Fortuna reports updated Mineral Reserves and Mineral Resources

2025-03-12

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VANCOUVER, British Columbia, March 12, 2025 (GLOBE NEWSWIRE) -- Fortuna Mining Corp. (NYSE: FSM | TSX: FVI) provides its updated Mineral Reserve and Mineral Resource estimates as of December 31, 2024, for its four operating mines in West Africa and the Americas as well as the Arizaro Project located at the Lindero Mine in Salta, Argentina, the Diamba Sud Gold Project in Senegal and the San Jose Mine in Mexico. All references to dollar amounts in this news release are expressed in US dollars. Gold equivalent ounces referred to in this news release are calculated using metal prices of $1,880/oz for Au, $23/oz for Ag, $2,000/t for Pb, and $2,700/t for Zn.

Highlights of Mineral Reserve and Mineral Resource Update

Consolidated Inferred Mineral Resources are reported containing 2.2 M gold equivalent ounces (GEOs) representing a year-over-year increase of 29 percent. Consolidated Measured and Indicated Resources exclusive of Mineral Reserves are reported containing 1.5 M GEOs representing a year-over-year increase of 36 percent. Primary drivers for the net increase in Mineral Resources are the result of infill drilling and the discovery of new Inferred Resources representing 741,000 GEOs, offset by the upgrading of resources to reserves. Consolidated Proven and Probable Mineral Reserves are reported containing 2.7 M gold GEOs representing a year-over-year decrease of 11 percent. Primary driver for changes in Mineral Reserves is production related depletion in 2024 of 526,000 GEOs offset by the upgrading of resources to reserves representing 204,000 GEOs.

2024 Mineral Reserves and Mineral Resources

| Mineral Reserves - Proven and Probable | Contained Metal | | | | | | | | | Property | Classification | Tonnes (000) | Ag (g/t) | Au (g/t) | Pb (%) | Zn (%) | GEOs (000) | | | Gold Mines | Séguéla, Côte d’Ivoire | Proven | 914 | N/A | 1.52 | N/A | N/A | 45 | | Probable | 8,837 | N/A | 2.66 | N/A | N/A | 1,016 | | | | Proven + Probable | 9,751 | N/A | 3.38 | N/A | N/A | 1,061 | | | | Yaramoko, Burkina Faso | Proven | 30 | N/A | 4.23 | N/A | N/A | 4 | | | Probable | 597 | N/A | 7.65 | N/A | N/A | 147 | | | | Proven + Probable | 627 | N/A | 7.49 | N/A | N/A | 151 | | | | Lindero, Argentina | Proven | 23,276 | N/A | 0.56 | N/A | N/A | 420 | | | Probable | 45,897 | N/A | 0.53 | N/A | N/A | 786 | | | | Proven + Probable | 69,174 | N/A | 0.54 | N/A | N/A | 1,206 | | | | Total | Proven + Probable | 79,552 | N/A | 0.95 | N/A | N/A | 2,417 | | | Silver Mine | Caylloma, Peru | Proven | 34 | 201 | 0.67 | 2.51 | 2.98 | 6 | | Probable | 2,407 | 81 | 0.14 | 2.73 | 4.16 | 301 | | | | Proven + Probable | 2,441 | 82 | 0.15 | 2.73 | 4.15 | 307 | | | | Total | Proven + Probable | 2,441 | 82 | 0.15 | 2.73 | 4.15 | 307 | | | Total | Proven + Probable | 2,724 | | | | | | |

| Mineral Resources – Measured and Indicated | Contained Metal | | | | | | | | | Property | Classification | Tonnes (000) | Ag (g/t) | Au (g/t) | Pb (%) | Zn (%) | GEOs (000) | | | Gold Mines | Séguéla, Côte d’Ivoire | Measured | 0 | N/A | - | N/A | N/A | 0 | | Indicated | 3,438 | N/A | 3.59 | N/A | N/A | 396 | | | | Measured + Indicated | 3,438 | N/A | 3.59 | N/A | N/A | 396 | | | | Yaramoko, Burkina Faso | Measured | 17 | N/A | 12.48 | N/A | N/A | 7 | | | Indicated | 245 | N/A | 4.47 | N/A | N/A | 35 | | | | Measured + Indicated | 261 | N/A | 4.98 | N/A | N/A | 42 | | | | Lindero, Argentina | Measured | 1,735 | N/A | 0.52 | N/A | N/A | 29 | | | Indicated | 28,989 | N/A | 0.42 | N/A | N/A | 392 | | | | Measured + Indicated | 30,724 | N/A | 0.43 | N/A | N/A | 421 | | | | Total | Measured + Indicated | 34,423 | N/A | 0.78 | N/A | N/A | 859 | | | Silver Mines | Caylloma, Peru | Measured | 234 | 95 | 0.27 | 1.47 | 2.52 | 23 | | Indicated | 766 | 84 | 0.19 | 1.27 | 2.34 | 66 | | | | Measured + Indicated | 1,000 | 86 | 0.21 | 1.31 | 2.38 | 89 | | | | San Jose, Mexico | Measured | 60 | 160 | 1.39 | N/A | N/A | 6 | | | Indicated | 1,131 | 160 | 1.14 | N/A | N/A | 113 | | | | Measured + Indicated | 1,191 | 160 | 1.15 | N/A | N/A | 119 | | | | Total | Measured + Indicated | 2,191 | 126 | 0.72 | N/A | N/A | 208 | | | Gold Project | Diamba Sud, Senegal | Measured | 0 | N/A | - | N/A | N/A | 0 | | Indicated | 7,751 | N/A | 1.90 | N/A | N/A | 473 | | | | Measured + Indicated | 7,751 | N/A | 1.90 | N/A | N/A | 473 | | | | Total | Measured + Indicated | 7,751 | N/A | 1.90 | N/A | N/A | 473 | | | Total | Measured + Indicated | 1,540 | | | | | | |

| Mineral Resources – Inferred | Contained Metal | | | | | | | | | Property | Classification | Tonnes (000) | Ag (g/t) | Au (g/t) | Pb (%) | Zn (%) | GEOs (000) | | | Gold Mines | Séguéla, Côte d’Ivoire | Inferred | 6,765 | N/A | 2.84 | N/A | N/A | 618 | | Yaramoko, Burkina Faso | Inferred | 141 | N/A | 5.83 | N/A | N/A | 26 | | | Lindero, Argentina | Inferred | 30,364 | N/A | 0.46 | N/A | N/A | 449 | | | Total | Inferred | 37,270 | N/A | 0.91 | N/A | N/A | 1,094 | | | Silver Mines | Caylloma, Peru | Inferred | 3,794 | 106 | 0.55 | 2.13 | 3.10 | 480 | | San Jose, Mexico | Inferred | 1,053 | 164 | 1.23 | N/A | N/A | 110 | | | Total | Inferred | 4,847 | 119 | 0.70 | N/A | N/A | 590 | | | Gold Projects | Arizaro, Argentina | Inferred | 32,400 | N/A | 0.37 | N/A | N/A | 389 | | Diamba Sud, Senegal | Inferred | 3,133 | N/A | 1.47 | N/A | N/A | 148 | | | Total | Inferred | 35,533 | N/A | 0.47 | N/A | N/A | 537 | | | Total | Inferred | 2,220 | | | | | | | | | | | | | | | | |

Notes:

1. Mineral Reserves and Mineral Resources are as defined by the 2014 CIM Definition Standards for Mineral Resources and Mineral Reserves. 2. Mineral Resources are exclusive of Mineral Reserves. 3. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. 4. Factors that could materially affect the reported Mineral Resources or Mineral Reserves include changes in metal price and exchange rate assumptions; changes in local interpretations of mineralization; changes to assumed metallurgical recoveries, mining dilution and recovery; and assumptions as to the continued ability to access the site, extend and/or retain mineral and surface rights titles and permits, maintain environmental and other regulatory permits, and maintain the social license to operate. 5. Mineral Resources and Mineral Reserves are reported as of December 31, 2024. 6. Mineral Resources for the San Jose Mine are reported within underground mineable shapes using an estimated NSR cut-off grade of 153 g/t Ag Eq based on assumed metal prices of US$27.50/oz Ag and US$2,300/oz Au; estimated metallurgical recovery rates of 89% for Ag and Au and average mining costs of US$56.44/t; processing costs of US$22.79/t; and other costs including distribution, administrative and general service costs of US$25.83/t based on actual operating costs in 2024. 7. Mineral Reserves for the Caylloma Mine are reported above NSR breakeven cut-off values based on underground mining methods including; mechanized (breasting) at $91.85/t; mechanized (uppers) at $73.33/t; semi-mechanized at $93.05/t; sub-level stoping at $82.77/t; and a conventional method at $153.40/t; using assumed metal prices of $23/oz Ag, $1,880/oz Au, $2,000/t Pb and $2,700/t Zn; metallurgical recovery rates of 82 or 86 % for Ag, 22 or 58 % for Au, 90 or 88 % for Pb and 89 or 87 % for Zn. Mining, processing and administrative costs used to determine NSR cut-off values were estimated based on actual operating costs incurred from July 2023 through June 2024. Mining recovery is estimated to average 95 % with average total mining dilution of 17 % depending on the mining method. Mineral Resources are reported at an NSR cut-off grade of $75/t for veins classified as wide (Animas, Animas NE, Nancy, San Cristobal) and $130/t for veins classified as narrow (all other veins) based on the same parameters used for Mineral Reserves, and a 15 % upside in metal prices. 8. Mineral Reserves for the Lindero Mine are reported based on open pit mining within a designed pit shell based on variable gold cut-off grades and gold recoveries by metallurgical type: Met type 1 cut-off 0.26 g/t Au, recovery 75.4 %; Met type 2 cut-off 0.25 g/t Au, recovery 78.2 %; Met type 3 cut-off 0.25 g/t Au, recovery 78.5 %; and Met type 4 cut-off 0.29 g/t Au, recovery 68.5 %. Mining recovery is estimated to average 100 % and mining dilution 0 % having been accounted for during block regularization to 10m x 10m x 8m size. The cut-off grades and pit designs are considered appropriate for long term gold prices of $1,880/oz, estimated base mining costs of $1.39 per tonne of material, total processing and G&A costs of $10.28 per tonne of ore, and refinery costs net of pay factor of $13.44 per ounce gold. Reported Proven Reserves include 9.9 Mt averaging 0.41 g/t Au of stockpiled material. Mineral Resources are reported within a conceptual pit shell above a 0.23 g/t Au cut-off grade based on the same parameters used for Mineral Reserves and a 15 % upside in metal prices. Mineral Resources for Arizaro are reported within a conceptual pit shell above a 0.23 g/t Au cut-off grade using the same gold price and costs as Lindero and an additional $0.52 per tonne of ore to account for haulage costs between the deposit and plant. A slope angle of 47° was used for defining the pit. 9. Mineral Reserves for Yaramoko are reported at a cut-off grade of 0.56 g/t Au for the 109 Zone open pit, 4.26 g/t Au for 55 Zone underground, 3.10 g/t Au for Bagassi South QVP and QV underground based on an assumed gold price of $2,040/oz, metallurgical recovery rates of 96.9 %, underground mining costs of $177/t, surface mining costs of $4.07/t, processing cost of $32/t and G&A costs of $37/t. Underground average mining recovery is estimated at 90 % for Bagassi South QV and QVP, 94 % for 55 Zone SLS stopes, and 84 % for sill drifts. A mining dilution of 0.2m and 0.2m dilution skin has been applied for shrinkage mining, 0.3m and 0.4m for SLS stopes and 0.3m and 0.65m for sill drifts, respectively. Surface mining recovery is estimated to average 100 % and mining dilution 0 %, having been accounted for during block regularization to 5m x 5m x 5m size within an optimized pit shell, and only Proven and Probable categories reported within the final pit designs. Yaramoko Mineral Resources are reported at a gold grade cut-off grade of 1.4 g/t Au for the 55 Zone open pit, 0.6 g/t Au for the 109 Zone open pit, and 2.7 g/t Au and 2.5 g/t Au for underground 55 Zone and Bagassi South respectively, based on an assumed gold price of $2,160/oz and the same costs, metallurgical recovery and constrained within an optimized pit shell. The Yaramoko Mine is subject to a 10 % carried interest held by the government of Burkina Faso. 10. Mineral Reserves for the Séguéla Mine are reported on a 100 % ownership basis at an incremental gold grade cut-off of 0.75 g/t Au for Antenna, 0.80 g/t Au for Agouti, 0.78 g/t Au for Boulder, 0.78 g/t Au for Koula, 0.84 g/t Au for Ancien, 0,86 g/t for Badior and 0.81 g/t Au for Sunbird deposits based on a gold price of $1,880/ounce, metallurgical recovery rates of 94 %, surface mining costs ranging between $3.76/t to $4.28/t, processing cost of $17.87/t and G&A cost of $14.45/t, and only Proven and Probable categories reported within the final pit designs. The Mineral Reserves pit design for Antenna, Ancien, Koula and Badior were based on inter-ramp angles of 30.6° to 38.3° for oxide material, 42.9° for transitional material, and 59.6° for fresh material. Agouti and Boulder pits were designed with inter-ramp angles of 36.8° for oxide, 44.2° for transitional, and 60.0° for fresh material. The Sunbird pit was designed with inter-ramp angles of 40.7° for oxide, 36.5° to 59.6° for transitional, and 52.2° to 61.2° for fresh material. The Mineral Reserves are reported with modifying factors of mining dilution and mining recovery represented by regularizing the block models to an appropriate selective mining unit (SMU) block size. Mineral Resources for Séguéla are reported at a cut-off grade of 0.65 g/t Au for Antenna and Kestrel, 0.70 g/t Au for Agouti, Boulder, Koula, Sunbird and Kingfisher, and 0.75 g/t Au for Ancien, Badior and Gabbro North based on an assumed gold price of $2,160/oz and constrained within preliminary pit shells. Underground Mineral Resources are reported inside MSO shapes at a gold cut-off grade of 2.4 g/t Au based on sublevel stoping mining method. The Séguéla Mine is subject to a 10 % carried interest held by the State of Cote d'Ivoire. 11. Mineral Resources for Diamba Sud are reported on a 100 % ownership basis at SMU block sizes and at an incremental gold cutoff grade for oxide/transitional material of 0.28 g/t Au for Area A, 0.29 g/t Au for Area D and Karakara, 0.31 g/t Au for Kassassoko and 0.32 g/t Au for Western Splay, with fresh material reported based on a cutoff of 0.36 g/t Au for Karakara, 0.37 g/t Au for Area A, 0.40 g/t Au for Area D and Kassassoko, and 0.41 g/t Au for Western Splay in accordance with the varying ore differential parameters and varying metallurgical recoveries for oxide, transitional and fresh rock associated within shell optimizations, assuming a long-term gold metal price of $2,160/oz and metallurgical recoveries for the following deposits: Area A oxide and transitional rock 89.8 %, Area A fresh rock 93.1 %; Area D oxide and transitional rock 89.8 %, Area D fresh rock 85.4 %; Karakara oxide and transitional rock 88.6 %, Karakara fresh rock 94.9 %; Western Splay oxide, transitional and fresh rock 88 %; and, Kassassoko oxide, transitional and fresh rock 93 %. 12. Eric Chapman, P. Geo. (EGBC #36328), is the Qualified Person responsible for Mineral Resources; Raul Espinoza (FAUSIMM (CP) #309581) is the Qualified Person responsible for Mineral Reserves; both being employees of Fortuna Mining Corp. 13. Gold equivalent calculated using metal prices of $1,880/oz for Au, $23/oz for Ag, $2,000/t for Pb, and $2,700/t for Zn. 14. N/A = Not applicable. 15. Totals may not add due to rounding.

Séguéla Mine, Côte d’Ivoire

Year-over-year, the operation successfully replenished what was mined, with Mineral Reserve gold ounces remaining relatively unchanged, while gold grade increased by 11 percent to 3.38 g/t Au. Inferred Resources increased by 121 percent over the same period, primarily due to the addition of the Kingfisher deposit.

As of December 31, 2024, the Séguéla Mine has Proven and Probable Mineral Reserves of 9.8 Mt containing 1.1 Moz Au, in addition to Indicated Resources of 3.4 Mt containing 396,000 oz Au and Inferred Resources of 6.8 Mt containing 618,000 oz Au.

The Company disclosed an updated estimate of Mineral Reserves and Resources as of October 31, 2024 ( refer to Fortuna news release dated December 10, 2024 ). Since the publication of this update, Mineral Reserves increased by 0.4 Mt and 45,000 gold ounces. Changes were due to the upgrading of the Badior deposit Inferred Resources to Probable Reserves offset by mining related depletion in the last two months of 2024.

Measured and Indicated Resource gold ounces, exclusive of Mineral Reserves, remain unchanged.

Inferred Resources decreased 0.5 Mt or 59,000 oz Au in relation to the upgrading of the Badior deposit to Mineral Reserves.

The Brownfields exploration program budget for 2025 at Séguéla is $13.5 million, which includes 73,000 meters of exploration drilling, supporting resource upgrade drilling primarily at the Sunbird underground project, and infill and expansion of the Kingfisher deposit, along with continued target generation ( refer to Fortuna news release dated January 21, 2025 ).

Yaramoko Mine, Burkina Faso

In 2024, the operation continued replenishing Mineral Reserves depleted through mining, with the addition of 0.2 Mt containing 64,000 oz Au via underground developments and drilling of the Zone 55 and Bagassi South QV Prime veins.

As of December 31, 2024, the Yaramoko Mine has Proven and Probable Mineral Reserves of 0.6 Mt containing 151,000 oz Au, in addition to Measured and Indicated Resources, exclusive of Mineral Reserves, of 0.3 Mt containing 42,000 oz Au, and Inferred Resources of 0.1 Mt containing 26,000 oz Au.

Year-over-year, Mineral Reserve tonnes decreased 27 percent, while gold grades decreased 5 percent to 7.49 g/t Au. The changes are due to mining related depletion in 2024 of 0.5 Mt of material containing 120,000 oz Au counteracted by the successful replenishment program described above.

Measured and Indicated Resource gold ounces, exclusive of Mineral Reserves, decreased by 2,000 ounces and Inferred Resources increased by 10,000 ounces as a result of depletion through the removal of isolated non-economic mineralization, and the discovery of extensions to mineralization in the 55 Zone and Bagassi South underground mines.

Lindero Mine and Arizaro Gold Project, Argentina

In spite of year-over-year mining depletion, there were minimal changes to Mineral Reserves at Lindero, with tonnes and gold grade decreasing by 3 percent and 4 percent, respectively.

As of December 31, 2024, the Lindero Mine has Proven and Probable Mineral Reserves of 69.2 Mt containing 1.2 Moz Au, in addition to Measured and Indicated Resources, exclusive of Mineral Reserves, of 30.7 Mt containing 421,000 oz Au, and Inferred Resources of 30.4 Mt containing 449,000 oz Au.

Mineral Reserve depletion of ore delivered to the heap leach pad in 2024 comprising 6.4 Mt containing 121,000 oz Au, was largely offset by a decrease in the reporting cut-off grade due to higher gold prices.

Measured and Indicated Resource gold ounces, exclusive of Mineral Reserves, remained relatively unchanged year-over-year.

Inferred Resource tonnes increased by 5.1 Mt or 20 percent, to 30.4 Mt year-over-year, with the gold grade remaining relatively unchanged at 0.46 g/t. The increase in Inferred Resources is due to reporting at a lower cut-off grade and updated pit optimization related to the application of a higher gold price.

As of December 31, 2024, the Arizaro Gold Project has Inferred Mineral Resources of 32.4 Mt averaging 0.37 g/t Au containing 389,000 oz Au, an increase of 34 percent in tonnes and 26 percent in gold ounces compared to last year as a result of the application of a higher gold price and subsequent adjustments in the pit shell.

The Brownfields exploration budget for Lindero is $3.4 million, which includes 5,000 meters of exploration drilling at Arizaro, following up on recent reinterpretations driven by additional geochemical sampling, and alteration mapping completed in 2024 ( refer to Fortuna news release dated January 21, 2025 ).

Caylloma Mine, Peru

Year-over-year, Mineral Reserve tonnes increased by 7 percent, while silver, lead and zinc grades remained relatively unchanged as the operation successfully replaced and added to the reserves that were mined through the year.

As of December 31, 2024, the Caylloma Mine has Proven and Probable Mineral Reserves of 2.4 Mt containing 6.5 Moz Ag, 12,000 oz Au, 67,000 tonnes Pb, and 101,000 tonnes Zn, or 307,000 GEOs, in addition to Inferred Resources of 3.8 Mt containing 12.9 Moz Ag, 67,000 oz Au, 81,000 tonnes Pb, and 118,000 tonnes Zn or 408,000 GEOs.

The increase in Mineral Reserve tonnes is due to the conversion of 557,000 tonnes, or 79,000 GEOs, of Inferred Resources to Mineral Reserves, offset by mining related depletion of 489,000 tonnes or 68,000 GEOs; a decrease of 124,000 tonnes, or 12,000 GEOs, as a result of changes in commercial terms and metal price; and a decrease of 112,000 tonnes, or 9,000 GEOs, due to adjustments in the estimation parameters and geologic interpretation.

Measured and Indicated Resource tonnes, exclusive of Mineral Reserves, decreased by 44 percent year-over-year to 1.0 Mt with silver, lead and zinc grades decreasing by 1, 21, and 13 percent, respectively, due to the removal of crown pillar material and isolated narrow mineralized structures from the inventory.

Inferred Resource tonnes decreased by 16 percent year-over-year. Silver grades increased 7 percent, whereas lead and zinc grades decreased by 12 and 16 percent, respectively. The decrease in Inferred Mineral Resources is a result of an increase in cut-off values used for reporting Mineral Resources from $130/t to $135/t, resulting in a decrease of 55,000 tonnes, or 4,000 GEOs, and adjustments in the geologic interpretation, changes in commercial terms, and sterilization of material associated with isolated or narrow mineralization resulting in a decrease of 274,000 tonnes, or 69,000 GEOs, offset by the discovery of 176,000 tonnes, or 22,000 GEOs, through exploration drilling of the Animas and Animas NE veins.