Pantoro Gold Ltd (ASX: PNR) has reported a fresh series of high-grade gold intercepts from underground drilling at the Mainfield mining centre, with results reaching up to 263.61 g/t gold and supporting the development of a third underground mine at its Norseman Gold Project in Western Australia.
Pantoro Returns High-Grade Gold From First Underground Drilling at Mainfield in 20 Years
Pantoro Gold Ltd has returned a series of high-grade gold intercepts from underground drilling at the Butterfly area within the Mainfield mining centre at its Norseman Gold Project.
The results come from drilling undertaken off the Bullen Decline, where the company is targeting extensions of the historic Mararoa Reef system, an area that has previously produced an estimated 1.4 million ounces of gold.
Pantoro Gold’s underground drilling at Mainfield returns high-grade results, confirming the development of a third underground mine. [Australian Mining]
The latest assays include multiple intersections grading above 40 g/t gold and up to 263.61 g/t across both the Crown South and O’Briens Reefs.
All holes drilled to date have intersected the Crown South structure at the expected depth, with several showing coarse visible gold. Headline results include 2.40 metres at 43.19 g/t gold, including 0.30 metres at 195.87 g/t and 0.43 metres at 104.15 g/t.
Drilling at the Butterfly area has also returned 1.5 metres at 81.23 g/t gold, including 0.5 metres at 223.65 g/t. Earlier drilling in the same zone produced a bonanza intercept of 3 metres at 485.43 g/t, including 1 metre at 1,420 g/t in the Mararoa Reef. These are the first underground drill intercepts at Mainfield in two decades.
Why These Drill Results Signal a Major Shift for the Norseman Gold Project
The Mainfield results carry weight beyond their grades alone. Returning to one of Australia’s most historically productive gold districts with modern drilling methods, and consistently hitting the reef where the geology predicted it would be, reinforces the reliability of the structural model Pantoro has been building.
Pantoro confirmed that the investment decision to develop the third underground mine was made without assuming further resource growth at either O’Briens or Crown South, despite ongoing drilling continuing to return high-grade intersections.
That conservative position signals financial discipline. The development case already stands on existing data, with any further drilling success representing additional upside.
For the broader gold sector in Western Australia, the results reflect a pattern of established producers revisiting historically significant ground with renewed confidence.
Pantoro’s Mainfield program demonstrates that systematic underground drilling on well-understood geology can unlock significant value without the exploration risk associated with greenfield discoveries.
Pantoro Gold: The Company Behind the Norseman Expansion
Pantoro Gold Ltd is an ASX-listed gold producer with a 100% interest in the Norseman Gold Project, located at the southern end of the Norseman–Wiluna greenstone belt in Western Australia.
The project currently hosts 4.6 million ounces of gold in mineral resources and 859,000 ounces in ore reserves. Pantoro completed construction of a 1.2 million tonnes per annum processing plant in 2022 and operates both open pit and underground mining across the project.
In the December 2025 quarter, the company produced 22,071 ounces of gold at an all-in sustaining cost of $2,571 per ounce, generating EBITDA of $83.6 million and operating cashflow of $39.2 million.
That financial position gives Pantoro the capacity to fund its Mainfield expansion largely from internal cash generation, without relying on equity raisings or external debt.
How Pantoro Plans to Develop Mainfield Into a Multi-Mine Hub
The Mainfield program sits at the centre of Pantoro’s broader growth plan for Norseman. Under its growth strategy, the company aims to expand underground mining operations, with a near-term target of around 100,000 ounces annually and a longer-term ambition to grow output beyond 200,000 ounces per year.
The Butterfly zone sits just 70 metres east of the recently developed Butterfly Decline, providing relatively straightforward access to high-grade ore. Known mineralisation in the Butterfly zone extends approximately 1.5 kilometres to the south and remains open at depth, indicating further resource growth potential as drilling continues.
Key Strategic Focus Areas
- O’Briens Reef development — first ore production targeted for the December 2026 quarter, forming the foundation of the confirmed third underground mine.
- Crown South advancement — development access planned for the March 2027 quarter, with the deposit remaining open in all directions as drilling continues.
- Butterfly zone expansion — an initial 26-hole diamond drilling program is underway, with strong early results expected to support a significantly expanded campaign.
- Processing plant utilisation — the existing 1.2 million tonnes per annum plant requires no major capital upgrades to process higher-grade underground feed from Mainfield.
Map of Mainfield underground zones highlighting O’Briens Reef, Crown South, and Butterfly areas targeted for expansion. [Yahoo Finance]
From Drilling to Production: Pantoro’s Development Schedule Through FY27
Pantoro is currently undertaking resource modelling across the Crown, Crown South, and expanded O’Briens areas, with updated mineral resource and ore reserve estimates targeted for the September 2026 quarter. The company’s schedule is structured to maintain momentum across multiple fronts simultaneously through the remainder of FY26 and into FY27.
Pantoro’s existing 1.2 million tonnes per annum processing plant is ready to handle high-grade underground ore from Mainfield’s expansion. [Mining Monthly]
A fifth underground drill rig is scheduled to arrive at Norseman in April 2026 to accelerate the Mainfield program. With approximately 250,000 metres of drilling planned for FY26, the exploration intensity at Norseman is among the highest the project has seen in recent history.
Key Timeline Details
- March 2026 — high-grade drill results reported from the Butterfly area and Crown South reef at Mainfield.
- April 2026 — fifth underground drill rig scheduled to arrive at Norseman to accelerate Mainfield drilling.
- September 2026 quarter — updated mineral resource and ore reserve estimates expected across Crown, Crown South, and O’Briens.
- December 2026 quarter — first ore development anticipated at O’Briens Reef, marking the start of the third underground mine.
- March 2027 quarter — Crown South ore zone development expected to commence following O’Briens Reef access.
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What the Mainfield Expansion Means for Pantoro’s Long-Term Production Strategy
The Mainfield program positions Pantoro as a company in active expansion rather than steady-state production. Ongoing drilling continues to demonstrate the significant scale of the Mainfield system, providing confidence that O’Briens will be the first of several new underground mining areas developed over the coming years.
If resource updates reflect the consistency of current intercepts, Pantoro could have multiple independent production sources feeding its processing plant within two years.
Execution risk remains a genuine consideration. The transition to Redpath as sole underground contractor, delivery of the fifth drill rig, and the complexity of developing a third underground mine simultaneously with existing operations all carry operational variables.
Any delays to the O’Briens or Crown South development schedules could affect production volumes and the timeline to meeting longer-term output targets.
On balance, the combination of consistent high-grade drilling results, a conservative development decision, strong quarterly cash generation, and additional drilling capacity arriving in April 2026 gives Pantoro a credible pathway toward its 200,000-ounce production ambition.
How efficiently the company navigates the next 18 months of underground development will determine whether Norseman establishes itself as one of Australia’s more significant gold operations of the decade.
FAQs
Q1: What are the latest drill results from Pantoro Gold at Mainfield?
Ans. Pantoro Gold has reported high-grade underground drilling at Mainfield, with assays reaching up to 263.61 g/t gold, supporting the development of a third underground mine.
Q2: Where is the Mainfield mining centre located?
Ans. The Mainfield mining centre is part of Pantoro Gold’s Norseman Gold Project, situated in the Norseman–Wiluna greenstone belt in Western Australia.
Q3: Which areas at Mainfield are showing strong mineralisation?
Ans. Key areas include O’Briens Reef, Crown South, and the Butterfly zone, all returning high-grade intersections and remaining open for further drilling.
Q4: When is the third underground mine expected to start production?
Ans. O’Briens Reef is scheduled for first ore development in the December 2026 quarter, with Crown South following in March 2027.
Q5: How does this drilling impact Pantoro Gold’s production goals?
Ans. The Mainfield expansion positions Pantoro to grow underground production toward 200,000 ounces annually, using the existing processing plant with minimal additional capital.
Disclaimer
This article is for informational purposes only and does not constitute financial or investment advice. Crypto and mining markets carry significant risk. Always conduct your own independent research and consult a qualified financial advisor before making any investment decisions.
Sources
- Pantoro ASX Announcement — Third Underground Mine Decision https://www.asx.com.au/asx/statistics/displayAnnouncement.do?display=pdf&idsId=02839919
- Pantoro ASX Announcement — Mainfield Drill Results https://www.asx.com.au/asx/statistics/displayAnnouncement.do?display=pdf&idsId=02831456
- Pantoro Investor Centre — December 2025 Quarterly Report https://www.pantoro.com.au/investor-centre/asx-announcements/
- Stockhead — Pantoro Mainfield Drill Results Coverage https://stockhead.com.au/resources/pantoro-norseman-mainfield-drilling/
