Global gold heavyweight Gold Fields has fired up the drill rig at Great Southern Mining's high-priority Mt Dillon copper-gold target in north Queensland, putting one of the company's most exciting exploration plays to the test.
Gold Fields is bankrolling the 1300-metre program under a farm-in agreement where the mining giant can spend up to $15 million to earn a 75 per cent interest in the expansive Edinburgh Park project.
The project itself sits in a monster gold province 100km south of Townsville, a region known for its large-scale epithermal and intrusion-related gold systems (IRGS).
Nearby deposits include the colossal 10-million-ounce Ravenswood, the three-million-ounce-plus Mt Leyshon and the two-million-ounce Mt Carlton mines, putting Great Southern in some seriously well-endowed elephant country.
The company says the highly anticipated program at Mt Dillon will test a tantalising induced polarisation (IP) chargeability anomaly lurking beneath a preserved lithocap.
Lithocaps are zones of resistant, silica-rich alteration formed at shallow depths that typically occur above the fabled porphyry copper-gold systems. These hardened structures tend to remain wholly or partly intact rather than being eroded away and often hint at monster copper-gold potential below.
Great Southern says the shallow IP anomaly, sitting just 200m to 300m below surface, could represent sulphide minerals associated with a preserved IRGS. Even more intriguing, a second resistivity anomaly sits directly beneath the chargeability target, potentially pointing to the intensely altered core of a buried porphyry copper-gold system.
Management says the level of alteration, metal depletion and preserved topography at Mt Dillon are all consistent with the leached lithocap portion in the upper zone of a large intrusive system.
Discovering major deposits under these geological formations is not unusual. Globally, several large-scale deposits have been discovered below lithocaps, including AngloGold Ashanti’s 7-million-ounce gold Quebradona deposit in Colombia and the massive Far Southeast porphyry deposit in the Philippines, which hosts a staggering 20 million ounces of gold.
Great Southern Mining managing director Matthew Keane said: "This is an exciting chapter for the Edinburgh Park project, with Mt Dillon representing the highest-priority target defined to date. The Mt Dillon target contains several compelling attributes including shallow IP anomalism below a preserved lithocap and multi-element anomalism which is consistent with epithermal and/or intrusion-related systems.”
With a global gold giant such as Gold Fields running the show and footing the bill, Great Southern finds itself in an enviable position. All the geological pointers for a significant IRGS discovery appear to be lining up at Mt Dillon and the company is getting a free ride on the exploration.
With drilling expected to take between four and six weeks, it may not be long before the company finds out if the smoke at Mt Dillon leads to a fire down below.
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By Andrew Todd
