Exploration results and corporate activity drove broad gains across the mining small-cap space, with Great Southern Copper delivering the headline event as porphyry-style alteration at Piedras Blancas validated its exploration model and triggered a move to drill Artemisa North. Elsewhere, Amaroq reported its first quarterly revenue figures of the year, East Star Resources added an Endeavour Mining-linked director to its board, and Orosur Mining extended a shallow gold system with a 30-metre step-out hit.
Great Southern Copper confirms porphyry model, drills Artemisa North
Great Southern Copper (AIM:GSCU) rose 10.71% to 3.1p after scout reverse circulation drilling confirmed pervasive phyllic alteration and potassic overprints across four holes at Piedras Blancas, results the company said validate the porphyry exploration model at the project. The findings were sufficient to immediately advance the programme, with scout RC drilling now under way at the adjacent Artemisa North target.
The porphyry signature at Piedras Blancas is a meaningful de-risking step for Great Southern Copper's Chilean portfolio, providing the geological framework needed to justify systematic follow-up drilling at Artemisa North and potentially across the broader licence area.
Amaroq posts $18.9m Q1 revenue as Nalunaq ramps
Amaroq (AIM:AMRQ) reported Q1 2026 revenue of $18.9m as the Nalunaq gold project in Greenland continued to build production momentum, with the company reiterating its full-year 2026 production guidance alongside the quarterly update. The shares slipped 1.9% to 101.535p, a modest pullback that likely reflects profit-taking after recent strength rather than any concern with the underlying numbers.
The revenue figure marks a tangible step in Nalunaq's transition from development asset to producing mine, and the unchanged guidance signals management confidence that the ramp trajectory remains on track.
East Star Resources adds Endeavour Mining representative to board
East Star Resources (AIM:EST) surged 16.47% to 3.96p after appointing Sonia Scarselli to its board with immediate effect, a move that formalises the strategic relationship with Endeavour Mining following the larger miner's acquisition of a 14.3% stake in the company. Scarselli joins as Endeavour's designated representative, bringing senior industry experience to a board that is now backed by one of Africa's largest gold producers.
The appointment signals that Endeavour's involvement extends beyond a passive financial stake, adding strategic weight to East Star's exploration programme and raising the profile of its central Asian asset base.
Panther Metals completes Winston Tailings assay programme
Panther Metals (AIM:PALM) released the sixth and final batch of Vibracore assay results from its Winston Tailings Project, with the data showing consistent grades across the deposit. The company said the completed dataset is expected to underpin a NI 43-101 Mineral Resource estimate and support a recovery-permit application pathway. The shares added 1.2% to 123.975p.
Completion of the assay programme removes a key near-term uncertainty for Winston, with the resource estimate now the next material milestone that could define the scale of the reprocessing opportunity.
Rome Resources joins airborne geophysical survey over DRC tin licences
Rome Resources (AIM:RMR) confirmed it will participate in a helicopter-borne geophysical survey covering its two Bisie licences in the Democratic Republic of Congo, with the programme designed to calibrate existing anomalies and identify priority tin targets for follow-up ground work. The shares edged up 0.78% to 0.388p.
The airborne survey represents a cost-effective method of advancing the Bisie licences, which sit in one of the world's most significant tin-producing regions, and should provide Rome with a clearer picture of drill targets ahead of any ground-based programme.
Orosur Mining extends Pepas West gold system with step-out drilling
Orosur Mining (AIM:OMI) climbed 6.77% to 20.5p after returning multiple thick, shallow gold intersections at Pepas West in a 30-metre step-out from previously drilled ground, with the results indicating a potential extension to the gold system. The shallow nature of the mineralisation is a positive indicator for the economics of any future development scenario at the project.
Thor Explorations returns high-grade shallow oxide hits at Douta
Thor Explorations (AIM:THX) published its first 2026 drill results from the Douta Project in Senegal, with multiple shallow, high-grade oxide intercepts returned across the programme. The company said the results could support an upgrade to the existing mine plan, adding potential resource upside at a project already in the development pipeline. The shares gained 0.94% to 75.299p.
Guardian Metal Resources stakes 193 claims to expand Tempiute tungsten footprint
Guardian Metal Resources (AIM:GMR) identified approximately 550 acres of tungsten-enriched historical tailings at its Tempiute project in Nevada and staked 193 new claims, increasing the project's footprint by more than 375%. An auger drilling programme is planned for June to test the reprocessing potential of the tailings material, with tungsten's strategic commodity status adding commercial context to the expansion.
