Great Boulder Resources Ltd has resumed extensional reverse circulation (RC) drilling at Mulga Bill North in the Side Well Gold Project in Western Australia and is confident that the combined Mulga Bill corridor can contain more than one million ounces.
This drilling plan at Mulga Bill North will include RC holes following up high-grade results in late 2024, including 29 metres at 3.15 g/t gold from 91 metres and 8 metres at 5.67 g/t from 103 metres.
As of late 2023, drilling at Mulga Bill had defined a resource of 568,000 ounces at 2.7 g/t gold, which makes up most of Side Well's 668,000 ounces at 2.8 g/t.
Further potential
With the significant high-grade exploration success during 2024, which is yet to be added to the resource inventory, and at least 1.5 kilometres of highly prospective strike to the north, Great Boulder believes that the combined Mulga Bill corridor has million-ounce potential.
This would make Mulga Bill one of the most significant deposits in the Meekatharra Gold Field.
Side Well Project map including the location of Mulga Bill and Side Well South.
Open to the north
Great Boulder’s managing director Andrew Paterson said: “Great Boulder’s exploration team has completed first-pass aircore drilling on priority targets at Side Well South and the rig is now back at Mulga Bill North to continue resource definition drilling along the prospective dacite contact we defined late last year.”
“Analysis of all the geochemistry we’ve collated along the 6-kilometre Mulga Bill corridor suggests the dyke at the north end of the Mulga Bill resource may be the centre of the mineralised system.
“If that’s correct, we have another 3 kilometres of target to the north which we haven’t yet drilled, and gold and associated pathfinder elements are very much open to the north.”
Mulga Bill North is a priority area for the company’s resource definition work in 2025, with similar characteristics to the Mulga Bill area.
Holes have also been planned to continue defining high-grade, vein-hosted gold mineralisation towards the northern end of Mulga Bill.
Later aircore drilling will test a poorly defined gold trend northeast of Mulga Bill which may be a parallel zone about 200 metres east of the main corridor.
Plan view of Mulga Bill corridor showing the spatial extent of the pyrite envelope containing gold and pathfinder elements. The +1g/t gold contour is in red, over geology draped onto a gravity image.
Resource update
Results from the RC program are expected to be incorporated into a resource update for the Mulga Bill area, extending the resource footprint northwards.
Previous work by Great Boulder has defined mineralisation up to 1.5 kilometres north of Mulga Bill, forming part of a 6-kilometre corridor highlighted by gold and associated pathfinder elements including bismuth, molybdenum, tin, copper, arsenic and antimony.
Analysis of the pathfinder distribution indicates the mineralised corridor is likely to continue further north beyond the current limit of GBR’s drilling and in fact the centre of the system may be close to the position of the cross-cutting Proterozoic dyke.
If future exploration confirms this theory, the total length of the mineralised system may be up to 9 kilometres north-south.
More results coming
GBR has completed 71 aircore holes at Side Well South since drilling resumed in January. An additional 22 aircore holes have been drilled on targets north-northeast of Saltbush.
With assay turnaround times for gold analysis increasing to approximately four weeks, the first results from these programs are expected to be received shortly.
Further drilling programs at Mulga Bill North will be designed as exploration progresses.
“We are also expecting initial assays from Side Well South in the next two weeks, with 71 aircore holes recently drilled there plus another 22 aircore holes targeting repetitions of the Saltbush area,” Paterson said.
“We’ll continue to deliver very strong news flow through March and into the rest of the year.”