Highlights

  • Surface diamond drilling begins at Novales with 20 fully permitted holes designed to test zinc continuity across the San José, Emilia, Margarita and Udías corridors.
  • Underground diamond drilling at Emilia Level -2 continues, with assays for the first nine holes pending — channel sampling there returned up to 21.10% zinc.
  • Novales hosts a 3.38Mt at 7.61% zinc and 0.88% lead mineral resource at a 2% combined cut-off, covering only part of a 12-kilometre trend.
  • A unified Novales resource targeting the broader corridor is planned for the March 2027 quarter, with Asturmine as modelling consultant.

Strip the paint off Spain's old mining towns and you often find zinc underneath. Altoro Metals (ASX:ARO), formerly Variscan Mines, is betting that four historical centres along the Basque-Cantabrian Basin can be shown to share a continuous mineralised corridor — and it has started drilling surface holes at Novales to find out. The company announced the start of its 20-hole programme on 29 October 2026.

The Surface Campaign

The initial surface diamond campaign of 20 fully permitted holes is designed to test zinc continuity between the San José workings, Margarita, Emilia and Udías — four centres previously mined as separate operations. Drilling began on 20 October with an inclined hole at the San José mine site, using a rig relocated from the completed Guajaraz programme. That hole targets a gap in a line of historical holes and aims to test at depth a north-east trending fault visible from the San José portal, which Altoro considers a possible first-order feeder zone.

Near Emilia, drill pad preparation, landowner access agreements and water logistics are progressing. Altoro has not disclosed total programme metres or target depths. No assays have been reported from the surface programme.

Underground Work at Emilia

Underground diamond drilling continues on Level -2 at Emilia, approximately 2.3 kilometres northeast of San José. Recent work indicates the mineralised system is more than 100 metres wide within a jog of the north-east trending fault. Laboratory assays for the first nine underground holes are pending. Earlier channel sampling at Emilia returned up to 2.65 metres at 21.10% zinc and a composite of 4.50 metres at 13.71% zinc — channel samples from exposed rock faces, not equivalent to drill intercepts.

The Existing Resource and the Gap

Novales' current mineral resource, reported in December 2024, totals 3.38 million tonnes at 7.61% zinc and 0.88% lead, or 8.49% combined zinc and lead, at a 2% cut-off. It covers only the San José and north-eastern Udías areas — a small fraction of the 12-kilometre trend. Altoro is targeting an upgraded, unified resource estimate for the March 2027 quarter, working with modelling consultant Asturmine. Demonstrating continuous mineralisation between the historical centres would provide the geological basis for that expanded estimate.

Guajaraz Complete and Logistics

At the wholly owned Guajaraz zinc-lead-silver project in Toledo province, Altoro completed a five-hole maiden diamond programme between July and October 2026. Effective core recovery totalled 1,061.80 metres from 1,318.20 metres drilled. Core is being logged and sampled at Novales before dispatch to ALS, and no assays have been reported. The Novales project sits about 180 kilometres by road from the San Juan de Nieva zinc smelter in Asturias, operated by Asturiana de Zinc — a Glencore company — giving it a plausible logistical route to a processing facility.

Altoro has also submitted a mine and plant project and restoration plan to Cantabrian mining authorities, targeting submission by year end, and is assessing newly gazetted mineral permits in northern Spain ahead of a 60-day tender window.