Marimaca Copper's Pampa Medina Step-Out Drilling Returns 424 metres at 0.58% Copper Across 5 Stacked Mantos

• Marimaca Copper reported new assay results from its ongoing 2026 step-out exploration drilling program at the Pampa Medina deposit, located approximately 28 kilometres east of the company's Marimaca Oxide Deposit (MOD) in northern Chile.
• The program is drilling at 150-metre spacing to test continuity between previous 300-metre scout holes, with this release covering 10 holes across the initial 3-kilometre-by-1.5-kilometre area of interest.
• One central zone hole returned 424 metres at .58% total copper and 2.2 grams per tonne silver from a depth of 424 metres, containing 5 vertically stacked high-grade mantos within a mineralised package exceeding 400 metres in thickness, with a peak sub-interval of 8 metres at 2.54% total copper and 21 grams per tonne silver.
• A second central zone hole intersected 166 metres at .50% total copper and 3.9 grams per tonne silver from 222 metres, including a peak 4-metre sub-interval at 4.60% total copper and 50.5 grams per tonne silver from 234 metres.
• A south-western step-out hole drilled 300 metres beyond a previously released result intersected 68 metres at .73% total copper and 5.1 grams per tonne silver from 532 metres, including 30 metres at 1% total copper and 7.3 grams per tonne silver.

Company Overview

Marimaca Copper Corp. (TSX: MARI) is a copper exploration and development company focused on the Marimaca Oxide Deposit (MOD) and the Pampa Medina project in the Antofagasta Region of northern Chile. The company holds a tenement package of approximately 14,500 hectares at the broader Sierra de Medina project area, comprising a mix of mining and exploration concessions held through its subsidiaries ICAL and SCM Elenita.

Program Overview & Geological Setting

Marimaca Copper reported new assay results from its ongoing 2026 step-out exploration drilling program at the Pampa Medina deposit, located at low altitude approximately 28 kilometres east of the company's MOD. The program drills on 150-metre spacing to test continuity between previous 300-metre scouting holes, with this release covering 10 holes targeting the central high-grade zone and the south-western extent of the sediment horizon.

Pampa Medina is a manto-style copper deposit hosted in Jurassic-Triassic sedimentary units overlain by andesitic volcanics and underlain by an Upper Palaeozoic complex of metamorphosed sediments, volcanics, and intrusions. The oxide zone is dominated by atacamite, chrysocolla, and secondary chalcocite, with primary sulphide mineralisation at depth comprising chalcopyrite, bornite, covellite, and chalcocite. Elevated silver grades are present in both oxide and sulphide zones and are reported as generally correlating with copper grade.

All drilling is conducted as reverse circulation (RC) collared and diamond drill hole (DDH) tailed, with DDH drilling commencing at the contact between the upper volcanics and upper sedimentary units. True widths are estimated at 80% to 90% of reported downhole intercept lengths based on downhole bedding and structural measurements.

Central Zone Results

One central zone hole, drilled at 150-metre spacing, returned 424 metres at 0.58% total copper and 2.2 grams per tonne silver from a depth of 424 metres, containing 5 high-grade, vertically stacked mantos. Sub-intervals include: 32 metres at 1.02% total copper and 3.1 grams per tonne silver from 432 metres (oxide); 22 metres at 1.23% total copper and 11.8 grams per tonne silver from 492 metres (mixed), including 8 metres at 2.54% total copper and 21 grams per tonne silver; 22 metres at 1.53% total copper and 13.6 grams per tonne silver from 564 metres (sulphide), including 8 metres at 2.70% total copper and 24.5 grams per tonne silver; 10 metres at 1.38% total copper and 4.4 grams per tonne silver from 698 metres (sulphide); and 8 metres at 1.29% total copper and 10.8 grams per tonne silver from 752 metres (sulphide).

The company stated that the stacking of multiple high-grade mineralised sedimentary units is a key difference between Pampa Medina and other known sedimentary-hosted copper deposits globally, referencing the Kupferschiefer and Kamoa-Kakula deposits.

Two further central zone holes on 150-metre spacing returned: 146 metres at 0.41% total copper and 1.9 grams per tonne silver from 286 metres, including 50 metres at 0.56% total copper and 2.4 grams per tonne silver and 10 metres at 1.90% total copper and 10.6 grams per tonne silver from 306 metres; and 166 metres at 0.50% total copper and 3.9 grams per tonne silver from 222 metres, including a 4-metre sub-interval at 4.60% total copper and 50.5 grams per tonne silver from 234 metres. A fourth central zone hole intersected 14 metres at 0.31% total copper from 52 metres (oxide), with the company noting results were partially affected by pre- and post-mineral dyking.

Vice President of Exploration of Marimaca Copper, Sergio Rivera, commented:

"Our 2026 step-out drilling program continues to deliver exceptional results at Pampa Medina. We are not only seeing consistent, high-grade copper intersections, with multiple broad intervals returning above 2% copper across the western step-out holes, but also compelling continuity in the central high-grade zone. Multiple holes in this release intersected >3 high-grade stacked mantos, each reporting thick intersections of strong grades."

South-Western Step-Out Results

One south-western step-out hole, drilled 300 metres beyond a previously released result, intersected 68 metres at 0.73% total copper and 5.1 grams per tonne silver from 532 metres, including 30 metres at 1% total copper and 7.3 grams per tonne silver and a 4-metre sub-interval at 2.29% total copper and 29 grams per tonne silver from 596 metres. A second south-western hole, drilled 300 metres west of a prior result, returned 28 metres at 0.52% total copper and 1.5 grams per tonne silver from 202 metres, 12 metres at 0.67% total copper and 3.2 grams per tonne silver from 418 metres, and 6 metres at 1.01% total copper and 11 grams per tonne silver from 454 metres.

Four additional south-western holes intersected mineralisation in upper sediments, basement metasediments, and upper volcanics, though several were affected by pre- and post-mineral dykes. The company stated that mineralisation extends to the upper volcanics, thereby adding continuity to the rock units that cover the sediments.

Rivera added:

"The copper and silver mineralisation we see across both the oxide and sulphide zones is consistent with our geological model and confirms the scale and grade potential of the Pampa Medina system. We are increasingly confident that we are dealing with a deposit of genuine district significance."

Next Steps

Marimaca Copper plans further work at Pampa Medina, including geophysical surveys, reverse-circulation drilling, and diamond core drilling. The company's stated focus for further work is potential extensions of the deposit to the north and west.

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