Fortuna’s high-grade Diamba Sud hits in Senegal: project and pit design notes for engineers
Reviewed by Joe Ashwell

First reported on MINING.com
30 Second Briefing
Fortuna Mining has reported high-grade intercepts at the Southern Arc zone of its Diamba Sud gold project in Senegal, including 40.8 metres at 3.9 g/t from 228 metres (hole DSR1149) and 12 metres at 6.8 g/t from 96 metres (hole DSDD699), extending mineralisation at depth and along strike. Since February, 196 RC and diamond holes totalling 36,592 metres have been drilled, with Southern Arc results to be folded into year-end resource and reserve updates and further step-outs planned for 2027. A C$11 million 2026 drilling campaign with six rigs is also testing the Kabewest target 2.3 km from the proposed Diamba Sud plant, ahead of a planned 2028 production start and a final investment decision this quarter.
Technical Brief
- Diamba Sud’s April 2026 probable reserve stands at 20.5 Mt at 1.75 g/t Au (1.15 Moz).
- Fortuna targets gold production start in Q2 2028, contingent on a near-term final investment decision.
- Feasibility work indicates an after-tax NPV5 of US$1 billion at US$3,500/oz gold.
- The same study reports a 60% after-tax IRR and a one-year post-commissioning payback period.
- Diamba Sud is planned to contribute to lifting Fortuna’s group output to 500 koz Au-eq by 2028.
- Six rigs are active in a C$11 million 2026 drilling campaign, including at Kabewest near Diamba Sud.
- Kabewest lies 2.3 km from the proposed Diamba Sud plant, favouring shared processing and infrastructure.
- Geological logging at Kabewest notes breccia-hosted mineralisation and alteration styles analogous to Diamba Sud.
Our Take
With Diamba Sud already contributing about 18% of Fortuna Mining’s net asset value and an NPV of roughly US$1 billion, the new high‑grade Southern Arc intercepts suggest upside that could rebalance capital allocation away from mature Latin American assets highlighted in Fortuna’s 2026 spending plans.
The proximity of Kabewest (2.3 km from the planned Diamba Sud plant site) combined with Fortuna’s recent US$200 million acquisition of the Bambadji properties from Barrick and IAMGOLD points to a hub‑and‑spoke development model in eastern Senegal, where multiple satellite pits could be trucked to a single central plant.
In our database of 1259 Mining stories, West Africa gold pieces featuring Senegal and Côte d’Ivoire – including Fortuna’s Séguéla expansion – increasingly emphasise rapid permitting and build times, which likely underpins the aggressive drilling pace at Diamba Sud (196 holes and six rigs) ahead of the targeted 2028 horizon.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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