Historic Kiwi project yields high-grade gold, antimony for Siren

Siren Gold is making waves at its Langdons antimony-gold project, in New Zealand’s Paparoa goldfield in the South Island, after recent fieldwork unearthed high-grade gold and antimony assays to spotlight a historic mining hub last worked in the 1950s. 

Open-pit channel sampling at the Langdons antimony reef returned a standout 38.5 grams per tonne (g/t) gold and 5.7 per cent antimony over 0.8 metres within a shear zone packed with disseminated arsenopyrite and stibnite lenses. 

Mullock samples from below the collapsed No.2 adit, hit an impressive 37.8g/t gold and a hefty 20.9 per cent antimony, while a mullock dump near the No.2 shaft delivered 10.8g/t gold and 9.5 per cent antimony. 

The results echo earlier bonanza grades from January last year, including 506g/t gold and 6 per cent antimony from mullock samples and rock chip results up to 10.9g/t gold and 9.3 per cent antimony, confirming the project’s high-grade potential.

The Langdons antimony reef dips 40 degrees southwest and extends along strike for more than 400m before it contacts the overlying Paparoa coal measures. Soil geochemistry, including ionic leach assays, traces gold and antimony anomalism for a further 200m northwest under cover. Two newly mapped antiforms 800m further north suggest further upside. 

Sampling of smaller adits southwest of the main pit at the antimony reef produced 1.99g/t gold from a mineralised zone at the project’s No.3 adit, while seemingly barren white quartz veins at the No.4 adit returned 0.37g/t gold, suggesting hidden potential.

The separate Langdons gold reef, which sits 90m below the antimony reef, outcrops over 25m with a 2m-thick mix of puggy quartz breccia, milky veins and sheared country rock laced with pyrite and arsenopyrite. 

Channel samples of the gold reef reported grades of up to 1.05g/t gold. The higher grades were found towards the reef’s western junction with the Antimony and Midnight reefs, pointing to a prime exploration target in the area. 

The Langdons project sits within a 5 kilometre by 1km window of Greenland Group metasediments, folded into northwest-southeast antiform-synform pairs, which is interpreted as a rotated cousin of the geology at the company’s Reefton Goldfield project.

Siren Gold chief executive officer Zane Padman said: “These results are highly encouraging. We are systematically unlocking a goldfield that has produced exceptional grades in the past, and our work confirms that potential still exists today.”

Padman said as well as defining significant gold mineralisation, the exposure to antimony as a critical mineral adds a significant strategic dimension to the project.

Historic mining in the area kicked off in 1879, targeting reefs such as Langdons, Victory, Liberty and Julian, with early reports hailing eye-watering grades up to 2610g/t gold and 1120g/t silver. 

A stamp battery was established in 1885, which saw Langdons and Victory produce 1586 ounces of gold from 809 tons at an average grade of 60g/t gold. A 1911 sample assayed 8.8g/t gold and 14.1 per cent antimony, while Dominion Laboratories in 1933 hit 89.9g/t gold and 64.1 per cent antimony.

A 1936 drill hole at Victory Reef, about 200m east of Langdons, intercepted 30g/t gold over 1m, with gold tied to quartz-stibnite veins and wall-rock arsenopyrite, mirroring Reefton’s Auld Creek prospect. 

The Langdons and Victory mines were revitalised after World War II, adding 60m of new drives and refurbishing 105m of existing drives, but operations declined by 1952. 

Siren’s August fieldwork, backed by a $4 million capital raise, helps build momentum across the company’s Kiwi project portfolio. 

The raise will also fund drilling at the company’s Sams Creek project, about 200km north of Langdons, where past intercepts include 9.48m at 9.5g/t gold from 3.62m at the Carapace prospect and 12.6m at 5.53g/t gold from 13.4m at South-East Traverse. 

Additionally, the company has already secured low-impact access to explore its Queen Charlotte project, which is home to the historic Endeavour Inlet antimony mine, north of Picton in the South Island. 

At Langdons, ongoing mapping and trenching aim to identify more old workings, and geochemistry will be employed to link the Langdons, Midnight and Liberty reefs, while other extended soil surveys will sniff out similar mineralised structures further north of the main area of workings.

The company plans to integrate all its ongoing mapping, sampling and soil geochemistry data into a comprehensive 3D model to prioritise future drill targets. 

With gold prices soaring past US$3700 (A$5656) per ounce and antimony fetching US$60,000 (A$91,000) per tonne, Langdons’ dual-metal punch could pack some serious economic clout. 

With its 81.9 per cent stake in the 824,000-ounce Sams Creek deposit and 17 per cent in RUA Gold for its Reefton-Hauraki exposure, Siren looks set to lead New Zealand’s gold renaissance. 

As it peels back the bush, each assay must feel like unfolding a treasure map, with Langdons’ high-grade reefs hinting at a modern-day bonanza just waiting to be drilled. 

Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.gold