The Dandoko Project covers 134km2 and is located to the east of the prolific Senegal-Mali Shear Zone. Surrounding the Project are numerous world-class gold deposits including B2Gold’s 7.1Moz Fekola gold project (30km west) and Barrick’s 18Moz Loulo-Gounkoto Gold Mining complex (50km north-northwest).
In March 2021, the Company reported a highly robust initial JORC 2012 compliant Mineral Resource Estimate (MRE) at Dandoko of 11.3Mt at 1.83g/t gold for 668.5kOz contained gold, with 79% of the MRE classified in Measured & Indicated category, which remains open and is expected to grow with ongoing drilling along strike and at depth.
The Dandoko MRE encompasses the Seko, Koko, Disse and Diabarou deposits, which all remain open and are expected to grow with ongoing drilling either along strike or at depth. The robust MRE is constrained within optimised pit shells with 56% of the contained ounces reporting to the Measured category and 23% to the Indicated category, an important milestone for Oklo and will underpin a scoping study on a potential low-cost open pit mining operation.
65% of the MRE comprises soft oxide mineralisation, and when combined with high metallurgical recoveries from initial metallurgical test work , enables potential for a straightforward process flowsheet with a low capital requirement. Additionally, the MRE allows significant optionality for a potential future mining operation, with an increase in modelled cut-off grade providing potential for very high grade production scenarios.
Significant drill intersections and numerous wide zones of gold mineralisation occur outside of the optimised pits and are not included in the MRE, with the potential for continued exploration success to enable them to be incorporated into the resource in the future.
Initial metallurgical test work at has highlighted straight forward, non-refractory characteristics of the ore, with a likely processing route incorporating a simple, industry standard cyanide leach circuit. Test work results included encouraging leach kinetics and rapid leach times, physical inputs comparable to other operations in the region as well as oxide mineralisation amenable to gravity concentration.
Dandoko is underlain by Proterozoic Birimian meta-volcanic and meta-sedimentary sequences. A series of dominant NNE-trending faults, displaced by a second set of ESE-trending faults, have been mapped or interpreted from aeromagnetic data. Oklo considers that the NNE-trending structures are splays emanating from the Senegal-Mali Shear Zone (“SMSZ”), a regional NNW-trending strike-slip fault that plays an important role in controlling gold mineralisation in the region. The SMSZ is extensively mineralised and hosts no fewer than six major gold deposits for an endowment estimated at greater than 40Moz, including Sadiola (13.5Moz), Loulo (12.5Moz) and Gounkoto (5.4Moz).
Oklo’s exploration programs within the Project area have led to the discovery of the multiple gold discoveries, with an initial MRE providing a central foundation for continued resource growth within the 15km long Dandoko gold corridor.
Note 1: The information on the Dandoko Project JORC (2012) Compliant Mineral Resource Estimate is extracted from ASX announcement 30 March 2021, “Oklo Delivers Robust Initial Mineral Resource Estimate For Dandoko” Note 2: Open pit optimisations included an overall allowance of 10% for dilution and 7% for ore loss, and were undertaken using appropriate Malian royalties and taxes, metallurgical recovery data, mining, production, and environmental costs from nearby producing mines and utilising a low pit wall angle of 38o within the deep oxide profile observed and a 50o slope in fresh rock. Based on the preliminary optimisation work, a lower cut-off grade of 0.3g/t Au within a US$2,000/oz cut off shell provides a positive NPV indicating a reasonable prospect for eventual economic extraction.