Highlights

  • Octava Minerals (ASX:OCT) has launched the first modern exploration program at its West Sierra Grande fluorspar project in Río Negro Province, Argentina.
  • The staged program begins with mapping, remote sensing, and drone magnetics before progressing to drill permit applications and testing at four historical mine sites.
  • The project covers approximately 400 square kilometres in what the company describes as Argentina's largest and highest-grade historical fluorspar producing district.
  • Fluorspar is a strategically significant mineral used in battery electrolytes, steel production, aluminium processing, and a range of advanced industrial applications.

Octava Minerals Limited (ASX:OCT), the Western Australian-based critical minerals explorer, has outlined the commencement of a staged exploration program at its West Sierra Grande fluorspar project in Río Negro Province, Argentina. The program marks the first modern technical investigation of the project area, which contains four historical fluorite mines and covers approximately 400 square kilometres of tenure in what the company describes as Argentina's largest and historically most productive fluorspar district. Octava acquired an interest in the project through a binding conditional agreement entered into in late September 2026.

Staged Exploration Approach

Octava's exploration strategy at West Sierra Grande follows a deliberate sequenced approach designed to efficiently identify and rank targets ahead of drilling. The initial phase encompasses satellite and aerial Remote Sensing analysis, drone-based magnetic surveying to map subsurface geological structures without ground disturbance, and systematic geological mapping and rock chip sampling at and around the historical mine sites. This reconnaissance phase is designed to generate an evidence-based understanding of the geological framework before committing to drill programs. Managing Director and CEO Bevan Wakelam highlighted the company's clear, staged approach — with the near-term emphasis on drill testing of extensions around the known mines and a parallel target generation campaign across the wider project tenure. Drill permit applications are being progressed as the surface work advances. The fluorspar veins at West Sierra Grande are characterised as structurally controlled hydrothermal systems hosted in Jurassic volcanic rocks — a geological setting that the company views as prospective for additional mineralisation beyond the previously mined zones, which were worked to relatively shallow depths using historical techniques.

Project Background and Acquisition

Octava entered into a binding conditional share sale agreement in September 2026 to acquire up to 100 per cent of Aybull S.A., the Argentine company holding the West Sierra Grande exploration tenure, through a transaction with Argentina Critical Minerals (ACM), a Subsidiary of Global Strategic Commodities, an Argentina-focused critical minerals project generator. The 400-square-kilometre project is located 17 kilometres west of the town of Sierra Grande in Río Negro Province, situated adjacent to a paved national highway and approximately 47 kilometres west of the Punta Colorada export port. These infrastructure characteristics are considered favourable for a potential future development scenario, reducing the logistical constraints that commonly challenge remote mineral projects. Mining activity in the district commenced around 1964, peaked in the late 1970s, and subsequently declined as global fluorspar prices fell in the 1980s. All four historical mines lie within the Octava tenement, preserving the full district resource opportunity within a single tenure package.

Fluorspar's Critical and Strategic Role

Fluorspar, the commercial name for the mineral fluorite (calcium fluoride, CaF₂), has transitioned from a conventional industrial workhorse to a recognised strategic resource. At the metallurgical level, it is consumed in steel making, ferroalloy production, and aluminium processing as a fluxing agent that improves processing efficiency and product quality. At the chemical level, acid-grade fluorspar is the feedstock for hydrofluoric acid production — a precursor to lithium hexafluorophosphate, the dominant electrolyte salt in lithium-ion batteries. This connection to energy storage technology has elevated fluorspar's profile alongside the global growth in electric vehicle Manufacturing and grid-scale battery storage. Global production is heavily concentrated in China, and this Supply concentration has drawn attention from governments and industry participants in other regions seeking to develop alternative domestic and allied-nation sources for this now-critical industrial input.

Octava's Broader Portfolio and Strategy

West Sierra Grande represents a geographic and Commodity Diversification for Octava, which also holds the Byro Critical Minerals Project in Western Australia. Byro is a large-scale black shale system containing rare earth elements, lithium, and vanadium, for which an extensive conceptual exploration target has been defined following a 16-hole air-core drilling program. The company has also been active at the Federation copper-zinc-silver project in Tasmania, where diamond drilling at the Sweeney's prospect has returned high-grade indium, copper, zinc, silver, and antimony results from a historically worked but poorly understood mineralised zone. Together, the three-project portfolio reflects Octava's focus on critical minerals relevant to advanced industrial and energy technology applications, spanning battery inputs, rare earths, and industrial processing materials. The Capital for current exploration activities has been funded through targeted placements to sophisticated investors.

Key Insights

Octava Minerals' launch of a staged exploration program at West Sierra Grande brings a historically productive fluorspar district in Argentina under systematic modern technical assessment for the first time in several decades. The company's sequenced approach — building geological knowledge from remote sensing and mapping through to drill permit applications and eventual drill testing — is appropriate for an early-stage project where establishing a comprehensive technical framework will improve the quality of subsequent drilling decisions. Fluorspar's growing strategic importance as a battery supply chain material and a key industrial input provides a supportive commercial context for projects with credible resource potential in favourable jurisdictions.