Perseus Mining Ltd (ASX:PRU, TSX:PRU, OTC:PMNXF) has declared a maiden underground ore reserve of 2.2 million tonnes at 3.58 g/t gold for 259,000 ounces at the Yaouré Gold Mine in Côte d’Ivoire.
This will support the initial stages of mining of the CMA orebody by underground methods beneath the existing CMA open pit and adds further value to the Yaouré mine.
CMA probable ore reserves.
Part of PFS
A pre-feasibility study (PFS) on the drilled-out portion of the CMA deposit at Yaouré, about 200 metres down dip, has been completed which has proven the economic and technical viability of underground mining immediately beneath the existing open pit, supported by the maiden ore reserve.
Indicated mineral resources at CMA underground amount to 3.7 million tonnes at 4.48 g/t for 537,000 ounces of contained gold and inferred resources are estimated at 3.7 million tonnes at 4.1 g/t containing 488,000 ounces.
CMA measured & indicated mineral resources.
CMA inferred mineral resource.
Possible extension
And ongoing drilling by Perseus has shown that mineralisation extends deeper allowing for a possible extension to the inferred resources at depth.
The first hole in a drilling program to test a target generated from a 2020 3D seismic survey has intersected CMA mineralisation significantly further down dip than any previously drilled hole, intersecting 6 metres at 2.11 g/t, including 2 metres at 5.5 g/t.
Provides “further confidence”
Perseus’s managing director and CEO Jeff Quartermaine said: “Having attained the goal of producing gold at a rate of 500,000 ounces per year across our three gold mines, we are now working to maintain, and where possible, exceed that level of production over the next decade and beyond.
"These latest drill results from Yaouré give us further confidence in the high-grade gold contained beneath the CMA open pit and the results of a pre-feasibility study and maiden ore reserve for the first portion of CMA Underground Project are encouraging.”
The addition of the CMA underground to the Yaouré Gold Mine has the potential to extend the life-of-mine and increase the annual ounce production profile by substituting low-grade open pit feed with higher-grade underground ore reserves.
Exploration ongoing
An extension of inferred mineral resources and continued drilling success down-dip provides strong encouragement for further expansion of the CMA underground.
Perseus is focusing exploration on the Yaouré permits at the CMA Down-dip and CMA Deeps prospects, both within two kilometres of the Yaouré mill.
Results received continue to demonstrate the potential for the company to materially grow its gold inventory at Yaouré through further drilling success.
Early results from CMA Deeps seismic drilling are promising and continue to demonstrate the potential to grow the gold inventory by organic means.
The highlight result is 6.0 metres at 2.11 g/t gold from 543 metres, including 2.0 metres at 5.50 g/t from 547 metres.
This intersection is 200 metres down-dip from previous drilling and assays remain pending for the lower part of YDD570 which tested previously undrilled targets generated using the 3D seismic data in the footwall of the CMA.
Reducing average AISC
"The initial stage of the development will carry the bulk of the development costs of the underground operation, and as further resources and reserves are delineated by the drilling programs currently underway on the site, the average AISC should be reduced turning the CMA underground into a very profitable extension of the already profitable open pit operation,” Quartermaine added.
"We look forward to progressing Perseus’s first underground mining development which is also likely to be the first large-scale underground mine operating in Côte d’Ivoire.”
Drilling continues
Perseus is undertaking resource definition drilling and down-dip exploration drilling for the CMA underground project, in order to convert inferred resources to the indicated category and to extend the inferred resource further down-dip, and to the northwest of the current CMA ore reserve.
Drilling is underway on the CMA northwest orebody (currently comprising 1% of the underground ore reserve) and an infill program to convert the inferred resource to indicated is planned later in the year, stepping out the reserve up to 200 metres further down dip.
In addition, preliminary assays from the first hole of a six-hole deep drilling program under the CMA structure have revealed the additional mineralisation extends a further 200 metres down dip.