Mr. Michael Haworth reports

MARIMACA ANNOUNCES THE APPOINTMENT OF ZENON WOZNIAK TO ITS BOARD OF DIRECTORS; GIANCARLO BRUNO APPOINTED INDEPENDENT NON-EXECUTIVE CHAIR; BOARD CHANGES

Marimaca Copper Corp. has appointed Zenon Wozniak, formerly director, projects, at First Quantum Minerals Ltd, as an independent non-executive director, effective March 27, 2026. The company also announces that Giancarlo Bruno Lagomarsino has been appointed as independent non-executive chair, succeeding Michael Haworth, who will remain as a non-executive director. In addition, non-executive directors Alan Stephens and Clive Newall have announced their retirement from the board, effective March 27, 2026.

Mr. Wozniak appointed to board of directors

Mr. Wozniak is a qualified engineer with over 40 years of international experience across the natural resources sector. He has spent the majority of his career at First Quantum Minerals, one of the world's leading copper producers, where he served as director, projects, through to 2026. Mr. Wozniak was responsible for a global development portfolio, which at times exceeded $10-billion (U.S.) in value across multiple concurrent projects. As director, projects, Mr. Wozniak's experience includes the construction and delivery of the Cobre Panama copper mine in Panama and the Kansanshi copper mine in Zambia. His mining experience spans project design, project engineering, construction, commissioning, project management and operational leadership across copper, nickel, gold and diamonds, with direct exposure across Australia, Latin America, Europe and Africa. Mr. Wozniak will chair the company's project steering and technical committee.

Board changes

Mr. Lagomarsino has been appointed independent non-executive chair with immediate effect. A Chilean national and mechanical engineer by training, Mr. Lagomarsino is a seasoned mining professional with 35 years of experience in executive mining management across some of Chile's most significant copper operations. Most recently, he served as chief executive officer of Mantos Copper SA, the operator of the Mantos Blancos and Mantoverde mines prior to the combination with Capstone Copper. He has served as a non-executive director of Marimaca Copper since 2023.

Mr. Haworth will step down as non-executive chair with immediate effect and will remain a non-executive director and assume the role of chair of the audit committee. Mr. Haworth served as executive chair of the board from February, 2020, to April, 2021, where he transitioned to the role of non-executive chair. The company extends its thanks to Mr. Haworth for his valued contribution as chair of the board since February, 2020.

The company also wishes to recognize the exceptional and long-standing contributions of Mr. Stephens and Mr. Newall, both of whom retire from the board effective March 27, 2026. Mr. Stephens co-founded Coro Mining in 2005, bringing the geological expertise and knowledge of Chilean copper exploration that were foundational for the company's success. Mr. Newall's significant experience and insight gained from building First Quantum Minerals into a global copper major were instrumental for Marimaca over the past five years as it made the transition from explorer to developer.

Mr. Haworth, outgoing non-executive chair of Marimaca Copper, commented: "We are delighted to welcome Zenon to the Marimaca board. His extensive experience in developing world-class copper mines at First Quantum, one of the world's leading copper producers and mine builders, will be a tremendous asset as we advance the MOD toward a construction decision and continue to build the organizational and governance capability required to deliver the next major copper mine in Chile.

"We are also thrilled to welcome Giancarlo Bruno as the new board chair. Giancarlo's extensive experience in Chilean copper development and operations will be invaluable as we progress through the development of the MOD. I will be working closely with Giancarlo as he transitions to his new role and look forward to continuing to support the company as a non-executive director through this next phase of development.

"On behalf of the entire board and management team, I would like to sincerely thank Alan and Clive for their outstanding contributions to Marimaca during their tenure. Alan and Clive were instrumental in building this company from the ground up. Their collective contribution to Marimaca is immeasurable and I wish them the very best in their retirement."

About Marimaca Copper Corp.

Marimaca is a Toronto Stock Exchange- and Australian Securities Exchange-listed copper company focused on the development of high-quality copper assets in northern Chile. The company's flagship asset is the Marimaca oxide deposit project (MOD), located in Chile's prolific Antofagasta region. It is one of the few globally significant greenfield copper discoveries made in the past decade and represents a low-risk development opportunity, given the proximity to the city of Antofagasta and port of Mejillones, with substantial exploration upside. The company also controls additional exploration properties at Pampa Medina and Madrugador within the Sierra de Medina region, located 30 kilometres from the MOD, where recent drilling has identified both oxide extensions and high-grade sulphide mineralization at depth.

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