Marimaca Copper Confirms High-Grade Silver at Pampa Medina But Stays Disciplined on Capital

• Marimaca Copper has consolidated all Pampa Medina drilling to date, with completed inductively coupled plasma (ICP) assaying confirming silver is elevated, consistent, and broadly correlated with copper across both oxide and sulphide zones over a 3-kilometre by 2-kilometre area of interest.
• Phase I metallurgical programs at Pampa Medina remain incomplete, meaning copper equivalent grades cannot yet be reported, and the economic contribution of the silver component is not determinable at this stage.
• The company holds a US$165.6 million cash position with zero debt, reflecting gross proceeds from the Canadian Offering, and is maintaining a gated capital allocation strategy rather than deploying the treasury into an accelerated sulphide drill program.
• Properly infilling the Pampa Medina sulphide footprint will require 200,000 to 300,000 metres of drilling over several years; the company is targeting internal cash flow from the Marimaca Oxide Deposit to self-fund that program without returning to equity markets.
• The 2025 Definitive Feasibility Study (DFS) for the Marimaca Oxide Deposit (MOD) outlines a pre-production capital cost of US$587 million and a base case production of 50,000 tonnes per annum of copper cathode, with the company targeting an increase to 70,000 or 75,000 tonnes per annum through oxide expansion at Pampa Medina via a hub-and-spoke infrastructure model.

Silver Confirms System Scale - Development Path Remains Unchanged

Marimaca Copper (TSX: MARI | ASX: MC2)  is treating the Pampa Medina silver confirmation not as a near-term resource headline, but as long-term by-product optionality that can be monetised once the Marimaca Oxide Deposit (MOD) is cash-flowing and the share structure is protected. Marimaca Copper has consolidated all drilling results to date at its Pampa Medina deposit in Chile's Antofagasta region, releasing complete silver assay data that confirms consistent copper and silver mineralisation across a 3-kilometre by 2-kilometre area of interest. Phase I metallurgical programs remain incomplete, and copper equivalent grades cannot yet be reported, meaning the silver data adds by-product optionality but does not alter the development path.

Capital Discipline: A Structural Necessity, Not a Preference

Properly infilling the 3-kilometre by 1.5-kilometre sulphide footprint will require 200,000 to 300,000 metres of drilling over several years, a capital commitment that would materially consume the current treasury if pursued immediately. That makes the gated approach a structural necessity rather than a preference: gating sulphide drilling trades headline resource growth for reduced dilution risk, preserving the US$165.6 million cash position and zero debt balance to advance the MOD to a final investment decision (FID) by the end of 2026.

Chief Executive Officer and Director of Marimaca Copper, Hayden Locke, outlined the contrast:

"If you were a BHP or a Rio, you would probably just throw 150 million bucks at it and drill to your heart's content and try and delineate a resource." 

Locke added:

"For us, it'll probably be a little bit more gated than that, and will take a little bit more controlled approach."

The sequencing logic is tied directly to protecting the share structure. Once the MOD is generating cash flow, Locke confirmed:

 "Once we start producing cash flow, then we don't have to issue any more shares to go out and continue to chase these amazing expiration targets." 

The self-funding objective targets the full Pampa Medina sulphide drill-out over several years without returning to equity markets.

What the Silver Data Confirms & What It Does Not

The completion of ICP assaying across all drilling to date establishes that silver is present in both the oxide and sulphide copper-mineralised zones and is broadly correlated with copper grade across the deposit. Marimaca Copper noted that silver by-products are common in Chilean manto-type deposits, citing Capstone Copper's Mantos Blancos and Antofagasta Minerals' Cachorro deposit as regional analogues where silver by-products are common.

What the data does not establish is the economic weight of that silver component. Phase I metallurgical programs remain incomplete, copper equivalent grades have not been reported, and the contribution of silver to any future cost or revenue model is not determinable at this stage.

Drill Consistency Across a Large Footprint

The key takeaway from the consolidated database is not individual high-grade intervals, but the consistency of mineralisation across a large footprint. Drilling across the area of interest, including zones affected by post-mineralisation faulting and dyke intrusions, still returns consistent hits. This supports a laterally extensive sediment-hosted system, rather than isolated high-grade pockets.

Standout intercepts include 100 metres at 1.28% copper and 6.9 grams per tonne silver from 580 metres depth, including 6 metres at 11.98% copper and 82.0 grams per tonne silver, and 102 metres at 1.20% copper and 12.2 grams per tonne silver from 250 metres, including 18 metres at 5.11% copper and 53.4 grams per tonne silver. True widths are estimated at 80% to 90% of reported downhole intersection widths. Marimaca Copper currently has five rigs operating on site, with a rig count increase targeted over April and May 2026 to accelerate the 2026 drilling program.

Near-Term Path: Oxide Expansion Via Hub-and-Spoke

The shallower oxide mineralisation at Pampa Medina, situated approximately 28 kilometres east of the MOD, offers a nearer-term production growth pathway through a hub-and-spoke infrastructure model supported by oversized key equipment for cost-effective future production expansions. The 2025 DFS for the MOD establishes a pre-production capital cost of US$587 million and a base case production of 50,000 tonnes per annum of copper cathode, with a post-tax net present value at an 8% discount rate (NPV8%) of US$1.1 billion at a 39% internal rate of return (IRR) at US$5.05 per pound copper, numbers that underpin the MOD's role as the cash flow engine for the broader district strategy.

Advancing the extensional oxide zones at Pampa Medina through Phase I metallurgical and geotechnical work supports the company's target of increasing total copper cathode production to 70,000 or 75,000 tonnes per annum. That expansion, framed against the DFS economics, represents the highest immediate return on exploration dollars while the broader sulphide story matures. Marimaca is treating Pampa Medina's silver not as a near-term catalyst, but as optionality that accrues value once the MOD is producing and the share structure no longer depends on exploration-driven equity raises.

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