Pampa Medina Drilling Continues to Validate Sedimentary-Hosted Copper Manto Model
Pampa Medina Drilling Continues to Validate Sedimentary-Hosted Copper
Manto Model
VANCOUVER, British Columbia, Nov. 11, 2025 -- Marimaca Copper Corp. (“Marimaca Copper” or the “Company”)
(TSX:MARI, ASX:MC2) is pleased to announce the final results from it’s 10,000m discovery drilling campaign at the Pampa
Medina deposit, 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). The drilling results continue to demonstrate material extensions to the
high-grade sedimentary-hosted sulphide copper horizon, as well as upside to the known extent of the near-surface oxide
mineralization. The Company has subsequently commenced a 30,000m follow-up Phase II drilling program with five drilling rigs
currently on site.
Highlights
• Central Pampa Medina drilling continues to improve confidence in high grade oxides and sulphides
◦ SMRD-22 intersected 48m of 2.05% Cu from 186m, within 160m of 0.92% Cu from 102m (oxides)
• Southern Pampa Medina drilling confirms primary mineralized sedimentary horizon extends 900m south of
previous drilling
◦ SMR-19 intersected 16m of 2.29% Cu from 464m within 28m of 1.44% Cu from 464m (sulphides)
◦ SMR-07 intersected 6m of 3.17% Cu from 334m within 14m of 1.69% Cu from 330m (sulphides)
• North and north-west step-outs continue to demonstrate continuity of mineralization in the favourable
sedimentary horizon
◦ SMRD-20 intersected 38m of 1.48% Cu from 540m (sulphides) within 90m of 0.96% Cu from 488m, both
within a broader intersection of 198m of 0.65% Cu (mixed oxides/sulphides)
◦ SMRD-17 and SMRD-18 intersected subparallel post-mineral WNW-trending faulting and dykes across
favourable horizons
◾ SMRD-17 intersections, impacted by late faulting, include 10m at 1.34% Cu from 590m (sulphides)
and 18m at 0.73% Cu from 206m (oxides)
◾ SMRD-18 intersections, impacted by late faulting, include 6m at 1.56% Cu from 392m (mixed)
and 40m at 0.40% Cu from 40m (oxides)
• Reverse-circulation scout drilling (“RC drilling”), testing for shallow oxides to the south and west, intersected
discreet mineralized volcanics
◦ SMR-09 intersected 8m of 1.11% Cu from 54m (oxides)
◦ SMR-10 intersected 4m at 1.68% Cu from 424m (mixed)
◦ SMR-11 intersected 10m at 0.53% Cu from 444m (oxides)
• The favourable mineralized stratigraphic sequence is now defined by drilling across a 1.6km x 1.4km area at
the Pampa Medina deposit and remains open – extensional drilling will focus on step outs toward the north
and west
• Results conclude the Company’s successful Phase I discovery drilling program at Pampa Medina
• The Company has commenced it’s 30,000m Phase II program with five rigs currently on site
Sergio Rivera, VP Exploration of Marimaca Copper, commented:
“The discovery drilling program at Pampa Medina was remarkably successful, with the definition of a potentially significant new
deposit in Chile. We are encouraged by this new set of intersections demonstrating continuity of the high-grade sedimentary
horizon in the south – 900m from the previously announced drilling.
”The 30,000m follow-up campaign, now underway, will provide us with vital geological information to further our understanding
of the controls, and extent, of this deposit. Pampa Medina is shaping up to be a tier one opportunity and anchors our vision for
growth in the district beyond the rapidly-advancing Marimaca Oxide Deposit.”
Hayden Locke, President & CEO, commented:
“The work that Sergio Rivera and the rest of Marimaca’s exploration team have delivered at Pampa Medina continues to
reinforce our objective at Marimaca: to define credible district growth potential beyond the 50ktpa capacity outlined in the
MOD DFS. These results, coupled with our recent RCA for the MOD, is certainly putting us on the path to achieve this
objective. We look forward to continuing to define the district scale potential in our Phase II drilling program and updating our
stakeholders accordingly."
Overview of Pampa Medina
Pampa Medina is a stratiform manto-style copper deposit dominantly hosted in Jurassic-Triassic sedimentary units
(sandstones, conglomerates, tuffs and black shales) overlain by andesitic volcanics and underlain by an Upper Paleozoic
complex of metamorphosed sediments, volcanics and intrusions. Key lithological units are intruded by a dyke swarm and
affected by post mineral normal faulting. 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 bornite
and chalcopyrite which extend at depth 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 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 continuity in the
intact lithological sequence in deeper blocks for primary mineralization to be tested by Marimaca’s 2025 and 2026 drilling
campaigns. In addition to the sulphide extensions, the Marimaca discovery drilling has identified opportunities for significant
extensions to the oxide footprint of the deposit, most notably to the north and west, which will be followed up on during the
Phase II program (30,000m).
Figure 1: Regional Map – Marimaca, Pampa Medina and Regional Infrastructure
Figure 2 – Pampa Medina Deposit and Step-out Drilling Locations
Figure 3 – Pampa Medina Long Section 407,000 E
Figure 4 – Cross Section Looking North – Pampa Medina 7,441,100 N
Figure 5 – Cross Section Looking North – Pampa Medina 7,440,500 N
Figure 6 – SMRD-22 Downhole Sequence
Hole Total
Depth (m) From (m) To (m) Intersection
(m) % CuT
SMR-07 584
296 312 16 0.52
330 344 14 1.66
Including 334 340 6 3.17
SMR-08 578 328 350 22 0.69
SMR-09 256 54 62 8 1.11
SMR-10 678 424 428 4 1.68
SMR-11 548 444 454 10 0.53
536 548 12 0.43
SMD-04 536 214 216 4 0.59
SMRD-17 752
200 224 24 0.61
Including 206 224 18 0.73
590 600 10 1.34
SMRD-18 900
42 82 40 0.40
Including 70 82 12 0.57
138 164 26 0.51
Including 152 164 12 0.86
392 408 16 0.75
Including 392 398 6 1.56
866 880 14 0.51
SMR-19 594 464 492 28 1.44
Including 464 480 16 2.29
SMRD-20 850
460 658 198 0.65
Including 488 578 90 0.96
Including 540 578 38 1.48
600 642 42 0.67
SMRD-21 697.1 342 350 8 0.46
414 428 14 0.53
SMRD-22 898
102 262 160 0.92
Including 162 236 74 1.62
Including 186 234 48 2.05
306 328 22 0.56
746 756 10 0.58
844 856 12 0.45
Table 1: Table of Intersections
Hole ID TYPE Easting Northing Elevation Azimuth Dip Depth
SMR-07 RC 406,996.96 7,440,200.50 1,269.54 240 -60 584
SMR-08 RC 407,092.11 7,440,288.59 1,268.44 240 -60 578
SMR-09 RC 406,001.19 7,439,099.11 1,285.64 270 -60 256
SMR-10 RC 405,350.06 7,440,944.92 1,310.86 270 -60 678
SMR-11 RC 405,598.78 7,440,939.93 1,303.65 270 -60 548
SMD-04 DDH 407,699.04 7,441,101.50 1,267.95 270 -60 536
SMRD-17 RCD 407,316.02 7,441,099.03 1,268.61 270 -60 752
SMRD-18 RCD 406,903.96 7,441,100.03 1,272.63 270 -60 900
SMR-19 RC 406,946.78 7,440,199.94 1,270.58 270 -60 594
SMRD-20 RCD 406,499.15 7,441,099.87 1,283.59 270 -60 850
SMRD-21 RCD 407,099.56 7,441,404.17 1,269.90 270 -60 697.1
SMRD-22 RCD 406,999.44 7,440,502.13 1,270.51 270 -60 898
Table 2: Drill Collars
Sampling and Assay Protocols
True widths are estimated as 95% of reported intervals, based on down-hole bedding and structural measurements. DDH holes
were sampled on a 2m continuous basis, halved by a conventional core splitter on site with one half sent to the Andes
Analytical Assay preparation laboratory in Copiapó and the pulps then sent to the same company laboratory in Santiago for
assaying. Samples were prepared using the following standard protocol: drying; crushing all sample to -1/4” and passing
through a secondary crusher to better than 80% passing -10#; homogenizing; splitting; pulverizing a 400-600g subsample to
95% passing -150#; and a 125g split of this sent for assaying. All samples were assayed for %CuT (total copper); %CuS (acid
soluble copper). A full QA/QC program, involving insertion of appropriate blanks, standards and duplicates was employed with
acceptable results. Pulps and sample rejects are stored by Marimaca Copper for future reference.
Qualified Person / Competent Person
The technical information in this news release, including the information that relates to geology, drilling and mineralization was
prepared under the supervision of, or has been reviewed by Sergio Rivera, Vice President of Exploration, Marimaca Copper
Corp, a geologist with more than 40 years of experience and a member of the Colegio de Geólogos de Chile and of the
Institute of Mining Engineers of Chile, and who is the Qualified Person for the purposes of NI 43-101 responsible for the design
and execution of the drilling program.
The information in this announcement which relates to exploration results for the Pampa Medina Project is based on, and fairly
reflects, information and supporting documentation prepared by Sergio Rivera, VP Exploration of Marimaca, a Competent
Person who is a member of the Comision Minera (Chilean Mining Commission), Colegio de Geólogos de Chile and of the
Institute of Mining Engineers of Chile. Mr. Rivera has sufficient experience that is relevant to the style of mineralisation and
types of deposit under consideration and to the activity being undertaken to qualify as a Competent Person as defined in the
2012 Edition of the Joint Ore Reserves Committee Australasian Code for Reporting of Exploration Results, Mineral Resources
and Ore Reserves. Mr. Rivera consents to the inclusion in this announcement of the matters based on his information in the
form and context in which it appears.
Contact Information
For further information please visit www.marimaca.com or contact:
Tavistock
+44 (0) 207 920 3150
Emily Moss / Ruairi Millar
Forward Looking Statements
This news release includes certain “forward-looking statements” under (without limitation) applicable Canadian securities
legislation, including, without limitation, statements regarding the development of activities at Pampa Medina, the potential
growth of Pampa Medina, and the discovery’s potential to complement the MOD. There can be no assurance that such
statements will prove to be accurate, and actual results and future events could differ materially from those anticipated in such
statements. Forward-looking statements reflect the beliefs, opinions and projections on the date the statements are made and
are based upon a number of assumptions and estimates that, while considered reasonable by Marimaca Copper, are
inherently subject to significant business, economic, competitive, political and social uncertainties and contingencies. Many
factors, both known and unknown, could cause actual results, performance or achievements to be materially different from the
results, performance or achievements that are or may be expressed or implied by such forward-looking statements and the
parties have made assumptions and estimates based on or related to many of these factors. Such factors include, without
limitation: risks that the development activities at Pampa Medina will not progress as anticipated, or at all, risks related to
share price and market conditions, the inherent risks involved in the mining, exploration and development of mineral properties,
the uncertainties involved in interpreting drilling results and other geological data, fluctuating metal prices, the possibility of
project delays or cost overruns or unanticipated excessive operating costs and expenses, uncertainties related to the
necessity of financing, uncertainties relating to regulatory procedure and timing for permitting submissions and reviews, the
availability of and costs of financing needed in the future as well as those factors disclosed in the annual information form of
the Company dated March 27, 2025 and other filings made by the Company with the Canadian securities regulatory authorities
(which may be viewed at www.sedar.com). Readers should not place undue reliance on forward-looking statements. Marimaca
Copper undertakes no obligation to update publicly or otherwise revise any forward-looking statements contained herein
whether as a result of new information or future events or otherwise, except as may be required by law.
None of the TSX, ASX or the Canadian Investment Regulatory Organization accepts responsibility for the adequacy or
accuracy of this release.
This announcement was authorised for release to the ASX by the Board of Directors of the Company.
Appendix 1 – JORC Code 2012 Table 1 (ASX Listing Rule 5.7.1)
Section 1 Sampling Techniques and Data
Criteria JORC Code explanation Commentary
Sampling
techniques • Nature and quality of sampling (eg cut channels,
random chips, or specific specialised industry
standard measurement tools appropriate to the
minerals under investigation, such as down hole
gamma sondes, or handheld XRF instruments,
etc). These examples should not be taken as
limiting the broad meaning of sampling.
• Include reference to measures taken to ensure
sample representivity and the appropriate
calibration of any measurement tools or systems
used.
• Aspects of the determination of mineralisation
that are Material to the Public Report.
• In cases where ‘industry standard’ work has been
done this would be relatively simple (eg ‘reverse
circulation drilling was used to obtain 1 m
samples from which 3 kg was pulverised to
produce a 30 g charge for fire assay’). In other
cases more explanation may be required, such
as where there is coarse gold that has inherent
sampling problems. Unusual commodities or
mineralisation types (eg submarine nodules) may
warrant disclosure of detailed information.
All current drilling conducted at Sierra Medina (including
Pampa Medina, Pampa Norte Extension and Pampa
West) was completed under the supervision of a
registered professional geologist as a Competent
Person/Qualified Person (QP) who is responsible and
accountable for the planning, execution, and supervision
of all exploration activity as well as the implementation
of quality assurance programs and reporting.
• Drilling reported is Reverse Circulation “RC” and
Diamond (“DDH”) drilling
• Assay samples were prepared at a laboratory
site in Copiapó and assayed by Andes Analytical
Assay Ltd. (AAA) in Santiago.
• Sierra Medina´s DDH holes are drilled and
sampled on a continuous 2-meter basis, halved
by a conventional core splitter on site, with one
half sent to the Andes Analytical Assay
preparation laboratory in Copiapó and the pulps
then sent to the same company laboratory in
Santiago for assaying.
• Marimaca RC holes are drilled and sampled on a
continuous 2-meter basis and riffle split on site
up to one-eighth (12.5%) of its volume, after
which samples are sent for preparation and
assaying.
• Marimaca staff supervised all the drilling and
sampling.
• DD recoveries were controlled by accurate core
recovery measurement control was extended
toward the division process realized in the drill
location.
• DD recoveries were measured by core length
measurement and compared with the effective
core run. Marimaca technical staff checked all
data.
• Measured recoveries are over 95% for DDH
drilling, without significant variations and
unrelated to copper grades.
• RC recoveries were controlled by weighing
samples and accurate control was extended
toward the division process realized in the drill
location.
• RC recoveries were measured in weight percent
as compared with a theoretical sample weight.
Marimaca technical staff checked all data.
• Measured recoveries are over 95% for RC drilling,
without significant variations and unrelated to
copper grades.
Drilling
techniques • Drill type (eg core, reverse circulation, open-hole
hammer, rotary air blast, auger, Bangka, sonic,
etc) and details (eg core diameter, triple or
standard tube, depth of diamond tails, face-
sampling bit or other type, whether core is
oriented and if so, by what method, etc).
• Drilling reported is both DDH and RC drilling
• DDH drilling is drilled in HQ and NQ standard
core diameters
Drill
sample
recovery
• Method of recording and assessing core and chip
sample recoveries and results assessed.
• Measures taken to maximise sample recovery
and ensure representative nature of the samples.
• Whether a relationship exists between sample
recovery and grade and whether sample bias may
have occurred due to preferential loss/gain of
fine/coarse material.
• Sierra Medina´s DDH holes are drilled and
sampled on a continuous 2-meter basis, halved
by a conventional core splitter on site, with one
half sent to the Andes Analytical Assay
preparation laboratory in Copiapó and the pulps
then sent to the same company laboratory in
Santiago for assaying.
• Marimaca RC holes are drilled and sampled on a
continuous 2-meter basis and riffle split on site
up to one-eighth (12.5%) of its volume, after
which samples are sent for preparation and
assaying.
• Marimaca staff supervised all the drilling and
sampling.
• DD recoveries were controlled by accurate core
recovery measurement control was extended
toward the division process realized in the drill
location.
• DD recoveries were measured by core length
measurement and compared with the effective
core run. Marimaca technical staff checked all
data.
• RC recoveries were controlled by weighing
samples and accurate control was extended
toward the division process realized in the drill
location.
• RC recoveries were measured in weight percent
as compared with a theoretical sample weight.
Marimaca technical staff checked all data.
• Measured recoveries are over 95% for RC drilling,
without significant variations and unrelated to
copper grades.
Logging
• Whether core and chip samples have been
geologically and geotechnically logged to a level
of detail to support appropriate Mineral Resource
estimation, mining studies and metallurgical
studies.
• Whether logging is qualitative or quantitative in
nature. Core (or costean, channel, etc)
photography.
• The total length and percentage of the relevant
intersections logged.
• All holes were geologically logged on digital data
capture.
• The data collected are rock, structure, alteration
and mineralization based on drilling intervals,
recoveries and analytical results.
• After validation, the mineral and alteration zones
were defined.
• The results were entered in the database as a
table with all mapped data and a consolidated log
of the drill was prepared.
• Most of this work was done by experienced
senior consultant geologist supported by
consultant junior geologist.
• In addition to measuring deviations, most of the
holes were surveyed using an optical tele viewer
(OPTV or BHTV), with structures and orientation
measurements, which continuously and
thoroughly recorded the holes’ walls and