PolarX (ASX: PXX) Hits 9.8% Copper at Caribou Dome

PolarX has reported wide, high-grade copper and silver intersections from its 2026 drilling campaign at Caribou Dome in Alaska, with results strengthening both the near-surface grade profile and the potential depth of the deposit.

The strongest result came from close to surface, while a separate deeper intercept extended known mineralisation well below the current resource envelope.

Caribou Dome already contains 224,375 tonnes of copper within its JORC Mineral Resource. The current exploration program is being fully funded by Northern Star Resources through the companies’ Alaska Range joint venture.

Near-Surface Grades Stand Out

Hole CD26-007 returned 24.8 metres at 9.8% copper and 14.5 grams per tonne silver from 2.4 metres downhole, with an estimated true width of 16.6 metres.

The interval included 4.9 metres at 13.6% copper and 20.4 grams per tonne silver, as well as 4.4 metres at 14.1% copper and 16.9 grams per tonne silver.

Nearby, CD26-004 intersected 22.6 metres at 8.1% copper and 13.5 grams per tonne silver from 3.7 metres. PolarX estimated the true width at 16 metres.

That hole also contained a higher-grade section of 5.8 metres at 12.4% copper and 21.3 grams per tonne silver.

The reported intersections are downhole lengths, with calculated true widths provided where PolarX said the geological geometry could be interpreted with sufficient confidence.

Historical Grades Under Review

CD26-004 and CD26-007 were drilled beside historical holes completed between 1964 and 1970 and incorporated into the existing resource estimate.

The modern drilling returned higher copper grades over wider intervals than the adjacent historical results, prompting PolarX to investigate whether earlier assay work understated parts of the deposit.

The company has begun systematically re-analysing available historical sample pulps, with those results to be incorporated alongside the new drilling in future resource work.

Where historical material is unavailable, additional drilling is planned.

Both twin holes ended earlier than intended after unexpectedly intersecting old underground exploration adits. CD26-004 terminated in mineralisation at the northern hanging-wall boundary.

Mineralisation Extended at Depth

Separately, hole CD26-003 returned 0.3 metres at 3.5% copper and 4 grams per tonne silver from 453.7 metres.

While narrow, the intercept extended known mineralisation by about 170 metres beneath its previously deepest position.

PolarX now sees potential for the mineralised system to extend to roughly 500 metres below surface, compared with about 300 metres for the current resource.

Further drilling will be required to establish whether that deeper mineralisation has meaningful scale and continuity.

Northern Star Funds Expansion Work

PolarX said about 1,700 metres of drilling remained in the current program, which is scheduled to finish by the end of September.

Work is now focused on western extension targets where visual sulphides have recently been reported and assays remain pending.

Northern Star has contributed US$6 million for the second year of exploration and has earned a 30% joint-venture interest. It can increase that stake to as much as 70% through scheduled contributions totalling US$39 million.

PolarX retains a 60% beneficial interest in Caribou Dome, which currently hosts 7.2 million tonnes grading 3.1% copper and 6.5 grams per tonne silver.