Fortuna intersects 7.8 g/t gold over 12.8 meters at Southern Arc, Diamba Sud, and advances exploration at Bambadji, Senegal

VANCOUVER, British Columbia, Oct. 13, 2026 (GLOBE NEWSWIRE) — Fortuna Mining Corp. (NYSE: FSM | TSX: FVI) is pleased to report updated results from exploration drilling at the Southern Arc and Kassasoko deposits at the Diamba Sud Gold Project located in Senegal, and the start of drilling at Kabewest on the recently acquired and contiguous Bambadji properties.

Paul Weedon, Senior Vice President of Exploration, commented, “The recently completed reverse circulation and diamond drilling program adjacent to the Southern Arc and Kassasoko deposits has continued to return very encouraging results beyond the current pit designs. Results such as the 3.9 g/t Au intersection over an estimated true width of 40.8 meters from 228 meters in drill hole DSR1149 highlight the opportunity to further expand the Diamba Sud Mineral Reserve.” Mr. Weedon continued, “At our recently acquired Bambadji properties, exploration drilling has commenced at Kabewest, with six drill rigs operating as part of an $8 million drilling campaign for the remainder of 2026. Kabewest is the largest and most advanced drill-defined target on the property and is located only 2.3 kilometres from the proposed Diamba Sud plant site. Initial drill core samples have highlighted strong similarities to the breccia-hosted mineralization at Diamba Sud, and we look forward to receiving the assay results.”  

Southern Arc Drilling highlights

Since the previous exploration results update in February 2026, a further 196 reverse circulation (“RC”) and diamond drilling (“DD”) holes, totalling 36,592 meters, have been completed at Southern Arc (refer to Figure 1), concluding the program (refer to Fortuna news release dated February 25, 2026, “Fortuna intersects 6.0 g/t gold over 24.1 meters at Southern Arc, Diamba Sud Project, Senegal”). The program successfully identified depth and strike extensions to the northeast and southwest, as well as parallel structures to the southeast, where mineralization remains open. For example, DSR1132 intersected 4.5 g/t gold over an estimated true width of 20.0 meters from 65 meters within a broad zone of mineralization beyond the current pit design (refer to Figure 2). This zone remains open at depth, further demonstrating the open nature of the mineralization. An updated estimate is intended to be prepared for Mineral Resource and Mineral Reserve reporting as at year-end, and further step-out drilling is planned for 2027.

Mineralization at Southern Arc occurs as variable fine stockwork vein arrays and diffuse pyrite-silica flooding, with a strong spatial association to hydrothermal breccias and carbonate units. The system commonly exhibits extensive hematite alteration, consistent with mineralization observed at other Diamba Sud deposits.

Figure 1: Diamba Sud Gold Project: Location of Mineral Resource Deposits and Exploration Targets

Figure 2: Diamba Sud Gold Project: Southern Arc Deposit, Long Section 375NE

Kassasoko Drilling Highlights

A program of 53 RC and DD holes, totalling 8,787 meters, has been completed at Kassasoko since the previous exploration update. This program was designed to test for expansion of the mineralized footprint through step-out drilling and evaluate its link to the nearby Western Splay deposit. Mineralization remains open at depth and along strike.

Mineralization at Kassasoko occurs within intercalated hydrothermal breccias, carbonate metasedimentary units, and granitic to dioritic intrusive rocks. It is typically associated with vein arrays preferentially hosted within hydrothermal breccias.

Bambadji, Senegal: Exploration Work Program

Drilling has commenced on the recently acquired Bambadji project (refer to Figure 3), with five DD rigs and 1 RC rig currently operating as part of an $8 million, 51,000-meter exploration program for the balance of 2026 (refer to Fortuna news release dated August 10, 2026, “Fortuna acquires highly prospective Bambadji Project in Senegal from Barrick and IAMGOLD”).

Figure 3: Bambadji Gold Project: Location of Exploration Targets

^{Note: Probable Mineral Reserves of 20.5 million tonnes averaging 1.75 g/t Au, containing 1.15 million ounces of gold have been reported for Diamba Sud (refer to Fortuna news release dated June 29, 2026, “Fortuna delivers robust Feasibility Study for the Diamba Sud Gold Project in Senegal: After-tax IRR of 60% and NPV5% of US$1 billion using US$3,500/oz”).}

Following an extensive data review, more than eight drill-ready targets have been identified and prioritized for drilling in 2026. Six drill rigs are currently operating at Kabewest, the most advanced target, located approximately 2.3 kilometers from the proposed Diamba Sud plant site. An initial Inferred Mineral Resource estimate for Kabewest is expected to be included in the Company’s annual Mineral Reserve and Mineral Resource update, planned for publication in the first quarter of 2027. Drilling will progressively advance to additional prospects, including Fatima, Djenebou, Latifa, Kach, Wari, and Kabetea, throughout the remainder of 2026 and into the first half of 2027.

In addition, work is continuing to further refine targets for the 2027 field season across the more than 60-kilometer strike length of the newly acquired permits. Three highly prospective mineralized trends have been identified based on geophysical and geochemical data and supported by field mapping. Limited historical drilling was generally shallow and widely spaced, with several multi-kilometer gaps along these anomalous gold trends providing compelling targets for Fortuna’s 2026 and 2027 exploration programs.

Geological logging of the initial DD holes at Kabewest has highlighted strong similarities to the nearby Diamba Sud style of mineralization, including extensive hydrothermal brecciation, hematite-silica alteration, and pyrite development (refer to Figure 4), consistent with mineralization previously modelled by Barrick (refer to Figure 5). Assay results are pending.

Integration of the former Barrick technical staff into Fortuna’s Senegal exploration team has been successfully completed, providing valuable continuity, supporting the rapid advancement of field and drilling activities, and enhancing the Company’s understanding of the region’s broader geological architecture.

Figure 4: Examples of hydrothermal breccia from Kabewest highlighting similarities to the Area D mineralization style at Diamba Sud

Figure 5: Cross section 150SW through Kabewest highlighting historic mineralized interval 

^{Note: For historic drilling details, refer to Fortuna news release dated August 10, 2026 “Fortuna acquires highly prospective Bambadji Project in Senegal from Barrick and IAMGOLD”}

Refer to Appendix 1 for full details of the drill holes 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 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 ppm 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 in Argentina, Côte d’Ivoire, and Peru, and the feasibility-stage Diamba Sud Gold Project in Senegal. Our exploration portfolio spans our operating jurisdictions as well as Guinea and Guyana. 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
CEO and Director
Fortuna Mining Corp.

Investor Relations:

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 include, without limitation, statements about the Company’s plans for its mines and mineral properties; statements regarding the development of the Diamba Sud project, including the proposed plant site, that an updated Mineral Resource and Mineral Reserve estimate is intended to be prepared for year-end, and drilling plans for 2027; statements that an initial Inferred Mineral Resource estimate for Kabewest is expected in the first quarter of 2027; the Company’s drilling plans at the Bambadji project; the Company’s business strategy, plans and outlook; the merit of the Company’s mines and mineral properties; the future financial or operating performance of the Company; the Company’s ability to comply with contractual and permitting or other regulatory requirements; approvals and other matters. Often, but not always, these Forward-looking Statements can be identified by the use of words such as “estimated,” “potential,” “open,” “future,” “assumed,” “projected,” “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 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, Israel- – Hamas, and Iran – Israel and United States conflicts, and the impacts such conflicts 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 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. 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 head 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; 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 including for the construction of a mine at the Diamba Sud Project and the underground mining method at the Séguéla Mine; 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 Mineral Resources and Mineral Reserves

Technical disclosure regarding the Company’s properties included herein has 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. Canadian standards, including NI 43-101, differ from the requirements of the Securities and Exchange Commission, and information included herein may not be comparable to similar information disclosed by U.S. companies.

Appendix 1: Diamba Sud Gold Project, Senegal: Drill program details and assay results

Notes:
1. EOH: End of hole
2. Depths and widths reported to nearest significant decimal place
3. NSI: No significant intercepts
4. ETW: Estimated true width
5. RC: reverse circulation drilling | DD: diamond drilling tail | RCD: reverse circulation drilling with diamond tail

Photos accompanying this announcement are available at