Tertiary Minerals' Zambian drilling and heavyweight JV backing sharpen small‑cap case

Tertiary Minerals reported further high‑grade results from early drilling at its Mushima North project in Zambia’s Copperbelt, reviving attention on the London‑listed explorer whose market value remains very small relative to investments committed by its joint‑venture partners.

The company said the second pass of drilling at the A1 target returned the project’s highest grades to date, including an interval of 73 metres at 32 grams per tonne silver, with a peak grade of 223 g/t silver and copper values just above 1 percent. Geologists also mapped mineralisation extending about 225 metres further north than previously known. Follow‑up laboratory assays and metallurgical testing are expected in the coming weeks.

The Mushima North A1 zone was first tested with less than 1,500 metres of drilling that produced encouraging intersections, including a hole reporting 66 metres at 26 g/t silver with 0.13 percent copper and 0.26 percent zinc starting about 13 metres down. Many holes ended in mineralisation at roughly 100 metres depth and the zone has been traced more than 250 metres in width. Tertiary said the latest data will be used to define an exploration target at A1; additional drilling will be required for a maiden resource estimate.

Managing Director Richard Belcher described Tertiary as a "project generator," noting the company’s strategy of advancing early targets and bringing in larger partners to fund and operate follow‑up work. That model underpins joint ventures across several of its assets, notably with First Quantum Minerals at Mukai and with KoBold Metals at Konkola West.

Mushima North’s proximity — about 20 kilometres — to Moxico Resources’ Kalengwa Mine, which is being brought back into production, could be strategically significant if future development enables low‑cost open‑pit mining and toll milling arrangements, analysts said. Tertiary also retains access to historical exploration data assembled by larger operators including First Quantum and BHP, which could accelerate target development.

Beyond Mushima, Tertiary owns 100 percent of the Mupala licence, where a copper‑in‑soil anomaly measuring about 1.8 by 0.6 kilometres shows values up to 422 parts per million and aligns with a fault system commonly associated with mineralisation. Mupala lies adjacent to an Arc Minerals–Anglo American joint venture that includes a planned investment of $88.5 million for up to 70 percent of that project.

The Jacks project targets near‑surface horizons within the same Roan formations. Early drill work — four holes totaling 746 metres — returned hits such as 1.8 percent copper over 6 metres from 105 metres depth and 0.8 percent copper over 14 metres from 27 metres. Mukai, the First Quantum joint venture, sits in the Lower Roan within the Tirosa basin, about 17 kilometres north of First Quantum’s Sentinel mine. Surface soil anomalies at Mukai extend over kilometres; limited drilling to date logged 0.12 percent copper over nearly 4 metres and 558 ppm nickel over 63 metres.

Konkola West, partnered with KoBold, lies within a prolific mining corridor a few kilometres from the Konkola Deeps Mine and KoBold’s Mingomba discovery. KoBold has drilled deeply on the licence, completing what the parties say is Zambia’s deepest exploration hole at 2,711 metres and continuing a second deep hole as part of campaigns testing the possible continuation of the Konkola Deeps system.

Outside Zambia, Tertiary holds early‑stage targets that management characterises as "sleeper" opportunities. In Nevada the Brunton Pass licence includes a volcanic‑hosted window with a multielement soil anomaly and limited trenching that returned wide, low‑grade copper intervals and a narrow gold intersection of 2.7 g/t over 2.7 metres. Drilling there comprised four holes totalling 890 metres and intersected anomalous copper more than 100 ppm over intervals in excess of 100 metres.

In Sweden the long‑running Storuman fluorspar project remains in permitting limbo. A mining permit previously granted to the project was overturned and is now under appeal, a process that Tertiary said was initiated in March. The company points to European policy support for critical raw materials as potentially favourable to projects like Storuman. Tertiary has highlighted local infrastructure, an estimated net present value of about $33 million and a projected payback period of less than three years in prior studies; the company says a successful appeal would materially change the asset’s strategic importance.

Market analysts and investors following the stock note a recurring theme: Tertiary's market capitalisation is small relative to the size of partner commitments and the quality of nearby mines and discoveries. That mismatch has attracted attention because heavyweight partners are bearing much of the cost and technical risk of exploration in Zambia.

Tertiary cautioned that further work is needed to establish the geometry and continuity of mineralisation at Mushima North and elsewhere, and that the timing of additional campaigns will depend on the speed of assay turnaround and the onset of Zambia’s rainy season, which typically constrains field work toward the end of the year. The company reiterated that all exploration targets remain subject to further drilling and technical studies before any mineral resource or reserve can be declared.

Industry observers also emphasise the risks inherent in early‑stage exploration. Permitting setbacks, volatile commodity prices and geopolitical shocks can alter project timelines and valuations. While Zambia is generally regarded as one of Africa’s more stable mining jurisdictions, the company and market participants note that broader geopolitical instability can affect investment sentiment and operational planning.

For now, Tertiary’s near‑term catalysts include additional assay and metallurgical results from Mushima North, further drilling results from its Zambian joint ventures, progress on the Storuman appeal in Sweden and continuing work at Brunton Pass in Nevada. Whether one of those developments will materially re‑rate the stock will depend on the scale, continuity and economic characteristics of any discovered mineralisation and on partners’ decisions to fund larger‑scale programmes.