Andean Silver Cerro Bayo Drilling Results Deliver Record Gold Grades

The Geological Economics of Bonanza-Grade Silver: Why Epithermal Systems Rewrite the Rules

Not all silver deposits are created equal. Across the global mining landscape, the distinction between a marginal bulk-tonnage silver operation and a high-grade epithermal vein system can be the difference between a project that barely survives a commodity downcycle and one that generates outsized cash margins even at depressed metal prices. Understanding this structural divide is essential context for interpreting the significance of the latest Andean Silver Cerro Bayo drilling results, which have delivered the highest gold grades ever recorded at the project.

The Cerro Bayo project in southern Chile sits firmly in the latter category. With a current JORC-compliant mineral resource of 20.0Mt at 211 g/t silver equivalent (AgEq) for 136 million ounces AgEq, this is not a resource defined by volume alone. It is defined by exceptional concentration, a factor that fundamentally reshapes the economic conversation around development costs, mill throughput requirements, and payback timelines.

At a Glance: Cerro Bayo Key Metrics (2026)

How Epithermal Architecture Produces Bonanza-Grade Intercepts

The Geological Engine Behind Exceptional Silver-Gold Grades

Epithermal vein systems form at relatively shallow crustal depths, typically between 1 and 5 kilometres below the ancient surface, where hydrothermal fluids rich in dissolved metals cool and precipitate their mineral cargo into fracture networks. The mechanics of this process are critical: as fluid pressure drops and temperatures fall, metals concentrate rapidly within discrete vein structures rather than dispersing uniformly through large volumes of host rock.

This is the geological reason why epithermal systems produce what miners call bonanza grades. The term is not merely colloquial. It describes intercepts where metal concentration within a narrow vein interval is so high that a single metre of core can contain more economic value than hundreds of metres of typical porphyry-style mineralisation. At Cerro Bayo, this phenomenon is well documented, with the peak intercept of 30,202 g/t AgEq standing as a reference point for just how concentrated the mineralisation can be.

Cerro Bayo sits within the Patagonian Andes of southern Chile, a metallogenic province that shares geological affinities with Argentina's Deseado Massif, one of the most productive epithermal terranes in the Southern Hemisphere. The structural controls on mineralisation at Cerro Bayo reflect classic low-to-intermediate sulphidation epithermal characteristics, with silver and gold deposited together in quartz-adularia veins hosted within Jurassic volcanic sequences. Furthermore, silver's dual role as both a precious and industrial metal adds an additional layer of demand resilience that strengthens the long-term economics of high-grade silver projects.

Grade Benchmarking: Where Do These Results Sit on a Global Scale?

The numbers produced by the 2026 drilling program are not just strong in a relative sense. They are exceptional by any global standard for this style of mineralisation.

What makes the 268 g/t Au intercept particularly noteworthy is its deviation from the project's predominantly silver identity. Gold-rich zones within a silver-dominant epithermal system often indicate proximity to the feeder structures that originally channelled mineralising fluids, sometimes referred to as the roots of the system. When gold becomes anomalously elevated relative to silver, it can signal that drilling has intersected a zone of higher fluid flux, which correlates with greater total metal endowment at depth.

A resource grade of 211 g/t AgEq exceeds the threshold most metallurgical engineers associate with strong mill feed economics. At this grade, even a relatively small daily throughput operation can generate meaningful revenue per tonne processed, reducing the capital intensity of early production scenarios.

Critically, the 85-93% metallurgical recovery rates reported for silver and gold at Cerro Bayo align with or exceed what historical plant performance demonstrated during the project's prior operating life. This is not speculative. The project produced approximately 45 million ounces of silver and 650,000 ounces of gold over roughly 15 years of operation before care and maintenance, providing a substantial real-world metallurgical dataset that greenfield discoveries cannot replicate.

What the 2026 Andean Silver Cerro Bayo Drilling Results Actually Mean

Infill Drilling: The Distinction Between Discovery and Conversion

A common misconception among retail investors is that all drilling is exploration drilling, intended to find new ounces. In reality, much of the drilling required to advance an exploration-stage project toward economic studies serves a fundamentally different purpose: converting what is already known to exist in the ground into a category of resource that meets the evidentiary standard required for engineering studies. Understanding drilling program economics is therefore essential for investors evaluating the true significance of infill campaign results.

Under JORC 2012 reporting standards, Inferred resources carry too much geological uncertainty to serve as the basis for a feasibility study. For that, a company needs Indicated or Measured resources, classifications that require drilling close enough to demonstrate geological continuity with confidence. This is precisely the objective driving the current infill program at the Laguna Verde Mine Complex.

The strategic intent is clear: converting approximately 80% of Inferred resources into the Indicated and Measured categories to underpin a future Feasibility Study. Achieving this conversion does not add new ounces to the total resource, but it dramatically changes the confidence level of the resource, which in turn changes what a bank, offtake partner, or project financier will accept as the basis for a development decision.

Headline Intercepts and the Gold-Rich Zone Discovery

The two headline results from the latest Andean Silver Cerro Bayo drilling program carry significance that extends beyond their raw numerical impact:

• 268 g/t Au represents the highest gold-equivalent grade ever recorded at the project, confirmed by the company
• 3,045 g/t Ag is consistent with bonanza-grade silver mineralisation found in the best epithermal systems globally
• Earlier campaign peaks included 30,202 g/t AgEq, 21,282 g/t AgEq, and 13,707 g/t AgEq from multiple holes

The gold-rich zones identified within parts of the system carry particular economic relevance. In a project where silver is the primary revenue driver, disproportionately gold-rich intercepts can tilt the overall metal revenue mix in ways that improve project economics during periods when silver underperforms relative to gold, effectively providing a natural hedge within the ore body itself. In addition, ongoing silver supply deficits continue to support the structural case for high-grade silver projects globally.

New Vein Structures: Temer, Cristal, and Coyita

Among the most strategically consequential findings from the 2026 program is the identification of new vein structures outside the immediately defined resource boundary. The Temer, Cristal, and Coyita zones represent extensions and newly defined trends within the broader Cerro Bayo system, and their characteristics suggest meaningful upside potential:

• All three structures are located within 1.5 kilometres of the existing processing mill, a proximity advantage that is difficult to overstate in capital expenditure terms
• Combined strike length of approximately 1.3 kilometres with 200 metres of vertical extent has been confirmed
• Three active drill rigs are simultaneously targeting the Temer, Appaloosa, Delia SE, and Coyita zones
• Parallel mineralised trends have been identified, indicating the system footprint is broader than prior geological models suggested

The infrastructure proximity factor deserves particular emphasis. In conventional mine development, the cost of building a processing facility from scratch often rivals or exceeds the cost of the mining operation itself. A new vein discovery that lies within 1.5 kilometres of an existing, already-commissioned mill is not merely a geological discovery. It is a capital efficiency windfall.

Discovery costs averaging approximately A$0.20 per silver ounce position Cerro Bayo among the most capital-efficient silver exploration programs currently active on the ASX, a metric that reflects both the high success rate of drilling and the low incremental cost of adding ounces within an already-understood geological system.

Resource Growth Trajectory and the 65,000-Metre Campaign

From 111Moz to 136Moz: What a 22% Upgrade Represents

Resource growth at Cerro Bayo has followed a consistent upward trajectory through successive drilling cycles, each adding both ounces and confidence to the overall estimate.

The movement of approximately 60 million ounces into the Indicated category is as significant as the total ounce growth. Indicated resources are the currency of economic studies. They represent the portion of the resource that engineers, banks, and offtake counterparties will actually model when assessing project viability. For investors, interpreting drill results in this context is crucial to understanding why resource classification matters as much as raw ounce counts.

The Dual-Track Drilling Strategy Explained

The 65,000-metre program planned for 2026 is more than double the 30,000 metres completed in 2025, and it is structured around two distinct and complementary objectives:

1. Infill drilling within the Laguna Verde Mine Complex, targeting conversion of Inferred resources to Indicated and Measured categories to support feasibility-level economic modelling
2. District-scale resource growth drilling across the broader Cerro Bayo land package, representing the first systematic district-wide drilling program in over 20 years

The Trinidad shoot is the primary district-scale growth target, with mineralisation being tested both down plunge of the existing defined shoot and across a 400-metre northward extension of the main Trinidad mine area. Historical drilling data from more than 15 years ago provides the geological rationale for these targets, offering a roadmap to mineralised zones that have never been tested with modern drilling technology or geological interpretation.

This combination of near-term resource conversion and medium-term discovery potential creates a sustained pipeline of potential catalysts across the full drilling campaign, rather than concentrating value creation into a single event.

Development Pathway: From Exploration Success to Production Reality

The Phased Development Framework

Andean Silver's stated strategy centres on advancing the project through a structured sequence of milestones, moving from a predominantly exploration focus toward a combination of exploration and restart planning during 2026 and into 2027.

One of the more underappreciated aspects of the Cerro Bayo development scenario is the potential for an early production phase using the existing mill infrastructure to process low-grade stockpiles ahead of a full mine restart. This pathway, if confirmed through the feasibility study process, could enable cash generation to begin well before the capital-intensive ramp-up phase of a full restart, partially self-funding the project's transition from explorer to producer.

Capital Position and Financial Runway

The funding question is often the critical variable that separates exploration stories with genuine development momentum from those that stall at the feasibility stage. On this measure, the current capital position is substantive:

• Cash on hand as of March 2026: A$53.4 million
• New financing secured: A$60 million
• Combined capital base: sufficient to support the 65,000-metre drilling campaign, concurrent feasibility workstreams, and permitting activities

A well-funded exploration company retains optionality that undercapitalised peers do not. The ability to run infill drilling, district-scale exploration, and feasibility study work simultaneously, rather than sequentially, compresses the development timeline and reduces the window of exposure to commodity price volatility.

Key Risk Factors Investors Must Understand

Geological and Technical Risks

• Vein continuity at depth: Infill drilling confirms strong continuity at current depths, but epithermal vein systems are inherently discontinuous geological features that can thin or terminate unpredictably below certain elevations. Not all currently defined structures will extend indefinitely downward.

• Grade variability in bulk mining scenarios: Bonanza-grade intercepts are localised by definition. The headline figures of 268 g/t Au or 3,045 g/t Ag represent exceptional individual intersections. Bulk mined tonnes from a full mining block will average considerably lower grades, and mine planning must account for internal dilution from lower-grade or waste material within the vein envelopes.

• Metallurgical complexity: While historical recovery rates of 85-93% are strong, any variation in the mineralogical character of newly identified vein structures relative to the historically processed ore types could affect processing performance and recoveries.

Development and Jurisdictional Considerations

• Chilean regulatory environment: Chile is a mature and well-regarded mining jurisdiction, but permitting timelines, community engagement processes, and environmental assessment requirements must be navigated before production can begin.

• Feasibility study dependency: The resource estimates and drilling results currently available do not constitute a production decision. Economic viability is only confirmed after a full feasibility study incorporating engineering costs, metallurgical testwork, infrastructure assessment, and market analysis.

• Timeline risk: The 2027-2028 production timeline is aspirational and contingent on multiple regulatory, technical, and market conditions aligning favourably.

Disclaimer: Resource estimates and development timelines referenced in this article are forward-looking in nature and subject to material uncertainty. This article does not constitute financial advice. Readers should conduct independent research and consult a licensed financial adviser before making any investment decisions related to exploration-stage companies.

Frequently Asked Questions: Andean Silver Cerro Bayo Drilling Results

What grades has Andean Silver returned at Cerro Bayo?

The highest recorded intercept from the 2026 program reached 30,202 g/t AgEq, with the most recent infill results including 268 g/t Au and 3,045 g/t Ag, the highest gold grades ever recorded at the project. The latest drilling announcement provides full technical details of these exceptional intercepts.

What is the current mineral resource at Cerro Bayo?

As of June 2026, the JORC-compliant resource stands at 20.0Mt at 211 g/t AgEq for 136 million ounces silver equivalent, with approximately 60Moz in the Indicated category suitable for use in economic studies.

How large is the 2026 drilling program?

Andean Silver is executing a 65,000-metre program in 2026, more than double the 30,000 metres completed in 2025, targeting both resource classification conversion and district-scale growth.

What is the discovery cost per ounce at Cerro Bayo?

Discovery costs are tracking at approximately A$0.20 per silver ounce, a figure considered highly competitive relative to industry peers and reflective of the high geological efficiency of drilling within an already-understood mineralised system.

When could Cerro Bayo restart production?

A feasibility study is underway with a potential full mine restart targeted for 2028. An early production scenario using the existing mill infrastructure and low-grade stockpiles could potentially be activated as early as 2027, subject to study outcomes and permitting requirements.

How much cash does Andean Silver have?

As of March 2026, the company held A$53.4 million in cash, supplemented by A$60 million in new financing secured to fund the ongoing drilling program, feasibility workstreams, and development activities.

What the Next 18 Months Must Deliver for Cerro Bayo's Investment Case to Strengthen

The analytical threads running through the Andean Silver Cerro Bayo drilling results converge on a consistent conclusion: this is a project where the geological fundamentals are strengthening with each successive drilling cycle, and where the structural conditions for a compelling development case are progressively being established.

The 22% resource upgrade to 136Moz AgEq, the elevation of approximately 60Moz into the Indicated category, an exceptional peak intercept of 30,202 g/t AgEq, and a discovery cost of roughly A$0.20 per ounce collectively describe a silver-gold system that is becoming incrementally harder to dismiss as speculative. The dual-track strategy of simultaneous resource growth and feasibility advancement creates a multi-catalyst environment across the remainder of 2026 and into 2027.

What the next 18 months will need to demonstrate is whether the district-scale drilling program can deliver a meaningful resource addition from previously untested zones, whether infill conversion achieves the targeted approximately 80% Indicated and Measured categorisation, and whether the feasibility study can translate exceptional grades into equally compelling project economics. Each of these outcomes represents a distinct and independently meaningful value inflection point for investors tracking this story.

For readers seeking broader coverage of ASX-listed silver and gold explorers, mineral resource estimation methodologies, or Chilean mining jurisdiction analysis, ongoing reporting is available at themarketonline.com.au, which provides continuous coverage of ASX materials and mining sector developments.

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