Brunswick Exploration Files Maiden Mineral Resource Estimate NI 43-101 Technical Report for Mirage Project

MONTREAL, Feb. 27, 2026 (GLOBE NEWSWIRE) -- Brunswick Exploration Inc. (TSX-V: BRW, OTCQB: BRWXF; FRANKFURT:1XQ; “BRW” or the “Company”) is pleased to announce that it has filed on SEDAR the “NI 43-101 Technical Report for the Mirage Maiden Mineral Resource Estimate, Eeyou Istchee James Bay, Quebec, Canada”, with an effective date of January 7, 2026. The Mineral Resource Estimate (“MRE”) was prepared in accordance with the National Instrument (“NI”) 43-101 standards by PLR Resource Inc. and Synectiq Inc.

The full technical report is now available on SEDAR+ under Brunswick’ profile, as well as on the Company’s website. The key results of this Maiden Mineral Resource Estimate were summarized in Brunswick’s press release dated January 8, 2026 and are also presented below.

Mr. Killian Charles, President and CEO of BRW, commented: “Brunswick Exploration remains one of the most compelling companies in the lithium space through the unique combination of advanced exploration in Quebec at both Mirage and Anatacau alongside an exciting global grassroot exploration program. I wish to thank the team and our consultants for this momentous achievement.”

Highlights include:

• Inferred resource of 52.2Mt at 1.08% Li2O and 131ppm Ta2O5 (see Table 1) at a cut-off grade of 0.5% Li2OEq for total contained lithia in excess of 550,000 tonnes. This places Mirage among the largest undeveloped hard rock lithium resources in the Americas.
• Additional Exploration Target of 40Mt to 50Mt grading between 0.80% and 1.10% Li2O and 120ppm and 145ppm Ta2O5 indicating a significant opportunity for continued near-term growth at Mirage. The potential quantity and grade are conceptual in nature. There has been insufficient exploration to define a mineral resource and that it is uncertain if further exploration will result in the target being delineated as a mineral resource.
• The maiden resource and Exploration Target are confined to a core area measuring approximately 1.5 by 3.0 kilometers. Substantial exploration potential exists both across this area, as seen in the Exploration Target, and further along strike, throughout the rest of the property where lithium mineralization is observed up to 3.5km from the MRE area.
• Over 70% of the MRE is contained within five dykes found above a vertical depth of 150 meters from surface, all of which remain open in several directions.
• Metallurgical testwork demonstrates the potential for a dense media separation (“DMS”) only processing flowsheet, producing a high-quality concentrate.
• The maiden MRE and Exploration Target were estimated after only 23,626 meters of drilling and 62 channel samples, significantly less than its peer group and similar projects.
  
  

Table 1: Mirage Project Deposit In-pit Mineral Resource Estimate

1. The independent qualified persons for the MRE, as defined by National Instrument (“NI”) 43-101 guidelines, is Pierre Luc Richard, P.Geo., of PLR Resources Inc., with contributions from Patrick Frenette, P.Eng., of Synectiq Inc. for cut-off grade estimation and open pit optimization.
2. These Mineral Resources are not mineral reserves as they have no demonstrated economic viability. No economic evaluation of these Mineral Resources has been produced. The quantity and grade of reported Inferred Resources in this MRE are uncertain in nature and there has been insufficient drilling to define these Inferred Resources as Indicated. However, it is reasonably expected that the majority of Inferred Mineral Resources could be upgraded to Indicated category with continued drilling.
3. The Qualified Persons are not aware of any known environmental, permitting, legal, title-related, taxation, socio-political, marketing or other relevant issues that could materially affect the Mineral Resource Estimate.
4. Calculations used metric units (metres, tonnes). Metal contents in the above table are presented in percentages, part per million (gram per tonne) and tonnes. Metric tonnage was rounded, and any discrepancies in total amounts are due to rounding errors.
5. CIM definitions and guidelines for Mineral Resource Estimates have been followed.
6. Resources are presented as undiluted and in situ for the open-pit scenario within 5m x 5m x 5m blocks. The constraining pit shell was developed using overall pit slopes of 53 degrees. The pit optimization to develop the mineral resource-constraining pit shell was done using the pseudoflow algorithm in Deswik software (see Figure 2).
7. The MRE wireframe was prepared using Leapfrog Edge v.2025.1.1 and is based on 132 drill holes and four trenches, totalling 23,626 meters and 8,288 assays. The cut-off date for the drill hole database was December 9, 2025.
8. Composites of one metre were created inside the mineralization domains. High-grade capping was done on the composited assay data. Depending on individual statistical study for each zone, composites were capped between 1.50% Li2O and 4.50% Li2O and between 200ppm Ta2O5 and 900ppm Ta2O5.
9. Pit constrained Mineral Resource for the base case is reported at a cut-off grade of 0.50% Li2OEq. The cut-off grades may be re-evaluated in the future based on prevailing market conditions and costs. A ratio Ta2O5 to Li2O of 0.00008658 (based on selling price, recoveries and other variables) was used to obtain the Li2OEq grade used in the cut-off.
10. Specific gravity values were estimated using data available in the drill hole database. Density values where interpolated when data was sufficient to do so, and completed with fixed values. Density values between 2.57 g/cm3 and 2.90 g/cm3 were applied to the model for different domains and 2.00 g/cm3 for overburden.
11. Grade model resource estimation was calculated from drill hole data using an Ordinary Kriging interpolation method in a sub-blocked model using blocks measuring 5m x 5m x 5m in size and sub-blocks down to 0.625m x 0.625m x 0.625m. Ordinary kriging (OK), inverse square distance (ID2), Nearest neighbour (NN) interpolation methods were tested, resulting in no material difference in the Mineral Resource Estimates.
12. The Inferred Mineral Resource categories are constrained to areas where drill spacing is less than 150 metres and show reasonable geological and grade continuity. Cookie cutters were used to define categories based on the above parameters.
13. Effective date of the Mineral Resource Estimate is 7 January 2026
    
    

Figure 1: BRW Quebec Portfolio

Qualified Person

The scientific and technical information contained in this press release has been reviewed and approved by Mr. Simon T. Hébert, VP Development. He is a Professional Geologist registered in Quebec and is a Qualified Person as defined by National Instrument 43-101. The independent qualified persons for the MRE, as defined by National Instrument (“NI”) 43-101 guidelines, is Pierre Luc Richard, P.Geo., of PLR Resources Inc., with contributions from Patrick Frenette, P.Eng., of Synectiq Inc. for cut-off grade estimation and open pit optimization, and from Jarrett Quinn, P.Eng., of Synectiq Inc. for metallurgical aspect.

About Brunswick Exploration Inc.

Brunswick Exploration is a Montreal-based mineral exploration company listed on the TSX-V under symbol BRW. The Company is focused on grassroots exploration for lithium in Canada, a critical metal necessary to global decarbonization and energy transition. The company is rapidly advancing the most extensive grassroots lithium property portfolio in Canada, Greenland and Saudi Arabia underpinned by its Mirage project, one of the largest undeveloped hard-rock lithium Inferred Mineral Resource Estimate in the Americas, with 52.2Mt grading 1.08% Li2O.

Investor Relations/information
Mr. Killian Charles, President and CEO
Phone: 514 861 4441
Email: info@BRWexplo.com

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

Cautionary Statement on Forward-Looking Information

This news release contains "forward-looking information" within the meaning of applicable Canadian securities legislation based on expectations, estimates and projections as at the date of this news release. Forward-looking information involves risks, uncertainties and other factors that could cause actual events, results, performance, prospects and opportunities to differ materially from those expressed or implied by such forward-looking information. Factors that could cause actual results to differ materially from such forward-looking information include, but are not limited to, delays in obtaining or failures to obtain required governmental, environmental or other project approvals; uncertainties relating to the availability and costs of financing needed in the future; changes in equity markets; inflation; fluctuations in commodity prices; delays in the development of projects; the other risks involved in the mineral exploration and development industry; and those risks set out in the Corporation’s public documents filed on SEDAR at www.sedar.com. Although the Corporation believes that the assumptions and factors used in preparing the forward-looking information in this news release are reasonable, undue reliance should not be placed on such information, which only applies as of the date of this news release, and no assurance can be given that such events will occur in the disclosed time frames or at all. The Corporation disclaims any intention or obligation to update or revise any forward-looking information, whether as a result of new information, future events or otherwise, other than as required by 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 news release.

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