Altoro Metals Confirms High-Grade Zinc at Emilia Ahead of Novales Drilling

Altoro Metals Confirms Exceptional Zinc Grades at Emilia Ahead of Novales Drilling

Altoro Metals Limited (ASX: ARO) has reported high-grade zinc channel sampling results from the historic Emilia Mine within its Novales Project in Cantabria, northern Spain. Assays returned up to 2.65m at 21.10% zinc and 0.14% lead, providing modern, systematic exploration data from an area that sits outside the company's existing Mineral Resource Estimate (MRE). These results will be used to refine targets for an imminent surface drilling campaign along the more than 12km Novales zinc trend.

For investors, the significance lies in both grade and location. Emilia is not part of the current JORC resource footprint at San José and north-eastern Udías, so these results relate to potential resource growth rather than infill within an already defined resource.

Standout Zinc Grades Across Multiple Emilia Channels

In the announcement, Altoro said 28 cut channel samples were collected from 23 locations, including 25 underground samples and 3 from the adjacent open pit. Samples were submitted to ALS Laboratories, with the company stating that appropriate quality assurance and quality control procedures were applied.

What Were the Highest-Grade Results?

The highest-grade individual channel result was 2.65m at 21.10% Zn and 0.14% Pb from E-1. Other strong intervals included:

• 2.60m at 18.55% Zn and 0.18% Pb from E-2B
• 1.40m at 16.00% Zn and 0.54% Pb from E-6A
• 1.70m at 15.40% Zn and 3.24% Pb from E-7A
• 2.70m at 14.05% Zn and 0.13% Pb from E-11
• 2.90m at 13.30% Zn and 0.84% Pb from E-3
• 2.20m at 12.00% Zn and 0.26% Pb from E-11B
• 2.40m at 10.30% Zn and 0.03% Pb from E-12

The consistency across several channels is important. Rather than a single isolated result, the programme returned multiple metre-scale intervals above 10% zinc, which supports the interpretation that high-grade mineralisation is distributed through parts of the Emilia workings.

Furthermore, the announcement highlighted broader composited intervals, which combine adjacent channel samples where appropriate. These included:

• 4.50m at 13.71% Zn and 0.11% Pb from E-2 composite
• 3.90m at 9.44% Zn and 1.51% Pb from E-7 composite
• 3.65m at 8.74% Zn and 0.40% Pb from E-6 composite

These wider composites matter because they indicate that high grades are not limited to very narrow points along the workings.

Why Channel Sampling Matters in Zinc Exploration

For non-specialist investors, channel sampling is a method used to test the grade of exposed rock in a systematic way. Geologists cut a measured line into a mine wall or rock face and collect all material along that interval, rather than selecting only the best-looking mineralised pieces.

This makes it more reliable than a simple grab sample when assessing how mineralisation is distributed across a defined width. In Altoro's case, the company said the programme involved continuous cut-channel sampling, which provides a more systematic basis for assessing grade distribution at Emilia.

Key Technical Terms Explained

• Channel sampling is commonly used in underground workings and open exposures to assess visible mineralisation before drilling.
• JORC-compliant data refers to information collected and reported under the standards of the JORC Code (2012), the framework used on the ASX for public reporting of exploration results and mineral resources.
• QAQC means quality assurance and quality control, which includes standards, blanks and duplicate checks to test whether laboratory results are reliable.

Altoro reported a QAQC insertion rate of 17.6%, based on 34 samples submitted, including standards, blanks and duplicates. According to the JORC table in the announcement, this is within the typical 10% to 20% industry range.

There is, however, an important technical caveat. The company stated that no direct comparison has been made between the new channel sampling and historical face sampling because the methods differ. That distinction matters, as different sampling styles can produce different grade profiles. Even so, the new work provides a modern dataset collected from the same geological environment.

Emilia Sits Outside the Current Novales Resource Footprint

In the update, Altoro said Emilia lies approximately 2.3km north-east of the San José mine along the broader San José-Udías zinc trend, which extends for more than 12km across the Novales Project.

This geographic context is central to the investment case. The company's current JORC Mineral Resource Estimate, announced on 9 December 2024, applies to the San José mine and north-eastern Udías. Emilia is outside that existing resource area.

That means the new results are being interpreted as evidence of potential resource expansion rather than confirmation within the current MRE. If upcoming drilling demonstrates continuity between mineralised centres, the Emilia-Margarita corridor could add to the project's broader resource base.

According to the company, historical exploration across the wider Novales trend included 109 drillholes for approximately 6,720m. Much of that work predates modern JORC standards, but it still provides useful geological context.

Previously reported historical drilling at Emilia included results such as S-50: 0.85m at 23.47% Zn and S-60: 1.50m at 14.22% Zn. The new channel sampling does not validate those historical results directly, but it does provide fresh, modern data consistent with the area's known high-grade zinc mineralisation.

What Investors Should Watch in the Novales Drilling Campaign

The announcement makes clear that Emilia's new data will feed directly into Altoro's planned surface drilling campaign in Cantabria. The first phase is expected to focus on the area between Novales village, Emilia and Margarita.

According to the company, the drilling is designed to:

1. Test the continuity of zinc mineralisation between known historical mine centres
2. Establish geometry, thickness and depth continuity of the mineralised zones
3. Test prospective areas outside the existing MRE
4. Generate geological and assay data that may support a future MRE for this under-explored section of Novales

This is the key next catalyst. Channel sampling can indicate where mineralisation is exposed, but drilling is needed to test continuity at depth and between separate workings. That is particularly relevant in a structurally controlled zinc system, where mineralisation may occur in lenses, pods and stratiform zones shaped by faults and host rocks.

The market will likely be watching whether drilling can show that the high-grade material seen at Emilia extends in a connected way along the Novales trend, rather than remaining localised around historical workings.

The company also noted that mineralisation in the Emilia and Margarita area appears strongly influenced by sub-vertical feeder faults with lateral and vertical spreading into nearby carbonate rocks. In simpler terms, faults may have acted as pathways for mineral-rich fluids, helping form concentrated zinc zones near those structures.

Understanding Mississippi Valley Type Zinc Deposits

The Novales Project is described in the announcement as a Mississippi Valley Type (MVT) lead-zinc system. For investors, this deposit style is worth understanding because it shapes how exploration targets are assessed.

MVT deposits are typically:

• Hosted in carbonate rocks such as limestone or dolostone
• Formed by metal-bearing fluids moving through rock layers and faults
• Characterised by zinc and lead sulphide mineralisation
• Often found in clusters or districts with multiple deposits along the same trend

At Novales, Altoro said zinc strongly predominates over lead, with mineralisation occurring as stratiform, sub-horizontal, lenticular and podiform bodies, as well as along steeper structural pathways. In plain language, this means the zinc can occur both in relatively flat layers and in more irregular lenses near fault zones.

In addition, this deposit style is relevant to investors because high-grade mineralisation can reappear across multiple centres in the same district. That increases the importance of testing the gaps between historical mines such as San José, Emilia and Margarita.

Near-Term Milestones Across Altoro's Spanish Portfolio

The Novales work is part of a broader Spanish exploration programme. In the announcement, Altoro outlined several near-term activities that could shape news flow in coming months.

This gives the stock a pipeline of exploration updates rather than a single event. Guajaraz assays may provide one stream of news, whilst Novales drilling offers another.

Why the Altoro Exploration Update Matters to the Market

From an investor perspective, the Emilia results matter for four main reasons. First, grade — intervals above 20% zinc are uncommon in most exploration settings, and the broader set of assays indicates more than one high-grade point.

Second, resource growth potential. Emilia is outside the existing MRE, so success here could expand the current resource footprint rather than simply improve confidence within it.

Third, district scale. The Novales trend extends for more than 12km and includes multiple historical mine centres, giving the project room for additional discoveries or extensions if continuity is confirmed.

Fourth, modern data quality. Altoro's announcement places emphasis on systematic sampling, independent laboratory analysis and documented QAQC procedures, all of which are relevant when investors assess the reliability of early-stage exploration results.

The next step is clear. According to the announcement, the company is moving from surface and underground sampling toward drilling, with the aim of testing whether Emilia forms part of a broader connected zinc system along the Novales trend. If that continuity is established, the implications for future resource definition could become more material.

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