True North Copper Confirms Resource Growth at Great Australia Mine

True North Copper Drills Into Growth: Fresh RC Results from Great Australia Mine Reinforce Cloncurry Development Path

True North Copper (ASX: TNC) has released assay results from its 2026 reverse circulation (RC) drilling campaign at the Great Australia Mine (GAM), a cornerstone asset within its Cloncurry Copper Project (CCP) in Northwest Queensland. The True North Copper Great Australia Mine drilling results at Cloncurry Copper Project confirm copper-gold mineralisation extending beyond the existing resource boundary, adding weight to the company's near-term development thesis and its Pre-Feasibility Study (PFS) workstreams targeted for delivery in Q4 CY2026.

The programme — comprising seven RC holes totalling 1,706 metres and a parallel eight-hole diamond drilling (DDH) campaign for 1,303 metres — was designed not just to find more copper, but to build the technical and geological confidence needed to convert resources into reserves and advance the project toward a credible development decision.

Standout Results: Mineralisation Outside the Existing Resource

The headline intersections from this campaign come from two areas: Copper Mine Creek and the northern GAM targets. Together, they demonstrate that mineralisation at Great Australia extends beyond the currently defined resource envelope — a meaningful signal for future resource growth.

Key intersections from Copper Mine Creek (GAM26_010 and GAM26_009):

• 10m @ 0.88% Cu and 0.15g/t Au from 78m (GAM26_010)
• 51m @ 0.37% Cu and 0.07g/t Au from 133m (GAM26_010), including 30m @ 0.52% Cu and 0.09g/t Au from 154m
• 13m @ 0.38% Cu and 0.08g/t Au from 30m (GAM26_009), including 1m @ 2.01% Cu and 0.47g/t Au from 35m

These intercepts define a consistent zone of copper-gold mineralisation sitting approximately 75 metres away from the existing resource boundary, at shallow depths of between 25 and 100 metres below surface. That geometry — near-surface and outside the current model — is precisely the kind of result that can translate into incremental resource additions ahead of PFS finalisation.

The mineralisation is hosted in chalcopyrite-pyrite-carbonate veins and veinlets within altered metasediments and metavolcanics, consistent with the broader IOCG-style system that characterises the Great Australia deposit.

Breaking Down the Drilling Programme: Four Targets, Multiple Insights

The 2026 RC campaign tested four distinct target areas across the GAM mining leases. Each contributed meaningfully to the company's evolving geological understanding of the system.

At the Brown Snake target, two parallel north-south trending faults were tested roughly 100 metres apart. Both returned narrow but consistent copper-gold-cobalt intersections — 2m @ 0.52% Cu and 0.21g/t Au from 72m (GAM26_008) on the eastern structure and 2m @ 0.31% Cu and 0.10g/t Au from 40m (GAM26_006) on the western structure.

The company notes these structures may be modelled and incorporated into a future resource estimate, subject to further drilling and geological validation.

At the GAM hanging wall, GAM26_015 recorded intersections approximately 75 to 100 metres down-dip from previous resource-defining drill holes, suggesting potential for down-dip expansion of the flat-lying mineralised domain.

The Whip Target, an intense IP chargeability anomaly between the Taipan Resource and Copper Mine Creek, returned narrow mineralised intervals at depth. While not a stand-alone discovery, the drilling clarified the geological interpretation: the IP response is consistent with shallow, stacked flat-lying mineralised zones rather than a larger singular chute.

Understanding Cut-Off Grades: A Technical Primer for Investors

For investors newer to exploration geology, one concept worth understanding is the cut-off grade — and how it shapes the way drill results are reported.

A cut-off grade is the minimum grade of mineralisation considered economically worth mining. Reporting the same drill hole at different cut-off thresholds allows geologists and investors to understand both the broad envelope of mineralisation and the higher-grade core within it.

In TNC's reporting:

• 0.1% Cu cut-off captures the broader mineralised envelope, including lower-grade material that may contribute to bulk mining scenarios
• 0.3% Cu cut-off reflects typical open-pit economic thresholds for copper projects
• 0.5% Cu cut-off highlights economically robust portions of the mineralisation
• 1.0% Cu cut-off isolates the high-grade core — the kind of material that drives strong project economics

Furthermore, looking at GAM26_010 through this lens illustrates the quality of the Copper Mine Creek result. At 0.5% Cu cut-off, the hole returned 9m @ 0.60% Cu from 160m and 3m @ 1.34% Cu from 170m.

At the 1.0% Cu threshold, standout intervals include 3m @ 1.99% Cu from 83m and 1m @ 2.25% Cu from 170m. These higher-grade intervals within the broader mineralised zone are an important signal for future mine planning and reserve conversion work.

Key Mining and Exploration Terms

• RC Drilling (Reverse Circulation): A cost-efficient drilling method that returns rock chip samples to surface. Widely used for resource definition and exploration.
• DDH (Diamond Drill Hole): Core drilling that recovers a cylinder of rock for detailed geological, metallurgical, and geotechnical analysis.
• IOCG (Iron Oxide Copper Gold): A class of mineral deposit characterised by iron oxide alteration and copper-gold mineralisation. The Mt Isa region is globally recognised for IOCG systems.
• PFS (Pre-Feasibility Study): An engineering and economic study that assesses whether a project is technically and financially viable as a development opportunity.
• IP (Induced Polarisation): A geophysical survey method that helps identify subsurface mineralisation by measuring the electrical chargeability of rocks.

The Bigger Picture: Where the Cloncurry Copper Project Stands

These GAM results sit within a broader resource base that gives TNC meaningful scale as it advances toward a development decision. The Cloncurry Copper Project currently hosts a total Mineral Resource of 13.63Mt at 0.8% Cu and 0.19g/t Au for 109kt of contained copper, spread across multiple deposits.

The True North Copper Great Australia Mine drilling results at Cloncurry Copper Project reinforce the potential for incremental additions to the Great Australia portion of this inventory. As the company notes, the Copper Mine Creek intercepts may be incorporated into future resource re-estimates potentially prior to PFS finalisation — a near-term catalyst that investors should monitor closely.

Beyond Cloncurry, TNC's broader portfolio includes the Mt Oxide Vero Copper-Silver deposit, a separate and significant asset with its own resource of 15.03Mt at 1.46% Cu for 220kt contained copper plus 5.13Moz silver — one of the larger regional copper discoveries in Australia in recent decades.

Managing Director's Perspective

"These drilling results from Great Australia continue to support our broader strategy of building a robust and right-sized Cloncurry Copper Project with a credible near-term development pathway. The programme has focused on increasing our orebody knowledge and resource confidence, testing near-mine resource growth opportunities and delivering the metallurgical and geotechnical work required to support future reserve conversion and PFS studies."

— Andrew Mooney, Managing Director, True North Copper

What Comes Next: A Loaded Calendar Through Q4 CY2026

With drilling now complete across the CCP, the company shifts its attention from field work to data interpretation, technical studies, and study delivery. The next several months are dense with anticipated news flow.

The Wallace North and South RC results are of particular interest. Follow-up drilling at these targets has tested extensions to previously reported high-grade copper-gold intersections and several new geophysical targets.

Wallace North already carries the highest-grade resource in the CCP portfolio — 2.00Mt at 1.28% Cu and 0.77g/t Au for 25kt contained copper, plus 50,000oz of gold. Any positive extensions from the current campaign could meaningfully move the needle on project economics.

The diamond drilling programme — eight holes for 1,303 metres — was specifically designed to gather metallurgical, geotechnical, and geological data to underpin mine planning and reserve conversion. Results from these holes, expected progressively through to September, are integral to the PFS workstreams targeted for Q4 CY2026.

The Investment Case: Three Platforms, One Clear Direction

TNC's growth strategy rests on three complementary pillars, each at a different stage of maturity and each contributing to the overall investment thesis.

The Cloncurry Copper Project is the near-term value driver. The project has existing infrastructure on-site, a defined multi-deposit resource base, and a clear PFS delivery timeline. The 2026 drilling campaign has directly addressed the key technical inputs needed for that study — metallurgy, geotechnics, geological confidence, and resource boundary definition.

The new Copper Mine Creek intersections, moreover, introduce a potential resource addition that was not in the previous model. Even if modest in absolute tonnage terms, shallow near-mine additions can meaningfully improve mine plan optionality and reduce strip ratios — both of which feed directly into PFS economics.

The Mt Oxide asset, in addition, provides optionality at scale. With 220kt of contained copper and significant cobalt and silver credits, it is a potentially standalone development asset that adds considerable long-term upside to TNC's portfolio beyond the near-term CCP development pathway.

Why Investors Should Watch True North Copper

True North Copper occupies an increasingly important space in the Australian copper sector — a 100%-owned, multi-asset copper company with near-term development ambitions in one of the world's most copper-endowed geological regions, the Mt Isa Inlier.

The reasons to follow TNC closely over the next six months are concrete and time-bound:

1. Near-term assay news flow — Wallace North and South RC results are expected progressively through June and July, directly extending previously reported high-grade intersections.
2. Resource re-estimate potential — The Copper Mine Creek intercepts may be incorporated into an updated resource estimate ahead of PFS finalisation.
3. PFS delivery in Q4 CY2026 — This is the pivotal study milestone that will define the project's development parameters, economics, and pathway to production.
4. Multi-asset portfolio with scale — The combination of CCP and Mt Oxide gives TNC a copper resource inventory that is material in the context of ASX-listed copper developers.
5. Geological system with genuine upside — Ongoing confirmation of mineralisation outside the current resource envelope, across multiple targets, points to a system that remains open for growth.

However, it is the near-term newsflow that makes TNC particularly compelling to track. The True North Copper Great Australia Mine drilling results at Cloncurry Copper Project demonstrate methodical execution on the path from explorer to developer. With the PFS timeline and a series of near-term assay catalysts providing clear milestones for investors to track, the latest Great Australia RC results confirm resource growth potential at shallow depths — reinforcing both the project's technical foundation and the investment case heading into a critical second half of 2026.

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