Australia’s legendary Lachlan Fold Belt has long been one of the nation’s great mineral treasure chests, sprawling more than 700 kilometres through central New South Wales and into Victoria, featuring billions of dollars’ worth of copper and gold mineralisation being pulled from the ground each and every year.
The ancient belt is home to some of Australia’s most celebrated mineral deposits, including Newmont Mining’s plus-40-million-ounce Cadia-Ridgeway copper-gold complex, Evolution Mining’s Cowal gold mine and the Northparkes copper-gold operation.
Beyond the celebrated giant porphyry deposits, the belt boasts high-grade epithermal and volcanic-hosted massive sulphide (VMS) systems, all part of a mineral-rich geological network capable of spawning major discoveries of all shapes and make-up.
Despite more than a century of mining, vast tracts remain unexplored beneath younger sedimentary cover, leaving modern geophysics and deeper drilling plenty of room to unearth what earlier generations missed.
With copper prices soaring and Australia’s stable mining jurisdiction drawing serious attention, the majors are piling back in, chasing farm-in deals and drilling deeper in search of the next billion-tonne monster.
Newmont, Evolution, Gold Fields, AngloGold Ashanti and even Fortescue are in the mix, while well-positioned juniors are increasingly becoming potential takeover or farm-in targets for the big end of town.
One of the region’s established players, Kincora Copper, has turned that appetite for exploration into a business model of its own. The company has pivoted towards project generation, securing several deals potentially worth more than $100 million in partner-funded exploration over its expansive Lachlan tenement holdings.
Rather than give away the whole shop, the company has retained its Trundle and Fairholme flagship projects, preserving exposure to potentially significant discoveries while bringing outside capital to bear on its trickier porphyry exploration.
With cash rolling in, discoveries are beginning to emerge from the ground. Waratah Minerals recently uncovered a cracking find from extensional drilling at its Spur gold project west of Orange, returning 208.7m at 1.17 grams per tonne (g/t) gold from 514m, including 89m at 1.96g/t gold and a richer 38m at 3.61g/t gold.
Now boasting a market cap of around $300 million, Waratah could have plenty more to chase. The deep intercept has opened up fresh possibilities for its growing epithermal gold discovery, with deeper porphyry targets still waiting to be tested and potentially adding another lucrative dimension to the project.
Caption - Drilling on site at Kuniko Limited's Commonwealth-Silica Hill project, 100 km north of Orange in NSW.
Against this formidable geological backdrop, newcomer Kuniko Limited is carving out its own patch of the prolific Lachlan Fold Belt, marking the first year at the Commonwealth-Silica Hill gold-silver project, 100 kilometres north of Orange, with a string of promising exploration results.
In just 12 months, the company has completed two diamond drilling campaigns that notched up some eyebrow-raising precious-metal grades, expanded its exploration footprint and secured a majority ownership of Commonwealth-Silica Hill from joint venture partner Impact Minerals.
The standout results include a spectacular half-metre new discovery, grading 27g/t gold and an extraordinary 20,603g/t silver - once again from extensional drilling. To put that silver number into perspective, grades above 1,000g/t are often considered bonanza territory.
Another hole delivered a substantial eight metres at 3.3g/t gold, 186g/t silver and 5.6 per cent zinc, highlighting the project’s polymetallic nature and the potential for mineralisation extending beyond its eye-catching high-grade hits.
The geology adds another intriguing dimension, with two distinct styles of mineralisation sitting just 200 metres apart, potentially pointing to a much bigger mineral-rich system lurking at depth.
Commonwealth Main and South host a polymetallic VMS system, while Silica Hill contains an epithermal stockwork vein system. The combination has drawn comparisons with world-class deposits such as Canada’s Eskay Creek, renowned for its exceptionally high-grade precious-metal mineralisation.
While Kuniko is not claiming to have another Eskay Creek on its hands, the geological similarities offer a tantalising geological model as the company builds a better understanding of the broader mineralised system.
However, the existing discoveries may be only the opening act as a much bigger target takes shape. Kuniko’s geological and geophysical work has outlined a five-square-kilometre exploration opportunity, including a four-kilometre conductive corridor and multiple regional targets within one kilometre of known mineralisation.
The company says it has already identified six regional drill targets to test the broader system, with access secured and permitting progressing ahead of a planned first-quarter drilling blitz for the 2027 season.
Before the regional rigs arrive, however, several important milestones are lined up to help sharpen the picture.
Assays from the second five-hole diamond drilling campaign are expected this month, followed by downhole electromagnetic surveys designed to hunt for conductive sulphide extensions that may point to additional discoveries.
An updated mineral resource estimate is also targeted for December, allowing the company to incorporate its growing geological understanding into a clearer picture of the project’s scale.
Kuniko is far from the only junior explorer trying to turn the Lachlan Fold Belt’s geological riches into something much bigger.
Fellow ASX-listed Locksley Resources has been assembling its Greater Tottenham Copper District in central NSW, bringing together its existing Tottenham copper-gold resource and the nearby Iron Duke project.
Tottenham already hosts a resource of 9.86 million tonnes grading 0.73 per cent copper, while Iron Duke carries a historical JORC 2004 inferred resource of 1.3 million tonnes at 1 per cent copper and 0.6g/t gold.
The bigger picture is the sheer size of the ground still to be explored. Locksley’s Greater Tottenham tenure covers a whopping 1000 square kilometres, with more than 50 kilometres of prospective trends identified through geophysical interpretation.
That leaves plenty of scope for follow-up targeting and resource growth as the company works to stitch individual deposits and prospects into a broader district-scale copper play.
Meanwhile, Orbit Resources has also returned to the region to take another tilt at its Lewis Ponds gold-silver-base metals project, just 15 kilometres east of Orange.
Lewis Ponds already hosts a 17.52-million-tonne resource grading 1.12g/t gold, 53.34g/t silver, 2.06 per cent zinc, 1.10 per cent lead and 0.14 per cent copper for 1.7 million gold equivalent ounces.
The latest drilling push is aimed at expanding that polymetallic inventory and testing the project’s wider potential, adding yet another precious and base metals play to a region where the majors and juniors alike are looking for their next big discovery.
With the big miners circling, exploration dollars flowing and modern drilling opening fresh geological frontiers, the Lachlan Fold Belt is shaping up for another potentially lucrative chapter. For Kuniko and its fellow juniors, the prize is a discovery big enough to turn a market minnow into the next major mining success story.
Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au
