Altoro Metals has returned high-grade zinc assays from maiden modern underground drilling at the Emilia Mine in northern Spain, including 5 metres at 13.66% zinc and a 1-metre interval at 25.70%. The results sit outside the company’s existing Mineral Resource Estimate, but further drilling is needed to establish continuity and true widths.
- 5.00m at 13.66% zinc in EDDT001, including 1.00m at 25.70%
- Nine underground diamond holes completed for 285.50 metres
- Additional high-grade results from EDDT006 to EDDT009
- Emilia remains outside Altoro’s existing Mineral Resource Estimate
- Follow-up drilling and geological modelling planned
Emilia drilling delivers multiple high-grade zinc hits
Altoro Metals Limited (ASX:ARO) has found more than a single headline assay at the historical Emilia Mine, with nine modern underground holes returning a cluster of high-grade zinc intersections. The standout result was 5.00 metres at 13.66% zinc and 0.04% lead in EDDT001, including one metre at 25.70% zinc.
Other results included 4.00 metres at 6.01% zinc in EDDT006, 4.00 metres at 4.96% zinc in EDDT007, 11.00 metres at 2.79% zinc in EDDT008 and 5.49 metres at 5.69% zinc in EDDT009. Peak individual assays reached 18.90% zinc in EDDT005, 17.10% in EDDT006 and 15.40% in EDDT007.
Results extend a project area outside the current resource
The significance for Altoro is location as much as grade. Emilia sits about 2.3 kilometres northeast of the San José Mine along the interpreted 12-kilometre Novales-Udías zinc trend, but entirely outside the company’s existing MRE. Earlier Emilia channel sampling had returned zinc grades of up to 21.1%, and the latest drilling now adds modern subsurface assay data to that exploration picture.
The drilling was carried out from accessible historical workings at a mine operated in the early 20th century. Altoro said the compact underground programme was designed to test mineralisation exposed in or near historical pillars and interpreted sulphide-bearing horizons. It was intended to improve geological understanding at selected locations, rather than serve as a broad-spaced greenfields discovery programme.
Continuity and recovery remain the key technical tests
The results are reported as downhole lengths, and true widths have not yet been established. The company also says the current hole spacing is insufficient to demonstrate geological or grade continuity for a Mineral Resource Estimate, meaning the assays do not yet translate into a new resource or a defined increase in mineable inventory.
Core recovery averaged about 94% across 98 primary assay samples, although EDDT007 was an important exception. Recovery across its 4.00-metre composite averaged approximately 60.8%, including 47% in the first metre that assayed 15.40% zinc and 1.52% lead. Altoro said friable or partially oxidised mineralisation may have been lost during drilling, potentially understating the actual grade, but the reported composite was not adjusted for recovery.
Follow-up drilling will determine Emilia’s resource potential
Altoro plans to combine the new assays with historical workings, geological mapping and previous channel sampling before refining targets around Emilia and the wider Emilia-Margarita area. The company will then assess how much additional drilling is required to determine whether Emilia and surrounding deposits could contribute to a future resource update. The results arrive after nine Emilia holes pending assays were identified as a near-term catalyst in September.
The zinc backdrop is supportive but does not remove the geological work ahead. The company cited an International Lead and Zinc Study Group forecast for an 88,000-tonne refined zinc deficit in 2026, while LME cash zinc was approximately US$3,955 a tonne at the end of October. For Altoro, the more immediate question is whether the high grades repeat across a sufficiently continuous and accurately measured system to matter in the planned Novales consolidation.
Bottom Line?
The assays strengthen Emilia’s exploration case, but the next value test is continuity: true widths, recovery effects and follow-up drilling must turn isolated high-grade hits into a resource-quality geological model.
Questions in the middle?
- Will follow-up drilling confirm continuity between the strongest Emilia intersections?
- How will true widths compare with the reported downhole lengths?
- Can Emilia contribute meaningfully to a future Novales Mineral Resource Estimate?