Marimaca Copper Corp. Reports Encouraging Underground Channel Sample Results from the Cindy Target

Highlights

• Cindy is located approximately 5km north of the Company's flagship Marimaca Oxide Deposit ("MOD")
• Underground channel sampling defines broad zones of higher-grade mineralization including:
  • 38m @ 0.90% CuT, 112m @ 0.41% CuT, 36m @ 0.60% CuT, 48m @ 0.90% CuT and 160m @ 0.59% CuT

• Historical underground workings selectively exploited high grade copper mineralization in magnetite breccias
  • Consists primarily of copper oxides atacamite, brochantite and chrysocolla with some wad
• Drilling commenced at the end of April targeting a 1,300m long complex with several magnetite breccias with the potential to host high grade copper mineralization
  • Targeting sulphide extensions to historical underground workings as well as exposed oxides
  • Progressing well with first results expected by end of May 2021

Sergio Rivera, VP Exploration of Marimaca Copper, commented:

"We have now completed channel sampling of artisanal, underground, workings at Cindy. These are relatively shallow historic workings targeting high grade oxides and extend vertically over four levels, approximately 20 meters apart (giving 80 meters of vertical extent) and with over 200 meters of strike length resulting in several hundred meters of drifts.

"Sampling highlighted broad zones of continuous copper oxide mineralization, including one area with 160 meters at 0.59% CuT, which had several samples greater than 1% CuT. The artisanal miners were targeting grades significantly in excess of 1% CuT, and the mineralization that has been left behind is extensive.

"We have also confirmed the importance of magnetite breccias, which control the highest-grade copper mineralization and were targeted by the artisanal miners. Importantly, we have found evidence of several magnetite breccias outside the area of the underground workings which will be targeted in the current drill program."

Overview of Cindy Target

Cindy is located approximately 5km to the north of the MOD and is coincident with both a large magnetic anomaly (refer to announcement on 23 September 2020) and an extensive geochemical anomaly (refer to announcement on 17 February 2021). The underground mine workings cover approximately 200 meters of north south strike over four levels giving a vertical extent of 80 meters.

Figure 1: Map with Cindy Target and Geochemical Anomaly Relative to Marimaca Oxide Deposit
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Underground mapping has identified the key role that magnetite breccias play in hosting high grade copper mineralization, which was the target for the artisanal miners. Surface mapping and reconnaissance has defined a zone extending more than 1,300 meters along strike north and south surrounding the historical workings which contain copper oxides, key structural features and several high-grade magnetite breccias.

Figure 2: Cindy Underground Workings and Selected Channel Sample Results
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The channel sampling program returned broad zones of mineralization including two zones - in CL3-2 and CL4-2 - extending over 100 meters with average grades of 0.41% and 0.59% CuT respectively. A full summary of samples is shown in Table 1.

Table 1: Summary of Channel Sampling

Cindy is interpreted to be a complex system of tabular magnetite breccias extending over 1,300m, with the main mineralizing breccias oriented north-north-east and dipping to the east at between 60 and 70 degrees.

Magnetite breccias, which range in true thickness from 5m to 10m are the key host of the high-grade mineralization previously exploited at Cindy, consisting of dominant atacamite, lesser brochantite, chrysocolla and wad. The underground mapping indicates that lower grade mineralization extends beyond the limits of the mine workings, and surface mapping has identified several magnetite breccias which may be targets for extensions to higher grade mineralization.

Sampling and Assay Protocol

All secure and available mine workings walls were sampled by means continuous rock chips collected along 2 m sample intervals. Samples were prepared and assayed by CuT and CuS at Andes Analytical Assay, Santiago, following standard procedures and quality controls. 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), CuS (acid soluble copper) by AAS.

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 Sergio Rivera, Vice President of Exploration, Marimaca Copper Corp., a geologist with more than 36 years of experience and a member of the Colegio de Ge?logos 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.

Mr. Rivera confirms that he has visited the Marimaca Project on numerous occasions, is responsible for the information contained in this news release and consents to its publication.

Contact Information
For further information please visit www.marimaca.com or contact:

Tavistock
+44 (0) 207 920 3150
Jos Simson/Emily Moss
marimaca@tavistock.co.uk

Forward Looking Statements

This news release includes certain "forward-looking statements" under applicable Canadian securities legislation. 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 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, 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 29, 2021, the final short form base prospectus and other filings made by the Company with the Canadian securities regulatory authorities (which may be viewed at www.sedar.com). Accordingly, 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.

Neither the Toronto Stock Exchange nor the Investment Industry Regulatory Organization of Canada accepts responsibility for the adequacy or accuracy of this release.