Oriole Resources PLC (AIM:ORR) has taken an important step forward with the release of a maiden exploration target for its Mbe gold project in Cameroon, marking a significant milestone for the mine developer as it moves closer to defining a full mineral resource later this year.
The company’s independent consultant, Forge International, has estimated that the MB01 prospect, the primary focus of current drilling and trenching, could contain between 33 million and 44 million tonnes of ore, grading from 0.77 to 0.95 grams of gold per tonne.
This translates to roughly 820,000 to 1.34 million ounces of gold potentially contained within the deposit. Anything above 0.5g/t is often considered economically interesting in gold mining, particularly if it is near-surface.
This work draws on assay results from 13 of 15 diamond drill holes completed so far, alongside trenching data and geophysical surveys.
The model looks at mineralisation down to about 200 metres below the surface, and drilling is ongoing, with the programme expected to finish this quarter.
Oriole anticipates publishing a maiden mineral resource estimate by the final quarter of this year, which would provide a clearer picture of the project’s economic potential.
Martin Rosser, Oriole’s chief executive, said: “The maiden exploration target for the company’s Mbe project is a significant milestone achieved, and we are delighted with the target range, which has a median of 38 million tonnes at a mean grade of 0.86g/t for 1.1 million ounces contained gold.
"As drilling at MB01-S continues, we greatly look forward to reporting the maiden mineral resource estimate in the fourth quarter of 2025.”
The nature of the gold itself is notable. Detailed mineralogical analysis reveals that much of the gold occurs in telluride form, specifically calaverite and petzite, and is encapsulated within pyrite, a sulphide mineral.
This form of gold is more challenging to extract using standard cyanide leaching, which recovers gold by dissolving it into a liquid.
Tests indicate that approximately 54% of the gold is recoverable by standard carbon-in-leach processing, with further recovery possible through hydrochloric acid treatment, bringing total recoveries close to 67%.
Additional test work is underway to identify the best processing method, which could involve oxidising flotation concentrates or other techniques to liberate the gold from the host minerals.
This mineralogy is similar to that of Oriole’s Bibemi project nearby, and while telluride-associated gold is less common, it has been successfully mined and processed at globally significant goldfields, such as Kalgoorlie in Australia and Cripple Creek in the US.