Updated Mineral Resource Estimate at Doropo
08/09/2025 07:00
RNS Number : 3803Y
Resolute Mining Limited
08 September 2025
8 September 2025
Updated Mineral Resource Estimate at Doropo, Côte d'Ivoire
Resolute Mining Limited ("Resolute" or "the Company") (ASX/LSE: RSG), the Africa-focused gold miner, is pleased to announce an updated Mineral Resource Estimate ("MRE") for the Doropo Gold Project which is situated in Northern Côte d'Ivoire.
| Doropo Mineral Resource Estimate | ||||||
| September 2025 (0.3g/t Au cut-off, $3,000/oz pit shell, JORC 2012) | October 2023 (0.3g/t Au cut-off, $2,000/oz pit shell, CIM 2014) | |||||
| Classification | Tonnes | Grade (g/t Au) | Ounces (Au) | Tonnes | Grade (g/t Au) | Ounces (Au) |
| Measured | 1,550,000 | 1.57 | 78,000 | 1,510,000 | 1.60 | 77,000 |
| Indicated | 95,200,000 | 1.18 | 3,601,000 | 75,340,000 | 1.25 | 3,027,000 |
| Inferred | 17,440,000 | 1.21 | 680,000 | 7,370,000 | 1.23 | 292,000 |
| Total | 114,190,000 | 1.19 | 4,360,000 | 84,220,000 | 1.25 | 3,396,000 |
| Measured Mineral Resources (0.3 g/t Au COG) | |||
| Prospect | Mt | Au g/t | Au Moz |
| Attire1 | - | - | - |
| Chegue Main2 | 0.19 | 1.09 | 0.007 |
| Chegue South2 | 0.23 | 1.08 | 0.008 |
| Enioda2 | - | - | - |
| Han2 | 0.11 | 2.03 | 0.007 |
| Hinda1 | - | - | - |
| Hinda South1 | - | - | - |
| Kekeda2 | 0.20 | 0.81 | 0.005 |
| Kilosegui2 | 0.21 | 1.10 | 0.007 |
| Nare1 | - | - | - |
| Nokpa2 | 0.34 | 2.48 | 0.027 |
| Sanboyoro1 | - | - | - |
| Solo1 | - | - | - |
| Souwa2 | 0.27 | 1.88 | 0.016 |
| Tchouahinin1 | - | - | - |
| Vako1 | - | - | - |
| TOTAL | 1.55 | 1.57 | 0.078 |
| Indicated Mineral Resources (0.3 g/t Au COG) | |||
| Prospect | Mt | Au g/t | Au Moz |
| Attire1 | 0.42 | 1.86 | 0.025 |
| Chegue Main2 | 7.80 | 0.98 | 0.246 |
| Chegue South2 | 6.26 | 1.02 | 0.206 |
| Enioda2 | 3.95 | 1.24 | 0.158 |
| Han2 | 5.16 | 1.66 | 0.276 |
| Hinda1 | - | - | - |
| Hinda South1 | - | - | - |
| Kekeda2 | 5.72 | 0.95 | 0.175 |
| Kilosegui2 | 35.78 | 1.08 | 1.247 |
| Nare1 | - | - | - |
| Nokpa2 | 7.38 | 1.50 | 0.356 |
| Sanboyoro1 | 0.01 | 1.33 | 0.001 |
| Solo1 | - | - | - |
| Souwa2 | 20.23 | 1.31 | 0.853 |
| Tchouahinin1 | - | - | - |
| Vako1 | 2.48 | 0.73 | 0.058 |
| TOTAL | 95.20 | 1.18 | 3.601 |
| Inferred Mineral Resources (0.3 g/t Au COG) | |||
| Prospect | Mt | Au g/t | Au Moz |
| Attire1 | 0.71 | 2.43 | 0.055 |
| Chegue Main2 | 1.30 | 0.97 | 0.041 |
| Chegue South2 | 1.15 | 1.07 | 0.040 |
| Enioda2 | 1.49 | 1.08 | 0.052 |
| Han2 | 0.57 | 1.30 | 0.024 |
| Hinda1 | 0.15 | 1.54 | 0.007 |
| Hinda South1 | 0.84 | 0.78 | 0.021 |
| Kekeda2 | 0.61 | 0.68 | 0.013 |
| Kilosegui2 | 4.25 | 0.99 | 0.135 |
| Nare1 | 0.05 | 0.95 | 0.002 |
| Nokpa2 | 3.84 | 1.41 | 0.173 |
| Sanboyoro1 | 0.11 | 1.61 | 0.006 |
| Solo1 | 0.16 | 2.43 | 0.013 |
| Souwa2 | 1.03 | 1.89 | 0.063 |
| Tchouahinin1 | 1.06 | 0.96 | 0.033 |
| Vako1 | 0.12 | 0.71 | 0.003 |
| TOTAL | 17.44 | 1.21 | 0.680 |
| Resolute Matthias O'Toole-Howes motoolehowes@resolutemining.com | Public Relations Jos Simson, Tavistock resolute@tavistock.co.uk +44 207 920 3150 Corporate Brokers Jennifer Lee, Berenberg +44 20 3753 3040 Tom Rider, BMO Capital Markets +44 20 7236 1010 |
| Criteria | JORC Code explanation | Commentary |
| Sampling techniques | ● Nature and quality of sampling (eg cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. ● Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. ● Aspects of the determination of mineralisation that are Material to the Public Report. ● In cases where 'industry standard' work has been done this would be relatively simple (eg 'reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay'). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information. | ● The sampling was conducted using multiple techniques tailored to the project's geological and surface conditions. Soil sampling programs were extensive, collecting approximately 92,307 samples between 2014 and 2022. Soils were sampled from the mottled zone or the top of the saprolite horizon to obtain coherent gold anomalies, utilising standardised grid patterns (typically 400 m x 400 m, with infill at 200 m and 100 m where required). Auger drilling was employed in areas with thick lateritic cover (>3 m), reaching saprolitic material with depths averaging 6.22 m and up to 30 m in some cases. Auger drilling recovered material systematically for gold analysis and geochemical interpretation. ● Trenching programs (32 trenches to date) were used to expose in situ mineralised structures, allowing for systematic channel sampling. ● Reverse Circulation (RC) and Diamond Core (DD) drilling were the principal methods used for delineating Mineral Resources. RC drilling was conducted using 5¼ to 5¾ inch diameter face-sampling hammers to recover one-metre interval samples, typically dry unless groundwater was encountered. Diamond drilling employed HQ and NQ diameter core, with triple tube techniques for improving recovery in broken ground. RC samples were riffle split on site, and core samples were sawn to produce half-core for analysis. Sampling procedures incorporated QAQC measures, including the insertion of blanks, standards, and duplicates to ensure sample representivity. Assay protocols utilised 50 g fire assay (AAS finish) for gold, and multi-element analysis was performed where applicable. |
| Drilling techniques | ● Drill type (eg core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or standard tube, depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by what method, etc). | ● Drilling methods involved a combination of Reverse Circulation (RC), Diamond Core (DD), and auger drilling methods. RC drilling was primarily used for delineating near-surface mineralisation and preliminary resource definition. RC drilling employed face-sampling hammers with bit sizes ranging from 5¼ to 5¾ inches. Dry drilling was the standard procedure, with drilling halted at the water table to prevent contamination from wet samples; below groundwater, diamond drilling methods were applied. ● Diamond core drilling used HQ and NQ diameter core. Triple-tube systems were implemented in highly broken ground to maximise core recovery, while standard double-tube setups were used elsewhere. Orientation of diamond core was conducted selectively using Reflex ACT II core orientation devices to facilitate structural logging. Auger drilling was utilised for shallow exploration across areas with thick laterite cover. All drill methods were executed to a high standard with contractors experienced in gold exploration in West Africa. |
| Drill sample recovery | ● Method of recording and assessing core and chip sample recoveries and results assessed. ● Measures taken to maximise sample recovery and ensure representative nature of the samples. ● Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material. | ● Drill sample recovery was systematically monitored during both RC and diamond drilling programs. RC samples were weighed regularly, particularly from 2018 onwards, to monitor sample size consistency and ensure the representativeness of samples. Analysis of over 447,401 RC sample weights showed a consistent recovery trend stabilizing between 30-40 kg per metre after clearing the uppermost weathered horizons. Minor variations in sample weight were observed at shallow depths and in softer materials; however, statistical checks confirmed no significant bias in gold grade associated with sample mass. ● Diamond core recovery was measured, with an overall average recovery of approximately 96% across the project. Recovery rates improved with depth, with >90% core recovery recorded for 89.5% of core samples, and exceeding 97.5% recovery below 50 m depth. Core recovery measurements were recorded in the database for each run. The use of triple-tube drilling in broken ground contributed to maintaining high recovery standards. The overall conclusion, supported by quality control reviews, was that there is no significant sampling bias attributable to differential recovery. |
| Logging | ● Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. ● Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography. ● The total length and percentage of the relevant intersections logged. | ● Comprehensive geological and geotechnical logging was undertaken for all drillholes including RC and DD. Drillholes were logged systematically for a range of key geological attributes: lithology, alteration, mineralisation, texture, structure, weathering, and rock quality designation (RQD). RC samples were logged visually on site, with geological observations recorded both digitally and on physical log sheets where applicable. Diamond core was logged in greater detail, particularly for structural geology, alteration styles, mineral assemblages, and vein relationships, providing critical inputs for 3D geological modelling. ● Photographic records were maintained for all diamond drill core - photographed both wet and dry - before sampling. Logging captured sufficient detail to support resource estimation, mining studies, and metallurgical investigations. Logging procedures included the use of a standardised lithological and alteration coding scheme to ensure consistency across the drilling campaigns. Digital capture of logging data into a centralised database with validation rules also enhanced data reliability. |
| Sub-sampling techniques and sample preparation | ● If core, whether cut or sawn and whether quarter, half or all core taken. ● If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry. ● For all sample types, the nature, quality and appropriateness of the sample preparation technique. ● Quality control procedures adopted for all sub-sampling stages to maximise representivity of samples. ● Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling. ● Whether sample sizes are appropriate to the grain size of the material being sampled. | ● Systematic sub-sampling and sample preparation protocols were employed to ensure that samples remained representative of in situ mineralisation. For RC drilling, 1 m samples were split on site using a three-tier riffle splitter to achieve a target sample size of approximately 2 to 3 kg for laboratory submission. Wet samples encountered in shallow zones were left to dry naturally prior to splitting where possible. For diamond drilling, core was cut lengthwise using diamond-bladed core saws; half-core samples were collected for routine assay, while the other half was preserved for reference and potential future re-assay. ● Sample preparation at the laboratory followed industry best practices. Samples were oven dried, crushed to 70 to 85% passing 2 mm, then riffle split to produce a subsample for pulverisation. The pulverised material was milled to achieve at least 85% passing 75 microns, producing a pulp of approximately 150 to 250 g for fire assay analysis. Quality assurance measures were built into preparation workflows, including the regular inclusion of duplicate splits and check samples. Laboratory facilities used (primarily Bureau Veritas Abidjan, SGS Ouagadougou) operated to ISO 17025 standards, and internal laboratory QAQC reviews were conducted regularly. |
| Quality of assay data and laboratory tests | ● The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. ● For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc. ● Nature of quality control procedures adopted (eg standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (ie lack of bias) and precision have been established. | ● Assay methodologies were based on internationally recognised standards and utilised reputable laboratories. All drill samples were primarily analysed for gold using 50 g fire assay with atomic absorption spectroscopy (AAS) or inductively coupled plasma atomic emission spectroscopy (ICP-AES) finish. In cases where assays exceeded 10 g/t Au, samples were re-analysed using a gravimetric finish to improve accuracy. For some RC and trench samples, particularly those with coarse gold, photon assay techniques were trialled to validate fire assay results. ● Quality control procedures were rigorous. Certified reference materials (standards), field blanks, and field duplicates were inserted into the sample stream at regular intervals - approximately one QAQC sample every 20 to 30 samples. Laboratory duplicates, internal standards, and blanks were also monitored. QAQC data were routinely reviewed to ensure analytical accuracy and precision. Failures (e.g., a standard outside 3 standard deviations) triggered immediate re-assay of sample batches. No significant long-term bias or drift was observed across the assay dataset. Laboratories involved (Bureau Veritas, Abidjan and SGS, Ouagadougou) are ISO/IEC 17025 accredited, ensuring laboratory practices are consistent with industry best practice. |
| Verification of sampling and assaying | ● The verification of significant intersections by either independent or alternative company personnel. ● The use of twinned holes. ● Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. ● Discuss any adjustment to assay data. | ● Verification of sampling and assaying was undertaken through a combination of internal reviews, duplicate analyses, and independent data validation exercises. Field duplicates were collected regularly from RC drilling to monitor sampling precision, with results demonstrating satisfactory repeatability of gold grades. CRMs and blanks were inserted at regular intervals to monitor assay accuracy and contamination. QAQC charts were reviewed continuously by project geologists and external consultants during key drilling campaigns. ● The primary assay laboratories (Bureau Veritas and SGS) conducted their own internal QC programs, which were also monitored. Limited twin drilling was conducted, with twin RC holes and DD holes used to verify mineralisation continuity, grade reproducibility, and geological interpretation; results confirmed good spatial reproducibility. While external umpire (secondary lab) assay programs were not routinely undertaken, the performance of primary laboratories and internal QAQC programs were considered satisfactory for the reporting of Mineral Resources. Assay data and logging data were entered digitally into validated databases, and independent audits of the database have been performed during resource estimation reviews. |
| Location of data points | ● Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. ● Specification of the grid system used. ● Quality and adequacy of topographic control. | ● Drillhole collar locations were surveyed using a combination of differential GPS (DGPS) systems and total station surveying where higher precision was required. The DGPS surveys were conducted by trained field surveyors to ensure location accuracy suitable for Mineral Resource estimation, with horizontal and vertical accuracy generally within ±0.2 m. In areas of rugged topography or logistical difficulty, survey-grade handheld GPS units were temporarily used during initial exploration stages (soil sampling, auger drilling, trenching), but were later replaced with DGPS surveys for all critical drill collars. ● Elevation data were tied into the Nivellement Général de Côte d'Ivoire (NGCI) vertical datum. A topographic digital terrain model (DTM) was produced using high-resolution satellite imagery and ground-truthing, which was used for both resource modelling and mine planning. Grid systems used were WGS84, Zone 30N for initial exploration and UTM Zone 30N (WGS84 projection) for final resource definition. |
| Data spacing and distribution | ● Data spacing for reporting of Exploration Results. ● Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied. ● Whether sample compositing has been applied. | ● Drilling was conducted on nominal grid spacings appropriate for the level of confidence required for resource estimation. In the main mineralised zones (Souwa, Chegue, and Krakara), RC and diamond drilling was performed on approximately 25 m x 25 m to 50 m x 50 m grids. Some areas of denser drilling (for example, grade control drilling) achieved spacing as tight as 10 m x 10 m. ● Outside the main resource areas, reconnaissance and exploration drilling was more broadly spaced at 80 m x 80 m or larger intervals, appropriate for early-stage resource targeting. Soil sampling grids were generally established on 400 m x 400 m grids, with localised infill to 100 m or 200 m grids as needed. Data spacing was assessed during Mineral Resource estimation and was found sufficient to establish geological and grade continuity for the appropriate classifications (Measured, Indicated, and Inferred). No sample compositing was applied prior to resource estimation; raw assay intervals were used directly in estimation procedures. |
| Orientation of data in relation to geological structure | ● Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. ● If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material. | ● Drilling programs were designed to target mineralised structures as close to perpendicular as possible to the interpreted dip of mineralisation at each deposit. Most drillholes were oriented towards the southeast or southwest with an inclination of -50° to -60°, depending on the local structural orientation of gold-bearing zones. The mineralisation is generally hosted in north-northeast trending structures dipping moderately to steeply to the east or west, making these drill orientations appropriate to intersect mineralised zones at reasonable angles and to minimise bias in the intercept lengths. ● Geological interpretations and cross sections confirm that drilling achieved reasonably representative intersections of mineralisation. No significant sampling bias related to drilling orientation was observed during resource modelling and estimation. In areas of uncertainty or more complex structure (fold closures, sheared zones), multiple drill directions were employed to cross-validate mineralisation geometry. |
| Sample security | ● The measures taken to ensure sample security. | ● Sample security protocols were implemented to ensure the integrity of all collected samples from the point of collection through to laboratory delivery. After collection, samples were placed into pre-numbered, durable plastic bags and securely sealed. Multiple samples were then packed into larger polyweave sacks for easier handling and protection during transport. Samples were stored in a secure, supervised facility at the exploration camp before transportation. ● Transport to the assay laboratories (Bureau Veritas in Abidjan and SGS in Ouagadougou) was carried out either by company personnel or trusted, contracted couriers. Chain-of-custody forms were maintained throughout the transfer process, and receipt of samples was acknowledged in writing by laboratory staff. While rigorous internal controls were observed, there is no specific mention of external audits or independent oversight of sample security protocols. However, no incidents of sample loss, tampering, or contamination have been reported, and laboratory reconciliation of received samples consistently matched dispatch records. |
| Audits or reviews | ● The results of any audits or reviews of sampling techniques and data. | ● Audits and reviews of sampling techniques, assay data, and database integrity have been carried out periodically. Internal technical reviews were performed by Centamin's in-house geology and resource teams throughout the exploration and resource evaluation phases. These reviews covered sampling practices, QAQC data performance, logging standards, and database quality, ensuring consistent application of protocols and identifying areas for procedural improvement where necessary. ● Independent reviews of the Resource models and supporting exploration data were conducted as part of the NI 43-101 technical report preparation. Qualified Persons (QPs) signed off on the Mineral Resource estimates after assessing the drilling, sampling, and QAQC procedures. |
| Criteria | JORC Code explanation | Commentary |
| Mineral tenement and land tenure status | ● Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. ● The security of the tenure held at the time of reporting along with any known impediments to obtaining a licence to operate in the area. | ● The Doropo Project is located in the northeast of Côte d'Ivoire, in the Bounkani region approximately 480 km north of Abidjan, near the border with Burkina Faso. The project comprises a contiguous package of seven exploration permits ("Doropo Permit Package") covering a combined area of approximately 1,847 km². ● All tenements are held in good standing with the Côte d'Ivoire Ministry of Mines and have been maintained in accordance with local legal requirements. There are no known outstanding disputes affecting the licences. Surface rights, compensation arrangements with local communities, and environmental baseline studies have been addressed as part of the permitting and development process. Royalties include a standard 4% government royalty on gold production as prescribed under Ivorian mining law. No third-party ownership interests, material encumbrances, or joint venture arrangements affecting the Doropo Project have been disclosed. |
| Exploration done by other parties | ● Acknowledgment and appraisal of exploration by other parties. | ● Historical exploration activities prior to Centamin's involvement were limited. There are no records of systematic exploration or drilling by major international companies. Previous work primarily consisted of regional-scale geochemical surveys and government-sponsored mapping programs conducted by the Côte d'Ivoire geological survey and local government initiatives. These activities provided basic geological context but did not lead to significant discovery or development efforts. ● Centamin's exploration efforts since acquiring the permits have been responsible for the identification, systematic testing, and advancement of the Doropo Mineral Resource. No Mineral Resources or significant exploration targets from previous explorers were inherited by Centamin. All resources reported to date result from Centamin's soil sampling, auger drilling, trenching, and drilling campaigns. As such, historical data has not materially contributed to the current Mineral Resource Estimate. |
| Geology | ● Deposit type, geological setting and style of mineralisation. | ● The Doropo Project is located within the Birimian-age greenstone belts of the West African Craton, a prolific geological setting known for hosting orogenic gold deposits. Specifically, the project lies in northern Côte d'Ivoire, comprising a sequence of volcano-sedimentary rocks, including mafic volcanics, interbedded metasediments, felsic intrusives, and minor ultramafic units. The local geology consists predominantly of intermediate to mafic volcaniclastic rocks, intruded by granitoid bodies and crosscut by regional shear zones. ● Gold mineralisation is primarily structurally controlled, hosted within moderate- to steeply-dipping quartz-carbonate-sulphide vein arrays. These veins are developed along shear zones, fault splays, and lithological contacts. Mineralisation is associated with strong silica, sericite, carbonate, and minor chlorite alteration halos. Sulphide minerals such as pyrite, arsenopyrite, and lesser amounts of pyrrhotite are common, closely associated with gold occurrence. The mineralisation style is typical of orogenic lode gold systems, with gold generally occurring as free grains and fine inclusions within sulphides. Structural controls, including vein orientations and competency contrasts between rock units, are critical factors influencing the distribution and continuity of mineralisation. |
| Drill hole Information | ● A summary of all information material to the understanding of the exploration results including a tabulation of the following information for all Material drill holes: oeasting and northing of the drill hole collar oelevation or RL (Reduced Level - elevation above sea level in metres) of the drill hole collar odip and azimuth of the hole odown hole length and interception depth ohole length. ● If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case. | ● The NI 43-101 Technical Report provides comprehensive drillhole information, covering collar locations, drill hole depths, azimuths, dips, and key intersections. Drillhole collars were surveyed using differential GPS (DGPS) or total station equipment, and were tied into a local grid based on the UTM Zone 30N, WGS84 datum. Complete lists of drill collars, including northing, easting, elevation, azimuth, dip, and total depth, are included in appendices of the technical report for all holes used in Resource estimation. ● Significant exploration results and Mineral Resource drill intersections are reported systematically, with true thickness considerations discussed where relevant. The database includes 5,794 drillholes for a total of 547,805 m of drilling. The report also provides detailed composite intercept tables for representative drilling results across all principal deposits (Souwa, Chegue, Krakara, etc.), including downhole depth intervals, gold grades, and sample lengths. |
| Data aggregation methods | ● In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (eg cutting of high grades) and cut-off grades are usually Material and should be stated. ● Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail. ● The assumptions used for any reporting of metal equivalent values should be clearly stated. | ● Exploration results and Mineral Resource drill intercepts are reported based on compositing of contiguous mineralised intervals. Assay results were composited to ensure that sample length variability did not introduce bias. Only intervals above a certain cut-off grade (typically 0.5 g/t Au for mineralised zones) were included when reporting exploration results. ● No top-cutting (grade capping) was applied when presenting raw exploration results; however, top-cutting was considered and applied during Mineral Resource estimation to control the influence of extreme outlier grades. Composites used downhole lengths of 1 m, reflecting the RC and DD sampling intervals. Where lower grade material was present within higher-grade zones, internal dilution up to 2 m was accepted within the composited interval to maintain geological continuity. |
| Relationship between mineralisation widths and intercept lengths | ● These relationships are particularly important in the reporting of Exploration Results. ● If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported. ● If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (eg 'down hole length, true width not known'). | ● The majority of drilling was designed to intersect mineralisation as close as possible to true width by orienting drillholes approximately perpendicular to the dominant strike and dip of mineralised structures. Drillholes were typically inclined at -50° to -60° angles depending on local geological conditions, and aimed at intersecting mineralised zones that dip moderately (30°to 70°) towards the east or west (according to the individual deposit). As such, downhole intercept lengths reported in exploration results approximate true widths in most cases, particularly in the main Souwa, Chegue, and Krakara deposits. ● In cases where drilling was oblique to structures - particularly in folded or complex structural zones, true widths were estimated or commentary provided where necessary. No material bias in grade or continuity arising from drilling orientation was identified during Mineral Resource estimation. Geological modelling used structural measurements, cross sections, and 3D wireframes to constrain true thickness of the mineralised zones. |
| Diagrams | ● Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views. | ● The NI 43-101 Technical Report provides a variety of diagrams that illustrate the distribution of mineralisation, drill coverage, geological interpretation, and resource outlines. These include: ● Plan view maps showing drill hole collar locations and surface projections of the mineralised zones. ● Cross sections and long sections through key deposits (e.g., Souwa, Chegue, Krakara) depicting lithological units, interpreted mineralisation wireframes, and drill intercepts. ● 3D block models illustrating grade distribution and resource classifications. ● Regional geological maps. |
| Balanced reporting | ● Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results. | ● Exploration results are presented in a manner that is consistent with balanced reporting principles. Both positive results (significant gold intersections) and lower-grade or barren drilling outcomes are discussed in the report narrative. Significant intercepts are reported based on a gold cut-off (typically 0.5 g/t Au), and intervals that do not meet this threshold are not excluded without comment - their absence is implied where relevant. Where drill programs encountered areas of weak mineralisation or barren geology, this is acknowledged qualitatively in the discussion of deposit extents and geological domains. ● Resource estimation was based on all available drilling data, not just high-grade intervals. |
| Other substantive exploration data | ● Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances. | ● In addition to drilling and trenching, Centamin has completed several substantive exploration programs across the Project area, including extensive soil geochemistry, auger drilling, geophysical surveys, and baseline environmental studies. ● Soil geochemistry: Over 92,000 soil samples were collected between 2014 and 2022 on grids varying from 400 x 400 m down to 100 x 100 m, helping to identify coherent gold-in-soil anomalies that guided subsequent drilling. ● Auger drilling: Approximately 28,000 auger holes were drilled to sample through laterite cover to saprolite, providing a 3D geochemical signature where soil sampling was ineffective. ● Geophysics: Regional aeromagnetic and radiometric surveys were conducted by government agencies, with Centamin reprocessing this data to aid in geological interpretation and target generation. Ground-based induced polarisation (IP) surveys were conducted selectively over key prospects to assist in structural interpretation. ● Preliminary metallurgical testwork was performed on representative mineralised material. Testwork indicated that gold mineralisation was amenable to conventional gravity recovery and cyanide leaching, with excellent recoveries (>90% extraction) achievable. Additionally, environmental baseline studies have been completed across the Doropo permit area to support permitting requirements. |
| Further work | ● The nature and scale of planned further work (eg tests for lateral extensions or depth extensions or large-scale step-out drilling). ● Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive. | ● Future work will focus on advancing the deposit toward production readiness. Key programs planned include infill drilling to upgrade portions of the Mineral Resource from Indicated to Measured classification, particularly in the Souwa, Chegue, and Krakara deposits. Additional step-out and extensional drilling is also proposed to target near-mine exploration opportunities along the interpreted structural corridors, with the aim of increasing the overall resource base. ● Further geotechnical drilling and pit slope studies are planned to refine open-pit designs, along with additional hydrogeological investigations to support mine dewatering strategies. Metallurgical testwork will be expanded, including variability testing across different ore domains to optimise processing flowsheets. Environmental and social impact assessments (ESIA) will continue to ensure compliance with permitting obligations. |
| Criteria | JORC Code explanation | Commentary |
| Database integrity | ● Measures taken to ensure that data has not been corrupted by, for example, transcription or keying errors, between its initial collection and its use for Mineral Resource estimation purposes. ● Data validation procedures used. | ● The drillhole database has been developed and managed using industry-standard practices. Geological, geotechnical, and assay data were initially collected in field log sheets or digital capture tools and subsequently entered into a centralised SQL-based database system. Data entry protocols included validation checks to reduce transcription errors, including dropdown lists for logging codes and automated field validations. Independent verification of key fields (collar locations, assay results, geology codes) against original laboratory certificates and field records was carried out periodically. ● Database administration was performed by Centamin's in-house data management team, and periodic reviews and audits were conducted to check for consistency, missing fields, duplications, and logical errors. The database was exported and independently validated prior to each Mineral Resource estimation. Assay results were matched against original laboratory certificates to ensure accuracy, and downhole survey data was checked for consistency with expected drillhole trajectories. No material errors or significant discrepancies were identified during validation. |
| Site visits | ● Comment on any site visits undertaken by the Competent Person and the outcome of those visits. ● If no site visits have been undertaken indicate why this is the case. | ● Site visits were conducted by Qualified Persons (QPs) responsible for the Mineral Resource estimate. The site visits included direct observation of drilling operations (RC and diamond drilling), core handling and sampling practices, geological logging procedures, and data management workflows. ● During the site visits, the QP reviewed: drill collar locations, sampling representivity (soil, auger, RC, DD), core logging facilities, QAQC sample insertion and management, sample security and transport procedures. ● No material issues or inconsistencies were identified during the site visits. |
| Geological interpretation | ● Confidence in (or conversely, the uncertainty of ) the geological interpretation of the mineral deposit. ● Nature of the data used and of any assumptions made. ● The effect, if any, of alternative interpretations on Mineral Resource estimation. ● The use of geology in guiding and controlling Mineral Resource estimation. ● The factors affecting continuity both of grade and geology. | ● The Doropo Gold Project comprises sixteen prospects, Attire, Enioda, Chegue Main, Chegue South, Han, Hinda, Hinda South, Kekeda, Kilosegui, Nare, Nokpa, Sanboyoro, Solo, Souwa, Tchouahinin, and Vako. ● The geological interpretation for each is based on a combination of surface mapping, soil geochemistry, trenching, drilling (RC and diamond core), and geophysical data. The mineralisation is structurally controlled, typically hosted within quartz-carbonate-sulphide vein arrays aligned along north-northeast trending shear zones. Detailed geological logging of drill core and RC chips provided information on lithology, alteration, mineralisation styles, and structure, which were incorporated into the 3D geological models. ● Wireframes were constructed around logged mineralisation envelopes using a nominal cut-off of approximately 0.3 to 0.5 g/t Au, depending on deposit and geological domain. Interpretation of geological continuity, mineralised domain boundaries, and grade distribution is supported by close-spaced drilling (especially in Souwa, Chegue, and Krakara) and structural measurements taken from oriented core. Confidence in the interpretation is high where drilling density is greater, while areas of wider drill spacing retain a lower confidence, resulting in appropriate resource classification into Measured, Indicated, or Inferred. |
| Dimensions | ● The extent and variability of the Mineral Resource expressed as length (along strike or otherwise), plan width, and depth below surface to the upper and lower limits of the Mineral Resource. | ● The Doropo Mineral Resource comprises multiple discrete deposits, the largest of which are Souwa, Chegue, and Krakara. These deposits are structurally controlled lode gold systems that occur along northeast-trending shear zones. The mineralised zones are typically hosted in altered mafic to intermediate volcanic rocks and are characterised by moderate to steep dips. ● The combined strike length of individual mineralised lodes within the Doropo Project is over 12 km, with individual deposits ranging from 300 m to over 2.5 km in length. Mineralised zones are generally 3 to 15 m thick but can reach widths of up to 30 m in dilational zones or where stacked lodes coalesce. The mineralisation extends from near surface to vertical depths of 100 to 250 m, with some mineralised domains drilled to 300 to 400 m vertical depth, particularly in Souwa. |
| Estimation and modelling techniques | ● The nature and appropriateness of the estimation technique(s) applied and key assumptions, including treatment of extreme grade values, domaining, interpolation parameters and maximum distance of extrapolation from data points. If a computer assisted estimation method was chosen include a description of computer software and parameters used. ● The availability of check estimates, previous estimates and/or mine production records and whether the Mineral Resource estimate takes appropriate account of such data. ● The assumptions made regarding recovery of by-products. ● Estimation of deleterious elements or other non-grade variables of economic significance (eg sulphur for acid mine drainage characterisation). ● In the case of block model interpolation, the block size in relation to the average sample spacing and the search employed. ● Any assumptions behind modelling of selective mining units. ● Any assumptions about correlation between variables. ● Description of how the geological interpretation was used to control the resource estimates. ● Discussion of basis for using or not using grade cutting or capping. ● The process of validation, the checking process used, the comparison of model data to drill hole data, and use of reconciliation data if available. | ● Software used for the Mineral Resource estimate included Geoaccess Professional, Leapfrog Geo, Surpac and Isatis v2018.5. ● The Mineral Resource estimate for the Doropo Project was estimated using Ordinary Kriging (OK) interpolation and Local Uniform Conditioning (LUC). Estimation was conducted within hard boundary mineralisation domains defined by 3D wireframes, constructed based on geological logging, assay results, trenching, and geophysical interpretations. Drillhole data was composited to 1 m intervals prior to estimation. High-grade outlier values were assessed through statistical analysis of gold grade distributions by domain, and top-cuts were applied on an individual domain basis to reduce the influence of extreme grades. In some areas a distance limiting constraint was applied. Variogram models were developed in Gaussian space to model the spatial continuity of gold grades and back transformed prior to estimation. Search ellipses were oriented along the dominant structural trends observed in the mineralisation. ● The block models were constructed for each deposit with a parent block size of 5 m x 5 m x 2.5 m - the assumed ultimate SMU block size and rotated according to the orientation of the deposit. The OK interpolation was undertaken into relatively large panel blocks - predominantly 20 m x 20 m x 5 m but variable depending on deposit. Sub-blocking was utilised to accurately honour geological and mineralisation boundaries. ● No mining dilution or recovery factors were applied; the estimate reflects in-situ grades and tonnages. ● Only gold was estimated; no deleterious elements were modelled. No by-products were considered, and no correlations between variables were assumed as only gold was economically significant. ● The model was validated through visual inspections, comparison of input composite grades to block grades, swath plot analysis, and global statistical checks. No reconciliation to mining production was possible as the Doropo Project remains pre-production at this time. |
| Moisture | ● Whether the tonnages are estimated on a dry basis or with natural moisture, and the method of determination of the moisture content. | ● Tonnages are estimated and reported on a dry basis. |
| Cut-off parameters | ● The basis of the adopted cut-off grade(s) or quality parameters applied. | ● The Mineral Resource estimates for the Doropo Project were reported using a 0.3 g/t Au cut-off grade. This cut-off was selected based on PFS assumptions that reflect open pit mining methods, anticipated processing costs, metallurgical recoveries, and a long-term gold price assumption. ● The 0.3 g/t Au cut-off represents a reasonable expectation for economic extraction in a conventional open-pit scenario with moderate stripping ratios and CIL (carbon-in-leach) gold recovery. |
| Mining factors or assumptions | ● Assumptions made regarding possible mining methods, minimum mining dimensions and internal (or, if applicable, external) mining dilution. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential mining methods, but the assumptions made regarding mining methods and parameters when estimating Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the mining assumptions made. | ● Mining factors and assumptions are based on the expectation of open pit mining methods using conventional truck and shovel operations. Optimised pit shells were generated using Whittle optimisation software to test the reasonable prospects for eventual economic extraction. These pit shells informed the reporting constraints applied to the Mineral Resource estimate. ● The pit optimisations were generated by Orelogy with key mining parameters summarised below; ● All models were re-blocked to 10 mX x 10 mY x 5 mRL; ● Gold price assumption of USD3,000 per troy ounce; ● Overall pit wall slope angles used are (in the range of): o 24° in oxide; o 28° in transitional; o 48° in fresh; ● Mining Recovery of 92% (8% ore loss); ● Mining Dilution of 14%; ● Process Recovery: o Oxide: 93.5% |
| Metallurgical factors or assumptions | ● The basis for assumptions or predictions regarding metallurgical amenability. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential metallurgical methods, but the assumptions regarding metallurgical treatment processes and parameters made when reporting Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the metallurgical assumptions made. | ● Preliminary metallurgical testwork has been conducted on representative mineralised material from the Doropo Project. Samples were collected across a range of deposits (Souwa, Chegue, Krakara) and across different oxidation states (oxide, transitional, and fresh rock). Testwork was performed at certified laboratories and included gravity recovery tests, cyanidation leaching tests, and bottle roll tests. ● The results indicate that gold mineralisation is amenable to conventional gravity recovery followed by CIL (carbon-in-leach) processing, achieving high gold recoveries generally exceeding 90%. Oxide material exhibited slightly higher recovery rates than fresh rock, but all major ore types demonstrated favourable leach kinetics. No significant metallurgical challenges, such as refractory gold or deleterious elements affecting processing, were identified during initial testwork. |
| Environmen-tal factors or assumptions | ● Assumptions made regarding possible waste and process residue disposal options. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider the potential environmental impacts of the mining and processing operation. While at this stage the determination of potential environmental impacts, particularly for a greenfields project, may not always be well advanced, the status of early consideration of these potential environmental impacts should be reported. Where these aspects have not been considered this should be reported with an explanation of the environmental assumptions made. | ● Environmental and social baseline studies have been conducted across the project area, including flora and fauna surveys, water quality sampling, heritage site assessments, and social impact studies. These baseline investigations were undertaken to inform the Environmental and Social Impact Assessment (ESIA) process, which is a legal requirement for obtaining a Mining Licence in Côte d'Ivoire. ● An ESIA and Resettlement Action Plan (RAP) were prepared in accordance with Ivorian regulations and submitted to the relevant authorities. Environmental certificates and approvals have been granted as part of the Mining Licence issuance. Key environmental risks identified (such as water management, waste disposal, and biodiversity preservation) have been assessed at a preliminary level and mitigation measures proposed, although final designs (e.g., for tailings storage facilities and mine waste dumps) will be completed during Feasibility Studies. ● There are no known environmental issues that would materially affect the reasonable prospects of eventual economic extraction of the Mineral Resources. Ongoing monitoring and additional environmental studies are planned as the project advances toward development. |
| Bulk density | ● Whether assumed or determined. If assumed, the basis for the assumptions. If determined, the method used, whether wet or dry, the frequency of the measurements, the nature, size and representativeness of the samples. ● The bulk density for bulk material must have been measured by methods that adequately account for void spaces (vugs, porosity, etc), moisture and differences between rock and alteration zones within the deposit. ● Discuss assumptions for bulk density estimates used in the evaluation process of the different materials. | ● Bulk density measurements were taken systematically using drill core samples from across the various deposits and oxidation zones (oxide, transitional, and fresh rock). The measurements were conducted using the Archimedes principle (water immersion displacement method) on core samples. Samples were oven-dried before testing to ensure that moisture content did not artificially influence the density readings. ● A substantial dataset of 19,587 bulk density measurements were collected and statistically analysed. Density values were assigned to different oxidation domains as follows: ● Oxide material: average bulk density ~1.8-2.0 t/m³, ● Transitional material: ~2.3-2.5 tm³, ● Fresh rock: ~2.7 t/m³. ● These domain-specific densities were applied to the block model based on the oxidation state of each block. Density variability was reviewed, and no significant spatial inconsistencies were identified that would materially affect the Mineral Resource estimate. |
| Classification | ● The basis for the classification of the Mineral Resources into varying confidence categories. ● Whether appropriate account has been taken of all relevant factors (ie relative confidence in tonnage/grade estimations, reliability of input data, confidence in continuity of geology and metal values, quality, quantity and distribution of the data). ● Whether the result appropriately reflects the Competent Person's view of the deposit. | ● The Mineral Resource has been classified and reported in accordance with the CIM Definition Standards. Resources were classified into Measured, Indicated, and Inferred categories based on a combination of drilling density, geological confidence, continuity of mineralisation, and data quality. ● Measured Resources were assigned in areas where drilling density was highest (nominally on 10 m x 10 m grids), geological and mineralisation continuity was well established, and data quality (assays, surveys, logging) was considered excellent. ● Indicated Resources were defined in areas of moderate drilling density (typically 25 m to 30 m spacing) where mineralisation continuity and geological controls were reasonably well understood. ● Inferred Resources were assigned to zones with broader drill spacing up to 50 m x 50 m, lower geological confidence, or where extrapolation beyond drilling data was required. ● The classification approach appropriately reflects the level of confidence in the underlying geological models, sampling methods, and assay results. |
| Audits or reviews | ● The results of any audits or reviews of Mineral Resource estimates. | ● No independent audit has been completed on the Doropo Mineral Resource Estimate. ● Cube undertook regular internal peer reviews during the course of the MRE work. |
| Discussion of relative accuracy/ confidence | ● Where appropriate a statement of the relative accuracy and confidence level in the Mineral Resource estimate using an approach or procedure deemed appropriate by the Competent Person. For example, the application of statistical or geostatistical procedures to quantify the relative accuracy of the resource within stated confidence limits, or, if such an approach is not deemed appropriate, a qualitative discussion of the factors that could affect the relative accuracy and confidence of the estimate. ● The statement should specify whether it relates to global or local estimates, and, if local, state the relevant tonnages, which should be relevant to technical and economic evaluation. Documentation should include assumptions made and the procedures used. ● These statements of relative accuracy and confidence of the estimate should be compared with production data, where available. | ● The relative accuracy and confidence of the Doropo Mineral Resource estimates are considered appropriate for the classification levels assigned. ● No production data is available for direct reconciliation, as the project is still in the exploration and development phase. ● At the global scale, the Mineral Resource estimate is considered to have an accuracy commensurate with industry expectations for a project at the advanced exploration and prefeasibility stages. |