Marimaca Copper Corp. (TSX: MARI) is pleased to announce further results from the 2022 infill drilling campaign. Results reported in this release reflect 8,444m of drilling across 41 reverse circulation drill holes predominantly located in the northern portion of the Marimaca Oxide Deposit. The results further improve confidence in the newly identified higher-grade centres located in the northern MOD which were intersected in previously reported drill holes from the 2022 campaign (see press release dated November 21, 2022).

Highlights

• Infill drilling continues to improve confidence in the higher-grade centers identified in the northern infill drilling announced on November 21^st, 2022, and the higher-grade central MOD (MAR-175)
  • Results continue to demonstrate potential for improved grade profile in the northern sector from previous grade interpolation of the northern MOD
  • Target of the northern infill campaign is to improve the resource categorization from dominantly Inferred Resources (refere to technical report dated November 28, 2022) to Measured and Indicated categories for the purpose of future mine planning
    • Updated MRE remains on schedule for early 2023

• Results from today’s release will be discussed on the Webinar with Sergio Rivera, VP Exploration, scheduled today at 11:00am ET (see details above)

• Highlights from reported results are noted below
  • MAR-175 intersected 50m at 1.38% CuT from 64m
  • ATR-146 intersected 86m at 0.62% CuT from 2m including 44m at 0.92% CuT from 34m
  • ATR-158 intersected 158m at 0.50% CuT from 26m including 20m at 0.95% CuT from 138m
  • ATR-142 intersected 148m at 0.49% CuT from 2m including 34m at 0.83% from 114m
  • ATR-138 intersected 120m at 0.40% CuT from 2m including 38m at 0.65% CuT from 76m
  • LAR-104A intersected 114m at 0.45% CuT from 32m including 54m at 0.60% CuT from 32m
  • TAR-35 intersected 42m at 0.81% CuT from 2m
• Remaining drilling from the 2022 campaign, currently awaiting final assays (approximately 3,000m of RC and 3,000m of diamond drilling), will be released ahead of the planned 2023 MRE

Sergio Rivera, VP Exploration of Marimaca Copper, commented:

“The infill drilling results from Marimaca continue to provide positive surprises and we are very pleased with the current results, which are, once again, above the interpolated grades in the recently released MRE for the northern end of the MOD.

“Prior to the 2022 campaign, the northern MOD represented the least-densely drilled area of the deposit and as a result, the least well-understood. The current results provide additional support to the exceptional results released on 21 November 2022, and have further improved our interpretation of the geology and confidence in continuity of the copper mineralization. Most importantly, both sets of results demonstrate upside to the previously interpolated grades from our 2022 MRE for the northern MOD as we prepare for our final updated resource in early 2023, which will focus on conversion of the majority of resources into the Measured and Indicated Categories.

“The new high-grade core to the north is expected to add further copper tonnes to our mineral inventory, which will underpin the proposed change in production for the future DFS to either 50ktpa or 60kpta of copper cathode for a life of mine which we expect to be greater than 12 years. Clearly, we would expect this to also add significant economic value to the MOD as compared to the 2020 PEA¹, which outlined already exceptional economics including industry leading capital cost to production and return on invested capital metrics.”

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¹ The 2020 PEA is  titled “Preliminary Economic Assessment, Marimaca Project, Antofagasta, II Region, Chile” (effective date: August 4, 2020), filed by the Company in September 2020 (the “2020 PEA”) no longer reflects the current economic potential of the project, should be seen as historical in nature and should not be relied upon.  As the 2020 PEA is no longer current, information related to an “advanced property” as defined in NI 43-101. The Company’s current technical report (the “2022 MRE”) on the Marimaca Copper Project is dated November 28th, 2022 and is the technical report most recently filed on SEDAR at www.sedar.com under the Company’s profile.

Overview of Drilling Campaign Objectives

Marimaca’s 2022 drilling campaign consisted of over 41,500m of RC and diamond drilling between the MOD infill and the MAMIX zone, the depth extension of the MOD. The 2022 MRE, announced on October 13, 2022 incorporates 19,580m of the approximate 41,500m of drilling completed in 2022 for a total of over 110,000m of drilling completed since 2016. The balance of the 2022 infill drilling program, including the 8,444m of drilling announced today, will be included in a subsequent MRE planned for early 2023 with the objective of converting the remaining Inferred Resources to the Measured and Indicated Categories to underpin a Definitive Feasibility Study (“DFS”) planned for later in 2023.

Figure 1: Plan View of Infill Drilling Results is available at:

https://www.globenewswire.com/NewsRoom/AttachmentNg/2a76bcec-a1bf-4316-aaff-89ad61a5c31e

Table 1. Summary of Drill Results

(*) Target depth not reached because underground working intercept
(**) Twin from underground working intercept hole (3 -5 m apart but angle 70 to 75°)

Table 2. Drill Collars and Survey

(*) Target depth not reached because underground working intercept
(**) Twin from underground working intercept hole (3 -5 m apart but angle 70 to 75°)

Sampling and Assay Protocol

True widths cannot be determined with the information available at this time. RC holes were sampled on a 2m continuous basis, with dry samples riffle split on site and one quarter sent to the Andes Analytical Assay preparation laboratory in Calama and the pulps then sent to the same company laboratory in Santiago for assaying. A second quarter was stored on site for reference. Samples were prepared using the following standard protocol: drying; crushing to better than 85% passing -10#; homogenizing; splitting; pulverizing a 500-700g subsample to 95% passing -150#; and a 125g split of this sent for assaying. All samples were assayed for %CuT (total copper) and %CuS (acid soluble copper) by AAS. 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

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 Paola Kovacic, Exploration Manager, Marimaca Copper Corp, a geologist with more than 20 years of experience and a member of the Colegio de Geólogos de Chile and of the Society of Economic Geologist USA, and who is the Qualified Person for the purposes of NI 43-101 responsible for the design and execution of the drilling program.

The QP confirms she has visited the project area, has reviewed relevant project information, is responsible for the information contained in this news release, and consents to its publication.