Marimaca Drills Pampa Medina Sulphides – Intersects Exceptional 6m of 12.0% Cu within 26m of 4.1% Cu in dominantly Bornite in SMRD-13, 40m of 2.1% Cu in SMD-02
News Release
Marimaca Drills Pampa Medina Sulphides – Intersects Exceptional 6m of 12.0% Cu
within 26m of 4.1% Cu in dominantly Bornite in SMRD-13, 40m of 2.1% Cu in SMD-02
Vancouver, British Columbia, July 3, 2025 – Marimaca Copper Corp. (“Marimaca Copper” or the “Company”)
(TSX:MARI, ASX:MC2 ) is pleased to announce significant, high grade , sediment-hosted copper sulphide and oxide
intersections which materially extend the Pampa Medina deposit in all directions. Pampa Medina is located at low altitude
approximately 28km east of the Company’s Marimaca Oxide Deposit (“MOD”) in a flat “pampa” valley within the Atacama
Desert (Figure 1) . Drilling targeted extensions of the shallow oxide -chalcocite mineralization at Pampa Medina and
intersected ultra high-grade, bornite-chalcopyrite, disseminated chalcopyrite and high-grade oxide mineralization, which
is hosted in a regionally extensive system of interbedded sedimentary rocks hosting the Pampa Medina deposit.
The Company will host a n investor presentation, covering today’s announcement, via the Investor Meet Company
(“IMC”) platform on July 8, 2025. Further details can be found below.
Highlights
• Drilling confirms Pampa Medina is part of a significant, flat lying, sediment hosted (stratiform) manto system,
unique in Chile, that appears more analogous to the Kupfershiefer or African sediment hosted Cu deposits
• Thick (>15m true thickness), ultra high grade (>5% CuT) zones identified more than 600m apart in the same
lithological horizon between SMRD-13 and SMR-01
• High-grade (>1.0% CuT), sedimentary-hosted copper mineralization defined by diamond drilling across a 600m east-
west x 1,000m north-south area, with further drilling intersections indicating potential extensions to 1.4km x 1.2km
• Ultra high-grade bornite and chalcopyrite manto zones east, immediately down-dip, of Pampa Medina Deposit
― Highest grades correspond to interbedded shales, sandstones, conglomerates and tuffs
― Complements previous ultra high-grade zone encountered in SMR-01
• Hole SMRD-13 (true widths estimated to be 95% of reported intersection):
― 6m of 12.0% Cu from 594m downhole within 26m of 4.1% Cu from 580m and a broader 100m of 1.3% Cu from
580m
• Hole SMD-02 (drilled on section in between SMD-12 and SMD-13)
― 40m of 2.1% Cu from 282m downhole within 132m of 1.0% Cu from 278m
• Hole SMD-01 (~600m north-west of SMD-13)
― 68m of 1.2% Cu including 20m of 2.3% Cu from 298m downhole (previously reported)
― 22m of 1.7% Cu from 602m downhole
• Hole SMRD-12 (600m west of SMD-13)
― 56m of 1.4% Cu from 566m downhole
• Hole SMR-01 (adjacent to SMD-01) (previously reported)
― 56m of 2.1% including 18m of 5.0% Cu from 296m downhole within a broader 102m of 1.2% from 250m
• Hole SMD-03
― 42m of 0.72% Cu from 226m
• Primary sedimentary manto confirmed to carry high-grade (>>1% Cu) over significant true thickness (>70m) and
area (600m x 1,000m) as demonstrated in SMR-01, SMD-01, SMRD-12, SMRD-13, SMD-02 and SMD-03
• Sedimentary units are generally flat lying, with a gentle easterly dip, and gentle northerly plunge, and both uplifted
and down-dropped in certain blocks via a series of north-south faults
• Similar to the MOD, Pampa Medina’s location is expected to drive significant infrastructure and permitting benefits:
― Proximity to other mines and associated infrastructure (Figure 1): 28km from the MOD, 64km from Sierra Gorda
(South32/KGHM), 40km from Mantos Blancos (Capstone Copper), 77km from Spence (BHP), 54km from
Antucoya (Antofagasta Minerals)
― Low altitude, flat “pampa” type surface provides sufficient space for future facilities and infrastructure
― Proximity to existing powerlines, water pipelines, major ports and regional populations
― No private land ownership, limited human impact (no nearby local or indigenous population), extremely arid
location indicates low permitting risks (comparable or superior to the MOD) associated with potential
development
• The Company has added a second diamond drill rig at Pampa Medina and has budgeted a 14-hole follow up
program targeting extensions and delineation of the mineralized manto (Figure 2)
• The previously announced Preliminary Economic Assessment (“PEA”) for Pampa Medina will be paused as the
Company assesses what these drilling results may mean for the scale and development strategy of Pampa Medina
• Definitive Feasibility Study (DFS) for the MOD is near-complete, undergoing final review and will be released to the
market in the near-term
Sergio Rivera, VP Exploration of Marimaca Copper, commented:
“Pampa Medina appears to be a Tier 1 prospect. Our exploration model, which is unconventional in Chile, has been proven
correct. Firstly, the sedimentary units, which host Pampa Medina, are extensive and mineralized over many square
kilometers and, secondly, the potential is confirmed for significant, very high grade, sulphide mineralization in these units.
This is the first time in my 40-year career that I have seen stratiform, sediment hosted, ultra high-grade copper in Chile of
this potential scale. The intensity of bornite and chalcopyrite mineralization is truly remarkable. Between holes SMR-01,
SMD-01, SMD-12, SMD-02, and now SMRD-13, we have defined an area of over 1,000m x 600m where we see continuity
of the high-grade mineralization, well above 1% CuT, with some exceptionally high-grade areas as seen in SMRD -13 and
SMR-01.
We are completing 10,000m of drilling across 14 diamond holes in the next phase. Our objective is to try to define the limits
of the prospective sedimentary units, to understand the full potential of the Pampa Medina opportunity. We look forward
to updating the market as we progress exploration on this exciting discovery.”
Hayden Locke, President & CEO of Marimaca Copper, commented:
“These results add a new dimension to our strategy and, we believe, strengthens our potential to be a globally significant
copper producer intime. Our assessment is that the Pampa Medina and Madrugador oxide deposits already give us the
potential to expand our copper cathode production profile and extend our mine life meaningfully from the nominal rates
we are contemplating in the MOD DFS. With these thick, high-grade, sulphide intersections we now see the potential for a
much larger scale copper system . Importantly, the location of Pampa Medina means it benefits from the same
characteristics as our flagship MOD, such as access to first class infrastructure, proximity to workforces, lower permitting
risk, and therefore any new discovery brought into development should be extremely competitive on a capital intensity
basis.
Our primary objective remains to bring the MOD into production as quickly as is feasible and, in this respect, our DFS is
largely complete and undergoing final peer reviews in preparation for release . Additionally, our permitting is progressing
well with encouraging interactions across all of our stakeholder groups in Chile.
“Our exploration portfolio is vast and virtually untested. This extensional discovery highlights the ongoing opportunity for
copper discoveries on a district scale. Our strategy remains two-fold: we will continue to advance the exciting exploration
potential, both at Pampa Medina and other targets, whil st also transitioning, in the near -term, into a copper cathode
producer.”
Investor Presentation
Marimaca will host an investor presentation via the IMC platform on Tuesday, July 8 2025 , covering today’s
announcement.
The online event will take place at 07:00 a.m. (local time in Vancouver, British Columbia) / 15:00 p.m. (local time in London,
UK) with Hayden Locke (President & CEO) and Sergio Rivera (VP Exploration) presenting from the Company.
The presentation is open to all existing and potential shareholders. Questions can be submitted prior to this presentation
via the IMC dashboard up until Monday, July 7 2025, 01:00 a.m. (local time in Vancouver, British Columbia) / 09:00 a.m.
(local time in London, UK) or at any time during the live presentation.
Investors can sign up to IMC for free and add to meet Marimaca Copper via:
https://www.investormeetcompany.com/marimaca-copper-corp/register-investor
Investors who already follow Marimaca Copper on the IMC platform will be automatically invited.
Overview of Pampa Medina
Pampa Medina is a manto -style copper deposit dominantly hosted in Jurassic -Triassic sedimentary units (sandstones,
conglomerates, tuffs and black shales) overl ain by andesitic volcanics and underlain by a Upper Paleozoic complex of
metasediments and intrusions . Copper was originally identified in near-surface oxide mineralization dominated by
atacamite, chrysocolla and both secondary and primary chalcocite , and has now been identified in high -grade zones of
chalcopyrite and bornite which extend laterally down-dip beyond the oxide-primary transition.
Following Marimaca’s consolidation of the project area and surrounding land packages in 2024, the Company
reinterpreted all available geological information (for the first time as one) and developed an updated geological model
for Pampa Medina, which identified the lower sedimentary units of interbedded sandstones, shales and conglomerates as
the productive horizons for future drill targeting. Oxide copper mineralization was logged in historical drilling in near -
surface, uplifted blocks , with the model of c ontinuity in the intact lithological sequence in deeper blocks for primary
mineralization to be tested by Marimaca’s 2025 drilling campaign.
Hole SMRD-13 was collared 300m east from hole SMD-02, and 600m east on section from hole SMRD-12 to a total drilled
depth of 800m (Figure 2). The hole intercepted the volcanic- sedimentary contact at 248m, where a lower -grade upper
chalcopyrite manto was observed from 392 m to 428m hosted by the tuff unit. Lower grade chalcopyrite mineralization
was observed in the underlying shales and lesser sandstones up to 516m whe re a post-mineral diorite dyke intrudes the
sediments. Beneath this, the main bornite-rich manto was intercepted from 580 to 606m. Mineralization transitioned
form c halcopyrite>bornite into semi -massive bornite with fracture -fill and replacement textures. Highest -grade
mineralization corresponded to a unit of heavily altered black shales stratabound between two sandstone units. Beneath
this, weakly mineralized chalcopyrite and pyrite mineralized conglomerates and black shales were mapped to the bottom
of hole (Figure 3).
Hole SMD-01 was drilled approximately 400m north of the northern margin of the known deposit at Pampa Medina.
SMD01 was collared at Azimuth 270°, Dip -60° and drilled to a total depth of 950m (Figures 2 and 4). The collar was located
12m SE from SMR -01 but further deviated, reaching approximately 70m at the 650m depth. High grade copper oxide
mineralization was intersected from 252m-494m downhole depth in an upper unit of sandstones and shales. Rhyolitic tuff,
intruded by late dykes was intersected below the upper sediments from 492m to 564m and bel ow that another more
clastic rich unit extends up to the bottom of the hole. Metasediment basement was not reached at depth in hole SMD-01,
meaning that the productive sedimentary unit increases in thickness towards the north. Mineralization transitioned t o
primary chalcopyrite and bornite mineralization at 550m . SMD-01 confirms the sediment -hosted oxide mineralization
encountered in SMR-01, which is largely interpreted as the extension of the sediment -hosted manto deposits of Pampa
Medina main. Historical drilling at Pampa Medina was generally limited to a depth of 400m, potentially too shallow to
intersect the chalcopyrite-bornite dominant manto mineralization found in SMR-01, SMD-01 and now SMRD-13.
Holes SMD-02 and SMRD-12 and SMRD-13, were drilled at 300m spacings along an EW section N7440800, located 600m
south from the SMR-01 & SMD-01 section (Figures 2, 3 and 4). The holes were designed to test the extension of the upper
oxidized manto and the potential for a lower sulphide manto, as encountered in SMD -01. SMR D-02 intercepted
mineralized sediments from 242m, consisting of shales and minor interbedded sandstones. The upper oxidized manto was
intercepted from 282 to 324m. At depth , two consecutive mineralized mantos were encountered from 348m to 366m,
with mixed mineralization, hosted in tuffs and from 376m to 410m of primary mineralization hosted by sandstones.
SMRD-12 intercepted weakly mineralized sandstones from 414m, increasing in intensity until the main chalcocite-bornite
mineralized manto was intercepted from 566 to 620m hosted by lower sandstone units (Figure 4). At depth, a late diorite
dyke intruded the sediments carrying trace pyrite and chalcopyrite. Hole SMD-03 was designed to test the continuity of
the mineralization through a NW trending dyke corridor. The upper manto was intercepted with oxide mineralization from
226m to 268m, hosted by sandstones. The hole confirmed the previously interpreted WNW orientation of most of the
post-mineral dykes.
Figure 1: Regional Map – Marimaca, Pampa Medina and Regional Infrastructure
25km
Figure 2 – Pampa Medina Deposit and Step-out Drilling Locations
Figure 3 – Pampa Medina Lithology – SMRD-13 Downhole Sequence
Figure 4 – Long Section Looking West – Pampa Medina