By Penny Langford
Pilbara Gold has extended gold mineralisation at depth at its Mt York Gold Project in Western Australia, with hole 26MYDD022 returning 94 metres at 0.88 grams per tonne gold from 275 metres.
The company said the intercept sits about 100 metres below previous drilling and outside the current pit-shell boundaries at Main Hill, providing evidence that the mineralised system continues deeper than outlined in the existing geological model.
The result is important because it could support both a future mineral resource update and a review of the optimal open-pit design. It does not, by itself, establish additional reserves or demonstrate economic viability. Further drilling, geological modelling and engineering studies will be required before any deeper mineralisation can be incorporated into mine planning.
Key result from Main Hill
According to Pilbara Gold’s drilling announcement, hole 26MYDD022 intersected:
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| Drill hole | Prospect | Interval | Grade | Reported significance |
|---|---|---|---|---|
| 26MYDD022 | Main Hill | 94 m from 275 m | 0.88 g/t Au | Approximately 80 m estimated true width; extends mineralisation below existing drilling and the current pit shell |
The company also reported internal zones of higher grade within the broader interval, including 57 metres at 1.00 g/t gold, 9 metres at 2.45 g/t gold and 8 metres at 1.62 g/t gold.
A separate interval higher in the hole returned 6 metres at 3.19 g/t gold from 225 metres, including 3 metres at 5.56 g/t gold, Pilbara Gold said.
The company described the broad intercept as wider than modelled, with much of the mineralisation outside the current resource envelope.
Diamond drilling tests the depth and continuity of mineralisation beneath the existing Mt York model.
Why the deeper result matters
The immediate significance of 26MYDD022 is geological continuity. The hole was designed to test the down-dip extension of mineralisation identified in earlier drilling, including hole 25MYDD031, which Pilbara Gold reported as 53 metres at 1.45 g/t gold from 212 metres.
By intersecting a broad mineralised zone approximately 100 metres deeper, the new hole gives the company additional information about the thickness and geometry of the Main Hill orebody. Pilbara Gold said the result indicates that mineralisation remains open at depth.
For resource conversion, the distinction between an isolated intercept and a repeatable mineralised domain is central. A single hole cannot convert material into a higher-confidence resource category. However, a result that confirms continuity beyond the existing model may help define new geological domains when combined with additional drill sections and quality-control data.
The company’s next resource estimate will need to assess the spacing, orientation and consistency of drilling, along with assay reliability, geological interpretation and density information. Material classified as inferred, indicated or measured has different levels of geological confidence and cannot be treated interchangeably in mine planning.
The deeper position of the intercept also means that any potential addition to the resource will need to be assessed against the mining method. Mineralisation below the current pit shell may require a deeper pit, a revised pit shell or, depending on geometry and economics, consideration of underground mining. The present result does not determine which option will be selected.
Implications for the pit shell and mine plan
Pilbara Gold’s Mt York project disclosure reports an April resource of 61.7 million tonnes at 1.05 g/t gold for 2.08 million ounces. The resource was reported within an optimised pit shell based on a A$5,500-per-ounce gold price and a 0.40 g/t gold cut-off grade, according to the company.
The current pit shell is a planning boundary derived from economic and technical assumptions. It is not a geological limit. Drilling beyond that boundary can therefore test whether mineralisation continues into areas that were previously excluded from the mineable model.
The practical questions for mine planning include:
- Does the deeper mineralisation maintain sufficient thickness and continuity?
- Can additional ounces be included without materially increasing strip ratio?
- Would a deeper pit require more waste movement, haulage capacity or infrastructure?
- Could changes to pit depth affect mine sequencing, schedule or processing feed?
- Does the mineralisation have metallurgical and geotechnical characteristics consistent with the existing study assumptions?
These questions will become more important as Pilbara Gold advances its Mt York prefeasibility study. The company said the 2026 drilling program is intended to expand the resource, improve confidence in selected areas and support the study and a potential maiden reserve estimate.
Core logging links individual assays to geological continuity and future resource models.
Drilling program continues
Pilbara Gold said the result forms part of a planned more than 50,000-metre drilling campaign at Mt York. The program is targeting deeper extensions at Main Hill, Main Hill Extension, Breccia Hill and Gossan Hill, as well as infill drilling intended to improve resource confidence.
The company has also reported drilling results from Gossan Hill. Hole 26MYDD008 returned 21 metres at 1.42 g/t gold from 228 metres, including 7 metres at 3.54 g/t gold, within a broader interval of 45 metres at 0.75 g/t gold.
Pilbara Gold said drilling at Main Hill and Main Hill Extension remains focused on testing mineralisation below the current resource and pit-shell boundaries. The company has also identified satellite targets across the wider Mt York area, including Gilt Dragon, Zakanaka, Lucky 13 and Carlindi.
Mt York is hosted by a continuous banded iron formation trend extending over approximately 4.2 kilometres, according to the company. Pilbara Gold owns 100% of the project and is using the current campaign to test both resource extensions and areas requiring closer-spaced drilling.
Deeper drilling can influence pit geometry, waste movement and mine sequencing if continuity is confirmed.
What comes next
The next stage is to determine whether the 26MYDD022 result can be replicated across adjacent drill sections. Additional holes will help establish the limits of the mineralised zone, its dip and strike continuity, and whether the grade distribution is consistent enough to support a revised geological model.
Pilbara Gold said it expects to incorporate the 2026 drilling results into a later Mt York mineral resource update. The company is also advancing metallurgical, geotechnical and mine-planning work as part of its prefeasibility study.
The result therefore represents an exploration milestone rather than a completed development decision. Its value will depend on how successfully the company converts a deeper drill intercept into a coherent resource domain, and whether that domain can be incorporated into a practical and economically supportable mine plan.
For operators and project analysts, the main takeaway is the potential change in the shape of the Mt York system. Hole 26MYDD022 indicates that Main Hill mineralisation extends materially below the current model. The remaining work is to determine how much of that deeper mineralisation can be defined with sufficient confidence and whether it improves the project’s mineable inventory.
