Beyond the Degrussa Era: Why ASX explorers believe the Bryah Basin’s best days lie ahead

• Sandfire’s withdrawal in 2023 from the Bryah Basin drew investors’ focus away from the once hot WA mining region
• With gold at record highs, a new cohort of explorers have moved into the area 
• These ASX explorers are using updated models and different exploration techniques to revisit the ground

When Sandfire Resources (ASX:SFR) pulled the last ore from its world-class DeGrussa copper-gold mine and quietly withdrew from the Bryah Basin in mid-2023, investor attention shifted elsewhere and the region was viewed as a played-out chapter.

But a new wave of explorers armed with fresh thinking and modern technology are backing a contrarian view.

This suggests the best discoveries may still lie beneath the surface on the strength of the basin’s 2Moz gold heritage and extensive alteration footprint.

With gold prices at record highs and companies like Solara Minerals (ASX:SLA), Star Minerals (ASX:SMS), Horseshoe Metals (ASX:HOR) and Tambourah Metals (ASX:TMB) exploring untested targets, the question isn’t whether the Bryah Basin is dead, it’s whether the industry has been looking in all the wrong places.

Solara moves past “clone hunting”

Jennifer Neild, recently appointed general manager at Solara Minerals, believes the thesis driving this renewed interest marks a shift from the formulaic grid drilling that dominated 2009’s DeGrussa nearology rush.

“Successful exploration cannot rely on ‘rinse and repeat’,” she told Stockhead.

“We need to evolve our methods beyond the formulaic exploration which has been applied to the basin.

“Grid drilling is a logical approach to cover a vast land package, but it has meant that subtle anomalies were underappreciated and left untested.”

Solara, which counts legendary Azure Minerals boss Tony Rovira as its executive director, completed the acquisition of its Bryah Basin tenements in August 2025. They comprise key projects including Degrussa West, 17km along strike from Sandfire’s old mine, and the Wilgeena project, 15km southeast of Westgold Resources’ (ASX:WGX) Peak Hill gold mine.

Drilling is set to get underway in December at Degrussa West following the award of a $180,000 grant to test highly prospective targets across the 310km2 tenement package as part of the WA Government’s Exploration Incentive Scheme.

“Once Sandfire pulled out of the region, there was a window for companies to get in and fill the void,” Neild said.

“This meant availability of great projects and value for money. The team has been selective, choosing projects with advanced datasets offering untested targets that require only minor refinements.

“Now it’s time to test with the pointy end.”

A step-change in exploration strategy

Sandfire’s DeGrussa discovery wasn’t a booming anomaly in the VTEM, referring to the airborne electromagnetic survey that guided its discovery, and companies like Solara are heading back to the Bryah with a reinvigorated approach to run the ruler over targets outside of the VMS model.

The volcanic massive sulphide (VMS) model that worked for DeGrussa became a template that subsequent explorers applied religiously, often to their detriment.

Grid drilling programs were designed to find clones at similar depths and with similar geophysical signatures, meaning that anything subtle, deeper or structurally different was systematically overlooked.

“With a huge alteration overprint across the basin, we need to look below the top 100m or think more about the structural model than has been done prior,” Neild added.

“At Degrussa West the initial theory was that there might be VMS potential below the top 200m, based on geochemical, structural and geophysical signatures.

“We’ve since evolved this. We now think there’s also strong potential for gold mineralisation similar to that seen at Peak Hill’s Harmony and Enigma deposits.”

Star Minerals lines up low-capex gold production

If Solara represents the exploration play, Star Minerals exemplifies the near-term production strategy that could validate the basin’s renewed gold credentials.

The company’s Tumblegum South project, 40km south of Meekatharra on a granted mining lease, hosts a JORC resource of 616,000t at 2.28g/t gold for 45,000oz.

Recent drilling has delivered exceptional shallow, high-grade results including 5 metres at 30.91g/t gold (including 2m at 75.45g/t), 5m at 10.85g/t gold, and 8m at 6.96g/t gold.

An updated scoping study projects production of 11,800 to 15,900oz over ~18 months with capital requirements of just $1.7m to $3.9m, made possible by the presence of multiple operating gold processing plants in the region offering tolling opportunities.

That kind of low-capital, near-term production scenario could generate cash flow whilst funding exploration on Star Minerals’ 694km2 West Bryah gold package, which sits adjacent to Tambourah Metals’ high-grade Beatty Park South discovery.

Gold-led targeting may unlock the next find

Reflecting on why the land grab that followed Sandfire’s 2009 discovery produced little, Star Minerals MD Ashley Jones said the issue was less about the quality of the ground and more about explorers being locked into fixed geological models and methods.

“The current gold price could be changing this approach,” he said.

“Looking for gold instead of the VMS could result in the discovery of the next VMS – often the later gold mineralising event reactivates weaknesses that are associated with the VMS deposits.

“This was seen at Horseshoe Lights, so the extra activity chasing gold in the Bryah could be very rewarding,” Jones explained.

“Data processing and geophysical models are always improving, and history has told us that often deposits are found in areas that have been the focus of multiple companies prior.

“High grade narrow vein gold, especially smaller deposits, didn’t warrant the capex and trucking costs, but with the price increase these are now becoming economic targets.”

Recommissioning the Basin’s original copper-gold mine

Altogether different is Horseshoe Metals, which is rapidly recommissioning an historical, high-grade copper-gold asset with existing infrastructure for production.

Only 60km west of DeGrussa, Horseshoe Lights was the original copper-gold VMS discovery in the Bryah Basin.

It operated until 1994 and produced over 300,000oz of gold and 54,000t of contained copper, including over 110,000t of Direct Shipping Ore (DSO) grading between 20-30% copper.

Negotiations are underway with well-known commodity traders for offtake arrangements, meaning Horseshoe could become the Bryah Basin’s first new copper producer since DeGrussa ceased operations, albeit at a far more modest scale.

Site visits from potential partners beginning in September 2025 suggest there is commercial interest in the explorer’s restart strategy.

If successful, Horseshoe’s cash-generative operations could fund aggressive exploration across its 500km2 tenement package in the Peak Hill Mineral Field, testing for extensions to known mineralisation and new discoveries along the same VMS horizon that hosted Degrussa.

Tribeca backs Tambourah’s Bryah position

And Tambourah Metals is capturing the Bryah Basin’s gold comeback story at Beatty Park South with aircore drilling hits such as 24m at 18.78g/t gold from 20m.

Follow-up 1 metre re-sampling of the original 4-metre composite intervals delivered even more stand out grades – 10m at 38.9g/t gold from 22m, including 1m at 169g/t gold, equivalent to more than 5oz per tonne.

In October, barely two months after announcing the results, Tambourah secured a $3m placement from Tribeca Investment Partners, welcoming the globally renowned resource investment fund as a substantial shareholder.

The placement, at 8.5c per share, together with existing cash reserves provides Tambourah with approximately $4.5m to underwrite an aggressive exploration program at Beatty Park South.

For institutional investors who’ve been burned by failed Bryah Basin plays in the past, Tribeca’s involvement represents serious validation.

Rigs are now back on site testing the area immediately southeast and along strike from the high-grade intersections, with ~4000m of drilling planned to cover the strike extent of the 500-metre-long gold-in-soil anomaly associated with Beatty Park South mineralisation.

At Stockhead we tell it like it is. While Star Minerals and Horseshoe Metals are Stockhead advertisers, they did not sponsor this article.