Alkane Drills High-Grade Gold, Antimony at Brunswick South

Alkane Resources reported high-grade gold and antimony intercepts from 91 diamond drill holes at the Brunswick South deposit, part of the Costerfield operation in central Victoria. The best hit returned 50.1 grams per tonne gold and 26.2% antimony over 2.17 metres, with an estimated true width of 1.08 metres. The results confirm a new high-grade zone 400 metres south of the previously mined Brunswick vein and 200 metres from existing underground development.

Nic Earner, Alkane's managing director and CEO, said the deposit contains both high gold endowment and a significant quantity of antimony. "Excitingly, Brunswick South can be brought online without extensive access requirements," he said. The company is starting development this quarter and plans to make it a primary production source for Costerfield.

Brunswick South sits at the southern end of a 3-kilometre mineralised corridor that has produced gold and antimony since the 1860s. Modern mining at Costerfield has been continuous since 2006. Alkane acquired the operation through its 2023 purchase of Mandalay Resources and now runs three underground mines across Australia and Sweden.

The antimony component carries extra weight. The mineral is classified as critical by the United States, the European Union, and Australia. China supplies roughly half of global output. Export controls imposed in 2024 pushed antimony prices sharply higher, and supply remains tight. Costerfield is one of the few Western sources capable of producing antimony concentrate at scale.

Drilling defined two distinct styles of mineralisation. Above the Kiwi Fault, intercepts are antimony-rich and quartz-poor. Gold grades stay comparable to the rest of the field. Below the fault, the intercepts switch to quartz-dominated veins with high gold grades and little stibnite, the antimony ore mineral. The company said this deeper zone resembles the high-grade Youle Lode at the northern end of the corridor.

Of the 91 holes drilled since the previous release, total core length reached 28,421 metres. Ten intercepts graded above 10 grams per tonne gold equivalent over a diluted mining width of 1.8 metres. The drilling also picked up a previously unknown line of mineralisation 200 metres west of the main deposit, called Brunswick West. One hole there returned 8.4 g/t gold and 1.3% antimony over 0.32 metres.

Chris Davis, Alkane's chief geologist and the qualified person for the exploration results, said the spread of high-grade intercepts over 175 metres of strike below the existing access level shows structural continuity. The company noted that the mineralisation appears to roll into the Kiwi Fault plane and continue down-dip, a geometry similar to the Youle Lode system that made Costerfield a high-grade producer.

Development work has already started. Alkane said the results have been integrated into the Costerfield mine schedule. Capital development to access Brunswick South is scheduled for the third quarter of 2026. The company plans to follow up on several targets, including the continuation of the Kiwi Fault zone down-dip and the new Brunswick West structure.

For context on antimony's market dynamics, prices have roughly doubled since China tightened export rules. Alkane's ability to bring a new near-term production source online gives it a supply-side catalyst that few peers in the critical-minerals space can match. The company's commodities exposure spans both gold and antimony, which are priced in US dollars. The dual-commodity revenue stream cushions single-metal price moves. Alkane's three operating mines produced roughly 75,000 ounces of gold and 1,500 tonnes of antimony in the last financial year. Brunswick South could lift both figures from 2027 onward.