Oriole Resources reports 32.2Mt maiden marble resource at Wapouzé

Oriole Resources plc (LON:ORR), the AIM quoted exploration and development company focused on Central and West Africa, has announced the maiden Mineral Resource Estimate (MRE) for metamorphosed limestone at its 85%-owned Wapouzé project in north-eastern Cameroon.

Highlights

·          Maiden JORC Inferred MRE for the Project of 32.2Mt, with weighted average grades of 50.33wt% CaO, 1.13wt% MgO and 6.06wt% SiO₂ indicating the potential to support a multi-decade limestone mining operation.

·          The MRE, which used a 42wt% CaO lower grade cut-off, has defined six separate marble domains (M1-6) across the north-eastern part of the Wapouzé licence, covering a cumulative 2.6km strike length.

·          Four pit shells that demonstrate reasonable prospects for eventual economic extraction (“RPEE”) have been defined:

o        Pit 1 (comprising domains M1 and M2) delivers the best quality material and accounts for around one third of the Resource. 

o        At a potential production rate of around 400ktpa, Pit 1 alone contains an equivalent to 27.5 years of marble feed.

·          Outside of the MRE, an additional JORC Exploration Target has been estimated for between 5.5 and 14.0Mt, with average grades between 48 and 53wt% CaO and between 0.8 and 1.4wt% MgO^[1]. 

·          A local level Environmental and Social Impact Assessment (ESIA) is currently underway to support the submission of an Exploitation Licence Application (ELA) in Q4-2026.

·          The Company will now also prepare a preliminary economic assessment (PEA) and is ultimately looking to achieve a royalty-based income that could be used as additional funding for Oriole’s gold-focused exploration work in Cameroon.

Chief Executive Officer of Oriole Resources, Martin Rosser, said: “We are delighted with the Wapouzé maiden MRE as it shows that the Project has excellent potential for supporting a multi-decade limestone quarrying operation.  Using an assumed production rate of 400ktpa of limestone, we believe that, subject to the preparation of a PEA, the Project has the potential for an attractive economic return. 

“It is envisaged that the limestone product would be predominantly used as a key ingredient in making valuable cement in Cameroon and neighbouring Chad.  However, there are other possible uses for the limestone, including as chemical lime for use in gold ore processing and several chemical industry processes.  Regarding the latter, some of the drilling results show >54%wt CaO, which is very pure and could be used to make chemical grade calcium carbonate.  This material may, subject to testing of its brightness (or whiteness), be suitable for use in the mineral filler market for paint, paper, plastics etc.

“Based on the magnitude of the maiden MRE, we are hopeful that, in parallel with this underwriting the submission of an Exploitation Licence Application in this quarter, we have significantly enhanced the prospects of attracting an industry expert partner for the Project.”

Figure 1. Wapouzé MRE contained within four RPEE pit shells over satellite imagery

Further Details

The Wapouzé Project is in north-eastern Cameroon, approximately 100km NE of Garoua and 20km north of the Company’s Bibemi gold project.  Wapouzé was initially an early-stage gold exploration project but the Project was deemed less prospective for gold than Bibemi.  However, the Company noted the presence of large quantities of carbonate rock (predominantly marble) and applied for a change in commodity to marble, which was granted in 2022.

Since the change in commodity, a number of surface exploration programmes have focused on the potential high-grade marble (typically >50% CaO with low magnesium and silica) material that would make it potentially suitable for use in the cement industry (see announcement dated 21 April 2026). 

In September 2026, the Company published results from its 1,053.80m (21 holes) maiden diamond drilling programme that confirmed substantial downhole widths of high-quality marble, including: 53.50m at an average of 53.88wt% CaO and 0.88wt% MgO from 1.30m depth in WPDD012; and 37.15m at an average of 53.42wt% CaO and 0.82wt% MgO from 10.95m depth in WPDD014 (see announcement dated 24 September 2026).  The majority of holes returned high-quality marble (>50wt% CaO and <2% MgO) over more than 50% of their length.  

The Company today reports a maiden JORC Inferred MRE, contained with six marble domains (M1-6), of 32.2Mt with weighted average grades of 50.33wt% CaO, 1.13wt% MgO and 6.06wt% SiO₂ (Table 1).  The MRE was predominantly defined from geological and geochemical data acquired during the maiden drilling programme, together with results of a recently completed resistivity survey.

Table 1. JORC Inferred Mineral Resource Estimate for the six marble domains identified at Wapouzé

Notes and JORC Cautionary Statement:

• Effective date of the Mineral Resource Estimate is 28 September 2026, being the date the Oriole data room was shared with Forge International.
• Mineral Resource reported within the six interpreted marble domains (M1–M6) and constrained by the RPEE pit shell. The depth of the pits typically range from 50m to 150m, with a local maximum depth of approximately 180m in the largest pit area.
• The MRE was modelled over a cumulative strike length of approximately 2.9 km.
• Reported above a 42% CaO cut-off grade.
• Total reported Mineral Resource of approximately 32.2 Mt at weighted average grades of 50.33wt% CaO, 1.13wt% MgO and 6.06wt% SiO₂.
• Grade estimation was undertaken within hard-boundary geological domains to preserve the interpreted geological and geochemical differences between the individual marble formations.
• The reported Mineral Resource represents the portion of the block model considered to have reasonable prospects for eventual economic extraction under the preliminary open-pit optimisation assumptions.
• The Resource Estimate is shown on a gross (100%) basis for the Wapouzé Project.  Oriole currently holds an 85% net attributable beneficial interest.
• The Mineral Resource Estimate has been prepared by Robert Davies, EurGeol, CGeol, a Competent Person as defined by the 2012 Edition of the JORC Code.  Mr Davies is a Director of Forge International Limited and has sufficient experience relevant to the style of mineralisation, type of deposit and activity undertaken to qualify as a Competent Person.  Mr Davies consents to the inclusion in the announcement of the matters based on his information in the form and context in which it appears.
• All figures are rounded to reflect the relative accuracy of the estimate.  Apparent differences may occur due to rounding.
• Mineral Resources are not Mineral Reserves and further technical, economic and mining studies will be required before any potential conversion to Mineral Reserves.

The marble domains were constrained using preliminary open-pit optimisation using a range of parameters, including a limestone selling price of US$13/t, US$0.5/t selling cost, US$2/t mining cost, US$3.5/t processing cost, 5% mining dilution, 95% mining recovery, 98% processing recovery and 45 degree pit slopes.  This enabled the definition of four open-pit RPEE pit shells (Pit 1 – 4), with Pit 1 (covering domains M1 and M2) comprising approximately one third of the Resource, contributing 11Mt at an average grade of 52.68wt% CaO and 0.97wt% MgO. 

The cumulative strike length of marble covered by all four pits is approximately 2.6km.  At a production rate of around 400ktpa, Pit 1 alone contains roughly 27.5 years of marble feed.

Figure 2. 3D Isometric view of Pit 1 (M1, M2) and Pit 2 (M3) marble domain block models with downhole CaO (wt%) data, and two RPEE pit shells targeting the domains. Viewing ~NE. 

The Mineral Resource is entirely contained within the Wapouzé licence boundary.  A minor portion of the preliminary RPEE pit shell associated with Pit 1 extends beyond the licence boundary (Fig. 1); however, no Mineral Resource is reported outside the licence area.  This is not considered material to the reported Mineral Resource Estimate.  Future mine planning and optimisation will be constrained to the applicable licence boundary.

Outside of the MRE, Forge has also defined a JORC Exploration Target* of between 5.50 to 14.0Mt with average CaO grades between 48 and 53wt%, and MgO grades between 0.8 and 1.4wt% (Table 2, Fig 3).  This has been defined as areas of mapped marble occurrences outside of the MRE, where there is surface rock chip sampling and portable XRF data but no drilling.  The Exploration Target has been projected to vertical depths of 40m and 100m as the lower and upper bounds.

Table 2. JORC Exploration Target* for the material with mapped outcrop and rock chip data that sits outside of the MRE

*The potential quality and grade of the Exploration Target are conceptual in nature. There has been insufficient exploration to estimate a Mineral Resource, and there is no certainty that further exploration work will result in the determination of a Mineral Resource.

Notes and JORC Cautionary Statement

• Effective date: 28 September 2026.
• The Exploration Target is based on mapped limestone/marble outcrop, geological interpretation, surface rock-chip sampling and XRF data.
• The tonnage range has been derived by projecting the mapped limestone/marble occurrences to vertical depths of 40m and 100m, representing the lower and upper cases respectively.
• Indicative grade ranges of 48–53wt% CaO and 0.8–1.4wt% MgO have been assigned based on the available surface sampling and observed geological/geochemical characteristics.
• The Exploration Target is shown on a gross (100%) basis for the Wapouzé Project.  Oriole currently holds an 85% net attributable beneficial interest.
• The Exploration Target is conceptual in nature.  There has been insufficient exploration to estimate a Mineral Resource in these areas, and it is uncertain whether further exploration will result in the estimation of a Mineral Resource.
• The Exploration Target is not a Mineral Resource or Mineral Reserve and should not be considered equivalent to, or combined with, the reported Mineral Resource.
• Further geological mapping, systematic surface sampling and drilling will be required to test the interpreted continuity, thickness, depth extent and grade of the limestone/marble occurrences.
• All figures are approximate and have been rounded to reflect the conceptual nature and level of geological confidence of the Exploration Target.
• The Exploration Target has been prepared by Robert Davies, EurGeol, CGeol, a Competent Person as defined by the 2012 Edition of the JORC Code. Mr Davies is a Director of Forge International Limited and has sufficient experience relevant to the style of mineralisation, type of deposit and activity undertaken to qualify as a Competent Person. Mr Davies consents to the inclusion in the announcement of the matters based on his information in the form and context in which it appears.

Figure 3. 2D view of the Exploration Targets for Wapouzé and their spatial relationship with rock-chip sampling data and the MRE pit shells

The Company is also undertaking a local-level ESIA for Wapouzé which, once completed, will form part of an ELA for the Project.  The ELA, which is expected to be for a simple quarrying operation for the extraction of the marble, is targeted for submission in Q4-2026.

Commercially, a significant limestone deposit at Wapouzé could be highly suitable for use within Cameroon’s cement industry, which is believed to be worth several hundred million pounds per year, largely supported by expensive imports of required clinker material.  The Company believes that there is a significant demand for cement (for concrete) within Cameroon and neighbouring Chad (with its capital, N’Djamena, approximately 250km NNE of Wapouzé).  Furthermore, Cameroon has seen substantial foreign investment made into expanding its cement manufacturing capacity, with neighbouring plants to Wapouzé producing cement from similar material, and the government is keen to see its reliance on imported clinker reduce significantly.

The Company also recognises that crushed marble products of specific characteristics can also be used in other industrial processes outside of clinker/cement production.  For example, material with a high CaO (>54wt%) should qualify as chemical lime, which is a relatively valuable commodity and used in gold ore processing, but also in many chemical industry processes. 

Oriole Resources is continuing its discussions with potential industry partners that could advance Wapouzé towards development and exploitation on an expedited basis.  The Company is ultimately looking to achieve royalty-based income from a commercial scale quarrying operation, likely to be based upon the volume of material extracted, which would provide valuable in-country revenue that could be used additional funding for its gold exploration work in Cameroon.