Vancouver, British Columbia--(Newsfile Corp. - August 20, 2026) - Atlantico Energy Metals Corp. (CSE: ATLA) (FSE: 1CJ1) (WKN: A42CRT) (the "Company" or "Atlantico") reports findings from a property-scale ioGAS interpretation completed in January 2026 using its previously reported 231-sample first-pass dataset. The interpretation identified multiple anomalous rare earth element ("REE") response areas across the northeast, southeast, south and east of Novo Cruzeiro.

The 231-sample first-pass program provided broad reconnaissance coverage across the more than 240-square-kilometre Novo Cruzeiro property, including 170 stream-sediment samples collected at an average density of approximately one sample per 1.45 square kilometres.

Thirty-seven of 170 stream-sediment samples returned more than 500 ppm total rare earth oxides ("TREO"), and 13 returned more than 1,000 ppm, including a peak value of 1,427.05 ppm. The maximum straight-line separation between the 13 higher-TREO sample locations is approximately 19.4 kilometres, calculated from the reported SIRGAS 2000 / UTM Zone 24S coordinates.

Each of the 13 higher-TREO samples contains all four oxides included in Atlantico's magnet rare earth oxide ("MREO") calculation: neodymium, praseodymium, dysprosium and terbium oxides. Their consistent presence across all 13 higher-TREO samples is strategically relevant because these magnet rare earths are used in high-performance permanent magnets for electric vehicles, wind turbines, robotics, advanced electronics and defence systems.

Figure 1. Property-scale TREO, neodymium, praseodymium, dysprosium and terbium contour maps from the January 2026 ioGAS interpretation. The contours are January 2026 interpretation outputs. Sample counts and individual values reported in this release are from the finalized and ratified analytical schedule. Interpolated from discrete samples, the coloured contours allow geographic patterns to be compared but do not establish mineralization or continuity between sample locations.

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ioGAS is specialist geochemical-analysis software used to compare element relationships and spatial patterns across large datasets. Figure 1 presents Atlantico's interpretation of the 231-sample first-pass data, showing where the TREO, Nd-Pr and Dy-Tb indicators strengthen or overlap to guide follow-up.

"The importance of the first-pass results lies not in any one sample, but in the breadth of the response, with strong TREO and magnet rare earth indicators recurring at multiple locations across Novo Cruzeiro," said Bonn Smith, President and CEO of Atlantico. "The January 2026 ioGAS analysis of those results gave us a clear framework for higher-resolution work, and our field team has continued mapping and sampling across Novo Cruzeiro since then. We remain focused on following the evidence and advancing Novo Cruzeiro through disciplined technical work, with the goal of establishing a meaningful critical-minerals project in Brazil's Lithium Valley."

Thirteen Higher-TREO Samples Show Consistent Magnet Rare Earth Content

Across the 13 samples shown in Table 1, MREO values range from 205.76 to 284.40 ppm and represent approximately 18.8% to 21.5% of TREO. Combined neodymium-praseodymium ("Nd-Pr") oxides range from 177.50 to 262.23 ppm, while combined dysprosium-terbium ("Dy-Tb") oxides range from 10.33 to 30.20 ppm. The Nd-Pr and Dy-Tb ranges are reported separately, and their endpoints do not necessarily occur in the same samples.

Table 1. Stream-sediment samples returning more than 1,000 ppm TREO in the finalized first-pass dataset. TREO represents the arithmetic sum of the individual rare earth oxide values reported in the supporting schedules. MREO (%) represents MREO as a percentage of TREO.

For purposes of this release and the supporting schedules, MREO comprises Nd₂O₃, Pr₆O₁₁, Dy₂O₃ and Tb₄O₇. Sample-level analytical schedules for all 231 first-pass samples are available through the links below:

Principal Results & Pathfinders

Detailed Individual REE Oxide Results

Lithium Pathfinders Provide a Secondary Exploration Angle

Relationships among lithium, caesium and rubidium ("Li-Cs-Rb") can help identify areas warranting follow-up for lithium-bearing systems. At Novo Cruzeiro, preliminary Li-Cs-Rb patterns provide a secondary line of investigation alongside the more developed TREO and magnet rare earth interpretation. These early-stage patterns require field verification and do not confirm lithium mineralization, continuity or a lithium-bearing mineral species.

Figure 2. Lithium, caesium and rubidium contour maps from the January 2026 ioGAS interpretation. Contours are interpolated exploration guides derived from discrete surface samples and do not represent measurements between sample locations.

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Advancing Novo Cruzeiro to Higher-Resolution Exploration

The January 2026 interpretation established the framework for higher-resolution exploration that has continued since then. Atlantico's ongoing program is testing whether the broad surface responses repeat and can be better defined:

1. Continue field verification of the strongest rare earth response areas, including local geology, sampling conditions and areas where multiple magnet rare earth indicators occur together.

2. Continue closer-spaced stream-sediment, soil, saprolite and channel sampling to test repeatability and better define boundaries.

3. Integrate geochemistry with geology, drainage, structure and radiometric data to refine the controls on the strongest responses.

4. Where supported, advance selected areas to mechanical auger testing, trenching and geophysics, then evaluate potential drill targets.

Important Early-Stage Disclosure

This release presents a January 2026 interpretation of Atlantico's previously reported 231-sample first-pass program and filed NI 43-101 Technical Report dated February 9, 2026. It reports finalized and ratified values for that same first-pass dataset and does not report results from subsequent sampling or disclose a mineral resource, mineral reserve or economic study.

Novo Cruzeiro remains at an early stage, with no historic drilling, mineral resources or mineral reserves. Geochemical anomalies, interpolated contour maps and field observations are exploration indicators only. They do not establish grade, tonnage, continuity, mineralization, recovery, mineability or economic potential. Further mapping, sampling, analysis and, if warranted, drilling are required, and there is no assurance that future exploration will result in the discovery or definition of a mineral resource or mineral reserve.

Quality Assurance / Quality Control

Stream-sediment and rock-chip samples were transported under chain of custody to SGS Geosol in Vespasiano, Minas Gerais, Brazil. Stream-sediment samples were dried, disaggregated, sieved to minus 80 mesh (177 micrometres), and quartered to a 10-gram aliquot using SGS method PRS80J. Rock-chip samples were dried, crushed and pulverized to greater than 80% passing 70 micrometres before splitting to a 10-gram aliquot. All aliquots underwent sodium peroxide fusion followed by ICP-OES and ICP-MS determination using SGS method ICM90A.

At this reconnaissance stage, the Company did not insert independent certified reference materials, blanks or field duplicates and relied on SGS Geosol's internal preparation blanks, replicates and standards. The supplied SGS certificates include these internal controls, and no material QA/QC issue was identified in the certificates provided for this review. The remaining laboratory certificates underlying the ratified schedule were reviewed in connection with the filed NI 43-101 Technical Report. The Qualified Person considers the analytical data adequate for the early-stage exploration disclosure in this release. The sampling methods, analytical procedures and QA/QC measures are described in the Company's filed NI 43-101 Technical Report entitled "Technical Report on the Novo Cruzeiro Lithium & REE Project, Early-Stage Exploration, Eastern Brazil Lithium Province, Minas Gerais, Brazil," dated February 9, 2026.

Qualified Person Statement

Andrew Lee Smith, P.Geo., a Qualified Person as defined by National Instrument 43-101: Standards of Disclosure for Mineral Projects, has reviewed the ratified analytical schedule, the supporting technical information and the SGS certificates provided for this review, and has reviewed and approved the scientific and technical information contained in this news release. Mr. Smith is not independent of the Company within the meaning of NI 43-101 due to his role as a member of the Company's Advisory Board.

About Atlantico Energy Metals Corp.

Atlantico Energy Metals Corp. is a Canadian mineral exploration company built around a simple belief: a cleaner energy future needs critical minerals. The Company's flagship project is the Novo Cruzeiro Lithium and Rare Earth Elements Project, located in northeastern Minas Gerais, Brazil, within the region known as Brazil's Lithium Valley. Atlantico is advancing Novo Cruzeiro through disciplined technical work, transparent disclosure and responsible exploration, with a focus on creating long-term value for shareholders while contributing positively to the local communities and regions where the Company operates.

The Canadian Securities Exchange has neither approved nor disapproved the contents of this news release.

Forward-Looking Information

This news release contains "forward-looking information" and "forward-looking statements" within the meaning of applicable securities legislation. Forward-looking information includes, without limitation, statements regarding Atlantico's exploration plans, field verification, mapping, additional stream-sediment, soil, saprolite and channel sampling, mechanical auger testing, geophysics, trenching, drilling, the ranking of areas for follow-up, the potential significance of geochemical anomalies and element associations, the use and interpretation of ioGAS analysis, and the Company's objective of advancing Novo Cruzeiro through disciplined technical work and transparent disclosure.

Forward-looking information is based on assumptions that management considers reasonable as of the date of this news release, including assumptions regarding the availability of financing, the ability to obtain required permits and approvals, continued access to the project area, the availability of qualified personnel and contractors, the reliability of current technical information, and the Company's ability to complete planned exploration activities. Forward-looking information is subject to known and unknown risks, uncertainties and other factors that may cause actual events or results to differ materially, including risks related to mineral exploration, early-stage project development, commodity prices, capital markets, permitting, environmental and regulatory matters, political and economic conditions in Brazil, title and access matters, technical interpretation, and the risk that future exploration may not result in the discovery or definition of mineral resources or mineral reserves.

No undue reliance should be placed on forward-looking information. The Company undertakes no obligation to update forward-looking information except as required by applicable law.

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