Marimaca Copper (ASX:MC2) believes it could become a “large mid-tier copper producer” through development of its Pampa Medina Project, which sits 28km from the company’s namesake project in Chile.
This news comes after Marimaca received assay results from an ongoing drilling program at Pampa Medina, which demonstrate continuity of ‘ultra high-grade’ copper-silver mineralisation across the central zone.
Hole SPRD-05 intersected 96m @ 1.19% copper (Cu) and 11.7 grams per tonne silver (Ag), including 16m @ 5.7% Cu and 62.6g/t Ag and 4m @ 11.32% Cu and 144g/t Ag.
Recent assay results also continue to extend the central sulphide zone and confirm multiple stacked manto-style copper-silver horizons across the sedimentary and volcanic sequence. Hole SPRD-07 extended the ‘ultra high-grade’ bornite zone 300m south of previous drilling, returning 20m @ 2.65% Cu and 13.9g/t Ag, including 6m @ 6.11% Cu and 24g/t Ag.
Speaking to Mining.com.au, CEO Hayden Locke says the company believes Pampa Medina could become “far more valuable” than its Marimaca oxide deposit.
“We think the threshold to become a tier one opportunity is more than 100,000 tonnes of copper production per annum for a minimum mine life of 20 years,” Locke tells this news service.
“So in order to be able to achieve that goal, you have to have a minimum mineral endowment of probably 2.5 million tonnes of contained copper, maybe even 3 million tonnes of contained copper once you take into account mining and recovery losses.”
Mantos potential
Marimaca also reveals Pampa Medina hosts sulphide mantos, which shows strong lateral continuity across the defined area of interest, with 150m-spaced delineation drill holes continuing to intersect more than 2% copper over ‘significant’ widths in dominantly bornite and chalcocite.
Locke explains that typical manto deposits are stratigraphically controlled copper deposits.
“Typically they are hosted in a single lithologic geological unit, and normally that lithology is volcanic,” Locke adds.
“The difference with Pampa Medina, and it’s very unusual for Chile, is that it’s predominantly hosted in sandstones and shales.”
Marimaca Copper is spending just shy of $30 million from the beginning of 2026 until H2 2027 on exploration at Pampa Medina.
“So about 18 months of drilling and that will continue to move the Pampa Medina Project forward,” Locke says.
The company also intends to conduct a maiden resource estimate for Pampa Medina in early 2027. A follow-up 30,000m phase two drill program is currently ongoing, representing the first district-wide program designed to map the full extent of this opportunity.
“We are very hopeful that this will deliver something that shows that our view is that this is a tier one asset that is very much intact and that thesis holds,” Locke adds.
Pampa Medina, located within the southern portion of a broader 14,500-hectare property package, was acquired by Marimaca Copper in October 2024.
More about Marimaca
As previously reported, Marimaca Copper is also formally assessing funding partners for the development of its namesake project in Chile.
The Marimaca Project has a low capital intensity, high margin, and compelling near-mine and satellite resource expansion opportunity.
A 2025 Definitive Feasibility Study highlighted that the project has a post-tax net present value of US$1.1 billion ($1.6 billion) and an internal rate of return of 39%. Marimaca also has a pre-production capex of US$587 million, with a production target of 50,000 tonnes per year over a 13-year mine life.
Permits that have been submitted include the closure plan, open pit mining method, and several additional approvals required for the construction of core project infrastructure. These permits are expected to be approved in Q4 2026.
Marimaca Copper is a dual-listed copper company with assets located in the Antofagasta region of Chile.
Write to Aaliyah Rogan at Mining.com.au
Images: Marimaca Copper
