Experts say a new wave of exploration using a revised geological model and previously unavailable high-powered geophysics in Western Australia's Paterson Range could "reset the maturity clock" for copper and gold in the region and even across the other side of the continent in Queensland.
Rumors started circulating in 2017 that Rio Tinto had made a significant copper discovery in the Paterson, triggering a rush of juniors picking up ground in the area, and those companies' stocks have surged recently when local media releases satellite images of the iron ore major's 50-person work camp, believed to be enough to support at least three drilling rig crews.
Rio Tinto has also applied for a license to build an airstrip near the discovery, reportedly called Winu, and has expanded its Paterson acreage from about 1,000 square kilometers in 2017 to more than 11,000 square kilometers plus 1,760 square kilometers in joint ventures with the likes of Antipa Minerals Ltd. and Alloy Resources Ltd..
Then earlier this month, London-listed Greatland Gold Plc announced what CEO Gervaise Heddle described as "spectacular" copper-gold drill results on its Havieron property, prompting a series of electromagnetic, or EM, surveys strong enough to detect what's under cover looking for high-grade copper and elevated gold grades.
On Nov. 20 Antipa announced another airborne EM survey over its Citadel ground, while Artemis Resources Ltd. said two days later it was planning a high-resolution airborne magnetic survey over its Armada prospect, which surrounds Havieron on Greatland Gold's Paterson property.
Artemis Executive Director Edward Mead said "the time is right" to further investigate the ground given increasing news flow from Rio Tinto's rumored copper discovery in the Paterson Range and Greatland's results at Havieron which is contiguous to Armada, which in turn is about 40 kilometers east of the Nifty copper mine.
Even Fortescue Metals Group Ltd. has joined the exploration hunt, which also includes juniors like Sipa Resources Ltd., Red Metal Ltd., Carawine Resources Ltd., Encounter Resources Ltd. and Rumble Resources Ltd..
Metalicity Ltd. Managing Director Matthew Gauci, whose company secured license applications in the Paterson earlier this month adjacent to Rio Tinto, held operational roles at Rio Tinto's Kintyre uranium mine which he said was used as a camp from which to send out copper-gold exploration teams.
"There were geologists being dropped out in the middle of nowhere in the Paterson for years on ground that [Rio Tinto] had primarily auger-type drilling and geochemical sampling," he told S&P Global Market Intelligence.
"The Paterson has always been on everyone's list, with the right Proterozoic rocks and the right mix of geochemistry, geophysical and geological data to host a discovery."
Strategy shift
Encounter Managing Director Will Robinson told S&P Global Market Intelligence that if Rio Tinto has the kind of discovery rumors are suggesting, then "that just resets the maturity clock for the whole region."
"There has been a perception that Australia is a mature place for explorers, and if the rumors are right then that completely disproves that, as it shows you can find Tier 1 deposits under thin cover in a place like Australia. That's going to mean there will be a whole lot more explorers here," he said.
"There are also extensions at the Mount Isa Inlier as it extends undercover, with a series of good deposits there, which is probably where the next wave of discoveries will happen in that part of the world, with similar age rocks to the Paterson."
The hype has lured Independence Group NL as a major shareholder to help develop the Yeneena copper project Encounter holds in joint venture with Newcrest Mining Ltd..
Red Metal Managing Director Robert Rutherford, whose company holds ground in both the Paterson and Mount Isa Inlier, told S&P Global Market Intelligence that industry has shifted its thinking in the West Australian district where historically companies have looked for gold.
"Telfer was a gold ridge system but always had low-grade copper, but from what the rumors about Rio Tinto and what you're seeing with Greatland's discovery at Hevieron, they seem to be a lot more copper rich, and also elevated gold," he said.
"So comparing to the Mount Isa terrain, things like Minotaur Exploration Ltd.'s Eloise joint venture with OZ Minerals Ltd. seem to fit the description of Hevieron — an iron sulfide copper gold system — and what we have at Maronan."
Minotaur has also lured Japan Oil Gas & Metals Natl in the Osborne joint venture, while Newcrest and Rio Tinto are also present in the area looking for big copper-gold systems.