More on the NEWS out TODAY recent hole (TRDD028) at Trundle Park had intersected broad porphyry-style intrusions from near surface (to 467m), with the targeted deeper intrusive body also intersected.
Technical committee chair John Holliday, ex-Newcrest Mining (ASX:NCM) explorationist and discoverer of Cadia, said the occurrence of the targeted porphyry intrusive system from surface to depth in TRDD028, for which assays are pending, provided a new nearer surface and potentially open pit target in addition to the known deeper parts of the system at the Trundle Park prospect.
“This is a very positive development and consistent with a number of the vertically extensive intrusive deposits at Northparkes that extend from nearer surface to depth,” he explained.
Northparkes is Australia’s second-largest porphyry mine, hosting a series of five economic and vertically extensive intrusive systems with around 5.5 million ounces of gold and 4.5 million tonnes of copper. So, if you’re going to make a discovery, something with the hallmarks of Northparkes is definitely a win and Kincora’s Trundle project is considered to be a brownfield setting in the same mineralised system as Northparkes.
Also announced this morning were most recent assay results at the Trundle Park prospect for an extension and wedge off previous drill hole TRDD014. Top hits, amongst others, included 42m at 0.42 grams per tonne (g/t) gold and 0.12% copper from 358m, including 10m at 1.13g/t gold and 0.32% copper from 382m; 48m at 0.19g/t gold and 0.03% copper from 458m; and a broad 122m at 0.16g/t gold and 0.03% copper from 596m. Together with other announced intervals, cumulatively the extension of TRDD014 returned the widest mineralised intervals to date at the Trundle Park prospect and Trundle project.
Importantly, the results from earlier drill holes and visual interpretation of this latest drill hole have provided Kincora with further confidence that it is close to the core of a large porphyry intrusive system.
The results also support the working model of a vertically extensive mineralised intrusive system that has both open pit and underground target potential.
Holliday said the new assay results confirmed Kincora’s initial visual interpretations with broad intrusive intervals and higher-grade skarn zones.
“The widths of mineralised intervals returned in TRRD014W1 and visual intrusions in TRDD028 are very encouraging,” he said.
“We continue to see the right rocks and alteration in what is an increasingly large intrusive system.
“The recently commenced hole TRDD029 will test the nearer surface intrusive, and southern and western depth potential, with the west and south still open for further follow up drilling as we seek to intersect the higher grade and inner potassic core of the intrusive system.”
Trundle Park is part of the Trundle Project in the Macquarie Arc in resource-rich Lachlan Fold Belt of NSW. The Macquarie Arc is a look-a-like of British Columbia’s ‘Golden Triangle’, where Newcrest recently picked up a new mine and is establishing itself as the largest producer in that region.
Porphyry potential becoming clearer
Due to their size, with broad intervals of generally lower grade copper and gold, porphyry style deposits are responsible for about 60% of the world’s current copper supply and will play an increasing role going forward to meet even a fraction of the forecast demand and growth driven by decarbonization and electrification of the global economy.
CEO Sam Spring, a former Goldman Sachs analyst, explained that one of the weaknesses so far for the Trundle Park prospect had been the depth Kincora had been drilling at to test the porphyry.
“However, … the working geological model has always been that these finger porphyry systems are vertically extensive and as such likely to come closer to surface than where we have been intersecting them so far,” he said. “Today’s news confirms our model and addresses one of the key concerns often raised about the project.”
“We believe a number of our recent holes have intersected an interpreted outer potassic part of what is a large porphyry system. Generally the Macquarie Arc porphyry’s, like those neighbouring at Northparkes, have a very discrete but vertically extensive high-grade system situated in the inner potassic core. The outer potassic zone is adjacent to the inner core, generally not very wide, and you don’t see much encouragement unless you are in the potassic part of the system.”
“The lithologies, alteration, veining, mineral tenor and structural interpretations have provided further confidence of a proximal environment to the targeted inner potassic core of the system, as well as vectors for follow up drilling,” Spring explained.
“Nearer term, ongoing drilling at Trundle Park will be looking to confirm the nearer surface and open pit potential, and vector to the inner potassic core of the system.”