Fortuna drills 22.7 g/t gold over 21.6 meters at Southern Arc, Diamba Sud Gold Project, Senegal
NEWS RELEASE
Fortuna drills 22.7 g/t gold over 21.6 meters at Southern Arc, Diamba Sud
Gold Project, Senegal
Vancouver, August 13, 2025: Fortuna Mining Corp. (NYSE: FSM | TSX: FVI) is pleased to
report additional exploration drilling results from the Southern Arc deposit at the Diamba Sud Gold
Project located in Senegal , following the July 7, 2025 resource update (see Fortuna news release
dated August 5, 2025).
Paul Weedon, Senior Vice President of Exploration at Fortuna, commented “Exploration drilling at the
Southern Arc deposit has continued beyond the data cut -off date for its maiden resource estimate,
returning several high -grade intercepts. Highlights include drillhole DSDD488, which intersected
22.7 g/t Au over an estimated true width of 21.6 meters from a downhole depth of 53 meters.”
Mr. Weedon continued, “These results further demonstrate the potential for resource growth at Diamba
Sud. The deposit remains open to the south, east, and at depth, with current drilling only extending to
approximately 150 meters. Drilling is scheduled to resume in September, following the end of the rainy
season, with further results expected by year-end.”
Southern Arc Deposit Drilling highlights include
DSDD418: 6.3 g/t Au
23.3 g/t Au
14.2 g/t Au
17.9 g/t Au
over an estimated true width of 18.2 meters from 31 meters, including
over an estimated true width of 0.8 meters from 40 meters, and
over an estimated true width of 0.8 meters from 42 meters, and
over an estimated true width of 1.6 meters from 45 meters
DSDD440: 6.3 g/t Au
10.3 g/t Au
10.6 g/t Au
10.4 g/t Au
19.4 g/t Au
3.7 g/t Au
13.6 g/t Au
over an estimated true width of 16.8 meters from 30 meters, including
over an estimated true width of 1.1 meters from 30.7 meters, and
over an estimated true width of 2.4 meters from 34 meters, and
over an estimated true width of 0.8 meters from 41 meters, and
over an estimated true width of 0.8 meters from 43 meters
over an estimated true width of 11.0 meters from 54.2 meters, including
over an estimated true width of 0.8 meters from 54.1 meters
DSDD444: 4.5 g/t Au
14.0 g/t Au
33.5 g/t Au
13.0 g/t Au
13.1 g/t Au
over an estimated true width of 32.0 meters from 30 meters, including
over an estimated true width of 1.6 meters from 40 meters, and
over an estimated true width of 0.8 meters from 45 meters, and
over an estimated true width of 1.6 meters from 48 meters, and
over an estimated true width of 0.8 meters from 58 meters
DSDD4621: 9.7 g/t Au
21.9 g/t Au
18.4 g/t Au
13.4 g/t Au
14.2 g/t Au
16.8 g/t Au
over an estimated true width of 20.8 meters from 117 meters, including
over an estimated true width of 2.2 meters from 120.3 meters, and
over an estimated true width of 2.4 meters from 124 meters, and
over an estimated true width of 0.8 meters from 129 meters, and
over an estimated true width of 0.8 meters from 133 meters, and
over an estimated true width of 1.6 meters from 140 meters
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DSDD4841: 4.2 g/t Au
13.3 g/t Au
14.6 g/t Au
18.4 g/t Au
13.2 g/t Au
over an estimated true width of 31.2 meters from 5 meters, including
over an estimated true width of 0.8 meters from 7 meters, and
over an estimated true width of 1.6 meters from 15 meters, and
over an estimated true width of 0.8 meters from 19 meters, and
over an estimated true width of 1.6 meters from 32 meters
DSDD4871: 7.8 g/t Au
33.6 g/t Au
20.5 g/t Au
11.1 g/t Au
13.2 g/t Au
over an estimated true width of 22.4 meters from 31 meters, including
over an estimated true width of 1.6 meters from 44 meters, and
over an estimated true width of 0.8 meters from 51 meters, and
over an estimated true width of 1.6 meters from 53 meters, and
over an estimated true width of 0.8 meters from 56 meters
DSDD4881: 22.7 g/t Au
258.8 g/t Au
over an estimated true width of 21.6 meters from 53 meters, including
over an estimated true width of 1.6 meters from 66 meters
DSR933: 6.7 g/t Au
21.6 g/t Au
36.1 g/t Au
over an estimated true width of 4.0 meters from surface, and
over an estimated true width of 6.4 meters from 65 meters, including
over an estimated true width of 2.4 meters from 67 meters
DSR9761: 4.9 g/t Au
19.4 g/t Au
over an estimated true width of 23.2 meters from 51 meters, including
over an estimated true width of 3.2 meters from 63 meters
Note:
1. Not included in the resource estimate; see Fortuna news release dated August 5, 2025
Exploration drilling at Southern Arc has been a key focus for the Diamba Sud project with a further 152
reverse circulation (“ RC”) and diamond core drill holes for a total of 21,234 meters completed since
the previous exploration update ( see Fortuna news release dated May 27, 2025 ). The program at
Southern Arc has been paused for the rainy season with drilling expected to resume in mid-September.
Of the 152 drill holes, 5 3 were completed after the data cutoff for Southern Arc’s maiden Inferred
Mineral Resource estimate of 3.9 Mt averaging 1.57 g/t Au and containing 194 koz of gold (see Fortuna
news release dated August 5, 2025) and will, along with additional drilling planned for the fourth quarter
of 2025, be included in an updated resource estimate planned for the first quarter of 2026 . Details of
the completed holes are presented in Appendix 1.
Mineralization at Southern Arc occurs as variable fine stockwork vein arrays to diffuse pyrite -silica
flooding and has a strong correlation with certain of the tectonic breccias and carbonate units (refer to
Figures 1 to 3) and commonly demonstrates an extensive hematite alteration association, similar to
the other prospects and deposits at Diamba Sud.
Mineralization remains open at depth and along strike to the south and east.
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Figure 1: Southern Arc Section 600NE
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Figure 2: Southern Arc Section 650NE
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Figure 3: Southern Arc Section 700NE
Refer to Appendix 1 for full details of the drill holes and assay results for this drill program
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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 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 drilli ng 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 fac ility 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.
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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 Director
Fortuna Mining Corp.
Investor Relations:
Carlos Baca | [email protected] | fortunamining.com | X | LinkedIn | YouTube
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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 Mineral Resource estimates at Diamba Sud;
the Company’s proposed exploration plans at Diamba Sud; statements pertaining to the potential for resource
growth 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 a nd 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”, “a nticipated”,
“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 o r 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 C ompetition
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