Marimaca Copper: Low-Cost Path to Production in Chile

• US$1.1 billion post-tax NPV at 39% IRR with US$587 million initial capital requirement representing industry-leading capital intensity among global copper development projects.
• Resolución de Calificación Ambiental (RCA) received in Q4 2025 following rigorous permitting process, de-risking construction timeline for 50,000 tonnes per annum copper cathode production.
• Project situated 25km from Port of Mejillones and 40km from Antofagasta with access to recycled seawater, renewable power, skilled workforce, and established infrastructure lowering execution risk.
• 30,000-meter drilling program at Pampa Medina validates extensive sediment-hosted copper system with both oxide and sulphide mineralization offering significant resource expansion beyond 748,000 tonnes contained copper in reserves.
• US$78.7 million cash (September 2025) with backing from strategic investors including Greenstone Resources (21.6%), Assore International (18.9%), and Mitsubishi Corporation (3.9%) supporting path to construction decision.

Copper's structural supply deficit and role in global electrification have pushed prices toward US$12,000 per tonne in late 2025, creating favorable conditions for development-stage projects that can deliver near-term production at competitive costs. Marimaca Copper Corp has positioned itself at the intersection of these market dynamics with a fully permitted, low-capital-intensity oxide copper project in Chile's established Antofagasta mining district.

The completion of a Definitive Feasibility Study in August 2025 and subsequent environmental approval in November provide investors with visibility into a development timeline that could see first production within two years of a construction decision. The company's district consolidation strategy at Pampa Medina, where recent drilling continues to validate a large sediment-hosted copper system, adds optionality for production expansion and mine life extension beyond the initial 13-year reserve base.

The copper market context amplifies Marimaca's investment case. COMEX copper stocks surged 388% year-over-year while LME inventories declined, reflecting geographic demand shifts ahead of 2026. Structural demand from energy transition infrastructure, artificial intelligence data centers, and electrification initiatives supports long-term price forecasts in the US$10,000-11,000 per tonne range. Against this backdrop, Marimaca's second-quartile all-in sustaining costs of US$2.09 per pound position the project to generate substantial free cash flow across various price scenarios.

Company Overview

Marimaca Copper Corp operates exclusively in Chile's Antofagasta Region, focusing on the development of the Marimaca Oxide Deposit (MOD) and exploration of the adjacent Pampa Medina and Sierra de Medina properties. The company's strategy centers on three value pillars: advancing the MOD toward near-term production, defining district-scale resources at Pampa Medina, and systematically exploring complementary satellite targets that could feed future production scenarios.

The company's management team combines deep Chilean copper experience with international project development expertise. CEO Hayden Locke brings nearly 20 years in mining and finance, including corporate development roles at Papillon Resources. Vice President of Exploration Sergio Rivera has over 30 years of exploration geology experience in Chile and is credited with the original Marimaca discovery. This leadership team is supported by a Board that includes Clive Newall (co-founder of First Quantum Minerals), Giancarlo Bruno (former CEO of Mantos Copper), and Tim Petterson (founder and executive chairman of Minera Cobre).

Marimaca maintains dual listings on the Toronto Stock Exchange (TSX: MARI) and Australian Securities Exchange (ASX: MC2), providing access to capital markets in two major mining finance hubs. As of September 30, 2025, the company reported 118.5 million shares outstanding with a market capitalization of approximately C$1.28 billion. The shareholder base includes strategic investors with long-term copper exposure objectives: Greenstone Resources holds 21.6%, Assore International 18.9%, and Mitsubishi Corporation 3.9%.

The Marimaca Oxide Deposit: Definitive Feasibility Study Results

The August 2025 Definitive Feasibility Study for the MOD established robust project economics that compare favorably against other copper development projects globally. The study envisions a conventional open-pit mine feeding a 50,000 tonne per annum copper cathode operation via heap leaching and solvent extraction-electrowinning (SX-EW) processing. At a long-term copper price of US$4.30 per pound, the project delivers a post-tax net present value (8% discount rate) of US$709 million with a 31% internal rate of return.

At the three-month average COMEX spot price of US$5.05 per pound, the NPV expands to US$1.1 billion with a 39% IRR and 2.2-year payback period. Initial capital expenditure totals US$587 million, translating to capital intensity of US$11,700 per tonne of annual copper production capacity. This metric positions Marimaca among the lowest capital-cost copper development projects globally when compared against North and South American peers.

The capital efficiency derives from multiple factors: low strip ratio of 0.8:1 over mine life, simple metallurgy amenable to heap leaching, proximity to existing infrastructure eliminating need for greenfield port or power development, and relatively low elevation at 1,100 meters above sea level. The DFS includes 10% contingency on direct and indirect capital costs, with 80% of mechanical equipment pricing supported by budget quotes.

Operating costs benefit from similar structural advantages. The study projects steady-state (years 2-10) all-in sustaining costs of US$2.09 per pound of copper produced at US$5.05/lb copper price, placing the project in the second quartile of the global cost curve.C1 cash costs average US$1.84 per pound over mine life, with first five years of steady-state operation averaging US$1.45 per pound, with processing costs of US$6.25 per tonne and mining costs of US$2.00 per tonne. The operation will utilize leased mining equipment rather than capital purchases, reducing upfront investment.

Mineral Resources & Ore Reserves

The 2025 Mineral Resource Estimate established 213.5 million tonnes of Measured and Indicated resources grading 0.40% total copper for 854,000 tonnes of contained metal, plus 21.2 million tonnes of Inferred resources at 0.29% copper containing 62,000 tonnes of metal. This represents 93% of total resource tonnage in the Measured and Indicated confidence categories, reflecting the maturity of the deposit following over 135 kilometers of drilling since 2016.

Reserve conversion achieved 88% efficiency, with 178.6 million tonnes at 0.42% copper classified as Proven and Probable reserves containing 748,000 tonnes of metal. The reserve estimate assumes a copper price of US$4.25 per pound and average recovery of 72% through heap leaching. Proven reserves total 94.3 million tonnes at 0.46% copper, while Probable reserves comprise 84.3 million tonnes at 0.37% copper.

The life-of-mine strip ratio of 0.82:1 (waste to ore) increases to 0.96:1 when including pre-stripped material, remaining significantly below industry averages for open-pit copper mines. First four years of operation average a strip ratio of only 0.6:1, supporting rapid payback economics. The deposit remains open for expansion, particularly at depth where Inferred resources have not been included in the current development plan. Near-mine exploration targets including Mercedes, Robles, Cindy, and Tarso offer potential to add oxide resources that could extend mine life.

Environmental Approval and Permitting Progress

Marimaca received formal Resolución de Calificación Ambiental (RCA) approval in November 2025, marking the successful completion of the Declaración de Impacto Ambiental (DIA) permitting process initiated in December 2024. The RCA represents Chile's key environmental permit required before construction can commence and followed a rigorous evaluation process that included multiple years of environmental baseline studies, technical engineering submissions, and stakeholder engagement sessions.

The DIA route chosen by Marimaca reflects the project's relatively low environmental impact profile. Key factors supporting this classification include: no overlap with community land or indigenous territories, limited flora and fauna impact expected in the coastal Atacama Desert environment, use of recycled seawater rather than continental or fresh water sources, and certified renewable electricity supply. The company conducted voluntary stakeholder engagement sessions beyond regulatory requirements to build community support.

Marimaca has now advanced to the Sectorial Permits phase, which comprises auxiliary permits required for various stages of construction and operation. These include water extraction permits, explosives storage authorizations, waste management approvals, and construction permits for specific infrastructure components. The company reports being well advanced in this permitting phase, with multiple sectorial permits already secured or in final review stages. The combination of RCA approval and progress on sectorial permits positions the project to reach construction-ready status following a Final Investment Decision.

Pampa Medina: District-Scale Discovery Potential

The Pampa Medina and Madrugador properties, acquired in recent years and located approximately 25 kilometers from the planned MOD processing infrastructure, represent Marimaca's most significant exploration opportunity. A 30,000-meter drilling program initiated in 2025 continues to validate an extensive sediment-hosted copper system spanning both oxide and sulphide mineralization across an 1,800-meter strike length and extending to depths exceeding 600 meters.

Recent drilling results demonstrate the scale and grade potential of the Pampa system. Hole SMR-01 intersected 102 meters of 1.2% copper from 250 meters depth, including 18 meters of 5.1% copper from 320 meters. Step-out hole SMRD-13 encountered 26 meters of 4.1% copper from 580 meters depth, including 6 meters of 12.0% copper from 594 meters in sulphide mineralization. Hole SMRD-20, drilled 300 meters from the nearest previous intercept, returned 198 meters of 0.7% copper from 460 meters including 38 meters of 1.4% copper from 540 meters.

Hayden Locke, CEO and President, Marimaca Copper mentioned:

"The Pampa Medina drilling program continues to validate our geological model of an extensive sediment-hosted copper system with both near-surface oxide potential and high-grade sulphide mineralization at depth. The consistency of mineralization across 300-meter step-outs and the grades we're encountering in the sulphide zones position this as a potential district-scale discovery that could materially impact our production profile and mine life."

The company plans to complete the current drilling phase in 2026, followed by resource estimation work that will inform development options including potential satellite oxide operations feeding the MOD plant or stand-alone sulphide development scenarios leveraging shared infrastructure. The first-time consolidation of this entire land package under single ownership enables district-scale planning not previously possible.

Infrastructure & Execution Advantages

Marimaca's location in the Antofagasta Region provides access to world-class mining infrastructure that significantly reduces both capital requirements and execution risk. The MOD sits 25 kilometers from the Port of Mejillones, eliminating need for dedicated port facilities and providing direct access to copper cathode export markets. Antofagasta, Chile's fifth-largest city with a population exceeding 400,000, is located 40 kilometers from site, enabling a commute-based workforce model that avoids costly accommodation camp construction.

Power infrastructure requires only a 10-kilometer connection to existing transmission lines with certified renewable electricity supply available from Chile's northern grid. The company has secured a water option agreement for recycled seawater from the Bay of Mejillones, with permitted intake infrastructure already in place. A 32-kilometer pipeline with one pumping station will deliver 208 liters per second to site at a capital cost included within the US$587 million initial development budget.

Access to consumables further reduces operational risk and logistics costs. Sulfuric acid, the primary reagent for heap leaching, is produced in quantity at nearby copper smelters including those operated by Antofagasta Minerals and BHP. Transportation distances for acid, copper cathode, fuel, and other supplies measure in tens rather than hundreds of kilometers. Equipment maintenance facilities, technical services, and specialized mining contractors have established operations in the Antofagasta region supporting dozens of active mines.

Current Development Activities

Following DFS completion and environmental approval, Marimaca has initiated detailed engineering work with lead consultants Ausenco and NCL, both firms with extensive Chilean copper project experience including recent developments at Mantoverde and Santo Domingo. This engineering phase will advance the process plant design, mining plans, and infrastructure layouts from feasibility-level (±15% accuracy) to execution-level (±5-10% accuracy) required for equipment procurement and construction contracting.

Project financing activities are progressing in parallel with engineering work. The company is engaging with potential debt providers including export credit agencies, commercial banks with mining sector exposure, and project finance specialists familiar with Chilean copper operations. The combination of relatively modest debt requirement (estimated at US$300-400 million based on typical 60-40 debt-to-equity structures), strong project economics, and environmental approval position the financing process favorably.

Exploration activities continue systematically across the district. The Pampa Medina program delivers validation of scale and grade positioning this as a genuine second major asset for the company. The company also conducts reconnaissance work on near-pit oxide targets that could provide supplemental feed or mine life extensions. Drilling campaigns for 2025-2026 span both the Pampa Medina sulphide and oxide zones as well as near-MOD satellite targets including Mercedes, Robles, and other prospects.

Financial Position & Capital Requirements

Marimaca reported US$78.7 million in cash and equivalents as of September 30, 2025, with no debt obligations providing a clean balance sheet for project financing. The company completed an equity financing in 2025 that strengthened the treasury position ahead of expected development spending increases. Monthly burn rate through 2025 has averaged US$3-4 million covering corporate overhead, ongoing exploration programs, and project development activities.

The US$587 million initial capital requirement breaks down into US$437 million direct costs (74%), US$80 million indirect costs (14%), US$17 million owner's costs (3%), and US$53 million contingency (9%). Major direct cost components include crushing and agglomeration facilities (US$141 million), heap leach and SX-EW plant (US$223 million), infrastructure (US$49 million), and mine development (US$24 million). An additional US$77 million expansion capital in year 6 funds crusher capacity increase from 12 million tonnes to 16 million tonnes annually.

Life-of-mine sustaining capital totals US$529 million including deferred stripping, equipment replacement, and infrastructure maintenance. The company's dual listing on TSX and ASX provides access to diverse capital pools, while the presence of Greenstone Resources (21.6% shareholder) and Assore International (18.9% shareholder) as cornerstone investors suggests potential participation in future financings at attractive valuations.

Peer Comparison & Valuation Context

Among copper development projects approaching construction decisions, Marimaca's capital intensity of US$11,700 per tonne of annual production capacity ranks among the most competitive globally. Comparative projects such as Costa Fuego (US$13,400/t), Vizcachitas (US$15,000/t), and Santo Domingo (US$21,800/t) require significantly higher capital per unit of production capacity. This capital efficiency translates to lower financing requirements, faster payback periods, and higher returns on invested capital.

The company's current enterprise value of approximately US$1.15 billion (market cap less cash) represents roughly 2.0x the post-tax NPV at US$4.30/lb copper, below the 2.5-3.0x multiples often observed for advanced-stage development projects with similar de-risking milestones. Production-focused peers in Chile's copper sector provide reference points for potential valuation re-rating as Marimaca transitions from developer to producer.

The development risk discount embedded in Marimaca's valuation should compress as key milestones are achieved: detailed engineering completion, financing package announcement, and construction commencement. Historical precedents suggest development companies typically re-rate 40-60% from advanced-stage development through first production ramp-up. Marimaca's relatively short 24-month construction timeline and straightforward mining and processing methods support above-average probability of on-time, on-budget execution.

The Investment Thesis for Marimaca Copper

• Environmental approval and DFS completion reduce execution uncertainty; accumulate on weakness before Final Investment Decision.
• Project economics show 35%+ IRR sensitivity; price strength validates development timelines and supports sector rotation.
• Drilling success provides organic growth beyond 13-year reserve base; separate value creation pathway independent of MOD execution.
• Development projects like Marimaca offer higher beta to copper prices than established producers; combine for risk-adjusted positioning.
• Equipment procurement announcements and contractor selection indicate construction timeline confidence; use for entry points.
• Mitsubishi or Assore involvement in debt/equity package signals confidence; strengthens de-risking case ahead of construction.

Marimaca Copper has systematically de-risked its flagship Marimaca Oxide Deposit through completion of a robust Definitive Feasibility Study and receipt of environmental approval, positioning the project for potential construction decision in 2026 following financing arrangements and detailed engineering completion. The project's industry-leading capital intensity of US$11,700 per tonne of production capacity, second-quartile operating costs, and 39% internal rate of return at current copper prices establish strong investment fundamentals.

The Pampa Medina discovery adds significant upside optionality through validation of an extensive sediment-hosted copper system with both near-surface oxide and high-grade sulphide mineralization. Located 25 kilometers from planned MOD infrastructure, successful definition of economic resources at Pampa Medina could enable satellite development scenarios that leverage shared processing facilities and infrastructure, materially improving project economics and extending mine life beyond the current 13-year reserve base.

For investors seeking leveraged exposure to copper's structural supply deficit and electrification demand drivers, Marimaca offers a de-risked development opportunity in a Tier 1 jurisdiction with strong financial backing from strategic investors. The company's strong cash position (US$78.7 million at September 30, 2025) and support from cornerstone shareholders including Greenstone Resources (21.6%), Assore International (18.9%), and Mitsubishi Corporation (3.9%) provide financing confidence ahead of the capital-intensive construction phase.

TL;DR

‍Marimaca Copper (TSX: MARI) advances toward production at its Marimaca Oxide Deposit with industry-leading capital intensity of US$11,700/tonne copper capacity, environmental approval secured, and district-scale exploration upside at Pampa Medina where drilling validates sediment-hosted copper systems 25km from planned infrastructure.

FAQs (AI-Generated)