PolarX (ASX: PXX) Extends High-Grade Caribou Dome Copper Beyond Resource

PolarX has intersected a broad copper zone outside the existing mineral resource at its Caribou Dome deposit in Alaska, increasing the potential for an expansion of the project’s mineral inventory.

Diamond hole CD26-009 returned 58.5 metres at 2.0% copper and 3.9 grams per tonne silver from 138.7 metres. The downhole interval has an estimated true width of 36.8 metres and sits about 60 metres west of the current resource boundary.

Higher-grade sections within the broader intercept included 2.4 metres at 6.6% copper and 15.2 grams per tonne silver, 2.1 metres at 9.7% copper and 19.5 grams per tonne silver, and 2.7 metres at 7.2% copper and 13.3 grams per tonne silver. A peak individual assay returned 15.1% copper over 0.51 metres.

The result confirms visual mineralisation previously reported from the hole and adds to strong assays announced from the 2026 campaign, including 24.8 metres at 9.8% copper in CD26-007 and 22.6 metres at 8.1% copper in CD26-004.

Western target expands

The immediate significance of CD26-009 is its location beyond the resource rather than within the existing deposit model. PolarX said closely spaced magnetic survey data indicates the controlling structure may continue for at least another 500 metres west of the new intercept.

Geological observations from drill core also point to a possible feeder zone in the west. PolarX interprets the observed copper sulphide replacement mineralisation as evidence that the mineral system could be larger than previously understood, although further drilling is required to establish its extent.

The company plans to drill across the western extension target during the 2027 exploration season.

A second hole, CD26-008, tested the central deposit and intersected three mineralised zones. Its strongest result was a narrow 0.3 metres at 2.1% copper from 245.3 metres. While limited in width, PolarX said the hole provided information about fault offsets and supported the potential for mineralisation at depth.

Resource and funding context

Caribou Dome currently contains a JORC mineral resource of 7.2 million tonnes at 3.1% copper and 6.5 grams per tonne silver, representing 224,375 tonnes of contained copper. The nearby Zackly deposit contains another 45,000 tonnes of copper, as well as gold and silver.

PolarX holds a 60% beneficial interest in Caribou Dome through the Alaska Range joint venture. Northern Star Resources has earned a 30% interest in the wider joint venture after contributing US$11 million across 2025 and 2026. It can increase its stake to 70% through total contributions of up to US$39 million over five years.

Northern Star fully funded the 2026 campaign, which comprised 22 holes for 6,687 metres and was completed in September. Assays remain pending for another 13 holes, providing the next near-term source of geological information from the program.