Marimaca Copper (TSX:MARI) - Superior Grades Add Upside to December 2025 PEA Target

Key Concepts

Pamper Medina: A copper deposit being explored by Marramaca Copper.
Oxide Mineralization: Copper mineralization found near the surface, typically easier to process.
Sulfide Mineralization: Copper mineralization found at deeper levels, often requiring different processing methods.
Sedimentary Horizon: A geological layer where copper mineralization is found at Pamper Medina.
Block Model: A digital representation of the ore body used for resource estimation.
Step-out Drilling: Drilling holes further away from known mineralization to define its extent.
Infill Drilling: Drilling holes closer together within known mineralization to improve confidence and define continuity.
Inferred Resource: A preliminary estimate of mineralized material.
Postmineral Dykes/Faults: Geological features that formed after the main mineralization event, potentially disrupting it.
AMT Survey (Audio-Magnetotellurics): A geophysical method used to measure electrical resistivity, which can correlate with sulfide mineralization.
Super Pit: A large open-pit mine.
Feeder Zone: A geological area where mineralizing fluids are thought to have entered the deposit, often associated with higher grades.
Marker Horizon: A specific geological feature (e.g., black shale) that can indicate the presence of higher-grade mineralization.
Manto Deposit: A type of stratiform deposit, often found in sedimentary rocks.
Metallurgical Program (Met Program): Studies to determine the best way to extract copper from the ore.
Column Leaching: A method for extracting copper from oxide ores.
Cathode: The final product of copper processing.
Preliminary Economic Assessment (PEA): An early-stage study to assess the economic viability of a mining project.
DFS (Definitive Feasibility Study): A detailed study that provides a high level of confidence in the technical and economic viability of a project.
Capex (Capital Expenditure): Costs associated with building a mine.

Pamper Medina: Latest Drill Results and Exploration Strategy

Lo, President and CEO of Marramaca Copper, provides an update from Antagusta regarding the Pamper Medina project, focusing on recent drill results and the ongoing exploration strategy. The results are described as "more than confirming" the company's thesis on the deposit, with some grades being particularly impressive.

Oxide Mineralization Highlights

Significant Oxide Intersection: A press release highlights an oxide intersection of nearly 50 meters at 2% copper, within a broader zone of 160 meters at 1% copper.
Material Extension: This intersection represents a "material extension" to the oxide envelope and is higher grade than currently interpreted in the block model.
Growth Potential: The company sees further growth potential in the oxide portion of the resource.

Sulfide Mineralization and Step-Out Drilling

Aggressive Step-Out Campaign: Marramaca Copper is conducting an aggressive drill campaign with large step-outs, including drilling 900 meters to the south.
Sedimentary Horizon Confirmation: These step-out holes have intersected the same mineralized sedimentary horizon.
Impressive Sulfide Intercepts: While some zones were thinner, there were notable intersections of over 20 meters at 1.5% copper, and one nearly 40 meters at 1.5% copper.
Thesis Confirmation: These results continue to confirm the thesis put forward by Cirio, with the company aiming to define the full extent of the deposit.

30,000-Meter Drill Program Breakdown

The 30,000-meter drill program is divided into two main phases:

Extensions (20,000 meters):
- Focuses on continuing step-out drilling on 300-meter spacings, both to the west and on north-south fences.
- This aggressive approach aims to define the lateral and regional extent of the sedimentary-hosted copper deposits, which are known to be extensive.
- The goal is to define the limits before planning a more intensive infill program for an inferred resource.
Infill and Confidence Building (10,000 meters):
- Involves drilling on slightly tighter spacings to connect high-grade zones and assess geological continuity.
- This phase aims to provide more confidence in the overarching thesis and begin defining grade and thickness continuity between drill fences.

Addressing Geological Complexities: Fault Zones and Dykes

Fault Block Geometry: The deposit exhibits fault block geometry, which complicates drilling. A detailed understanding of these structures will be gained through the infill campaign targeting an inferred resource on a 100x100 meter spacing.
Postmineral Dykes: The importance of postmineral dyking in the deposit's formation is recognized.
Continuity Despite Discontinuities: Notably, discontinuities caused by postmineral dykes and faults are themselves postmineral, meaning they occurred after the deposit was emplaced. Even with these discontinuities, good grades and thicknesses are observed on either side, indicating continuity where these features are absent.
Dyke Mineralization: Previously interpreted as barren, dykes are now understood to contain some mineralization, which will contribute to the overall tonnage, albeit at lower grades than the sedimentary horizon.

Drilling Focus: West and South

Westward Expansion: The primary focus for step-out drilling is to the west.
Eastward Limitation: An uplifted fault block to the east has caused thinning of the sedimentary horizon, making it less of a priority, though oxide mineralization has been found at surface.
Southern Surprise: Drill holes to the south, 900 meters from the known mineralization, yielded thicker and higher-grade zones than expected, prompting further drilling in that direction.

Geophysical Data Correlation

AMT Survey Confirmation: An AMT survey, which measures resistivity, shows a good correlation with drilling results. Low resistivity zones in the AMT survey generally correspond to sulfide intersections in the sedimentary horizon.
Cirio's Exploration Model: The drilling continues to confirm Cirio's exploration model, even in areas with postmineral dykes and faults.

Deposit Type and Potential Scale

Sediment-Hosted Manto: Pamper Medina is characterized as a sediment-hosted manto deposit.
Extensive Sedimentary Basin: The sedimentary basin is extensive, spanning multiple kilometers east-west and a couple of kilometers north-south.
Standalone vs. Satellite:
- Oxides: Viewed as a satellite deposit, potentially utilizing existing infrastructure.
- Sulfides: Considered a "very different beast" with a distinct processing methodology, and "almost certainly a standalone" deposit.
Upside Potential: The oxide resource is showing significant upside beyond initial expectations of 20,000 tons of incremental copper for 10 years.
Potential for Super Pit: There is a growing view that Pamper Medina could be a "super pit" (large open-pit mine), challenging the initial assumption of it being solely an underground opportunity. This is based on the realization that lower-grade material in a halo around the high-grade core could be economically viable in an open-pit scenario.
High-Grade Cores: The deposit features higher-grade cores, potentially akin to feeder zones.

Identifying High-Grade Zones

Marker Horizon: A black shale interbedded between sandstones serves as a marker horizon, often indicating relatively high-grade mineralization (north of 1.5% copper). This helps geologists vector towards promising areas.

Metallurgical Program and PEA Timeline

Oxide Met Program Underway: A metallurgical program for Pamper Medina oxides is in progress, with column leaching being conducted.
Dominantly Atacamaite: The copper species is dominantly atacamite, unlike the mod deposit which also has chrysocolla.
Data Availability: Extensive technical data from previous campaigns (acid solubility, cyanide soluble data, analytical acid consumption) is available.
PEA by Year-End: Marramaca Copper is well into a standalone Preliminary Economic Assessment (PEA) for Pamper Medina, with a target release before the end of the year.
Standalone PEA Rationale: A standalone PEA avoids complications associated with re-releasing the Definitive Feasibility Study (DFS) if integrated with the Marramaca DFS. The standalone PEA assumes on-site mine, crush, leach, and cathode production.
Capital Cost Synergy: Utilizing Marramaca's oxide infrastructure would offer significant capital cost synergies, potentially improving the project's economics.

Company Sentiment and Future Outlook

Excitement and Caution: While the company is "very excited" about the drill results, there is an acknowledgment of the significant work ahead and the early stage of understanding the deposit.
Recent Tragedy: The company is experiencing a sober time due to the recent passing of a director.
Drill Results Timeline: Drill results are expected to be released in batches approximately every month. The delay is attributed to the extensive geological work required by their geologist, Cirio, and the logistics of managing five rigs with a small geological team.
Team Expansion and Execution Strategy: Marramaca Copper is focusing on the execution strategy, planning key hires, and optimizing capex. The CEO is on-site to identify areas for optimization and risk mitigation before commencing construction.

Conclusion and Next Steps

Marramaca Copper's Pamper Medina project is showing significant promise, with recent drill results exceeding expectations, particularly in oxide mineralization and the extent of sulfide mineralization. The company is aggressively pursuing definition drilling to understand the deposit's full potential, which may include a large open-pit scenario. A standalone PEA is anticipated by the end of the year, providing a clearer picture of the project's economic viability. Despite recent challenges, the company is focused on strategic planning and team expansion to advance the project towards development.