Fortuna Expands Southern Arc Mineralization with Drill Intercept of 1.7 g/t Au over 29.6 meters and a further 2.0 g/t Au over 20.0 meters from DSDD574 at the Diamba Sud Gold Project, Senegal | FSM Stock News

VANCOUVER, British Columbia, Dec. 08, 2025 (GLOBE NEWSWIRE) -- Fortuna Mining Corp. (NYSE: FSM | TSX: FVI) is pleased to report additional exploration drilling results from the Southern Arc deposit at its Diamba Sud Gold Project in Senegal. Diamba Sud is a PEA-stage project with robust economics, highlighted by an estimated after-tax NPV5% of US$563 million and an IRR of 72% at a gold price of US$2,750 per ounce. The project is currently advancing toward a feasibility study and a construction decision targeted for the second quarter of 2026. Paul Weedon, Senior Vice President of Exploration, commented “Southern Arc continues to deliver strong results with high grade intersections from both infill and extension drilling. Infill highlights include drillhole DSDD555, which returned 6.8 g/t gold over an estimated true width of 35.5 meters.” Mr. Weedon continued, “Importantly, drilling to the southwest of the current optimized pit shell is expanding mineralization, returning broad and consistent gold intervals. This includes drill hole DSDD574, which intersected 1.7 g/t gold over an estimated true width of 29.6 meters, and a further 2.0 g/t over an estimated true width of 20.0 meters.” Mr. Weedon concluded, “These results will feed into an updated resource estimate expected in the first quarter of 2026.” The PEA is preliminary in nature and includes inferred mineral resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves; as such, there is no certainty that the PEA results will be realized. Mineral resources that are not mineral reserves do not have demonstrated economic viability1 Southern Arc Prospect Drilling Highlights A further 63 reverse-circulation and diamond drill hole, totalling 9,619 meters, have been completed at Southern Arc (see Figure 1) since the Company´s previous exploration update (refer to Fortuna news release dated May 27, 2025). Drilling is continuing with five drill rigs, with key objectives including: ongoing infill drilling to support increased resource confidence, andcontinued step-out drilling to the southwest, east, and south, where mineralization remains open DSDD555:6.8 g/t Au over an estimated true width of 35.5 meters from 48.6 meters, including24.0 g/t Au over an estimated true width of 0.8 meters from 65 meters, and13.1 g/t Au over an estimated true width of 0.8 meters from 68.5 meters, and18.5 g/t Au over an estimated true width of 0.8 meters from 74 meters, and18.7 g/t Au over an estimated true width of 5.6 meters from 80 meters DSDD558:1.8 g/t Au over an estimated true width of 12.8 meters from 25 meters8.8 g/t Au over an estimated true width of 14.4 meters from 96 meters, including22.1 g/t Au over an estimated true width of 0.8 meters from 101 meters, and18.0 g/t Au over an estimated true width of 0.8 meters from 103 meters, and11.5 g/t Au over an estimated true width of 0.8 meters from 110 meters DSDD562:4.5 g/t Au over an estimated true width of 5.6 meters from 146 meters8.0 g/t Au over an estimated true width of 11.2 meters from 174 meters, including46.3 g/t Au over an estimated true width of 1.6 meters from 183 meters DSDD563:5.8 g/t Au over an estimated true width of 20.8 meters from 50 meters, including23.3 g/t Au over an estimated true width of 1.6 meters from 53 meters, and21.8 g/t Au over an estimated true width of 1.6 meters from 71 meters12.2 g/t Au over an estimated true width of 5.8 meters from 86 meters, including14.7 g/t Au over an estimated true width of 0.8 meters from 87 meters, and22.1 g/t Au over an estimated true width of 2.2 meters from 90 meters2.7 g/t Au over an estimated true width of 6.4 meters from 106 meters7.0 g/t Au over an estimated true width of 4.8 meters from 118 meters, including15.3 g/t Au over an estimated true width of 1.6 meters from 120 meters DSDD567:4.6 g/t Au over an estimated true width of 26.6 meters from 96.8 meters, including15.6 g/t Au over an estimated true width of 0.8 meters from 103 meters, and13.6 g/t Au over an estimated true width of 1.6 meters from 105 meters, and18.3 g/t Au over an estimated true width of 1.6 meters from 114 meters DSDD574:1.7 g/t Au over an estimated true width of 29.6 meters from 93 meters2.0 g/t Au over an estimated true width of 20.0 meters from 135 meters, including18.4 g/t Au over an estimated true width of 0.8 meters from 158 meters DSDD577:4.2 g/t Au over an estimated true width of 21.6 meters from 116.2 meters, including30.0 g/t Au over an estimated true width of 1.6 meters from 125 meters, and18.9 g/t Au over an estimated true width of 1.1 meters from 134.3 meters DSDD578:4.9 g/t Au over an estimated true width of 16.8 meters from 15 meters, including29.5 g/t Au over an estimated true width of 1.6 meters from 15 meters DSDD584:5.5 g/t Au over an estimated true width of 17.0 meters from 32.7 meters, including20.3 g/t Au over an estimated true width of 0.8 meters from 38 meters, and14.3 g/t Au over an estimated true width of 0.8 meters from 50 meters, and17.8 g/t Au over an estimated true width of 0.8 meters from 53 meters7.8 g/t Au over an estimated true width of 1.4 meters from 95.7 meters DSDD589:3.5 g/t Au over an estimated true width of 26.8 meters from 16 meters, including15.8 g/t Au over and estimated true width of 0.8 meters from 34 meters Mineralization at Southern Arc occurs as variably developed fine stockwork vein arrays to diffuse pyrite-silica flooding, showing strong correlation with several tectonic breccia and carbonate units (see Figures 2 and 3). Alteration commonly includes extensive hematite development, consistent with mineralized systems elsewhere at Diamba Sud. Overall, the latest drilling reinforces the strong potential for continued resource growth at Diamba Sud. Southern Arc remains open to the south, east, and at depth, with drilling to date testing to only approximately 150 meters below surface. Figure 1: Location plan showing Diamba Sud drilling and Mineral Resource Deposits Figure 2: Diamba Sud Gold Project: Southern Arc Prospect, cross section 550NE Figure 3: Diamba Sud Gold Project: Southern Arc Prospect, cross section 450NE Refer to Appendix 1 for complete drill hole collars, significant intercepts, and assay results for this drill program. Quality Assurance & Quality Control (QA - QC) All drilling data completed by the Company utilized the following procedures and methodologies. All drilling was carried out under the supervision of the Company’s personnel. All reverse circulation (RC) drilling used a 5.25-inch face sampling pneumatic hammer with samples collected into 60-liter plastic bags. Samples were kept dry by maintaining enough air pressure to exclude groundwater inflow. If water ingress exceeded the air pressure, RC drilling was stopped, and drilling converted to diamond core tails. Once collected, RC samples were riffle split through a three-tier splitter to yield a 12.5 percent representative sample for submission to the analytical laboratory. The residual 87.5 percent samples were stored at the drill site until assay results were received and validated. Coarse reject samples for all mineralized samples corresponding to significant intervals are retained and stored on-site at the Company-controlled core yard. All diamond drilling (DD) drill holes started with HQ sized diameter, before reducing to NQ diameter diamond drill bits on intersecting fresh rock. The core was logged, marked up for sampling using standard lengths of one meter or to a geological boundary. Samples were then cut into equal halves using a diamond saw. One half of the core was left in the original core box and stored in a secure location at the Company core yard at the project site. The other half was sampled, catalogued, and placed into sealed bags and securely stored at the site until shipment. All RC and DD samples were transported by Company vehicle or commercial courier to ALS Global’s preparation laboratories in Kedougou, Senegal or Bamako, Mali, with prepared sample pulps then transported via commercial courier to ALS Global’s analytical facility in Ouagadougou, Burkina Faso. Routine gold analysis using a 50-gram charge and fire assay with an atomic absorption finish was completed for all samples. Samples returning assays >10 parts per million Au were reanalyzed using a 50-gram charge and fire assay with a gravimetric finish. Quality control procedures included the systematic insertion of blanks, duplicates and sample standards into the sample stream. In addition, the ALS Global laboratory inserted its own quality control samples. Qualified Person Paul Weedon, Senior Vice President, Exploration for Fortuna Mining Corp., is a Qualified Person as defined by National Instrument 43-101 being a member of the Australian Institute of Geoscientists (Membership #6001). Mr. Weedon has reviewed and approved the scientific and technical information contained in this news release. Mr. Weedon has verified the data disclosed, including the sampling, analytical and test data underlying the information or opinions contained herein by reviewing geochemical and geological databases and reviewing diamond drill core. There were no limitations to the verification process. About Fortuna Mining Corp. Fortuna Mining Corp. is a Canadian precious metals mining company with three operating mines and a portfolio of exploration projects in Argentina, Côte d’Ivoire, Mexico, and Peru, as well as the Diamba Sud Gold Project in Senegal. Sustainability is at the core of our operations and stakeholder relationships. We produce gold and silver while creating long-term shared value through efficient production, environmental stewardship, and social responsibility. For more information, please visit our website at www.fortunamining.com ON BEHALF OF THE BOARD Jorge A. Ganoza President, CEO, and DirectorFortuna Mining Corp. Investor Relations: Carlos Baca | info@fmcmail.com | fortunamining.com | X | LinkedIn | YouTube Forward looking Statements This news release contains forward-looking statements which constitute “forward-looking information” within the meaning of applicable Canadian securities legislation and “forward-looking statements” within the meaning of the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995 (collectively, “Forward-looking Statements”). All statements included herein, other than statements of historical fact, are Forward-looking Statements and are subject to a variety of known and unknown risks and uncertainties which could cause actual events or results to differ materially from those reflected in the Forward-looking Statements. The Forward-looking Statements in this news release may include, without limitation, the projected economics of the Diamba Sud Project, including the net present value of the Diamba Sud Project and the internal rate of return of the Diamba Sud Project; the Company’s expectation that a construction decision will be targeted for the second quarter of 2026; statements regarding continued resource growth at the Diamba Sud Project and the expected timing of an updated resource estimate; the Company’s proposed exploration plans at Diamba Sud statements about the Company’s business strategies, plans and outlook; the Company’s plans for its mines and mineral properties; changes in general economic conditions and financial markets; the impact of inflationary pressures on the Company’s business and operations; the future results of exploration activities; expectations with respect to metal grade estimates and the impact of any variations relative to metals grades experienced; assumed and future metal prices; the merit of the Company’s mines and mineral properties; and the future financial or operating performance of the Company. Often, but not always, these Forward-looking Statements can be identified by the use of words such as “estimated”, “potential”, “open”, “future”, “assumed”, “projected”, “proposed”, “used”, “detailed”, “has been”, “gain”, “planned”, “reflecting”, “will”, “anticipated”, “estimated” “containing”, “remaining”, “to be”, or statements that events, “could” or “should” occur or be achieved and similar expressions, including negative variations. Forward-looking Statements involve known and unknown risks, uncertainties and other factors which may cause the actual results, performance, or achievements of the Company to be materially different from any results, performance or achievements expressed or implied by the Forward-looking Statements. Such uncertainties and factors include, among others, operational risks associated with mining and mineral processing; uncertainty relating to Mineral Resource and Mineral Reserve estimates; uncertainty relating to capital and operating costs, production schedules and economic returns; risks relating to the Company’s ability to replace its Mineral Reserves; risks related to the conversion of Mineral Resources to Mineral Reserves; risks associated with mineral exploration and project development; uncertainty relating to the repatriation of funds as a result of currency controls; environmental matters including obtaining or renewing environmental permits and potential liability claims; uncertainty relating to nature and climate conditions; laws and regulations regarding the protection of the environment (including greenhouse gas emission reduction and other decarbonization requirements and the uncertainty surrounding the interpretation of omnibus Bill C-59 and the related amendments to the Competition Act (Canada); risks associated with political instability and changes to the regulations governing the Company’s business operations; changes in national and local government legislation, taxation, controls, regulations and political or economic developments in countries in which the Company does or may carry on business; risks associated with war, hostilities or other conflicts, such as the Ukrainian – Russian, and Israeli – Hamas conflicts, and the impacts they may have on global economic activity; risks relating to the termination of the Company’s mining concessions in certain circumstances; developing and maintaining relationships with local communities and stakeholders; risks associated with losing control of public perception as a result of social media and other web-based applications; potential opposition to the Company’s exploration, development and operational activities; risks related to the Company’s ability to obtain adequate financing for planned exploration and development activities; property title matters; risks related to the ability to retain or extend title to the Company’s mineral properties; risks relating to the integration of businesses and assets acquired by the Company; impairments; risks associated with climate change legislation; reliance on key personnel; adequacy of insurance coverage; operational safety and security risks; legal proceedings and potential legal proceedings; uncertainties relating to general economic conditions; risks relating to a global pandemic, which could impact the Company’s business, operations, financial condition and share price; competition; fluctuations in metal prices; risks associated with entering into commodity forward and option contracts for base metals production; fluctuations in currency exchange rates and interest rates; tax audits and reassessments; risks related to hedging; uncertainty relating to concentrate treatment charges and transportation costs; sufficiency of monies allotted by the Company for land reclamation; risks associated with dependence upon information technology systems, which are subject to disruption, damage, failure and risks with implementation and integration; labor relations issues; as well as those factors discussed under “Risk Factors” in the Company's Annual Information Form for the fiscal year ended December 31, 2024. Although the Company has attempted to identify important factors that could cause actual actions, events, or results to differ materially from those described in Forward-looking Statements, there may be other factors that cause actions, events or results to differ from those anticipated, estimated or intended. Forward-looking Statements contained herein are based on the assumptions, beliefs, expectations and opinions of management, including, but not limited to, the accuracy of the Company’s current Mineral Resource and Mineral Reserve estimates; that the Company’s activities will be conducted in accordance with the Company’s public statements and stated goals; that there will be no material adverse change affecting the Company, its properties or its production estimates (which assume accuracy of projected ore grade, mining rates, recovery timing, and recovery rate estimates and may be impacted by unscheduled maintenance, labor and contractor availability and other operating or technical difficulties); the duration and effect of global and local inflation; the duration and impacts of geo-political uncertainties on the Company’s production, workforce, business, operations and financial condition; the expected trends in mineral prices, inflation and currency exchange rates; that all required approvals and permits will be obtained for the Company’s business and operations on acceptable terms; that there will be no significant disruptions affecting the Company's operations and such other assumptions as set out herein. Forward-looking Statements are made as of the date hereof and the Company disclaims any obligation to update any Forward-looking Statements, whether as a result of new information, future events, or results or otherwise, except as required by law. There can be no assurance that these Forward-looking Statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, investors should not place undue reliance on Forward-looking Statements. Cautionary Note to United States Investors Concerning Estimates of Reserves and Resources All reserve and resource estimates included in this news release have been prepared in accordance with National Instrument 43-101 Standards of Disclosure for Mineral Projects ("NI 43-101") and the Canadian Institute of Mining, Metallurgy, and Petroleum Definition Standards on Mineral Resources and Mineral Reserves. NI 43-101 is a rule developed by the Canadian Securities Administrators that establishes standards for public disclosure by a Canadian company of scientific and technical information concerning mineral projects. All Mineral Reserve and Mineral Resource estimates contained in the technical disclosure have been prepared in accordance with NI 43-101 and the Canadian Institute of Mining, Metallurgy and Petroleum Definition Standards on Mineral Resources and Reserves. Canadian standards, including NI 43-101, differ significantly from the requirements of the Securities and Exchange Commission, and mineral reserve and resource information included in this news release may not be comparable to similar information disclosed by U.S. companies. Appendix 1: Diamba Sud drill program details of the drill holes and assay results for Southern Arc Prospect HoleIDEasting (WGS84_29N)Northing (WGS84_29N)Elev. (m)EOH1,2 Depth (m)UTM AzimuthDipDepth2,3 From (m)Depth2 To (m)Drilled2 Width (m)ETW4 (m)Au (ppm)Hole Type5AreaDSDD4862322781426476148249150-50NSI DDSouthern ArcDSDD4932323471426501148207150-50165.0174.09.07.22.4DDSouthern Arc including168.0169.01.00.813.2DDSouthern ArcDSDD4942325321426112142131150-5038.049.011.08.81.4DDSouthern ArcDSDD4952323101426500149186150-50NSI DDSouthern ArcDSDD4962326741426074143176150-5038.350.011.79.42.2DDSouthern Arc including44.045.01.00.815.5DDSouthern Arc 96.0102.36.35.02.3DDSouthern Arc 107.0119.512.510.06.8DDSouthern Arc including115.0116.01.00.819.2DDSouthern Arc and117.0118.01.00.819.8DDSouthern Arc 135.0167.032.025.60.8DDSouthern ArcDSDD4972328841426027143129150-50108.8121.712.910.33.6DDSouthern Arc including117.0118.01.00.817.0DDSouthern ArcDSDD4982327141426155145132150-5084.389.75.44.31.9DDSouthern ArcDSDD5552328681426115144120150-5048.693.044.435.56.8DDSouthern Arc including53.253.70.40.4Core LossDDSouthern Arc and65.066.01.00.824.0DDSouthern Arc and67.267.80.60.5Core LossDDSouthern Arc and68.569.51.00.813.1DDSouthern Arc and70.671.20.60.5Core LossDDSouthern Arc and74.075.01.00.818.5DDSouthern Arc and80.087.07.05.618.7DDSouthern ArcDSDD5562327381426053144201150-50105.0134.029.023.21.5DDSouthern Arc 138.0153.015.012.02.8DDSouthern ArcDSDD5572328381426172143165150-5039.057.018.014.41.9DDSouthern Arc 67.073.06.04.81.2DDSouthern Arc 104.7127.022.317.83.8DDSouthern Arc including108.0109.01.00.811.8DDSouthern Arc and114.0115.01.00.830.4DDSouthern Arc 139.0141.02.01.63.7DDSouthern Arc 145.0161.216.213.03.4DDSouthern ArcDSDD5582328091426139144146150-5025.041.016.012.81.8DDSouthern Arc 96.0114.018.014.48.8DDSouthern Arc including101.0102.01.00.822.1DDSouthern Arc and103.0106.03.02.418.0DDSouthern Arc and110.0111.01.00.811.5DDSouthern Arc 118.0122.04.03.23.0DDSouthern ArcDSDD559232753142613114599150-50NSI DDSouthern ArcDSDD5602327851426176145170150-5043.055.012.09.61.9DDSouthern Arc 63.070.07.05.62.7DDSouthern ArcDSDD5612327701425988142126150-5059.068.09.07.20.7DDSouthern Arc 79.0100.021.016.80.7DDSouthern ArcDSDD5622327171426094144206150-50146.0153.07.05.64.5DDSouthern Arc 174.0188.014.011.28.0DDSouthern Arc including183.0185.02.01.646.3DDSouthern ArcDSDD5632327271426179145135150-5050.076.026.020.85.8DDSouthern Arc including53.055.02.01.623.3DDSouthern Arc and71.073.02.01.621.8DDSouthern Arc 86.093.37.35.812.2DDSouthern Arc including87.088.01.00.814.7DDSouthern Arc and90.092.82.82.222.1DDSouthern Arc 106.0114.08.06.42.7DDSouthern Arc 118.0124.06.04.87.0DDSouthern Arc including120.0122.02.01.615.3DDSouthern ArcDSDD5642327741426198145200150-5012.021.09.07.21.2DDSouthern Arc including15.016.01.00.8Core LossDDSouthern Arc 30.038.38.36.62.9DDSouthern Arc including37.538.30.80.611.7DDSouthern Arc 80.093.013.010.41.0DDSouthern Arc 160.0163.03.02.43.0DDSouthern ArcDSDD5652327611426008142147150-5070.079.09.07.20.7DDSouthern Arc 86.0106.020.016.01.5DDSouthern Arc 121.0123.02.01.62.6DDSouthern ArcDSDD5662327801426157145149150-505.011.06.04.81.4DDSouthern Arc 36.042.06.04.81.6DDSouthern Arc 46.056.010.08.02.5DDSouthern Arc 121.7134.012.39.82.0DDSouthern Arc including131.0132.01.00.814.3DDSouthern ArcDSDD5672327891426137145146150-501.38.06.75.41.1DDSouthern Arc 16.024.08.06.41.2DDSouthern Arc 34.045.011.08.81.6DDSouthern Arc 96.8130.033.226.64.6DDSouthern Arc including103.0104.01.00.815.6DDSouthern Arc and105.0107.02.01.613.6DDSouthern Arc and114.0116.02.01.618.3DDSouthern ArcDSDD5682326851426046143171150-5080.389.59.27.41.0DDSouthern Arc 111.0117.06.04.81.8DDSouthern Arc 123.0128.05.04.04.0DDSouthern Arc 144.0158.014.011.20.9DDSouthern ArcDSDD5692327591426223145183150-5051.058.07.05.61.2DDSouthern ArcDSDD5702326001426187145231150-50174.0191.017.013.60.9DDSouthern Arc 198.0209.011.08.83.6DDSouthern Arc including206.0208.02.01.614.9DDSouthern Arc 214.0217.03.02.41.8DDSouthern ArcDSDD5712327401426245145182150-50172.8178.05.24.21.9DDSouthern ArcDSDD5722326701426088144201150-5056.065.09.07.21.8DDSouthern Arc 118.0124.06.04.80.9DDSouthern Arc 180.0190.010.08.00.5DDSouthern ArcDSDD5732328121426161144185150-5027.040.013.010.43.0DDSouthern Arc 49.053.04.03.22.8DDSouthern Arc 57.082.025.020.03.2DDSouthern Arc Including60.061.01.00.813.4DDSouthern Arc 158.0161.03.02.41.9DDSouthern ArcDSDD5742327021426060143183150-5093.0130.037.029.61.7DDSouthern Arc 135.0160.025.020.02.0DDSouthern Arc Including158.0159.01.00.818.4DDSouthern ArcDSDD5752323191426368147129150-50NSI DDSouthern ArcDSDD576232908142603214395150-50NSI DDSouthern ArcDSDD5772323171426415148222150-5077.082.05.04.01.0DDSouthern Arc 116.2143.227.021.64.2DDSouthern Arc Including125.0127.02.01.630.0DDSouthern Arc And134.3135.71.31.118.9DDSouthern Arc 147.2154.27.05.61.1DDSouthern ArcDSDD5782323581426340146101.3150-500.09.09.07.21.1DDSouthern Arc 3.04.01.00.8Core LossDDSouthern Arc 15.036.021.016.84.9DDSouthern Arc Including15.017.02.01.629.5DDSouthern Arc 49.053.04.03.21.6DDSouthern ArcDSDD5792327061426011142141150-5057.066.09.07.21.5DDSouthern Arc 99.0100.01.00.816.3DDSouthern ArcDSDD580232899142606814392150-5022.827.24.53.62.1DDSouthern Arc 61.070.09.07.25.0DDSouthern Arc Including65.066.01.00.820.2DDSouthern ArcDSDD5812327381426016142143150-5072.087.015.012.01.6DDSouthern Arc 93.0101.08.06.42.8DDSouthern Arc 118.2131.112.910.31.7DDSouthern ArcDSDD582232393142637114798150-501.011.610.68.50.9DDSouthern Arc 2.03.01.00.8Core LossDDSouthern Arc 25.031.26.25.00.8DDSouthern ArcDSDD583232909142609414398150-503.09.06.04.81.1DDSouthern Arc 14.033.019.015.21.3DDSouthern Arc 52.058.06.04.82.5DDSouthern Arc 64.073.09.07.23.0DDSouthern ArcDSDD5842323471426395147192150-5032.754.021.317.05.5DDSouthern Arc Including38.039.01.00.820.3DDSouthern Arc And50.051.01.00.814.3DDSouthern Arc And53.054.01.00.817.8DDSouthern Arc 95.797.51.81.47.8DDSouthern Arc Including96.597.51.00.810.6DDSouthern ArcDSDD585232419142637114780150-5048.850.82.01.63.1DDSouthern ArcDSDD5862325331426235145200150-50NSI DDSouthern ArcDSDD5872326931426288146187150-50NSI DDSouthern ArcDSDD5882329511426129143104150-50NSI DDSouthern ArcDSDD589232926142606414380150-505.08.03.02.42.7DDSouthern Arc 16.049.533.526.83.5DDSouthern Arc Including34.035.01.00.815.8DDSouthern ArcDSDD5902325751426215145243150-50177.0198.021.016.80.6DDSouthern Arc 203.0210.07.05.61.6DDSouthern Arc 214.2237.022.818.21.4DDSouthern Arc DSDD5912329341426163143140150-50NSI DDSouthern ArcDSDD592232943142608214380150-5091564.81.9DDSouthern Arc 2230.48.46.71.7DDSouthern Arc 49.256.16.95.61.2DDSouthern ArcDSDD5932324861426282146222150-50NSI DDSouthern ArcDSDD5942325611426182144155150-50NSI DDSouthern ArcDSDD595232922142601114392150-50NSI DDSouthern ArcDSDD596232976142608714380150-50NSI DDSouthern ArcDSDD5972326481426163145249150-5014815354.02.1DDSouthern ArcDSDD598232936142604514398150-50NSI DDSouthern ArcDSDD599232957142605814381150-50NSI DDSouthern ArcDSDD6002327411426188145145150-504953.64.73.72.8DDSouthern Arc 128.15130.62.52.09.2DDSouthern Arc including129.3130.61.41.116.0DDSouthern ArcDSR10022322911426455148204150-5015715810.88.1RCSouthern Arc 1841981411.21.4RCSouthern ArcDSR10032326181426171145162150-50NSI RCSouthern ArcDSR10042325871426169145162150-5012913343.23.5RCSouthern Arc including12913010.811.3RCSouthern Arc 14915564.81.3RCSouthern ArcDSR10052327041426216146168150-50808664.83.8RCSouthern Arc including848510.814.6RCSouthern ArcDSR10062327771426087144144150-50NSI RCSouthern ArcDSR10072326161426126144160150-50NSI RCSouthern ArcDSR10082327401426153145132150-50NSI RCSouthern ArcDSR10092328251426115144144150-5010310632.42.9RCSouthern ArcDSR10102324191426343147120150-50NSI RCSouthern ArcDSR10112327261426247145120150-50NSI RCSouthern Arc Notes:1. EOH: End of hole2. Depths and widths reported to nearest significant decimal place 3. NSI: No significant intercepts4. ETW: Estimated true width5. RC: reverse circulation drilling | DD: diamond drilling tail | RCD: reverse circulation drilling with diamond tail Appendix 2 - PEA Key Highlights MetricsUnits ResultsGold price$/oz 2,750Life of mineyears 8.1Processing Duration years 7.9Total mineralized material mined1kt 17.8Contained gold in mineralized material mined1koz 932Strip ratioWaste: mineralized material 5.5:1Throughput initial 3 years (primarily oxide)Mtpa 2.5Throughput after 3 years (primarily fresh)Mtpa 2.0LOM gradeg/t 1.63Recoveries% 90Gold production Total Production over LOMkoz 840Average annual production over LOMkoz 106Average annual production over first 3 yearskoz 146Per unit costs LOM Mining$/t, mined 4.82Processing$/t, processed 13.9G&A$/t, processed 6.7Cash costs1 Average operating cash costs2over LOM$/oz 1,081Average operating cash costs2 over first 3 years$/oz 759AISC1 Average AISC2over LOM$/oz 1,238Average AISC2 over first 3 years$/oz 904Capital costs Initial capital expenditure$ M 283Sustaining capital expenditure + Infrastructure (includes closure costs)$ M 48Returns NPV5%, pre-tax (100% Project basis)$M 772Pre-tax IRR% 86NPV5%, after-tax (100% Project basis)$M 563After-tax IRR% 72After Tax Payback Periodyears 0.8Annual EBITDA 2 Average EBITDA2 over LOM$ M 167Average EBITDA2 over first 3 years$ M 277 Notes: The pit optimization shells used for the mine plan were generated using a gold price of $2,300 per ounce.This is a non-IFRS financial measure. The definition and purpose of this non-IFRS financial measure is included in the Company’s management’s discussion and analysis for the three and nine months ended September 30, 2025, under the heading “Non-IFRS Measures”. Non-IFRS financial measures have no standardized meaning under IFRS and therefore, may not be comparable to similar measures presented by other issuers.Average operating cash costs and average AISC represent costs for projected production for the LOM at the time of gold sales.The PEA is presented on a 100 percent project basis. However, upon the granting of the exploitation permit, the Senegalese Government is entitled to a 10 percent free-carried interest in Boya , with the right for the State to acquire an additional contributory interest of up to 25 percent.The economic analysis was carried out using a discounted cash flow approach on a pre-tax and after-tax basis, based on the gold price of $2,750/oz.The IRR on total investment that is presented in the economic analysis was calculated assuming a 100% ownership in Diamba Sud.The NPV was calculated from the after-tax cash flow generated by the Project, based on a discounted rate of 5% and an effective date of October 10, 2025.The PEA assumes that the percentage of certain royalties and taxes payable to the State, the percentage of the investment tax credit available to the company and the percentage payable to the social development fund will be in accordance with the provisions of the Mining Convention between Boya S.A. and the State of Senegal dated April 8, 2015. It should be noted, however, that the State retains the sovereign prerogative to review or revisit certain fiscal terms during the exploitation permit approval process, and as such, the current framework may be subject to amendment.The PEA is preliminary in nature, and it includes inferred mineral resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves, and, as such, there is no certainty that the PEA results will be realized. Mineral resources that are not mineral reserves do not have demonstrated economic viability.Further information regarding the PEA, including details on key assumptions, parameters, opportunities, risks and other factors are contained in the Technical Report prepared for the Company entitled “Diamba Sud Gold Project, Kedougou Region, Senegal” with an effective date of October 15, 2025, which has been filed on SEDAR+ and on EDGAR under the Company’s profile. PDF available: http://ml.globenewswire.com/Resource/Download/5b31b53c-28e4-4f9f-878d-ac43f2974f4c Figures accompanying this announcement are available at: https://www.globenewswire.com/NewsRoom/AttachmentNg/65e9cc3a-6c58-4000-b072-6d0bffca780b https://www.globenewswire.com/NewsRoom/AttachmentNg/6f5654b1-fda3-4dcb-ac32-106b267f1aed https://www.globenewswire.com/NewsRoom/AttachmentNg/2e29ea91-4813-4b97-8015-a5772e4b9112