Maiden JORC Exploration Target for Mbe

Oriole Resources PLC (AIM: ORR), the AIM quoted gold exploration company focused on West and Central Africa, is pleased to publish the maiden JORC Exploration Target for its 90%[1] owned Mbe orogenic gold project ('Mbe' or the 'Project') in Cameroon.

Highlights

• A maiden JORC Exploration Target range for the Project's MB01 prospect of 33 to 44Mt at 0.77 to 0.95g/t Au for 0.82 to 1.34Moz contained Au produced by independent consultant Forge International Limited.
• The Exploration Target covers the MB01-N and MB01-S targets and has been based on the assay data from the first 13 holes out of a planned 24-hole programme at MB01-S and the 2024 trenching data across both targets. The model has been limited to 200m depth below surface and uses a lower cut-off grade of 0.30g/t Au.
• Grade-tonnage sensitivity analysis shows strong retention of contained ounces at higher cut-off grades, with mid-range grades increasing to 1.07g/t Au at a 0.50g/t Au cut-off for 900,000oz and 1.33g/t Au at a 0.70g/t Au cut off for 700,000oz.
• The drilling programme at MB01-S is ongoing, with completion scheduled for this quarter. The Company anticipates publishing an independent consultant's maiden, pit-constrained Mineral Resource Estimate ('MRE') in Q4-2025 and believes that the Project could be mined by open pit mining methods.
• Independent assessment of mineralogy from drill hole MBDD002 confirms the material tested exhibits gold encapsulation in pyrite and the predominance of gold-telluride (calaverite and petzite) mineralisation. Further test work is planned to evaluate the optimum processing route from the various possible options.

Commenting, Chief Executive Officer of Oriole Resources, Martin Rosser, 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 38Mt at a mean grade of 0.86g/t for 1.1Moz contained gold. As drilling at MB01-S continues, we greatly look forward to reporting the maiden MRE in Q4-2025."

Figure 1. Plan view of mineralised domains and informing data for the maiden Mbe Exploration Target.

A maiden JORC Exploration Target for the Mbe project has been prepared by Forge and is presented in Table 1. It has been prepared to provide a preliminary indication of the potential scale and grade of mineralisation at the MB01 prospect, thereby informing the design and prioritisation of ongoing exploration activities. The Exploration Target* range of 33 to 44 million tonnes at 0.77 to 0.95g/t Au for 0.82Moz to 1.34Moz contained Au has been delineated based on diamond drilling results from holes MBDD001 to MBDD013 at MB01-S, as well as trenching data, and the interpretation of geophysical and geochemical anomaly maps from both MB01-N and MB01-S.

Table 1. Exploration Target* for the MB01 prospect at Mbe, comprising the MB01-N and MB01-S targets

Notes:

• The target has been delineated based on a dataset comprising 15 diamond drill holes and 16 trenches, totalling 11,582m. Assay data is currently only available for 13 of the 15 drill holes; the remaining two holes are pending analytical results and have not been included in the grade estimation.
• The Exploration Target was generated by constructing three-dimensional wireframe models representing interpreted mineralised bodies. Extrapolation is limited to 200m along strike, consistent with observed mineralised trends, and extended to a vertical depth of 200m below current surface topography.
• Oxidation modelling was not incorporated into this phase of work. As such, the impact of oxidation on grade distribution remains a source of uncertainty.
• A lower cut-off grade of 0.30g/t Au was applied to define mineralised blocks considered within the target. The grade range has been determined by applying a ±10% variation around the calculated mean grade above the selected cut-off.
• Tonnage estimates are derived from the modelled tonnage ±15%.
• A mean bulk density of 2.7t/m³ has been applied within the mineralised domains.
• All figures are rounded to reflect the inherent uncertainty and relative accuracy of the estimate.
• Infill drilling is recommended to advance the understanding of mineralisation continuity and grade distribution.
• The Exploration Target estimate has been prepared by Mr Robert Davies, EurGeol, CGeol, who is a Competent Person as defined by the JORC Code.

Grade-tonnage sensitivity analysis of the Exploration Target has confirmed that it shows strong retention of contained gold ounces at higher cut-off grades, with mid-range grades increasing to 1.07g/t Au at a 0.50g/t Au cut-off for 900,000oz and 1.33g/t Au at a 0.70g/t Au cut off for 700,000oz (Table 2).

Table 2. Grade Tonnage Sensitivity analysis

The Exploration Target remains open in all directions and at depth and it is anticipated that it will be succeeded by a maiden MRE in Q4 2025, following completion of the Phase 1 drilling programme later this quarter.

Metallurgical Testwork

Initial bottle roll tests on surface samples at the Project had indicated good gold recoveries from those samples from standard cyanide leaching. The Company today reports that more advanced mineralogical studies, on material from drill hole MBDD002, located within the dominantly fresh ore zone, has confirmed that the gold predominantly occurs as fine-grained tellurides (calaverite with lesser petzite). The mineralogy is therefore similar to that identified at the Company's Bibemi gold project, and therefore likely reflects a regional trend.

Diagnostic leaching test data indicates that 54.4% of the gold is recoverable via carbon-in leach processing, with an additional 12.4% (for a total of 66.8%) recoverable by hydrochloric acid ('HCl') leaching. Approximately 30% of the gold is strongly associated with the primary sulphide pyrite and is not amenable to standard cyanide leaching. As at Bibemi, it is expected that one processing option might be the oxidation of a flotation concentrate followed by cyanidation of the oxidised residue to achieve an acceptable gold recovery by negating the influence of telluride association and pyrite encapsulation. Further testwork, which will inform the optimal processing route from the various options available, is planned. This includes possible alternatives to pressure oxidation, such as other oxidation processes, e.g. the Albion process, as well as fine grinding of a flotation concentrate, more intensive cyanidation at high pH and a pre-leach treatment to dissolve tellurium ahead of gold leaching.

Whilst gold telluride mineralogy is somewhat uncommon, ores of this type have been mined and successfully processed using various processing methods. Examples include Kalgoorlie in Western Australia, one of the world's richest goldfields (approximately 60 million oz extracted to date since discovery in 1893), Cripple Creek in Colorado (approximately 21 million oz extracted), and the Emperor mine in Fiji.

Glossary and Abbreviations

After highly encouraging results from infill soil sampling, rock-chip sampling, and trench sampling, a fully funded maiden drilling programme commenced at the MB01-S target in late November 2024 for a planned 6,590m in 24 holes. BCM International has acquired an initial 10% interest in Mbe and is earning up to a further 40% interest by spending up to US$4 million on exploration.