Fortuna drills 8.6 g/t gold over 13.6 meters at Southern Arc prospect, Diamba Sud Project, Senegal
NEWS RELEASE
Fortuna drills 8.6 g/t gold over 13.6 meters at Southern Arc
prospect, Diamba Sud Project, Senegal
Vancouver, May 27, 2025: Fortuna Mining Corp. (NYSE: FSM | TSX: FVI) is pleased to provide an
update on its exploration programs at the Diamba Sud Gold Project in Senegal.
Diamba Sud Gold Project exploration highlights
Paul Weedon, Senior Vice President of Exploration, commented, “Our exploration work at Diamba Sud
continues to yield strong results, particularly from areas with limited historical drilling. Notably, recent
drilling at the Southern Arc prospect has delivered some of our most compelling intercepts to date -
highlighted by 8.6 g/t gold over an estimated true width of 13.6 meters in hole DSR906, and 9.3 g/t
gold over 11.8 meters in hole DSDD404. These results further reinforce the project’s potential for near-
term resource growth.”
Mr. Weedon concluded, “Infill drilling at Area A, Area D, and Karakara has also returned highly
encouraging results, including a standout intercept of 113.7 g/t gold over 6.4 meters estimated true
width in hole DSDD385 at Area D. Meanwhile, regional target generation is progressing steadily, with
systematic auger drilling identifying several promising gold -in-soil anomalies across the broader
property.”
Southern Arc Prospect Drilling highlights include:
DSDD366: 4.8 g/t Au
13.0 g/t Au
24.0 g/t Au
over an estimated true width of 21.6 meters from 11 meters, including
over an estimated true width of 1.6 meters from 17 meters, and
over an estimated true width of 1.6 meters from 26 meters
DSDD367: 4.0 g/t Au
23.9 g/t Au
over an estimated true width of 16.4 meters from 30 meters, including
over an estimated true width of 0.8 meters from 37 meters
DSDD368: 3.2 g/t Au
55.3 g/t Au
over an estimated true width of 20.8 meters from 89 meters, including
over an estimated true width of 0.8 meters from 91 meters
DSDD400: 2.2 g/t Au over an estimated true width of 18.4 meters from 24 meters
DSDD402: 8.6 g/t Au
81.9 g/t Au
over an estimated true width of 8.8 meters from 9 meters, including
over an estimated true width of 0.8 meters from 9 meters
DSDD404: 1.0 g/t Au
1.7 g/t Au
9.3 g/t Au
16.5 g/t Au
33.4 g/t Au
over an estimated true width of 4.5 meters from 41.3 meters, and
over an estimated true width of 9.6 meters from 52 meters, and
over an estimated true width of 11.8 meters from 72 meters, including
over an estimated true width of 0.8 meters from 72 meters, and
over an estimated true width of 2.4 meters from 76 meters
DSR906: 8.6 g/t Au
15.6 g/t Au
17.3 g/t Au
32.6 g/t Au
over an estimated true width of 13.6 meters from 135 meters, including
over an estimated true width of 1.6 meters from 136 meters, and
over an estimated true width of 1.6 meters from 140 meters, and
over an estimated true width of 0.8 meters from 143 meters
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Exploration drilling at the Southern Arc prospect (Figure 1) successfully intersected multiple zones
of mineralization. The program, comprising 38 reverse circulation (RC) and diamond core drill holes
for a total of 4,210 meters, was designed to test and refine the geological model - focusing on
lithological and structural interactions and their controls on mineralization.
Mineralization at Southern Arc is hosted within an extensive hematite-altered tectonic breccia and
occurs as stockworks or discrete veins - consistent with other prospects across the Diamba Sud
Project. Figure 2 illustrates the relationship between the tectonic breccia, mineralization, and the
overlying limestone units. Importantly, mineralization remains open at depth and along strike, with
further drilling ongoing. Results from this program will be incorporated into the next Diamba Sud
resource update.
In addition, several nearby coincident geochemistry and geophysical anomalies further underscore the
exploration potential of Southern Arc, including possible linkages to the adjacent Kassasoko deposit,
located approximately one kilometre to the west.
Figure 1: Diamba Sud Project location plan. Current deposits are highlighted in blue.
Date: 15 May 2025
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Figure 2: Cross Section through Southern Arc prospect showing recent results. Oblique section line,
view is looking north-east.
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Area A, Area D, and Karakara deposit infill drilling highlights include:
Area A
DSDD395:
1.7 g/t Au
12.2 g/t Au
25.5 g/t Au
over an estimated true width of 18.4 meters from 23 meters, and
over an estimated true width of 8.0 meters from 65 meters, including
over an estimated true width of 2.4 meters from 68 meters
Area A
DSDD399:
1.8 g/t Au
3.0 g/t Au
14.6 g/t Au
17.4 g/t Au
10.5 g/t Au
over an estimated true width of 5.6 meters from 135 meters, and
over an estimated true width of 28.8 meters from 153 meters, including
over an estimated true width of 0.8 meters from 158 meters, and
over an estimated true width of 0.8 meters from 165 meters, and
over an estimated true width of 0.8 meters from 167 meters
Area D
DSDD3851:
113.7 g/t Au
254.3 g/t Au
2.6 g/t Au
29.7 g/t Au
over an estimated true width of 6.4 meters from 26 meters, including
over an estimated true width of 2.8 meters from 27 meters
over an estimated true width of 40.0 meters from 39 meters, including
over an estimated true width of 1.2 meters from 47.5 meters
Area D
DSDD389:
3.4 g/t Au
26.6 g/t Au
2.0 g/t Au
over an estimated true width of 20.8 meters from 20 meters, including
over an estimated true width of 1.6 meters from 41 meters, and
over an estimated true width of 13.6 meters from 61 meters
Karakara
DSDD393:
1.5 g/t Au
3.4 g/t Au
17.6 g/t Au
45.2 g/t Au
over an estimated true width of 16.8 meters from 67 meters, and
over an estimated true width of 19.2 meters from 119 meters, including
over an estimated true width of 0.8 meters from 119 meters
over an estimated true width of 0.8 meters from 122 meters
Karakara
DSR869:
4.8 g/t Au
17.5 g/t Au
12.9 g/t Au
over an estimated true width of 10.4 meters from 82 meters, including
over an estimated true width of 1.6 meters from 86 meters, and
over an estimated true width of 0.8 meters from 93 meters
1. DSDD385 includes intervals of lost core due to poor drilling conditions. These intervals have been assigned nil assay value
for interval calculation.
An additional 33 drill holes for a total of 4,550 meters were completed at Area A, Area D, and Karakara
(Figure 1), concluding a final round of infill drilling. This program was designed to achieve several key
objectives: increasing resource confidence in targeted zones and confirming the geological controls
on high-grade mineralization at depth.
Notably, several drill holes intersected mineralization adjacent to - but outside - the currently proposed
open pit boundaries, indicating potential for further resource growth. For example, hole DSDD399 at
Area A returned 3.0 g/t gold over an estimated true width of 28.8 meters from a depth of 153 meters
(Figure 3), while hole DSDD385 at Area D intersected 2.6 g/t gold over 40 meters estimated true width
(Figure 4).
These encouraging results will be incorporated into the forthcoming resource update for the Diamba
Sud Project and underscore the potential for future resource expansion, particularly in Area A.
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Figure 3: Cross section through Area A deposit with results from DSDD399 - view looking east.
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Figure 4: Cross section through Area D deposit with results from DSDD385 - view looking east
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Moungoundi and Moungoundi North prospects
Moungoundi
DSDD347:
1.7 g/t Au
2.1 g/t Au
over an estimated true width of 5.6 meters from 52 meters, and
over an estimated true width of 8.0 meters from 75.1 meters
Moungoundi
DSDD348:
4.0 g/t Au
2.0 g/t Au
over an estimated true width of 3.2 meters from 74 meters, and
over an estimated true width of 14.6 meters from 89 meters
Moungoundi
DSR843: 2.1 g/t Au over an estimated true width of 8.8 meters from 20 meters
Moungoundi North
DSR819:
11.3 g/t Au
28.1 g/t Au
23.5 g/t Au
46.5 g/t Au
over an estimated true width of 15.4 meters from 38 meters, including
over an estimated true width of 1.4 meters from 44 meters, and
over an estimated true width of 1.4 meters from 49 meters, and
over an estimated true width of 1.4 meters from 52 meters
Moungoundi North
DSR825:
5.1 g/t Au
32.9 g/t Au
over an estimated true width of 4.9 meters from 33 meters, including
over an estimated true width of 0.7 meters from 37 meters
Exploration drilling at the pre-resource stage Moungoundi prospect and its northern extension,
Moungoundi North - located approximately 300 meters to the northeast - was successfully completed,
with a total of 85 RC and diamond core drill holes drilled for 9,472 meters.
The program significantly improved the understanding of this geologically and structurally complex
area, characterized by intercalated tectonic breccias, carbonate metasediments, and granitic and
dioritic intrusive units. Mineralization is typically associated with various vein arrays, preferentially
hosted within the tectonic breccias.
Results from this program will be incorporated into the next resource update for the Diamba Sud
Project, contributing valuable insight into the broader mineral system.
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Western Splay deposit
DSDD362: 3.2 g/t Au over an estimated true width of 8.1 meters from 39 meters
DSDD390: 1.5 g/t Au over an estimated true width of 26.1 meters from 5 meters
DSR785: 5.1 g/t Au
15.2 g/t Au
over an estimated true width of 13.5 meters from 49 meters, including
over an estimated true width of 2.7 meters from 59 meters
DSR884: 7.2 g/t Au
34.7g/t Au
over an estimated true width of 4.8 meters from 12 meters, including
over an estimated true width of 0.8 meters from 12 meters
A total of 24 RC and diamond core drill holes, totalling 2,531 meters, were completed at the Western
Splay deposit. The drill program was designed to test strike and dip extensions, perform select infill
following the previous drilling campaign (refer to Fortuna news release dated: September 12, 2024),
and the completion of the maiden resource estimate (refer to Fortuna news release dated: March 12,
2025).
Geologically, Western Splay shares similarities with the adjacent Moungoundi prospect and comprises
a series of tectonic breccias (previously classified as conglomerates), granitic and dioritic intrusive
units, and metasediments. Mineralization is primarily associated with vein arrays preferentially hosted
within the tectonic breccia units.
This recent drilling campaign has strengthened confidence in the local geological interpretation and
contributes to refining the broader geological and structural model at the project scale.
Refer to Appendix 1 for full details of the drill holes and assay results for this drill program.