• Exploration season completed, including two drill holes, at the 46 South Target located just 7 km west of Filo del Sol in the Vicuña District, at the south end of Sobek Central
• Results from the first drill hole testing the 46 South target confirm a structurally controlled hydrothermal system with anomalous copper/gold geochemical intervals
• A second drill hole was completed 300 m to the south of the first hole to test directly beneath the quartz-alunite breccia for stronger near surface mineralization; assays are pending
  

VANCOUVER, British Columbia, April 23, 2026 (GLOBE NEWSWIRE) -- Mirasol Resources Ltd. (TSX-V: MRZ) (OTC: MRZLF) (the “Company” or “Mirasol”) announces an update on the exploration and drilling at the Company’s 100%-owned Sobek Copper-Gold-Silver Project (“Sobek” or “the Project”) located 7 km west of Filo Del Sol in the Vicuña District of Chile. Two drill holes were completed this season to test the 46 South target located on the south end of Sobek Central, results from the second hole are still pending.

Figure 1: Vicuña District - Sobek Property Package including the 46 South Target

The first drill hole was designed to test the main structural corridor at 46 South target which resides on the southern margin of a district-scale magnetic high where both the airborne MT and magnetics surveys outlined distinct cylindrical anomalies. The ground based Deep Vectoring IP and MT geophysical survey launched late last year also defined a corresponding shallow coincident IP anomaly with strong MT-resistivity and chargeability responses. The grid-based soil survey over the area outlined a coincident, large and coherent copper-gold-moly geochemical anomaly on surface that directly overlays IP-PDP resistivity and chargeability responses from IP ground geophysics surveys (news release dated January 22, 2026).

The drilling confirmed that 46 South hosts a structurally controlled hydrothermal system intersecting multiple hydrothermal breccia zones with the strongest hydrothermal response closely tied to structurally controlled breccias and fault zones, as opposed to the hypothesized lithocap environment which was expected to host a much broader distribution of alteration and mineralization.

“These first drill holes at 46 South have improved our understanding of the target. Although initial assay results were modest, drilling has confirmed a structurally controlled hydrothermal system, with the strongest mineralization associated with hydrothermal breccias and fault-controlled corridors. The second drill hole was positioned to test directly below the outcropping expression of the quartz-alunite breccia to target more significant near-surface mineralization, geochemical results are currently pending. These results will help us refine our geological model and guide the next stage of targeting at Sobek, a highly prospective project located within a world-class copper-gold district,” stated Mirasol’s President and CEO Tim Heenan.

“Grassroots exploration requires continuous evaluation of targets. When results do not meet expectations, we pivot and redirect focus to higher-confidence opportunities. Through our project generator model, Mirasol maintains a pipeline of compelling assets with improving political framework in Argentina and now Chile driving increased interest from potential partners.”

Highlights from the First Drill Hole (S46-DDH-001) Testing the 46 South Target:

Hole DDH-001 was drilled in a SSW direction, to test the main 46 South structural corridor and to intersect the projected NW-trending structures beneath the surface alteration footprint. The principal anomalous intervals defined to date in DDH-001 include:

• 15.82 m from 147.18 m to 163.00 m averaging 158 ppm copper, 30 ppm moly, 0.03 g/t gold, 1.57 g/t silver, 261 ppm zinc, and 81 ppm lead, including:
  • 4.72 m from 147.18 m to 151.90 m averaging 252 ppm copper, 48 ppm moly, 0.03 g/t gold, 2.47 g/t silver, 398 ppm zinc, and 148 ppm lead
• 21.3 m from 204.0 m to 225.3 m averaging 112 ppm copper, 24 ppm moly, 0.04 g/t gold, 0.59 g/t silver, 93 ppm zinc, and 42 ppm lead
• 7.20 m from 566.75 m to 573.95 m averaging 720 ppm copper, 4 ppm moly, 0.01 g/t gold, 0.12 g/t silver, 121 ppm zinc, and 47 ppm lead
• A secondary anomalous interval exists between approximately 204.0 m and 225.3 m, represented by elevated gold and pathfinder values across several discrete samples rather than a single continuous copper intercept.
  

Table 1: Sobek Central - 46 South Target - Select Composite Geochemical Intervals from Initial Drilling

These intervals are hosted within hydrothermal breccias and are associated with silicification, argillic alteration, pyrite, sulphate-rich veining and pathfinder enrichment, particularly arsenic-antimony-lead-zinc-silver, with subordinate Cu-Mo.

Assays from DDH-001 indicate that the strongest geochemical response is not a copper-dominant intercept, but rather a pathfinder-rich hydrothermal signature characterized by arsenic-antimony-lead-zinc-silver with subordinate copper-moly. No significant copper intercepts were returned above a 0.10% copper cut-off, and the Company considers the results to be more indicative of a localized hydrothermal system rather than a broad copper-gold mineralized center.

Figure 2: Sobek Central - 46 South Target - Initial Drill Results

Geologically, the best results in DDH-001 are associated with hydrothermal breccias and zones of enhanced structural preparation. Alteration is dominated by silicification and argillic overprint, accompanied by sulphate rich veining and alteration mineral assemblages (silica/argillic) consistent with a structurally controlled hydrothermal system.

Mineralization is dominated by pyrite, with only minor localized chalcopyrite and molybdenite observed. Together, these features support interpretation of 46 South as a hydrothermal system, with metal enrichment focused along discrete structural corridors rather than throughout a large uniformly mineralized body.

Hole DDH-001 also intersected a moderate copper-bearing interval from 566.75 m to 573.95 m averaging 226.5 ppm copper, within the projected depth extension of the southern quartz-alunite breccia trend. While the hole did not intersect a quartz-alunite breccia at depth, this interval supports the interpretation that the southern hydrothermal corridor continues downward in the projected trend of that surface breccia domain.

Hole DDH-001 tested the projected continuation of the surface quartz-alunite breccia trend at depth. As alteration and mineralization did not appear to be strengthening with depth, the decision was made to halt the drilling at 600m.

Results from Second Drill Hole Pending

Following up on the encouraging mineralization encountered in the upper portions of hole DDH-001, a second hole was completed 300 m to the south. The second hole was testing for stronger near surface mineralization, directly beneath the surface expression of the quartz-alunite breccia. Geological logging and field observations from DDH-002 suggest the continuation of the structurally controlled hydrothermal system into the southern part of the target area, where alteration appears more oxidized and argillic in character. Assay results are currently pending and will be reported once received and evaluated.

High-Profile VicuñaCopper-Gold-Silver District

Mirasol staked the Sobek Project in 2016 based on prospective local geology and attractive structural architecture prior to the 2021 discovery of the high-grade feeder zone at the Filo del Sol gold-copper deposit and the 2023 discovery of Lunahuasi. The consolidated Sobek Project is located on the same regional N-S trending structural corridor and just 7km to the west of the Filo del Sol deposit and 3km to the southwest of NGEx Mineral’s discovery at Lunahuasi.

Sobek is located within a prospective geological environment with a compelling north-northeast trending mineralized structural corridor crosscut by a north-northwest trending deep-seated trans-cordilleran lineament. This is a common structural configuration hosting numerous Andean metal deposits in both Chile and Argentina.

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.

For further information, contact:

Tim Heenan, President & CEO
or
Troy Shultz, Vice President Investor Relations

Tel: +1 (604) 602-9989
Email: contact@mirasolresources.com
Website: www.mirasolresources.com

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.

QAQC: Mirasol applies industry standard exploration sampling methodologies and techniques. All geochemical rock chip, soil, and stream sediment samples are collected under the supervision of the company’s geologists in accordance with industry practice. Geochemical assays are obtained and reported under a quality assurance and quality control (QA/QC) program with insertions of controls (standards, blanks and duplicates) submitted to the laboratory. Samples were dispatched to ALS Global - Geochemistry Analytical Lab, in Santiago, Chile, an ISO 9001:2015 accredited laboratory, which is independent from the Company. Drill core samples were cut and prepared on site and transported to the reception facility of ALS in Copiapo, all under direct supervision of Mirasol personnel Drill core samples (1.5-2.5kg) were prepared with PREP31, and analyzed for Au with fire assay and Ag-Cu-Zn-Pb and Mo AA62 with multi-acid (4) digestion with   Atomic Absorption (HF-HNO3-HClO4 Digest, HCl leach) and multi-element (48) four acid ICP-MS (*ME-MS61m). Assay results from drill core, rock chip, soil and stream sediment, channel, and trench, samples may be higher, lower or similar to results obtained from surface samples due to surficial oxidation and enrichment processes or due to natural geological grade variations in the primary mineralization.

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.