Extensive geophysical exploration work has paid off for Great Southern Mining and Gold Fields Limited after the duo of companies picked up strong signals of a second large-scale induced polarisation (IP) target at their jointly owned Edinburgh Park gold and copper project in northern Queensland.
The latest target, dubbed Mt Dillon, follows an earlier discovery of an IP anomaly measuring more than 2 kilometres wide at Leichhardt Creek, which sits 10km to the northwest of the latest find.
The early identifiers are also almost identical to the Leichhardt Creek “tells” and, according to management, have boosted the chances of making large-scale intrusive-related discoveries across the lease.
Great Southern says Mt Dillon bears all the hallmarks of an intrusive-related anomaly with strong geochemical indicators, promising structural formations, nearby gold-bearing breccia pipes and surface alterations.
The new target lies beneath a massive silicified lithocap covering several square kilometres, mainly made up of quartz and other silica-type minerals, making it resistant to erosion.
It also has widespread argillic alteration – a process where the primary minerals in rock are replaced by clay minerals such as kaolinite, illite and montmorillonite – which is another classic indicator of an acidic, fluid-saturated system.
Adding to the intriguing target, the IP survey lit up with chargeability signals at depths of 200 metres to 300m, hinting at the presence of a sulphide-rich, well-preserved porphyry system waiting to be uncovered.
With two significant targets now under its belt, the joint venture is planning to bring out a truth-telling rig for a drilling program set to start in the second quarter of the year after it completes the necessary heritage and environmental surveys and northern Queensland’s wet season slows down.
Until then, geophysical surveys, on-ground mapping and helicopter-borne aeromagnetic studies will continue their work to uncover new targets that light up with the same signals as Mt Dillon and Leichhardt Creek.
Great Southern Mining managing director Matthew Keane said: “It is exciting to see large IP anomalies directly below two of the most favoured targets within the Edinburgh Park project, namely Mt Dillon and Leichhardt Creek.”
The early discovery of two big intrusive-related anomalies is exactly what Gold Fields was hoping for when it signed up to go elephant hunting at Edinburgh Park.
The project spans a vast area of 1750 square kilometres and encompasses a belt-scale porphyry play. It was always going to be too big for Great Southern to explore single-handedly, but it is exactly the sort of exploration grounds that a deep-pocketed miner, such as Gold Fields, could get its teeth stuck into.
After a rigorous due diligence process and offering the best deal in a competitive tender, Gold Fields sealed its joint venture agreement in late 2023. The deal grants the mining giant the option to earn a 75 per cent stake in the project by spending $15 million in exploration over six years.
As part of its commitment, Gold Fields has to spend at least $2.5m within the first two years, ensuring an aggressive early exploration push. Great Southern retains a 25pc free carried interest until the $15m is spent.
The Edinburgh Park project is strategically located at the northern end of the proven New England Orogeny and is about 100km southeast of Townsville. The region hosts multiple world-class deposits, including the revered 16.6m-ounce Charters Towers mine, the 2.3m-ounce Pajingo gold mine, the 10m-ounce Ravenswood gold mine and the now depleted 9m-ounce Mt Morgan gold mine.
Some of Great Southern’s Edinburgh Park wrap around Navarre Minerals’ 2m-ounce high-sulphuric epithermal Mt Carlton gold-silver-copper mine.
Now that Gold Fields is responsible for exploration funding and chasing massive exploration targets, Great Southern appears well positioned to leverage itself into what could be a major copper-gold discovery.
With multiple large-scale targets now defined, the upcoming drilling program in this underexplored region could be the catalyst the company needs to transform itself from mining junior to a key player in the Queensland mining sector.
Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au
By James Pearson
