Pantoro Gold Ltd (ASX:PNR, OTC:PNTOF) has returned another suite of ultra high-grade gold results from ongoing underground drilling in the Mainfield Mining Centre at its 100%-owned Norseman Gold Project in Western Australia, further strengthening the case for new mine development in the historic zone.
The latest assays from drilling off the Bullen Decline 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 to date have intersected the Crown South structure at the expected depth, with several showing coarse visible gold.
Visible gold in holes CSDD25_025 and CSDD25_029 from the O’Briens and Crown South Reef.
The program, designed to define high-grade shoots and prepare for near-term underground access, is ongoing.
Standout grades across two key reef structures
Headline results from the Crown South Reef and O’Briens Reef drilling 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.
- 1.15 metres at 38.95 g/t gold, including 0.31 metres at 125.83 g/t.
- 1.42 metres at 14.68 g/t gold, including 0.44 metres at 38.14 g/t.
- 0.30 metres at 263.61 g/t gold.
- 0.65 metres at 25 g/t gold.
Pantoro said drilling continues to extend the high-grade plunge at Crown South, where at least 225 metres of strike is now defined. Meanwhile, follow-up drilling at O’Briens Reef — which already holds a Mineral Resource of 130,000 tonnes at 9.57 g/t for 40,000 ounces — has outlined new high-grade mineralisation up dip and along strike.
The company plans to update the O’Briens resource once further step-out drilling is incorporated.
Dewatering and mine planning steps progress
Pantoro has also advanced mine rehabilitation in the Bullen Decline, completing more than 5,000 metres of dewatering to date. A new life-of-mine pump station is now in place, with full dewatering expected in the first quarter of 2026. Early mine planning work suggests potential development access to Crown South and O’Briens could begin within six to nine months.
Managing director Paul Cmrlec said the latest results reinforce the strength of the Mainfield system: “Drilling at the Crown South Reef has delivered exceptional results from the outset, with every hole intersecting the reef where expected and many holes having displayed visible gold,” Cmrlec said. “The grades returned confirm the outstanding potential of this orebody.”
He added that new intersections at O’Briens highlight “significant opportunities to extend O’Briens Reef both along strike and up dip, while both reefs remain open in all directions”, noting that Pantoro aims to move towards mining preparations as data density improves.
Reinvigorating one of Australia’s richest historic goldfields
Mainfield is a major component of the Norseman Gold Project, which sits at the southern end of the prolific Norseman–Wiluna greenstone belt. The field has produced about 3 million ounces historically, with Crown, Mararoa and Bullen reefs contributing strongly before modern mechanised development in the 1980s and 1990s.
Isometric view of Mainfield Reefs.
Pantoro is working to re-establish Mainfield as a long-life, high-grade underground hub feeding its 1.2-million-tonnes-per-annum plant, commissioned in 2022. The broader Norseman project hosts 4.6 million ounces in total Mineral Resources and 859,000 ounces in Ore Reserves.
The company reaffirmed during recent quarterly reporting that it is targeting 100,000 ounces per year as a near-term production profile, with a longer-term aspiration to exceed 200,000 ounces annually as underground growth accelerates.
With drilling under way across multiple reef structures and about 250,000 metres planned for FY26, Pantoro says it is well positioned to unlock further high-grade mineralisation and extend the life of one of Australia’s most storied gold camps.