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Perseus Mining Announces Significant Increase in Ore Reserves at Yaouré Gold Mine

Perseus Mining Limited is pleased to announce an increase to CMA underground Ore Reserves beneath the existing CMA open pit, at its Yaouré Gold Mine in Côte d’Ivoire of 2.7 Mt at 3.46 g/t for 300 koz. The total CMA underground Ore Reserve is now estimated by Perseus to be 4.9 Mt at 3.51 g/t for 559 koz. The CMA orebody remains open down plunge and down dip below the current Indicated Mineral Resource, and further extensions to the CMA underground Ore Reserves are expected with future drilling during FY24.

Feasibility-level studies on the CMA deposit at Yaouré (approximately four hundred metres down dip from the base of the open pit) have confirmed the economic and technical viability of underground mining. Resource definition drilling during FY23 has added Mineral Resources and Ore Reserves down-dip of the CMA underground Pre-Feasibility Study (PFS) Ore Reserves and readers are referred to ASX release “Perseus Updates Mineral Resource and Ore Reserve Estimates” dated 28 August 2022 for additional details on the CMA underground PFS.

More widely spaced drilling below the CMA underground Ore Reserve has shown that mineralisation extends deeper allowing an extension to Inferred Mineral Resources at depth. Extension of Inferred Mineral Resources and continued drilling success down-dip, provides strong encouragement for further expansion of the CMA underground.

As well as growth to Ore Reserves for the CMA underground, a drill campaign of 22,084 metres during FY23 at the adjacent Yaouré open pit has resulted in 6.9 Mt at 1.82 g/t for 403 koz of additional Yaouré open pit Ore Reserves (separate to the CMA open pit). Yaouré open pit Ore Reserves now total 11.8 Mt at 1.49 g/t for 565 koz. The increase to Yaouré Open pit Ore Reserves is based upon conversion of Inferred Mineral Resources immediately beneath the existing Yaouré open pit to Indicated Mineral Resources.

CMA underground and Yaouré open pit Ore Reserve increases are in addition to the existing Ore Reserves, adding additional value and mine life to the Yaouré Gold Mine. The CMA underground Feasibility Study (FS) and the Yaouré open pit expansion will be released in Perseus’ upcoming Yaouré Gold Mine Life of Mine (LOM) plan.


  • Indicated Mineral Resources at CMA underground have increased by 439 koz to 7.3 Mt at 4.17 g/t for 976 koz of contained gold, and Inferred Mineral Resources are estimated at 4.4 Mt at 3.4 g/t gold containing 485 koz of gold.
  • Underground Probable Ore Reserves estimated to date total 4.9 Mt of ore grading 3.51 g/t gold and containing 559 koz of gold, which is an increase for FY23 of 2.7 Mt at 3.46 g/t gold containing 300 koz of gold.
  • Yaouré open pit Indicated Mineral Resources have increased by 300 koz to 19.2 Mt at 1.27 g/t for 784 koz of contained gold, and Inferred Mineral Resources are estimated at 3.0 Mt at 1.3 g/t gold containing 124 koz of gold.
  • Yaouré open pit Probable Ore Reserves have increased in FY23 by 6.9 Mt at 1.82 g/t for 403 koz of gold, for a total of 11.8 Mt at 1.49 g/t gold containing 565 koz of gold.
  • Yaouré Gold Mine Ore Reserve increases at the CMA underground and the Yaouré open pit will extend the Yaouré Life of Mine (LOM) and all Ore Reserve additions are inside the mine fence and adjacent to the Yaouré processing facility. Perseus will prepare an updated LOM Plan for the Yaouré Gold Mine during the September 2023 Quarter.

Perseus’s Managing Director and CEO Jeff Quartermaine said:

Since pouring first gold at Yaouré, this mine has repeatedly exceeded our expectations on almost every measure and made a very significant contribution to the success of our company. The discovery of extensions to the CMA orebody at depth and confirmation that these Mineral Resources can be economically developed is further evidence that not only is the Yaouré Gold Mine an outstandingly good operation, but that it will also continue to contribute benefits to all of our stakeholders, well beyond our initial estimates.

The results that have been announced today are associated with the first 400 metres down dip from the base of the CMA open pit. Three dimensional seismic surveys have confirmed that the CMA and associated structures continue at depth for a much greater distance underground and it will require further drilling to confirm that these structures are mineralised with economically mineable grades at depth. However, based on what we have seen to date, we are optimistic that once established, the underground operation at Yaouré will continue for many years into the future.

The Yaouré underground mine is Perseus’s first foray into underground mining, with all previous operations having been open cut operations. While this represents a new style of mining and a new challenge for us as a company, it is certainly not new to many of the technical staff that are currently employed by Perseus who are very keen to demonstrate their skills in an underground mining setting. This depth of talent within our existing ranks gives us every confidence that the Yaouré Underground operation, when it commences, will be every bit as successful as the open pit operation that has preceded it”.


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