Mirasol Signs LOI for the Sale of the Rubi Copper Project for US$4 Million Plus 2% NSR Royalty

• San Lorenzo Gold to acquire Rubi Project for a total consideration of US$4.0 million
• Mirasol will retain a 2% NSR Royalty. Following the exercise of the third option, San Lorenzo may buy back the first 0.5% within twelve months for US$2.0 million, and following the commencement of commercial production another 0.5% within twelve months for an additional US$2 million
• Mirasol’s interest in the Rubi Project will be fully carried to decision to mine
  
  

VANCOUVER, British Columbia, March 19, 2026 (GLOBE NEWSWIRE) -- Mirasol Resources Ltd. (TSX-V: MRZ) (OTC: MRZLF) (the “Company” or “Mirasol”) is pleased to report the signing of a binding Letter or Intent (“LOI”) under which Mirasol grants San Lorenzo Gold Corp. (TSX-V: SLG) (OTC: SNLGF) (“San Lorenzo”) an exclusive option agreement (the “Option”) to acquire the mineral rights and landholdings within Mirasol`s 100% owned Rubi Copper Project (“Rubi”) located in Northern Chile.

“The sale of our Rubi Copper Project reflects Mirasol’s strategy to monetize our highly prospective yet undervalued assets within our portfolio of projects in Argentina and Chile,” Mirasol’s President Tim Heenan stated. “The payments of US$4 million will strengthen our ability to fund ongoing exploration, while the remaining royalty provides our shareholders with continued exposure to future success at the Rubi Project.”

Terms of the Rubi Project Agreement

Under the terms of the LOI, Mirasol has granted San Lorenzo the Option to acquire the Rubi Project for total consideration of US$4 million subject to conditions. The parties intend to finalize a definitive option agreement on or before March 31, 2026.

First Option to 70% (US$1.6 million over 3 years):

• US$50,000 on signing the LOI
• US$100,000 on signing Definitive Agreement
• US$100,000 one year after signing Definitive Agreement
• US$100,000 two years after signing Definitive Agreement
• US$1,250,000 three years after signing Definitive Agreement
  
  

Exploration Expenditures

• US$150,000 one year after signing Definitive Agreement
• US$150,000 two years after signing Definitive Agreement
• US$350,000 three years after signing Definitive Agreement
  
  

Upon completion of the First Option San Lorenzo shall grant Mirasol a 0.5% NSR royalty, not subject to any buy back, over three mineral claims held by San Lorenzo directly adjacent to the east of the Rubi Property.

Second Option to 85% (US$1.75 million over 2 years):

• US$500,000 four years after signing Definitive Agreement
• US$1,250,000 four and a half years after signing Definitive Agreement

Third Option to 100% (US$2.25 million over 2 years plus 2% NSR Royalty):

• US$500,000 five and a half years after signing Definitive Agreement
• US$1,750,000 six years after signing Definitive Agreement
• Mirasol retains 2.0% NSR (Net Smelter Return) royalty
  
  

Upon exercise of the Third Option, San Lorenzo will have earned 100% interest in the Rubi Project. Mirasol will retain a 2% NSR royalty on the Rubi Project. San Lorenzo will have a right to buy back the first 0.5% of the 2.0% NSR royalty for twelve months following the exercise of the Third Option for US$2,000,000, and the right to buy back an additional 0.5% NSR royalty for a further US$2,000,000 for twelve months following the commencement of commercial production.

Following exercise of the First Option and the Second Option, Mirasol shall maintain its 30% interest or 15% interest, as applicable, on a fully carried basis until a decision to mine is made.

Rubi Copper Porphyry Project

The 2,000 ha Rubi project is located within the Paleocene age porphyry belt of northern Chile that hosts a number of significant producing porphyry copper deposits. The project lies at relatively low elevation (1,900-2,100 m) within 20 km of the El Salvador and Potrerillos porphyry copper-moly-gold mines and has good access to port facilities at Chanaral approximately 80 km to the west.

In November 2021, Mirasol reported on the 1,887 m drill program completed at Rubi. Drilling was focused on the Lithocap and Zafiro targets, with the results supporting the presence of a large and strong prospective porphyry-style alteration system. Key indicators included the occurrence of porphyritic daci-andesite intrusive rocks and hydrothermal brecciation, which exhibit strong quartz-sericite (phyllic) alteration overprinting a relict K-feldspar alteration that host trace fine pyrite-chalcopyrite-magnetite mineralization. In addition, good ground preparation was observed, which is critical for ore deposit formation, with strong to locally intense fracturing infilled with late gypsum/anhydrite and calcite veining. Importantly, assay results confirmed the presence of anomalous copper, molybdenum and locally elevated gold over substantial intervals of approximately 200 m ().

About Mirasol Resources Ltd

Mirasol is a strategically positioned exploration company with over 20 years of operating, permitting and community relations experience in the mineral rich regions of Chile and Argentina. Mirasol is currently self-funding exploration at the flagship Sobek Copper-Gold Project located in the Vicuña Copper-Gold-Silver District of northeast Chile while continuing to advance a strong pipeline of highly prospective early and mid-stage projects.

About San Lorenzo Gold Corp

San Lorenzo is a mineral exploration company focused on unlocking high-value copper and gold opportunities in Chile’s premier Mega Porphyry Belt.

For further information, contact:

Tim Heenan, President & CEO

or

Troy Shultz, Vice President Investor Relations

Tel: +1 (604) 602-9989

Email:

Website:

Qualified Person Statement: Mirasol’s disclosure of technical and scientific information in this press release has been reviewed and approved by Tim Heenan (MAIG), the President for the Company, who serves as a Qualified Person under the definition of National Instrument 43-101.

Forward Looking Statements: The information in this news release contains forward-looking statements that are subject to a number of known and unknown risks, uncertainties and other factors that may cause actual results to differ materially from those anticipated in our forward-looking statements. Factors that could cause such differences include: changes in world commodity markets, equity markets, costs and supply of materials relevant to the mining industry, change in government and changes to regulations affecting the mining industry and to policies linked to pandemics, social and environmental related matters. Forward-looking statements in this release include statements regarding future exploration programs, operation plans, geological interpretations, mineral tenure issues and mineral recovery processes. Although we believe the expectations reflected in our forward-looking statements are reasonable, results may vary, and we cannot guarantee future results, levels of activity, performance or achievements. Mirasol disclaims any obligations to update or revise any forward-looking statements whether as a result of new information, future events or otherwise, except as may be required by applicable law.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.