Diamba Sud (100%)
The Diamba Sud project covers 53.2km2 and lies within the highly prospective Senegal Mali Shear Zone orogenic belt. The Project is located 12km southwest of Barrick’s Loulo mine (12.5 million ounces) and only 7km west of Barrick’s Gounkoto mine (5.5 million ounces), both across the border in Mali.
Chesser acquired the Diamba Sud Project in 2017 and since then a large high-grade auger gold geochemical anomaly has been defined. Drilling to date has resulted in two shallow high-grade gold discoveries at Area A and Area D.
Extensive drilling has been undertaken on these discoveries to define the controls and size of these mineralised systems and a robust maiden mineral resource published in November 2021 containing 781koz @ 1.6g/t gold including ⁓500koz @ 3.0g/t gold. Chesser believes there is significant resource growth potential with resources open along strike and at depth.
Resource attributes include:
- High-grade ounces: 493koz @ 3.0g/t gold at a 1.5g/t cut-off or 692koz @ 2.0g/t gold at a 0.8g/t cut-off
- Shallow mineralisation: 95% of the ounces within 135m of the surface and 40% of the ounces occur within the near surface oxide mineralisation
- High confidence Resource: 69% of the ounces falling within the Indicated classification
- Robust Resources: 737koz falling within a US$1,500/oz gold price pit shell and 656koz falling within a US$1,350/oz gold price pit shell
- Significant Resource growth potential: mineralisation open along strike and at depth plus numerous exploration targets on the tenement
Area D oxide mineralisation forms a 20-40 m thick blanket of high-grade mineralisation, with gold mineralisation grading up to 100 g/t gold. Oxide mineralisation is bound to the SE by the NE trending fault that separates Area A and Area D. Oxide mineralisation trends in a NW direction possibly influenced by structures in that direction. Drilling to date has defined a strike length of over 400m in the NE-SW and NW directions.
Mineralisation below the high-grade oxide appears to be associated with two controls:
- The NE-SW trending fault exhibits as high-grade intercepts in brecciated mineralised sediments and has been intersected by a number of diamond drill holes along strike.
- A broad stockwork breccia zone in carbonate dominated lithologies, which act as a brittle definition zone and may also be influenced by the northwest structures.
The deepest drilling is only 150m vertical and additional drilling is required to fully understand the nature and extent of this mineralisation but represents a significant exploration target. The high-grade oxide mineralisation at Area D will supply very high margin, low strip ratio, free dig, ore feed for any future mining operation.
Area A, is a structurally controlled mineralised system with a NE-SW control being dominant. Two parallel mineralised structures have been defined to date. There is also a possible orthogonal NW-SE dilatational structure.
Mineralisation tends to favour the sedimentary units and there is only minimal oxide mineralisation at Area A.
Intense iron-carbonate alteration indicates significant fluid flow through the rocks and exhibits similar characteristics to other deposits on the Senegal Mali Shear Zone like Gounkoto and Fekola. The structures, alteration and host lithologies are identical to those being intersected by Barrick at their Kabewest prospect 2-3km along strike to the northeast. Mineralisation below the high-grade oxide appears to be associated with two controls.
Exploration activities undertaken on Diamba Sud
|Historical||Pre-2017||RC drilling – 9 holes for 651m|
|Auger Drilling||2018||3 Phases
Phase 1. 400m x 100m – 1,651 holes
Phase 2. 200m x 50m – 1,160 holes
Phase 3. 400m x 25m – 75 holes
|Phase 1||2019||RC drilling – 70 holes for 4,671m|
|Phase 2||2019||RC drilling – 26 holes for 2,873m IP Survey|
|Phase 3||2019-2020||RC drilling – 24 holes for 2,535m Diamond drilling – 13 holes for 2,035m|
|Phase 4||2020||RC drilling – 42 holes for 4,024m|
|Phase 5||2020-2021||RC drilling – 110 holes for 15,452m Diamond drilling – 21 holes for 4,147m|
|Phase 6||2021||RC drilling – 31 holes for 5,164m Diamond drilling – 34 holes for 4,393m|
|Phase 7||2021||RC drilling 33 holes for 4,178m|
The Diamba Sud exploration permit is located within the highly prospective Kédougou-Kéniéba Inlier which forms part of the Paleoproterozoic age Birimian Terrane of the West African Craton. Over 35 million ounces of gold has been discovered over the last 20 years within this inlier. The permit lies within the felsic volcanics and sediments of the Faleme Series, bound by the sediment-dominated Diale-Dalema Supergroup to the west and the SMSZ and the Kofi Series to the east.
The Faleme and Diale-Dalema supracrustal sequences are intruded by a series of variably deformed granitoid intrusions. Lithologies in the region are affected mainly by lower green schist grade metamorphism.