PolarX Drills More Hyper-Grade Copper at Caribou Dome, Launches 10,000m 2026 Program

Exceptional Copper Grades Confirmed at Caribou Dome

PolarX Limited (ASX:PXX) has released the final assays from its 2025 diamond drilling campaign at the Caribou Dome Copper Project in Alaska, part of a joint venture with Northern Star Resources. The standout result from hole CD25-008 delivered a blistering 3.0 metres at 11.23% copper and 12.63 g/t silver starting at 65.3 metres depth, rounding out a series of impressive high-grade intercepts from the nine holes drilled last year.

Eight of those nine holes intersected significant copper mineralisation, with highlights including 18 metres at 2.84% copper (CD25-005), featuring a high-grade 8.5m interval at nearly 6% copper, and 5.3 metres at 6.12% copper (CD25-009) at 240 metres depth. These results not only extend the known mineralisation at depth but also enhance the geological understanding of the deposit’s structural complexities.

Drilling Extends Mineralisation and Targets New Zones

The 2025 program’s detailed oriented core logging and surface mapping confirmed copper mineralisation hosted within semi-massive to massive sulphide horizons interbedded with shale units, typical of the deposit’s volcanic-hosted massive sulphide (VHMS) style. Notably, drilling on type section 4 uncovered mineralisation beneath previously unrecognised zones once thought to be only iron-bearing sulphides, suggesting the deposit remains open both at depth and along strike.

Structural faults causing minor offsets were identified, particularly on type section 2 where one hole missed mineralisation likely due to a minor fault displacement. Plans are in place to drill beneath this hole to confirm continuity. The deep intercept in hole CD25-009 at 282 metres vertical depth further underscores the deposit’s open-ended potential.

2026 Drilling Program Kicks Off with Expanded Scope

Building on the momentum from 2025, PolarX has commenced a 10,000-metre diamond drilling program for 2026, fully funded by Northern Star under their joint venture agreement. This campaign aims to test several new Induced Polarisation (IP) geophysical anomalies, as well as down-dip and strike extensions of the Caribou Dome mineralisation. The program is scheduled to run through to October, with ongoing updates expected as results come in.

Alongside drilling, PolarX will undertake a Mobile Magnetotelluric (MT) airborne survey over the recently identified Jupiter magnetic anomaly, which extends 3.5 kilometres north from the Zackly magnetite skarn deposit and coincides with high-grade surface copper and gold samples. This geophysical work is designed to refine drill targets within the broader Alaska Range Project, which encompasses Caribou Dome, Stellar, Zackly, and Gemini prospects.

Joint Venture Backed by Significant Funding Commitment

The Alaska Range Project joint venture with Northern Star Resources allows the latter to earn up to 70% interest through staged cash contributions totalling US$39 million over five years. Northern Star has already contributed US$11 million over the first two years, funding all exploration activities including the current drill program and geophysical surveys.

Caribou Dome itself boasts an updated Mineral Resource Estimate of 7.2 million tonnes grading 3.1% copper and 6.5 g/t silver, with mineralisation traced over 700 metres strike and open below 300 metres depth. The deposit’s high-grade intercepts and ongoing exploration upside underpin the project’s robust economics, highlighted in PolarX’s 2024 scoping study projecting an NPV of A$625 million pre-tax at conservative copper and gold prices.