This article is a sponsored feature from Mining.com.au partner Great Boulder Resources Limited. It is not financial advice. Talk to a registered financial expert before making investment decisions.
One might think that with Western Australia’s $12 billion gold mining industry dating all the way back to the 1880s, finding a significant and high-grade deposit in modern times might be near-on impossible.
In recent years, there has been a dearth of significant new discoveries and a decline in gold reserves.
Then in 2020-21, just a few short years after listing on the Australian Securities Exchange (ASX), Perth-based junior exploration company Great Boulder Resources (ASX:GBR) discovered the Side Well Gold Project, in the heart of a multi-million-ounce field.
Strategically located adjacent to Meekatharra in Western Australia, Side Well is a ‘high-grade’ gold project where Great Boulder is aggressively drilling at Mulga Bill, Ironbark, and other prospects within the project.
One of the best located exploration plays
Exploration Manager Daniel Doran explains that the Side Well asset has developed from the early stage exploration success story at Mulga Bill to a multi-deposit project with several different options for development.
“Simply put, the Side Well project is one of the best gold exploration projects on the ASX”
“Simply put, the Side Well project is one of the best gold exploration projects on the ASX due to 3 key factors – high-grade gold, multi-deposit potential, and location.”
At Side Well, the Mulga Bill and Ironbark discoveries contain ‘high-grade’ gold lodes that have open pit and underground mining potential. These resource definition activities are supported by a strong pipeline of early stage prospects that are being currently advanced using mapping, surface sampling and aircore drilling.
There is high-grade – and then there is high–grade.
On 20 October, the company released results from its phase three reverse circulation (RC) drilling at the Ironbark prospect within Side Well, which included intersections of 5m @ 51.65g/t Au from 106m, including 1m @ 193.50g/t Au from 107m in hole 22IBRC024. If that wasn’t enough, hole 22IBRC028 intersected 3m @ 27.06g/t Au from 145m, including 1m @ 79.80g/t Au from 147m.
Doran notes that Ironbark is a particularly important prospect that commands the company’s attention.
“Ironbark is significant for GBR as it has really opened up the eastern side of the project for further exploration. We have a significant part of the Paddy’s Flat host sequence trending down our eastern flank that remains poorly explored, so the Ironbark discovery has opened up a large search space.
In terms of Ironbark itself, the mineralisation geometry is relatively simple, it comes close to surface and is located right on the Goldfields highway 10km from Meekatharra so it provides good optionality to rapidly develop. We think it is highly prospective to find a series of Ironbark-like deposits to the north and south similar to that seen at Paddy’s Flat.”
Located in the northern part of the Murchison goldfield, the Paddy’s Flat district has recorded production of some 2Moz from multiple historic underground and open pit mines. Mineralisation within the Paddy’s Flat district is not limited to a particular rock type and mineralisation is highly structurally controlled by the Paddy’s Flat shear zone, which provides fluid-pathways for the mineralising fluid.
Doran, who is a geologist with extensive industry experience having had technical roles with majors Northern Star Resources (ASX:NST) and Barrick Gold (NYSE:GOLD), explains that the latest results from Ironbark are extremely exciting as they represent ‘by some way’ the highest magnitude gold grades seen yet at the prospect. Previously the company believed it was dealing with wide intervals of 4-5g/t ore, however these latest intersections have highlighted the potential for ‘high-grade’ plunges and the opportunity for future underground mining.
“All the drilling intersections to date fit within an open pit scenario with mineralisation coming close to surface, however these new intersections indicate that depth extensions could contain significant gold grades.”
He notes that having the Side Well project and these targets at this address in Western Australia is a boon for Great Boulder.
“The Side Well project is one of the best located exploration plays held by a junior explorer on the ASX. The project sits just 10km from Meekatharra along the well-established Goldfields Highway with major gold processing facilities within short trucking distance. The Meekatharra goldfield has been in operation for over 100 years with the major Paddy’s Flat gold camp sitting on the western side of regional fold structure.”
The exploration manager adds that the fold structure repeats the same geological setting to the east of Meekatharra where the Side Well project is located. Despite having the same geological setting as a multi-million-ounce camp, Side Well has been relatively underexplored, possibly due to various levels of deep transported cover.
“With the discoveries of Mulga Bill and Ironbark we have demonstrated the presence of multiple mineralised structures within the project. We (GBR) strongly believe there is high potential for another gold camp on the eastern limb of the fold and are putting a strong focus on exploring that area.”
Back to fundamentals
Doran says that the success Great Boulder is achieving at Side Well is very much from going back to basics after encountering some challenges in 2020.
“Our very first drill program at Side Well in 2020 was relatively disappointing. In hindsight it was a great reset point as we went back to fundamentals, looked at bedrock gold and pathfinder trends, and that highlighted the effect of the cover on gold dispersion. The next RC programs were consequently targeted in different locations and we drilled our discovery holes”.
Beyond the fact the project is situated in a prime location, recent exploration work has indicated that the grades are not just high, they are ‘bonanza’, and there could be a range of options available to develop the asset.
Doran says broadly, the Side Well Gold Project is demonstrating a potential open pit or underground mining scenario. The company recently extended the strike and plans are now underway for further RC drilling.
The Mulga Bill prospect is also emerging as a significant target. In late September, Great Boulder discovered a new ‘high-grade’ lode about 90m east of the Mulga Hill High-Grade Vein (HGV), with drilling returning 6m @ 25.83g/t Au from 268m at hole 22MBRC055. At hole 22MBRC056, drilling intersected 8m at 54.60g/t Au from 120m.
The current RC drill program has been aggressively tightening its drill spacing at Mulga Bill to provide resolution of the high-grade zones. The overall gold system at Mulga Bill is substantial with multiple mineralising events and lode orientations, so further drilling is continuing to build the interpretation and knowledge of the ore body.
“This drilling continues to provide high-grade intersections adding to the company’s belief that additional gold mineralisation is still to be discovered. Drilling has begun on a fourth phase of drilling at Ironbark. This deposit is interpreted to be a more typical orogenic shear hosted system with less complexity requiring less drilling.
The fourth phase will continue to test the boundaries of the mineralisation and infill areas of previous drilling to provide resolution moving into a maiden resource in 2023. With the strike and depth extents of the deposit still open there remains significant potential for growth at Ironbark.”
Options aplenty
Great Boulder has also delivered ‘high-grade’ first assay results from AC drilling at hole 21MBAC119 within the Flagpole prospect, which intersected 3m @ 8.56g/t Au from 147m, including 1m @ 23.78g/t Au to end of hole. This is 1km along strike and to the south of the Mulga Bill – Loaded Dog corridor.
Flagpole remains a ‘highly prospective’ zone around 6km along strike from the Mulga Bill deposit.
Doran explains: “Multiple high-grade veins within flat lying structures have been intersected and further drilling is needed to define their extents. Definition of additional mineralisation within the Mulga Bill Corridor such as Flagpole and Loaded Dog provide Further evidence that Side Well could host multiple gold deposits.
“Critically, at Ironbark, which is situated close to the initial Mulga Bill find, RC drilling has significantly improved the potential of the area”
Critically, at Ironbark, which is situated close to the initial Mulga Bill find, RC drilling has significantly improved the potential of the area.”
As such, Great Boulder is on track to continue doing great things in 2023.
While Side Well remains the flagship and the core focus of the company, Great Boulder has a strong portfolio of other projects that it is exploring in tandem. The Wellington project is a greenfields Pb-Zn exploration opportunity north-east of Wiluna in WA. The potential of this project is huge as it sits within the same geological setting as Rumble Resource’s Earaheedy Project where substantial mineralisation has been discovered. The company was a first mover in this region and is keen to get on the ground and start developing the target areas.
The Whiteheads Project near Kalgoorlie is a regional scale gold and nickel project in a ‘highly prospective’ region. Significant, shallow gold mineralisation was discovered by the company at the Blue Poles prospect in 2020 in a previously overlooked area and potential exists for further discoveries.
Sleeping giant
The company is returning ‘bonanza’ grades and is making significant inroads with its expansive exploration program; however, it appears the wider market is yet to catch on to the success it is having in the heart of a multi-million-ounce goldfield in Western Australia.
Doran believes there appears to be some caution in the market regarding gold stocks and exploration companies in general. In part, attention is being focused on battery and renewables focused companies, however investors seem happy to sit on the sidelines at the moment.
“There has been some great news coming out of the gold sector lately that hasn’t been recognised by investors but has created real values for those companies. There is opportunity there for investors because eventually this value creation will be recognised and the market will move.
We are still highly focused on expanding and defining gold mineralisation at Side Well. We have recruited a great team of talented geologists and field techs this year and the entire team is focused on continuing to make new discoveries at the project.”
Upcoming news flow for the company is expected to include results from the recently completed programs at Mulga Bill and Ironbark along with regional aircore drilling.
In tandem with continued RC drilling at Mulga Bill and Ironbark, the coming months will see a focus on generative work north and south of Ironbark that will lead into new drill targets for 2023. The company will continue to work towards the initial exploration targets and resource estimate for the project.
Doran notes: “Additionally, we hope to have first work being completed at the Wellington Pb-Zn project in early 2023. This will likely entail reconnaissance soil sampling and geophysical acquisition.”
Write to Adam Orlando at Mining.com.au
Images: Great Boulder Resources Ltd
