The overall Phase 3 exploration programme at ASX-listed Prospect Resources’ Mumbezhi copper project, in Zambia, is progressing to schedule and budget, with MD and CEO Sam Hosack reporting that about 20% of the planned diamond drilling and about 35% of the budgeted aircore drilling has been completed.

Diamond drilling is being undertaken at the southern end of the flagship Nyungu Central deposit, where ten resource extension holes have been completed, with copper mineralisation visually observed in several holes outside existing defined mineral resources.

About 40 m of visually mineralised chalcopyrite-chalcocite copper sulphide mineralisation from about 271 m depth was intersected in NCDD026, hosted by a muscovite-graphite-kyanite-garnet ore schist about 140 m east of the current Nyungu Central mineral resource estimate (MRE).

An estimated copper grade of 0.5% copper from 271 m to 275.5 m was determined from this intersection by portable X-ray fluorescence (pXRF) analyses.

Prospect says two diamond rigs continue to target shallow, up-plunge extensions at the southern end of the Nyungu Central deposit, both to the east and west of the defined mineral resources there.

Over the coming month, the company says diamond drilling is set to progress to other key targets within the “Nyungu Hub” – including Nyungu West and Nyungu South.

Meanwhile, aircore drilling – 81 holes for 1 480 m – has been completed west of the West Mwombezhi deposit and the defined inferred mineral resource.

Anomalous subsurface copper mineralisation at West Mwombezhi returned at shallow depths over an additional 1 km of strike in two separate north-south trending zones.

These coherent zones represent walk-up diamond drilling targets with no historical testing.

Prospect says the best vertical downhole drill intersections returned from this aircore drilling include 25 m at 0.05% copper from 2 m (still open at end of hole) (MWAC134); 18 m at 0.05% copper from 0 m (still open at end of hole) (MWAC142); 9 m at  0.1% copper from 17 m (still open at end of hole) (MWAC126); 14 m at 0.06% copper from 13 m (still open at end of hole) (MWAC076); 19 m at 0.04% copper from 1 m (still open at end of hole) (MWAC117); 17 m at 0.04% copper from 0 m (MWAC135); and 7 m at 0.08% copper from 15 m (still open at end of hole) (MWAC094).

The company says these new targets require subsurface drilling to test the continuity of the identified surface copper mineralisation to further depths. This follow-up extensional drilling is targeted to take place during the second half of this year.

In addition, an induced polarisation (IP) geophysical survey is underway south of the West Mwombezhi MRE, complementing the 2024 work. Historical soil sampling has shown anomalous copper geochemisty in this same area up to 2 km south of the current MRE footprint, which the IP survey is targeting.

KEY REGIONAL TARGETS

Prospect notes that aircore drilling began in early May and is now about 35% complete – of a total 8 000 m budget. To date, this Phase 3 aircore drilling has been undertaken at West Mwombezhi, Chalamba and areas peripheral to Nyungu Central – the latter for both copper and gold exploration.

At Chipimpa, a 33-line-kilometre ground-based geophysical IP survey has been completed targeting strong electromagnetic (EM) conductivity anomalies and encouraging surface copper geochemistry.

Recent termite hill sampling has also defined an additional north-western copper anomaly; all aimed at vectoring the initial diamond drill testing to begin during the third quarter of this year.

At Sharamba, Prospect says, exploratory diamond drilling began targeting a large combined conductive and resistive IP anomaly, a conductive EM anomaly and strong copper geochemistry. The first hole defined a 20-m-wide visually mineralised zone at 140 m vertical depth (assays pending), with the second hole now in progress.

Additionally, aircore drilling is presently testing regional transitional gold zones, and is then set for copper-focussed drilling at Shikezi, Kasombo and southern extensions to West Mwombezhi.

“We are confident the drilling at Nyungu Central will add important incremental tonnes to the existing mineral resources.

“The aircore drilling results, to date, have been highly encouraging, with the identification of a new zone west of West Mwombezhi that demands follow-up deeper drilling this year. We are also pleased to have recently commenced exploratory diamond drilling of the large-scale Sharamba target, with one hole completed to date and the second in progress,” comments Hosack.

SCOPING STUDY PROGRESS

Prospect notes that workstreams for an initial scoping study are on track for completion in the fourth quarter of this year or the first quarter of 2027.

The company says the board has now approved a modest resource-focused drilling programme to upgrade inferred resources to additional indicated resources at Nyungu Central.

Prospect is considering a number of development scenarios including a 12-million-tonne-a-year openpit mining operation at Mumbezhi.

To assist in improving the robustness of this initial study, a modest resource-focused infill drilling programme is being undertaken to increase confidence in the defined inferred mineral resource inventory to an indicated level of classification at the flagship Nyungu Central deposit.

Additional pit optimisation work is also underway for Nyungu Central to include gold and cobalt by-product resources, estimated in the latest MRE.

Lycopodium has been appointed to assist in the execution of the scoping study.

Prospect describes this as an important step that will underpin the company and allow comparison to other developmental options as well as providing a base on which further exploration success can be leveraged.

Results are expected by the first quarter of 2027.