Octava drills WA black shales for critical metals

Octava Minerals has officially fired the starting gun on drilling at its Byro critical minerals project in Western Australia’s Gascoyne region, launching a maiden exploration program designed to test a vast black shale system prospective for rare earth elements, lithium and vanadium.

The 1100-metre aircore drill program marks Octava’s first on-ground exploration at Byro and follows standout bioleaching test work carried out in 2025 by two independent groups — CSIRO and BiotaTec. 

Those tests delivered excellent recoveries of rare earths, lithium and vanadium using lab-grown microbes, opening the door to what Octava believes could be a large-scale, environmentally sustainable heap-leach-style operation, with the ‘micro-miners’ offering an effective and greener path to production.

Air-core drilling on a 2km x 2km grid will target Permian-aged black shales largely within the Coyrie Formation, the basal unit of the Byro Group and the key host horizon for critical minerals. About 18 holes are planned, testing to depths of approximately 60 metres across a broad footprint of about 10 kilometres by 8 kilometres. Octava expects the program to take around two weeks all up.

Notably, the drilling will not only help determine the scale and continuity of mineralisation but will also deliver fresh material for larger-scale bioleaching test work - a critical step in translating the earlier laboratory success into a potential development pathway.

Historic exploration has already identified the Byro sub-basin as potentially hosting a substantial accumulation of critical minerals, with the black shale package extending for around 25 kilometres of strike and up to 10 kilometres in width. Similar black shale systems have been successfully exploited using bioleaching techniques at operations such as the world-class Talvivaara nickel mine in Finland.

Byro sits on the West Australian Byro Plains, about 220 kilometres south-east of Carnarvon and is covered by two granted exploration licences totalling an impressive 555 square kilometres. 

Octava already has Native Title agreements in place and the project benefits from proximity to established infrastructure. It enjoys easy access to the port of Geraldton, power from the North West Gas Pipeline and potential future green energy developments being pushed by the Western Australian Government.

While drilling grabbed the headlines this week, Octava also quietly strengthened its commercial footing at Byro yesterday by agreeing to vary the terms of its acquisition agreement for the project. Following the successful bioleaching results, the company negotiated an extension to the agreement’s sunset date to 31 March 2026, providing additional time to complete technical work and secure approvals. 

In another positive tweak, the vendors’ entitlement to receive 2 million Octava shares upon publication of a scoping study has been replaced with performance rights tied to the same milestone. The change pushes any near-term dilution further down the track while keeping the vendors motivated to see the project succeed - a neat bit of housekeeping that tidies up the path to development as technical momentum builds.

In parallel with the start of drilling, Octava says it’s also working towards outlining an exploration target for the Byro black shale system - a key step in assessing whether the project can support the large, in-situ tonnages suggested by historic work.

Against a backdrop of surging demand for critical minerals used in clean energy, batteries and advanced technologies, Byro is shaping up as a timely and potentially significant new addition to Australia’s growing pipeline of next-generation mineral projects. 

With the drill rods now turning and the deal terms reset, Octava is wasting no time in putting Byro’s bio-mining story to the test.

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