Cobar’s long mining history is pointing the way forward for new discoveries
The Cobar Super Basin’s penchant for hosting long-lived polymetallic deposits continues to draw strong interest from explorers keen to make the next big find.
Cobar Basin polymetallic deposits provide natural hedging when one metal price goes belly up
Long mine lives are another point of attraction for explorers and miners alike
Cobar among the densest mining locations with strong community support
New South Wales has a long history of mining and nowhere is that clearer than the prolific Cobar Super Basin in the western part of the mineral-rich Lachlan Fold Belt.
Mining has been a primary industry in this region for more than 100 years beginning with the discovery of the Great Cobar copper mine in 1870 – predating the silver-lead-zinc discovery of Broken Hill in 1883 - that became Australia’s largest copper producer for some time.
While the mine closed in 1919, the region’s fortunes were revived by the discovery of the New Occidental Mine in 1934 and other subsequent mines.
Interestingly, Great Cobar is poised to enjoy a second lease of life as a satellite base metals and gold deposit for Aurelia Metals' (ASX:AMI) New Cobar mining complex at its Peak mine.
This also serves as a neat segue into one of the standout features of deposits in the Cobar. That is, they tend to be long-lived, multi-generational assets.
Along with their high-grade, polymetallic nature, this makes them extremely attractive for explorers and miners alike.
Speaking to Stockhead, Mount Hope Mining (ASX:MHM) managing director Fergus Kiley said the polymetallic nature of deposits in Cobar was a reason why it had been such a successful mining jurisdiction.
“If gold, for example, is not performing, copper might be the metal that's driving the mine economics or lead or zinc or silver. There's quite a lot of natural hedging or defendability in these deposits,” he noted.
Kiley also touched on their long life, saying they go on for kilometres into the ground.
“So when you find the deposits they have the ability to really make companies because they're such valuable and long-lived assets,” he added.
“Thirdly, because mining has been occurring there for so long, the community has strong support for these operations.
“So from a social licence perspective, you know, it's a really attractive jurisdiction where companies are able to get work done.”
This also lends itself to the high level of infrastructure with bitumen roads criss-crossing the region, a major gas pipeline and access to grid power.
The long history of mining in Cobar also means there are seven mills operating or on care and maintenance across a circa 210km stretch of land, the densest amount of mining activity per square kilometre of anywhere in the state.
Exploring the Cobar Basin
This proven prospectivity and long history of exploration and mining also lends itself to a firm understanding of the Cobar Basin.
“In the last two decades or so, people have come to an understanding that there's these major structural corridors that control the genesis of the basin, and all of the major deposits are generally associated with those faults,” Kiley noted.
“Our tenure has three major north-south trending faults that are basin surrounding or basin controlling structures that have been identified as areas of high priority.
“We see the evidence of mineralisation along those because there are five historical mines on our tenements that were mined at the turn of the 19th century.
“They all line up along these major structures so we're exploring where those structures intersect with slightly smaller cross-cutting fault architecture structures.”
While it is known that these intersections are what create the really long-lived deposits the Cobar Basin is known for, nobody had previously consolidated the land package that Mount Hope now holds.
Kiley added that having enough of the land that these major structures were located in was what enabled the company to apply the same exploration techniques that had found plenty of the other deposits in the region.
“That's what we've been able to do over the last year by getting our initial project and then expanding upon it with our additional land acquisitions,” he said.
Adding interest, he pointed to Australian Gold and Copper’s recent Achilles discovery to the southeast and Kingston Resources restarting the Mineral Hill mine, about 150-160km due east of MHM’s namesake project.
Kiley also highlighted Aurelia’s quick turnaround time for the Federation polymetallic mine.
“That was a deposit that was found in 2019 or 2020, so we're talking about something that took less than five years to go from discovery to production which is almost unheard off,” he added.
At the large end of town, Harmony Gold’s US$1bn acquisition of the high-grade CSA mine, which was first found in the 1800s and has been mined on and off since, is further evidence of the value placed in the long-lived Cobar polymetallic deposits.
Watch: Tapping into the prolific riches of the Cobar Basin
Mount Hope project
The company’s namesake project covers 422km2 of ground that is highly prospective for Cobar-style gold-polymetallic mineralisation.
While there is no current JORC resource, the project includes the historical Mount Hope, Comet and Great Central copper mines on the western side of the tenement package and the Mount Solitary and Solar gold mines on the east.
These demonstrate the project’s fertility whilst providing direct evidence of Cobar-style gold-polymetallic mineralisation.
Recent drilling at Mount Solitary returned results of up to 19m grading 4.5g/t gold from a down-hole depth of 39m.
Kiley said that while Mount Solitary was a known deposit, the company had developed an alternative structural model.
“We think we've got a different orientation for that project, so we're actively drilling that out,” he added.
“We'll be drilling right up until Christmas and then post-Christmas, we'll be drilling that project again.”
Kiley also expects 2026 to be an extremely active year on the exploration front as it drills and tests targets that are a long strike from known deposits within the project.
“We have other exploration targets across our tenements that fall within our new structural models, so areas where we think are highly prospective, where we've completed some electromagnetic surveys or geochemical ground-based soil or rock chipping to develop further targets,” he added.
“Then of course we're also looking at opportunities further afield where we're looking for further exposure to ground in the Cobar region.
“We made some land acquisitions already this year and we'll continue to expand our footprint and seek additional prospective grounds to explore.”
Other goals include advancing Mount Solitary towards a maiden resource and investigating the potential for toll treating or purchase agreements with the mills surrounding Mount Hope’s tenements.
Kiley noted that many of these mills were looking for additional feed and that such arrangements lowered the capital hurdle required to bring deposits into production.
Other players
While Mount Hope is pushing exploration at its namesake project, it is far from the only company that’s progressing their respective operations in the Cobar Super Basin.
Australian Gold and Copper (ASX:AGC) recently reported an exceptional assay of 6m at 2474g/t silver equivalent from the northern zone at its Achilles deposit.
Drilling has extended this zone to 150m in width at surface and to over 250m in depth.
This zone remains open with assays still pending for another 11 holes as of the beginning of December 2025.
Meanwhile, Kingston Resources (ASX:KSN) is conducting a new phase of drilling aimed at discovery and extending resources at its Mineral Hill project.
Underground drilling is underway to target extensions of high-grade mineralisation at the Southern Ore Zone and to upgrade inferred resources while surface drilling is focused on near-mine discovery potential.
The company is also ramping up production with underground development underway and higher output expected due to the higher gold and silver grades at Pearse South, where production is expected between December 2025 and June 2026.
Alchemy Resources (ASX:ALY) has an 80% stake in a package of assets in the Cobar region that includes the Overflow gold, West Lynn nickel-cobalt-high purity alumina and Yellow Mountain gold-base metals projects.
Overflow has a contained resource of 342,000oz gold equivalent that remains open along strike and at depth while West Lynn has resources of 21.3Mt at 0.84% nickel and 0.05% cobalt as well as 6.6Mt at 20.8% alumina.
In mid-November 2025, it started a follow-up induced polarisation survey across key target areas at Yellow Mountain to test mineralised zones up to 400m below surface and along strike of recent high-grade drill results such as 113m at 1.17% copper equivalent.
This will build on previous IP responses and will assist in refining targets for the next phase of RC and diamond drilling.
Other companies operating in the region include Lachlan Star (ASX:LSA) with its North Cobar project that has compelling drill-ready targets.
At Stockhead, we tell it like it is. While Mount Hope Mining and Alchemy Resources are Stockhead advertisers, it did not sponsor this article.
Originally published as Cobar’s long mining history is pointing the way forward for new discoveries
