PolarX Ltd (ASX:PXX) has uncovered a new copper discovery at the Caribou Dome Copper Project, a base metals exploration asset within the broader Alaska Range Project in Alaska.
The ASX-lister recently undertook diamond drilling over the high-grade Caribou deposit, intersecting finely disseminated and vein-hosted native copper in four holes over a 1.1-kilometre corridor.
PolarX is now waiting on assay results from these four holes, while planning for a follow-up drilling program is underway.
The company claims this discovery is particularly significant because it has the potential to add further scale to the existing resource at Alaska Range, which comprises Caribou Dome and the nearby Zackly deposit.
Caribou Dome mineral resources stand at 2.8 million tonnes at 3.1% copper, while Zackly’s mineral resource is 3.4 million tonnes at 1.2% copper and 2 g/t gold.
“Immense” exploration upside
PolarX managing director Dr Frazer Tabeart, who was recently on-site in Alaska for the duration of the drilling program, said: “This discovery is a potential game-changer for PolarX because the same volcanic host rocks, along with multiple IP and geochemical targets, are widespread at Caribou Dome, meaning the exploration upside here is immense.
“With copper being such an important metal for the green energy transition, we’re increasingly well placed to play a role in this market.
“We eagerly await the first assays from these new holes, and we will then plan a follow-up program to start quantifying the scale of this discovery at the first opportunity”.
Exploration drill holes
Last month, PolarX drilled four holes over the Caribou Dome Project, testing two of three coincident geochemical and geophysical anomalies.
Each target has copper anomalism in surface soil sampling and is associated with a 3D induced polarisation (IP) anomaly of the same magnitude as that associated with the known massive sulphide mineralisation
Both of the targets lie just over a kilometre apart and on the same broad IP anomaly, with native copper present in a very fine-grained to coarse-grained blebs in vesicle infills.
Not all flows are mineralised with copper, however, and the amount of copper varies from trace levels to up to 2% to 3% over short distances of a few centimetres.
Overall, the mineralisation stye is unusual, but not unknown.
It occurs in similar volcanic rocks elsewhere in the Nikolai Greenstones of Alaska and the Yukon — of which the lavas at Caribou Dome are thought to be a part.
Much more famously, it has been encountered in older volcanic rocks on the Keweenaw Peninsula in Michigan, where several significant deposits were mined at an average grade of 1.85% copper until the 1990s.
Over this time, the region produced more than 5 million tonnes of copper metal.
At this stage, it’s not possible to visually estimate the copper grades because of their fine-grained nature, so PolarX is waiting on assay results from the four drill holes.
Follow-up drilling will further test the copper prospectivity.