A big day has finally arrived for Great Southern Mining and Gold Fields Limited after the mining duo kicked off a high-stakes diamond drilling campaign at their Edinburgh Park project in Far North Queensland in a move that could unearth the region’s next major gold-copper system.
The program is targeting big-ticket induced polarisation (IP) anomalies at two key prospects dubbed Leichhardt Creek and Mt Dillon. Both targets show the geological hallmarks of large-scale intrusion-related gold-copper-silver systems.
The campaign is being funded by South African mining juggernaut Gold Fields, which liked what it saw at the project and inked a $15 million earn-in joint venture in 2023 to secure up to 75 per cent of the sprawling Queensland play.
The deal gives Gold Fields exposure to the entire province-scale project, which stretches across 11 exploration licences in a region teeming with potential.
The move came after Great Southern pinpointed 29 promising targets in outcropping mineralisation and through geochemical surveys over 4 years of exploration. For Gold Fields, it was enough to back the junior explorer with serious firepower.
The joint venture agreement was seen as a strong vote of confidence in what remains one of Australia’s most underexplored frontiers, 100 kilometres southeast of Townsville.
At Leichhardt Creek, the drill rig is set to punch out three deep holes for a total of 2200 metres. The first hole will plunge 1000m in depth and will test a shallow, arch-shaped IP chargeability anomaly. Gold Fields management says this signature looks eerily like the 3-million-ounce-plus Mount Leyshon gold-silver mine, positioned 120km west.
The rig will then pivot to a second hole to zero in on a potential mineralisation feeder mapped from earlier aeromagnetic data, before plunging 800m to chase another juicy chargeability anomaly.
A third hole will home in on the heart of the second anomaly, where conductivity readings have topped 50 millivolts per volt.
Field mapping has already firmed up multiple sulphides - including pyrite - in outcropping rocks - alongside a stockwork of quartz-pyrite veining spread over a whopping 4km by 1km area. Soil sampling also lit up with zoned gold, silver and base metals, while rock chips have returned up to 10.5 grams per tonne (g/t) gold.
When Leichhardt Creek is wrapped up, the rig will shift to Mt Dillon, where a large chargeability anomaly lies 200–300m beneath a prominent hill. A second, deeper resistivity anomaly, possibly linked to altered porphyry rocks, sits just below the higher anomaly.
Gold Fields has planned two holes to chase both zones and the signs are promising. Mt Dillon’s topography appears to be a preserved silicified lithocap, which is typical of a large porphyry-style system. Surface alteration, including clay, pyrite and silica with high sulphide content, has added fuel to the fire.
Globally, similar lithocaps have delivered monsters such as AngloGold’s Quebradona, containing 4.26 million tonnes of copper and 7 million ounces of gold. Other examples of lithocaps include ATEX’s Valeriano mine with 7.1Mt copper and 9.6M ounces of gold, and the massive Lepanto-Far Southeast system in the Philippines, which hosts more than 20M ounces of gold and 4.5Mt of copper.
Meanwhile, Great Southern and Gold Fields are using geophysical surveying to generate additional targets across the project’s 1750-square-kilometre footprint. Their Edinburgh Castle and Molongle prospects are next in line, with the latter already spitting out rock chips grading up to 5.27g/t gold.
With the rotary truth teller now spinning, Great Southern could be closing in on a major copper-gold prize and its heavyweight backer has the wallet to make it count.
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By James Pearson
