True North Copper Expands Mt Oxide to 2.3km as Chidna Zone Opens 300m Wide
Key Takeaways
- Maiden drilling at the Chidna zone has defined a mineralised width of ~300m — approximately five times the 40–60m envelope at the established Aquila discovery, located ~400m to the south.
- The headline intercept MOXRC26_007 returned 52m @ 0.85% Cu, 0.01% Co, and 1.7g/t Ag from 23m, including a high-grade sub-interval of 9m @ 1.89% Cu from 32m.
- The Mt Oxide mineralised trend has extended from ~1.8km to ~2.3km of strike, with Aquila now drill-defined over 1.3km and extended a further ~150m south by hole MOXRC26_011.
- Prospective structures mapped a further ~2.0km north raise the total potential corridor to ~4.3km — and the highest-priority shallow chargeability-conductivity anomaly at Chidna remains untested.
- TNC's existing Vero Resource of 220kt Cu, 5Moz Ag, and 21kt Co sits adjacent to the expanding Aquila-Chidna discovery, providing a resource base against which new mineralisation can be assessed.
Mt Oxide discovery grows to ~2.3km strike as maiden Chidna drilling opens a new ~300m wide zone
True North Copper (ASX: TNC) has released new drilling results from its 100%-owned Mt Oxide Project that extend the known mineralised trend from approximately ~1.8km to ~2.3km of strike. Maiden TNC drilling at the new Chidna zone, situated immediately north of the established Aquila discovery, has defined a mineralised width of up to ~300m, approximately five times the 40–60m envelope seen at Aquila. The system remains open in all directions, and with prospective structures mapped a further ~2.0km north, this discovery is getting bigger with every drill program.
All widths reported in this article are downhole intersections. True widths have not been confirmed.
Key results at a glance
- Mineralised trend extended to ~2.3km of strike, open in all directions
- Maiden Chidna drilling defines a ~300m wide mineralised zone, located approximately ~400m north of Aquila
- Headline intercept MOXRC26_007: 52m @ 0.85% Cu, 0.01% Co, 1.7g/t Ag from 23m, including 9m @ 1.89% Cu, 59ppm Co, 3.6g/t Ag from 32m
- Aquila mineralisation extended approximately ~150m further south, with the drill-defined zone now over 1.3km of strike
- Prospective structures mapped a further ~2.0km north, raising the potential corridor to approximately ~4.3km
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Aquila and Chidna — what the drilling is revealing
Aquila: high-grade shoots across 800 metres of strike
Aquila is the established discovery at Mt Oxide, now drill-defined over 1.3km of strike and to depths exceeding 300m below surface. Within a broader mineralised envelope typically 40–60m wide, two principal high-grade shoots have been defined: A499 and A494.
The headline result from this release, MOXRC26007, intersected 52m @ 0.85% Cu, 0.01% Co, 1.7g/t Ag from 23m, including a high-grade sub-interval of 9m @ 1.89% Cu, 59ppm Co, 3.6g/t Ag from 32m, plus 6m @ 1.39% Cu, 0.04% Co, 2.4g/t Ag from 67m and 37m @ 0.66% Cu, 0.05% Co, 3.7g/t Ag from 108m. Separately, MOXRC26011 extended Aquila mineralisation approximately ~150m to the south, demonstrating the system remains open at its southern boundary.
For context, previously reported results from the A499 shoot include 130m @ 0.67% Cu (MOXRC26010, previous release 11/8/2026) and 74m @ 0.73% Cu (MOXRC26009, previous release 11/8/2026). Discovery drilling in 2025 returned 59m @ 1.77% Cu (MOX255) and 33m @ 1.67% Cu (MOX263), including intervals exceeding 7% Cu.
| Hole ID | Prospect / Shoot | From (m) | Interval (m) | Grade (Cu %) |
|---|---|---|---|---|
| MOXRC26_007 (this release) | A499 | 23m | 52m | 0.85% Cu, incl. 9m @ 1.89% Cu from 32m |
| MOXRC26_010 (previously reported) | A499 | 180m | 130m | 0.67% Cu |
| MOXRC26_009 (previously reported) | A499 | 159m | 74m | 0.73% Cu |
| MOX255 (previously reported, 2025) | A499 | 134m | 59m | 1.77% Cu, incl. 7m @ 7.90% Cu from 134m |
All intercepts are downhole widths. Previously reported results sourced from prior TNC ASX announcements. True widths not confirmed.
Chidna: maiden drilling unlocks a structurally different and potentially larger target
Chidna sits approximately ~400–500m north of Aquila and was identified through IP geophysics. Two maiden reconnaissance drill holes, MOXRD26004 and MOXRD26006, were completed from the same pad during the Phase 1 program.
Topographic constraints limited optimal drill positioning, meaning both holes tested deeper parts of the geophysical anomaly rather than the core of the shallow coincident IP chargeability-conductivity target. That high-priority shallow target remains untested.
Results from MOXRD26_004 include:
- 23m @ 0.20% Cu, 61ppm Co, 1.1g/t Ag from 106m (including 1m @ 1.03% Cu from 122m)
- 14.55m @ 0.31% Cu, 0.06% Co, 1.5g/t Ag from 200.1m (including 1.5m @ 1.50% Cu from 211.3m)
- 39m @ 0.26% Cu, 38ppm Co, 0.6g/t Ag from 304m (including 9m @ 0.51% Cu from 331m)
Results from MOXRD26_006 include:
- 26.1m @ 0.10% Cu, 0.06% Co, 0.5g/t Ag from 154m
- 5m @ 0.31% Cu, 0.01% Co, 0.4g/t Ag from 251m
- 19.8m @ 0.17% Cu, 87ppm Co, 0.3g/t Ag from 291m (including 0.8m @ 1.57% Cu from 299.9m)
Geological logging of both holes revealed hydrothermal brecciation, multiphase copper sulphide veining, and epithermal-style silica-hematite textures not widely observed at Aquila. The announcement notes that these features suggest Chidna may represent a feeder zone or a distinct hydrothermal centre within the broader mineralising corridor. The increasing intensity of alteration and structural complexity at depth indicates the system remains open and fertile.
What is a dilational structural zone — and why does it matter for investors?
A dilational structure is a zone where the geometry of a fault creates space for mineralising fluids to accumulate. Think of it like a widening in a river channel, where the slowing current allows sediment to settle and build up. In a geological context, that “sediment” is copper-bearing fluid, and the wider the opening, the more space there is for mineralisation to form, potentially at higher grades.
At Aquila, the mineralised envelope is approximately 40–60m wide. At Chidna, geological interpretation suggests that width expands to approximately ~300m, interpreted to sit within what TNC describes as a major dilational structure within the Mt Gordon Fault Zone. More space can mean more mineralisation and potentially higher-grade cores, though this interpretation requires further drilling to confirm.
Andrew Mooney, Managing Director
“What is particularly exciting is the maiden TNC drilling at Chidna, immediately north of Aquila. The mineralised structure appears to open significantly from around 40–60 metres wide at Aquila to ~300 metres at Chidna, within what we interpret to be a major dilational structure. These structural settings can provide increased space for mineralising fluids, and the drilling has given us a number of compelling shallow and deeper targets for potential higher-grade mineralisation.”
What this tells you as an investor is that the geometry of the system is becoming more interesting as it extends north, not less. The maiden Chidna holes only tested the periphery of the anomaly. The core remains to be drilled.
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What comes next — and why the pipeline stays strong
The 2026 drilling program is ongoing, with a well-sequenced pipeline of catalysts ahead. TNC’s announced next steps are:
- Release further assay results from Mt Oxide over the coming months, providing a progressive pipeline of results that advance understanding of the project’s scale
- Continue drilling to expand the Aquila-Chidna mineral system along strike and at depth, targeting new higher-grade opportunities near surface and within deeper structural and hydrothermal breccia zones
- Complete follow-up IP geophysics and advance regional exploration across Mt Oxide to refine new and existing targets for Phase 2 drilling
- Progress technical studies, metallurgy and geological modelling to support the long-term development of the Mt Oxide Project
Those next steps sit within TNC’s broader three-platform growth strategy. The Grow platform is focused on the Mt Oxide Resource, anchored by the existing Vero Resource of 220kt Cu, 5Moz Ag and 21kt Co, which sits adjacent to the expanding Aquila-Chidna discovery. The Develop platform targets near-term revenue at the Cloncurry Copper Project. The Discover platform pursues regional Tier-1 IOCG targets including Chumvale, Marimo, and the Salebury IOCG system.
With approximately ~4.3km of prospective structural corridor now mapped at Mt Oxide, the system is open along strike and at depth. The maiden Chidna results have confirmed a structurally distinct and potentially wider mineralised centre just north of Aquila, and the highest-priority targets, including the shallow chargeability-conductivity anomaly at Chidna, are yet to be tested.
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