Deep Drilling Confirms Robust Gold Zones at Sunbird: Fortuna Reports 6.1 g/t Au Intercept Over 18.9 Meters

Fortuna Mining Corp. continues to make compelling discoveries at its Sunbird deposit within the Séguéla Mine in Côte d’Ivoire, with recent underground drilling results showcasing the true depth potential of the mineralized system. The latest round of exploration work, completed through February 2026, has expanded high-grade ore bodies at depth while simultaneously pushing the known mineralization envelope approximately 400 meters beyond previously defined reserves.

The standout result comes from bore hole SGDD148, which returned an impressive 6.1 g/t Au intercept over an estimated true width of 18.9 meters from 564 meters depth. This exceptional drill core interval included multiple higher-grade shoots, notably 25.4 g/t Au over 0.7 meters and 27.4 g/t Au over 0.7 meters, underscoring the vertical continuity of mineralized zones at this prolific deposit.

Expanding Deep-Level Ore Bodies Unlocks Resource Potential

Five active drill rigs are now focused entirely on the Sunbird deposit, systematically testing mineralization in multiple directions. Paul Weedon, Senior Vice President of Exploration at Fortuna Mining, noted that results confirm “high-grade mineralization remains wide open at depth,” a critical observation for resource model extension.

The drilling campaign has delineated ore-grade intercepts across a wide vertical range. SGRD2491 returned a composite result of 5.2 g/t Au over 8.4 meters, alongside a deeper intercept of 8.2 g/t Au over the same 8.4-meter true width. SGRD2477 delivered dual high-grade shoots: 10.9 g/t Au over 2.1 meters and 13.9 g/t Au over 4.9 meters. SGDD149 demonstrated mineralization continuity at extreme depth, with 13.0 g/t Au over 4.2 meters from 686 meters—among the deepest significant intercepts to date.

Beyond the headline results, an additional 22 drill holes totaling 9,816 meters have been completed as part of the underground resource confidence and extension program. Infill drilling between the upper and lower ore shoots has returned encouraging results, with intercepts such as 4.1 g/t Au over an estimated true width of 11.9 meters, suggesting stronger linkage between previously separated mineralized zones.

Strategic Drilling Campaign Validates Underground Geometry

The current drilling program prioritizes two key objectives: extending the lower ore shoot deeper and mapping the structural geometry between the upper and lower shoots. Results indicate that mineralization at Sunbird remains open both at depth and along strike, creating a compelling case for continued exploration through 2026.

The grade-width products from recent intercepts—particularly the combination of respectable tonnage-bearing intervals (8-18 meters) at moderate grades (4-6 g/t Au) with narrow, ultra-high-grade shoots (0.7-2.1 meters at 20-30 g/t Au)—reflect a mineralized system with both bulk-mineable and high-selectivity ore potential. This dual-character deposit may support multiple mining scenarios depending on final resource geometry and economic parameters.

Rigorous Quality Assurance Ensures Data Integrity

All drilling work adheres to strict industry protocols. Reverse circulation (RC) drilling employed a 5.25-inch pneumatic hammer with samples collected into 60-liter plastic bags, while diamond drilling (DD) followed standard HQ-to-NQ diameter reduction protocols. Samples underwent riffle splitting (RC) or diamond-saw cutting (DD), with one-meter or geological-boundary sampling intervals.

Assay analysis was conducted by two IACA-accredited laboratories: ALS Global (with sample preparation in Yamoussoukro and analysis in Ouagadougou, Burkina Faso) and Bureau Veritas (with preparation and analysis in Abidjan, Côte d’Ivoire). All samples received a 50-gram fire assay with atomic absorption finish; samples exceeding 10 ppm Au were re-analyzed using gravimetric finish for enhanced precision.

Quality control procedures included systematic insertion of blanks, duplicates, and standard samples into the analytical stream. Both contract laboratories independently inserted their own quality control matrices, creating a multi-layered verification framework. Coarse reject samples from all significant mineralized intervals were retained on-site at Fortuna’s controlled core yard for potential future reference and independent verification.

Fortuna’s Multi-Asset Portfolio Expands Its Resource Base

Fortuna Mining Corp. operates three producing mines and maintains a diversified exploration portfolio across Argentina, Côte d’Ivoire, Mexico, Peru, and Senegal. The Sunbird drilling success at Séguéla adds momentum to the company’s strategic objective of converting exploration discoveries into reserve growth. With sustainability embedded in operational philosophy, Fortuna balances efficient mineral production with environmental stewardship and community engagement across all jurisdictions.

Continued drilling at Sunbird throughout 2026 is expected to further refine the resource model and potentially unlock additional expansion scenarios. The deposit’s open-ended geometry at depth positions it as a core growth engine within Fortuna’s broader portfolio optimization strategy.

Paul Weedon, a member of the Australian Institute of Geoscientists (Membership #6001) and qualified under National Instrument 43-101, has independently verified all assay data, geological interpretation, and underlying technical information contained in this report.