Partners Newcrest Mining (60%) and Greatland Gold (40%) reported a maiden resource for Havieron of 52 million tonnes at 2 grams per tonne gold and 0.31% copper for 3.4 million ounces of gold and 160,000 tonnes of copper in December.
The figure comprised 18Mt at 3.8gpt gold and 0.61% copper for 2.2Moz of gold and 110,000t of copper in the Crescent Zone, and 34Mt at 1.1gpt gold and 0.15% copper for 1.2Moz of gold and 50,000t of copper in the Breccia Zone.
While the numbers were impressive, the partners see it as just the start.
On Thursday, further results were unveiled and highlighted the potential for the resource to get bigger.
Drilling in the South East Crescent returned 85m at 11gpt gold and 0.29% copper from 1345m, including 13m at 32gpt gold and 0.46% copper and 14.5m at 32gpt gold and 0.33% copper.
The high-grade zone remains open at depth.
"Our extensive growth drilling program at Havieron has identified several exciting results from the South East Crescent Zone which has extended the high-grade mineralisation beneath the initial inferred mineral resource," Newcrest managing director Sandeep Biswas said.
A hole in the Northern Breccia returned 84.5m at 2gpt gold and 0.05% copper from 683m, including 12.7m at 6gpt gold and 0.01% copper.
Assays are pending for two holes from the South East Crescent Zone, nine holes from the Northern Breccia and four holes at the Eastern Breccia.
At the latter, the holes were drilled along strike from previously reported hits, over a strike length of about 600m, with the aim of expanding Havieron's footprint.
Newcrest has completed 212 holes for 184,081m of drilling since starting exploration at the project in 2019 under a US$65 million farm-in with Greatland.
Newcrest's involvement came about after Greatland reported a spectacular hit of 275m at 4.77gpt gold and 0.61% copper at Havieron in mid-2018.
The gold major had once held the project, drilling six holes in the 1990s, with all hitting gold and copper anomalism with peak grades of 15.4gpt gold and 2.5% copper.
However, the company dropped the project and built the much shallower Telfer mine 45km away.
Newcrest and Greatland are currently building a A$146 million exploration decline at Havieron, with the box cut and portal completed in May.
The decline has advanced 69m with contractor Byrnecut moving to 24-hour operations.
"There is a tremendous amount of activity and excitement with the progress across the Havieron gold-copper project," Greatland CEO Shaun Day said.
"The drilling program keeps on delivering with every hole continuing to hit significant mineralisation while also growing the scale of the project.
"Drilling has identified several exciting results from the South East Crescent, extending the high-grade mineralisation beneath the initial inferred resource estimate.
"The ongoing success from each set of drill results builds confidence in the world class nature of the Havieron gold-copper project and its potential to expand.
"This de-risks the project as we progress it towards potential production and adds further upside to the value of the deposit."
A hotly anticipated prefeasibility study for Havieron is due later this year.
Newcrest is targeting first production through its Telfer plant, 45km away, within 2-3 years.
Last month, Canaccord Genuity analyst Sam Catalano suggested Havieron could become a 400,000-700,000ozpa producer, with a mine life of over 20 years, developed at low capital costs.
Telfer currently produces at a rate of about 400,000ozpa.
Canaccord's base case at Havieron is for an 8Mt per annum operation costing US$853 million and having all-in sustaining costs of $330 an ounce after by-product credits.
"We do believe that ongoing reporting of drill results will continue to be encouraging this year and will ultimately lead to significant upgrades in the overall resource base," Catalano said.
Newcrest Mining and Greatland Gold are nominated for Explorer of the Year in the 2021 MNN Awards.