Fortuna Mining Advances Sunbird Gold Discovery, Expanding High-Grade Mineralization at Séguéla Mine in Côte d'Ivoire

Fortuna Mining Corp., a Canadian precious metals producer listed on NYSE (FSM) and TSX (FVI), has announced encouraging results from its ongoing exploration campaign at the Sunbird deposit within the Séguéla Mine complex in Côte d’Ivoire. The latest drilling program, initiated following the company’s January 2026 mineral resource update, has successfully extended ore bodies at considerable depths while identifying a second prominent high-grade mineralized zone, signaling substantial potential for resource expansion.

The exploration initiative, which mobilized five drill rigs dedicated to the Sunbird property, has produced a series of significant intercepts that underscore the project’s growing economic potential. According to Paul Weedon, Senior Vice President of Exploration at Fortuna Mining, the latest results validate earlier geological assessments regarding the deposit’s extension characteristics. “The data demonstrates that premium-grade gold mineralization persists well beyond our initial resource estimates,” Weedon stated, emphasizing that drilling operations would continue throughout 2026 to fully delineate the newly identified zones.

Significant Gold Intercepts Reveal Deeper Mineral Potential

The drilling program has yielded multiple high-grade intercepts spanning various depths. Among the most notable results was drill hole SGDD148, which returned an exceptionally long intersection of 6.1 grams per tonne of gold (g/t Au) across an estimated true width of 18.9 meters starting from 564 meters depth. This intercept is particularly significant as it extends mineralization substantially beyond the current resource envelope. Within this broader zone, the drill core revealed several narrower, ultra-high-grade segments, including 25.4 g/t Au, 27.4 g/t Au, and 16.8 g/t Au across 0.7-meter true-width intervals.

Additional standout results include drill hole SGRD2491, which intersected 5.2 g/t Au over 8.4 meters true width starting at 513 meters depth, with internal high-grade stringers grading 12.0 g/t Au and 14.3 g/t Au. Similarly, SGDD149 returned 13.0 g/t Au across 4.2 meters true width at 686 meters depth, including a 1.4-meter true-width interval assaying 31.1 g/t Au. These discoveries approximately 400 meters beyond the existing mineral reserve boundary demonstrate the deposit’s downward extension potential.

Multi-Rig Exploration Program Validates Resource Growth Trajectory

The current phase of exploration drilling encompasses 22 completed drill holes totaling 9,816 meters, all completed after the June 30, 2025 data cutoff employed in the company’s most recent resource calculation. The drilling strategy targeted both the extension of the lower mineralized shoot and the linkage zone between the upper and lower ore bodies. One notable infill result, drill hole SGRD2487, produced 4.1 g/t Au across an estimated true width of 11.9 meters beginning at 499 meters depth, demonstrating the geometric continuity between the two main mineralized structures.

The extensive drill database reveals that high-grade zones remain open both at depth and along strike, suggesting the potential for continued resource upgrades as exploration advances. The multiplicity of drill stations and the geometric consistency of results across various intercepts indicate a robust, continuously evolving mineralization system rather than isolated pockets of enriched ore.

Quality Assurance and Data Integrity Framework

To ensure the reliability of reported assay results, Fortuna Mining implemented rigorous quality control procedures throughout the drilling and analytical process. Both reverse circulation (RC) drilling and diamond drilling (DD) operations were conducted under direct company supervision. RC samples were collected in 60-liter bags using 5.25-inch face-sampling pneumatic hammers, with pneumatic pressure maintained to exclude groundwater contamination. Core from diamond drill holes was systematically logged, sampled at one-meter intervals or along geological boundaries, and split with a diamond saw, with half retained for archive purposes and half submitted for analysis.

All samples were transported via company vehicle or courier to either ALS Global’s preparation facility in Yamoussoukro or Bureau Veritas’ laboratory in Abidjan. Routine gold determinations employed a 50-gram fire assay charge with atomic absorption finish, while samples returning gold values exceeding 10 ppm were reanalyzed using gravimetric finish methods. Both independent laboratories, ALS and Bureau Veritas, inserted duplicate samples, standards, and blanks throughout the analytical stream, ensuring cross-validation of results.

Paul Weedon, a Qualified Person as defined under Canadian National Instrument 43-101 and a member of the Australian Institute of Geoscientists (Membership #6001), has personally verified the technical data disclosed in this report by reviewing core samples, geological databases, and analytical records.

Strategic Significance and Outlook

The Séguéla Mine represents a cornerstone asset within Fortuna Mining’s global portfolio, which includes operating mines in Argentina, Mexico, and Peru alongside exploration initiatives in Senegal. The company’s commitment to both operational excellence and resource expansion through systematic exploration reflects its long-term development strategy. As drilling continues throughout 2026, additional intercepts are expected to refine the geometry and grade continuity of both the upper and lower shoots, potentially supporting a future resource upgrade and reserve expansion.

The depth and lateral extent of mineralization at Sunbird, combined with the consistent high-grade character of intercepts, positions the deposit as a meaningful contributor to Fortuna Mining’s precious metals production profile and shareholder value creation agenda.