Marimaca Defines Large Sediment and Volcanic Hosted Manto Copper System across the Pampa Medina Area
News Release
Marimaca Defines Large Sediment and Volcanic Hosted Manto Copper System
across the Pampa Medina Area
Vancouver, British Columbia, April 1 5, 2025 – Marimaca Copper Corp. (“Marimaca Copper” or the “Company”)
(TSX: MARI) is pleased to announce results from the re -interpretation of data in the Pampa Medina Project Area
(“Pampa Medina”) which incorporates the Pampa Medina and Madrugador deposits and the newly identified Pampa
West oxide zone, and is located approximately 25km from the Company’s flagship Marimaca Oxide Deposit (“MOD”).
The Company also announces results from five broad reconnaissance exploration holes, which were designed to
identify the limits of the mineralized horizon. This drilling, when combined with the full review and relogging of
historical drilling, shows consistent broad zones of oxide copper mineralization of variable grade s in the same
stratigraphic horizon over an area of approximately 5km by 4km, which is the current defined extent of the manto
horizon. Potential exists for further extensions in all directions, with ongoing step out programs.
Based on the extensive work completed, including the new drilling results extending Pampa Medina, the Company
believes that Pampa Medina may be the central part of a larger manto system, which genetically links the
Madrugador, Pampa Medina , Sierra Valenzuela (Antofagasta Minerals) and Pampa Nort e deposits. It was this
interpretation which led to the discovery of the new, shallow, oxide opportunity at Pampa West. Based on these
results, the Company will continue with its strategy o f large-scale step-out holes from known mineralization , and
deep sulphide-target drilling to try to identify the limits of the system.
Marimaca is considering alternatives for a significantly expanded program for the balance of 2025 to include both
reverse circulation (“RC”) and diamond drilling . The objectives of this program will be to continue to step out to
identify the limits of the system, to test the deeper units for primary copper mineralization and to delineate areas
for potential extensions of near-surface oxide mineralization.
Sergio Rivera, VP Exploration, commented:
“Our extensive reviews of existing data, our geophysical campaigns and the results from our initial step out discovery
campaign indicate Pampa Medina is likely to be part of a much larger manto system, which extends at least 5km east
to west and more than 4km north and south. As with all large -scale mineralizing systems, there is zonation and
variability of grade, but we are excited about both the continuity of mineralization in the productive sedimentary and
tuff horizons and the large-scale mineralizing events which have impacted them across this area.
“The significant east -west step outs at Pampa Norte, either side of the fantastic drill hole at SMR -01, encountered
offset faulting and a series of barren dykes, which are important controls of mineralization. However, we can now
clearly see the potential for 1,000m of east -west extent of the mineralized envelope for Pampa Medina, which
becomes important for resource growth potential in future programs.
“Our exploration model, which hypothesised that the majority of the historical drilling was not deep enough to
targeting the productive sedimentary units, has been confirmed and we see numerous opportunities for further
discovery and extension from our existing deposits.”
Hayden Locke, President and CEO, commented:
“With the Pampa Norte Extension we see a strong potential for additional leachable mineralisation in the short term,
and we will move to a de-lineation program later this year. In the longer term, the potential for a large scale discovery
is very much intact and we intend to test our exploration model thoroughly.”
“This is the first time that the Pampa Medina system has been largely consolidated under one operator , and as such
the first time that all available geological information has been consolidated and reviewed as one . While previous
interpretations considered each of our identified zones as separate and distinct deposits, we are excited about the
potential for Pampa Medina to rather represent a single, large scale mineralised system”
Highlights
• Pampa Medina now defined by five core zones interpreted to be genetically linked (see Figure 2):
― Pampa Medina Main, Pampa Norte, Pampa Medina West, Sierra Valenzuela (Antofagasta Minerals) and
Madrugador
• Relogging and reinterpretation of the consolidated historical data from Pampa Medina (41,000m of drilling)
and Madrugador (36,373m of drilling) indicates continuity of the manto system across the five zones
― Manto-type mineralization now identified in key stratigraphic sequences across area of interest spanning
4km x 5km (see Figure 3)
― Prior to consolidation, each zone was assumed to be an independent deposit and genetically unrelated
• Key stratigraphy identified across each zone (see Figure 4) with mineralization dominated by oxide copper in
the middle sedimentary unit, and transitioning to chalcopyrite-bornite mineralization in the lower basement
tuff and metasedimentary units
― Upper volcanic units also mineralized in the case of Madrugador (see Figure 3)
― Intensity of mineralization across the various stratigraphy illustrated well in previously reported SMR-01
(400m at 0.49% CuT from 250m including 102m at 1.20% CuT from 250m and 18m at 5.11% from 296m)
• Six reconnaissance drill holes now complete (including SMR-01)
― SMR-05 (400m step out to the east from SMR-01)
32m at 0.81% CuT from 470m and 10m at 1.17% CuT from 482m within a broader intersection of 54m of
0.54% CuT from 470m
50m at 0.42% CuT from 240m
― SMR-02 (Pampa Medina West)
90m at 0.40% CuT from 206m including 6m at 1.72% CuT from 290m
10m at 0.73% CuT from 94m
― SMR-03 (Pampa Medina West area)
6m at 1.03% CuT from 226m
Intersected a series of WNW trending barren dykes which are now understood to be important
mineralization controls
― SMR-04 (400m step out to the west from SMR-01) which intercept fault uplifted mineralized sediments as
compared with hole SMR-01, but significant post-mineral barren dykes which truncated mineralized zones
In the down-dropped sedimentary block (see Figure 6):
― 116m at 0.32% CuT including 56m at 0.50% CuT from 440m and 16m at 1.03% CuT from 440m
In the upper volcanic unit:
― 8m at 0.70% CuT from 210m
― 18m at 0.31% CuT from 258m
― SMR-06 (400m north stepout from SMR-01) intercepted low grade mineralized volcanics down-dropped by
an interpreted WNW fault and dyke corridor which interrupted the favourable sediment unit extension
toward the north
8m at 0.58% CuT from 302m including 2m at 1.30% CuT from 304m
• Further drilling in 2025 will focus on further step-out drilling, as well as infill drilling in the Madrugador, Pampa
Medina West and Pampa Medina Main areas to support and validate historical drilling results, a sample set
reported below*:
― Pampa Medina Main Historical Drilling
122m at 1.61% CuT from 199m from DDHSM-06 (Rayrock, 2012-2013)
117m at 1.15% CuT from 142.5m from DDHSM-04 (Rayrock, 2012-2013)
82m at 1.49% CuT from 258m from DDHSM-26 (Rayrock, 2012-2013)
102m at 1.14% CuT from 277m from DDHSM-35 (Rayrock, 2012-2013)
135m at 1.22% CuT from 285m from DDHSM-36 (Rayrock, 2012-2013)
36m at 2.75% CuT from 288m including 15m at 4.87% CuT from 309m from DDHSM-42 (Rayrock, 2012-
2013)
― Madrugador Historical Drilling
139m at 1.32% CuT from 42m from RQM-014 (Apoquindo Minerals, 2007)
65.5m at 1.81% CuT from 46m from DQM-003 (Apoquindo Minerals, 2007)
45m at 2.16% CuT from 31m from RCV-57 (Apoquindo Minerals, 2007)
― Pampa Medina West (previously known as Brac) Historical Drilling
36m at 1.08% CuT from 57m from RQM-57 (Apoquindo Minerals, 2007)
21m at 0.91% CuT from 113m from RQM-75 (Apoquindo Minerals, 2007)
18m at 1.42% CuT from 229m and 51m at 0.51% CuT from 80m from DDH-SM-69 (Rayrock, 2012-2013)
15m at 0.75% CuT from 75m from RQM-71 (Apoquindo Minerals, 2007)
12m at 0.80% CuT from 130m from RQM-87 (Apoquindo Minerals, 2007)
*Reporting of Historical Drilling
Historical drilling results reported above are the results from drilling activities conducted by past operators and not
Marimaca. Marimaca is not treating these drill results as current however the Qualified/Competent Person has
reviewed, re-logged and digitized all historical drilling completed at Pampa Medina. Marimaca considers these
historical results relevant to assist with target definition for future exploration programs, however readers are
cautioned that there has been insufficient exploration to define any mineral resource and it is uncertain whether
further exploration will result in the target being delineated as a mineral resource.
Relevant information pertaining to the drill holes is listed in Table 1 annexed to this Announcement.
Overview of Pampa Medina
Pampa Medina is a manto-style copper deposit dominantly hosted in Lower Jurassic sedimentary units (sandstones
and black shales) overlain by Jurassic andesitic volcanics and underlaying by a Paleozoic to Triassic complex of
metasediments and intrusions, which are also an important host of mineralization . Copper is found predominantly
in oxide species atacamite and chrysocolla and both secondary and primary chalcocite. Copper oxide mineralization
has been dominant in the upper unit of sandstones and volcani clastics and an underlying black shale unit at Pampa
Medina Main. At Madrugador, mineralization is hosted in the upper unit of andesitic volcanics with the (presumably)
underlying sediments remaining untested. In the basement, beneath the sediments, rhyolitic tuff s and
metasediments are dominant and mineralization appears to transition to primary chalcopyrite and bornite
mineralization a s encountered in drill hole SMR -01. Historical drilling at Pampa Medina (across all zones) was
generally limited to a depth of ~400m, potentially too shallow to intersect the chalcopyrite-bornite dominant manto
mineralization found in SMR-01 in the lower tuff and metasediments & diorite unit at a depth of 550m+.
Further RC and combined RC-DDH drilling in Q1 2025 will continue to target the productive sedimentary horizons for
high grade leachable copper at Pampa Medina Main, West, North and stepping out from each. A first diamond drill
rig will test the SMR -01 deep extension, and a diamond drill rig is also being added to test for primary extensions
beneath the sediments at Pampa Medina Main, as well as for deeper mineralization at Madrugador where the
historical drilling is limited to only the upper andesitic volcanics (see Figure 3).
Figure 1: Regional Map – Marimaca and Sierra de Medina
Pampa Medina
Figure 2 – Pampa Medina Deposit Zones
Figure 3 – Long Section – Madrugador to Pampa Medina Main
Figure 4 – Exploration Model Stratigraphic Column with SMR-01 for Reference
Figure 5 – Reconnaissance Drilling: Pampa Medina West and Pampa Medina Norte