Marimaca Copper's Pampa Medina Silver Assays: 7 Things You Need to Know

Pampa Medina's Silver Signal

Marimaca Copper Corp. (TSX: MARI, ASX: MC2) released its complete silver assay results alongside a consolidation of all Pampa Medina drilling results at its deposit in Chile's Antofagasta region. The release adds a new dimension to a copper story that has been building since Marimaca consolidated the project area in 2024. Silver is consistently present, broadly correlated with copper grade, and material as a by-product credit. With a 100,000 metre drill program underway in 2026 and the flagship Marimaca Oxide Deposit (MOD) advancing toward a construction decision, the silver dataset adds to framing the Pampa Medina asset.

1. Silver Is Present Across the Full Deposit, Not Just in Isolated Zones

The completion of inductively coupled plasma (ICP) assaying across all Pampa Medina drilling confirms silver mineralisation is a deposit-wide feature, present in both oxide and sulphide zones, and broadly correlated with copper grade.

The consolidated database spans the 3-kilometre by 2-kilometre area of interest, covering the full range of depths and mineralisation styles drilled to date. This confirms the working hypothesis that silver grades are elevated, consistent, and strongly correlated with copper grades across the known deposit area.

2. The Peak Grades Are High, But the Breadth of the Signal Is What Matters

The ICP assaying indicates consistent, high-grade silver mineralisation with the potential to be a predictable by-product credit at scale, a characteristic that holds across multiple holes, depths, and orientations.

Highlights from the ICP assaying include 82 grams per tonne silver from one hole within a 6 metre interval, returning 11.98% copper from 594 metres. Another hole returned 198 metres of 0.65% copper and 5.1 grams per tonne silver from 460 metres, including 30 metres of 1.70% copper and 20.9 grams per tonne silver from 548 metres. True widths are estimated at 80% to 90% of reported downhole intersection widths.

3. The Manto-Type Geological Setting Has Regional Precedent for Silver By-Products

Pampa Medina's manto-style copper deposit is hosted in Jurassic-Triassic sedimentary units, a geological setting directly comparable to nearby Chilean deposits where silver by-products are well established.

Silver by-products are common in Chilean manto-type deposits. The company references Mantos Blancos, owned by Capstone Copper, and Cachorro, owned by Antofagasta Minerals, both located in Chile's Antofagasta region, as nearby examples. The company includes Cachorro in its regional map alongside Pampa Medina and notes Marimaca's position as a leading landholder as an emerging tier 1 discovery belt in Chile.

Following Marimaca's consolidation of the project area and surrounding land packages in 2024, the company reinterpreted all available geological information and developed an updated geological model for Pampa Medina, which identified the lower sedimentary units as the priority target horizons for future drilling.

4. Silver Grades Are Elevated Across Both Oxide and Sulphide Zones

Elevated silver grades are present in both oxide and sulphide copper-mineralised zones at Pampa Medina and are generally correlated with copper grade.

The oxide zone is dominated by atacamite, chrysocolla, and secondary chalcocite. The deeper sulphide zone hosts bornite, chalcopyrite, covellite, and chalcocite. The company identifies Pampa Medina as carrying tier 1 potential as a large copper system across both oxides and sulphides.

5. Metallurgical Work Is the Pending Gate Before Economics Can Be Stated

No copper equivalent grades have been reported, and none can be reported until Phase I metallurgical programs are completed. Marimaca has not yet completed its Phase I metallurgical programs at Pampa Medina and is therefore not reporting copper equivalent grades at this time. The company has not disclosed a timeline for its completion.

6. The Company Is Releasing Silver Assays Alongside a Full Consolidation of Pampa Medina Drilling

The company released these silver assays alongside a consolidation of all Pampa Medina drilling results to date, covering the 3-kilometre by 2-kilometre area of interest, with the system remaining open in multiple directions.

Recent step-out holes to the west include holes which return silver alongside copper. One hole returned 38 metres of 1.43% copper and 11.8 grams per tonne silver from 694 metres. Another hole returned 74 metres of 1.21% copper and 7.9 grams per tonne silver from 520 metres. The company confirms that the 2026 drilling program is targeting extensions to the west, northwest, and northeast, with 5 rigs currently on site and plans to increase the rig count over April and May 2026. The company further lists an ongoing 100,000 metre drill program for Pampa Medina in 2026, and separately notes a 30,000 metre step-out and delineation program underway to test the extent of the mineralised system.

7. Pampa Medina's Silver Confirmation Fits Within Marimaca's Two-Asset District Strategy

The company notes that precious metal by-products in large primary copper deposits can surface exceptional value for builders and operators, as seen in recent and past transactions.

Marimaca positions Pampa Medina as one of three core value pillars under "Game Changing Growth" alongside the MOD as near-term production and near-mine exploration as complementary opportunities. Pampa Medina carries significant synergy potential with MOD, given its location from the planned MOD processing plant as defined in the Definitive Feasibility Study (DFS). This is to advance a hub-and-spoke district development plan that targets the development of Pampa Medina and Madrugador oxides to grow cathode production and increase mine life.

Key Takeaways for Investors

• Deposit-wide silver confirmation: Inductively coupled plasma (ICP) assaying across all Pampa Medina drilling confirms silver mineralisation is consistently present and broadly correlated with copper grade across both oxide and sulphide zones in a 3-kilometre by 2-kilometre area of interest, establishing silver as a potential predictable by-product credit at scale rather than a localised occurrence.
• Metallurgical gate remains open: Phase I metallurgical programs at Pampa Medina are not yet complete, and the company is therefore not reporting copper equivalent grades; no timeline for completion has been disclosed.
• Significant 2026 drill program underway: The company lists an ongoing 100,000 metre drill program for Pampa Medina in 2026, with 5 rigs currently on site and plans to increase the rig count over April and May 2026, targeting extensions to the west, northwest, and northeast.
• Strategic positioning within a two-asset district: The Pampa Medina has a significant synergy potential with the Marimaca Oxide Deposit (MOD), given its location approximately 25 kilometres from the planned MOD processing plant as defined in the Definitive Feasibility Study (DFS).

The Bottom Line

Marimaca's complete silver assay results, consolidated from all Pampa Medina drilling to date, confirm silver is consistently present and broadly correlated with copper grade across both oxide and sulphide zones. This indicates potential for a predictable by-product credit at scale, though no copper equivalent grades are reported pending Phase I metallurgical programs. The 2026 drill program, planned for 100,000 metres with 5 rigs currently active and expanding, continues step-outs to the west, northwest, and northeast to define the system's extent. Precious metal by-products are a recognised value driver in many primary copper deposits.