Octava powers up drill bit at Tassie copper-critical metals play

Octava Minerals is forging ahead on its dual-pronged assault on critical minerals, announcing ambitious drill programs and geophysical surveys at its Sweeney’s copper-zinc-silver-tin prospect within the Federation project in Tasmania.

With boots on the ground and rigs powering up, the junior explorer is progressing exploration at Federation’s Sweeney’s prospect for the first time in four decades. 

The project is nestled 12 kilometres west of the mining hub of Zeehan in Tasmania’s mineral-rich northwest and spans some 121 square kilometres. 

It sits in the shadow of the world-class Renison Bell tin mine, a behemoth that churned out more than 200,000 tonnes of tin since the 1890s and still boasts a 20-million-tonne resource at 1.18 per cent tin. 

Octava’s Sweeney’s prospect remains untouched by modern exploration and is shaping up as a potential core asset for the company in an excitable Aussie copper and critical metals market.

Renison drove some 18 diamond drill holes into Sweeney’s back in 1977, with 10 of them hitting meaningful sulphide zones. Standout intercepts included a 23-metre hit grading 1.19 per cent copper, 1.70 per cent zinc, 121 grams per tonne (g/t) silver and 1.17 per cent tin from 71m. Another hole struck 24m going 0.25 per cent copper, 0.52 per cent zinc, 42g/t silver and 0.27 per cent tin from 112m, while a third bored down into 31.4m grading 0.19 per cent copper, 1.92 per cent zinc, 31g/t silver and 0.62 per cent tin from 210m.

The company says its mineralisation remains open at depth and along strike and is waiting to be unlocked by a modern exploration toolkit. 

Octava is planning to run about 2000m of diamond drilling at Sweeney’s, targeting extensions to its high-grade bounty. Up to 22 holes are slated to kick off in November, pending approvals from the pro-mining Tassie government.

In parallel, Octava is gearing up for a ground-based electromagnetic (EM) geophysical survey in October, a first for Sweeney’s. 

Octava Minerals managing director Bevan Wakelam said: “We are onsite at Federation and have been able to locate all the old drill holes and workings. This visit has been essential for us in planning a significant drill program, and the approvals process is already underway.”

The prospect’s semi-massive sulphides are hosted in resistive Proterozoic quartzite and black shale, which are ideal conductors for EM, offering a prime chance to pinpoint feeder zones and deeper mineralisation.

The Federation licences sit on the flanks of the multiphase Heemskirk Granite, which pumped out hot metal-rich fluids during its final crystallisation stages. Large regional faults provided the plumbing that channelled those fluids into greisen-style zones rich in tin, zinc, silver and copper, which is exactly the style of mineralisation already seen at Sweeney’s.

The prospect’s proximity to Renison’s world-class infrastructure - complete with three-stage crushing, flotation circuits and access to Tasmania’s renewable hydropower grid - gives Octava a logistical edge, with nearby roads and the Port of Burnie for future development.

Octava is simultaneously keeping the momentum rolling at its Byro critical minerals project in WA’s Gascoyne region.

The company recently broke through on processing of the key magnet metals, neodymium, praseodymium and dysprosium, and 40 per cent for lithium, vanadium and terbium using biomining with European partner BiotaTec, which achieved up to 75 per cent recovery from Byro’s Permian black shales. 

The shales stretching 30km along strike and up to 100m thick hold the potential for a vast, low-cost supply of critical minerals, with biomining offering a greener path to extraction than traditional WA mining practices.

With Federation’s Sweeney’s prospect ready for the drill bit in a red-hot copper and critical minerals market, Octava’s Tasmanian tilt is ready to light up its prime new prospects for the first time in more than 40 years.

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