Orion Minerals has reported assay results from the second drill hole in its resource optimisation programme at the Flat Mine East prospect within the Okiep Copper Project in South Africa’s Northern Cape, confirming that the high-grade copper zone identified earlier this year continues to extend at depth and remains open below the current mineral resource envelope.
Orion Minerals — Okiep Copper Project, Flat Mine East: key drill intercepts
| Drill hole | Date | Intercept (m) | Grade (%Cu) | High-grade sub-interval | Notes |
|---|---|---|---|---|---|
| OFMED153 | Apr 2024 | 49.0m | 4.89% | 10.23m @ 12.47% | Highest-grade intercept ever reported at Flat Mines |
| OFMED157 | May 2026 | 7.88m | 9.24% | 3.33m @ 17.12% | 36m down-dip of prior high-grade; zone open at depth |
| OFMED158 | Jun 2026 | 3.96m | 4.64% | — | Confirms down-dip continuity from OFMED157; supports follow-up drilling |
| FME035 (historical) | 1995 (GFSA) | 59.1m | 3.55% | 10.12m @ 9.83% | Drilled by Goldfields of South Africa; never followed up due to low copper prices |
| Flat Mines combined mineral resource (current): 10.0Mt @ 1.3% copper | Flat Mine East: 4.4Mt @ 1.3% copper | Project ground holding: 703km² | Historical district production: 105Mt over 100 years | |||||
Sources: Orion Minerals; Kalkine; SmallCaps; Proactive Investors
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The second completed drill hole, OFMED158, returned 3.96 metres at 4.64% copper and confirmed the down-dip continuity previously revealed by OFMED157, uplifting understanding of the structural controls to mineralised mafic units and building on outcomes from the 2024 confirmation drilling programme. CEO Tony Lennox characterised the result as extending the recently identified high-grade copper zone further down-dip and demonstrating that the mineralised system remains open and continues well beyond the current resource envelope and block model.
The significance of OFMED158 lies not in its width but in its geometry. OFMED157 intersected 7.88 metres at 9.24% copper from 311.29 metres depth, with a high-grade sub-interval of 3.33 metres at 17.12% copper, designed to test an open zone 36 metres down-dip of previously reported high-grade mineralisation. OFMED158 was then designed to test the continuation of that zone further at depth, and the assay results confirm that the geological structure controlling the mineralisation — a norite-hosted mafic unit — persists along its plunge with consistent grade. For resource modelling purposes, two consecutive down-dip intercepts confirming structural continuity provide the geological foundation for converting inferred resources to the indicated category under JORC standards, which in turn enables inclusion in mine plans and potential reserve statements.
The Flat Mines project has a 12-year life-of-mine from first concentrate production, mining an estimated 65,000 tonnes per month at steady state at an average grade of 1.18% copper. A definitive feasibility study completed on the Flat Mines project in March 2025 confirmed the opportunity to develop a modern, fully mechanised copper mine. The resource optimisation drilling programme currently underway at Flat Mine East is separate from that foundational plan — its purpose is to expand the resource beyond what was incorporated in the DFS, potentially extending mine life, improving mine scheduling, and reducing the number of development headings required to access ore.
The Okiep Copper Project’s ground holding of 703 square kilometres covers the majority of the region where 105 million tonnes of material has been mined over the past century, with previous owners Newmont and Goldfields producing between 30,000 and 40,000 tonnes of copper metal per annum over several decades. The district’s production history is significant context for interpreting the current drilling results. Goldfields of South Africa drilled Flat Mine East in 1995, returning 59.1 metres at 3.55% copper, but never followed up the discovery due to the low copper price environment of the mid-1990s. Orion’s 2024 drilling confirmed and exceeded that historical result, returning 49 metres at 4.89% copper — believed at the time to be the highest-grade intercept ever reported at Flat Mines. The current resource optimisation programme is testing how far beyond that initial zone the mineralisation extends at depth.
The Okiep Copper Project’s 703 square kilometre ground holdings encompass most of the Okiep copper mining district. By integrating the latest results with insights from an ongoing geophysical survey, Orion intends to further refine drill targets and enhance the potential for discovery across the broader Flat Mine East area. Metallurgical testwork at Maelgwyn on the Flat Mines South deposit is running concurrently, designed to validate whether the process flowsheet developed for the North and East deposits performs comparably on South deposit material. If successful, the implication is a single unified processing circuit for all three sub-deposits — a finding with direct capital cost consequences by potentially avoiding separate processing infrastructure.
The copper price context in which this drilling is proceeding is materially more supportive than it was when Goldfields walked away from Okiep three decades ago. Copper has been identified by the International Energy Agency as a critical mineral for the global energy transition, with demand from electric vehicles, renewable energy infrastructure, and grid expansion expected to significantly outpace supply from existing mines by the early 2030s. The S&P Global Commodity Insights copper demand model projects a structural deficit emerging in the latter part of this decade. Projects with high-grade, historically productive geological settings and existing mining infrastructure — as Okiep has in the form of decline access and services at Flat Mine North and Flat Mine Nababeep — carry a commercial premium in that environment.
Orion completed the settlement of its final acquisition consideration for the Okiep Copper Project in March 2026, following receipt of exchange control approval from the South African Reserve Bank’s Foreign Surveillance Department. The company also received IDC conversion of its convertible loan facility into equity in its Prieska subsidiary, reducing balance sheet pressure across its Northern Cape portfolio. Prieska — Orion’s second Northern Cape asset, a copper-zinc mine that last operated in 1991 — carries a mining resource of 31 million tonnes at 1.2% copper and 3.6% zinc and represents a second production path running in parallel with the Okiep development timeline. Mr Price Group
Current drilling offers the potential for additional mineral resources at Flat Mines, where past drilling has proven extensions and infill potential. Sampling has been carried out using diamond drilling procedures with sampling areas selected through visual observation and handheld analyser reading. The next phase of drilling will be directly informed by the geological model being developed from the OFMED157 and OFMED158 assay results, integrated with the ongoing geophysical survey. Whether the mineralised zone continues to hold grade as drilling tests increasingly deeper extensions will be the critical variable determining the scale of the resource upgrade that Orion can pursue ahead of its bankable feasibility study.