Errington Metals Announces Maiden Mineral Resource Estimate for the Sudbury Basin Project

Errington Metals Announces Maiden Mineral Resource Estimate for the Sudbury Basin Project Canada NewsWire THUNDER BAY, ON, Sept. 22, 2026 Maiden Mineral Resource Estimate for the Sudbury Basin Project: M&I 14.20 Mt at 1.20% Cu, 4.02% Zn, 1.11% Pb, 0.83 g/t Au, 50.25 g/t Ag Inferred 3.44 Mt at 1.02% Cu, 4.62% Zn, 1.73% Pb, 0.57 g/t Au, 66.55 g/t Ag Over 80% of the total resources are classified as either Measured or Indicated Approximately 75% of the total M&I tonnes are defined at Errington, a key focus for preliminary development planning and future growth 3.44 Mt of Inferred Resources have been newly recognized, reflecting the high potential to discover additional mineralization All deposits remain open for expansion and will be the focus of the fully funded 55,000 m drill campaign currently ongoing Results from 30 drill holes at Errington are pending and not included in this Mineral Resource Estimate THUNDER BAY, ON, Sept. 22, 2026 /CNW/ -- Errington Metals Corp. (TSXV: EM) ("Errington" or the "Company") is pleased to announce a maiden mineral resource estimate for its Sudbury Basin Project, encompassing the Errington, Vermilion and Balfour deposits. All three deposits remain open for further expansion and are priority targets of the Company's current fully funded drill campaign expected to continue throughout 2027. The mineral resource estimate disclosed herein was prepared in accordance with National Instrument 43-101 – Standards of Disclosure for Mineral Projects ("NI 43-101"). Complete mineral resource estimate tables are provided below. A video overview of the estimate can be found at https://vrify.com/meetings/recordings/8978858d-a899-4562-b61a-0e377e453359. "This maiden mineral resource estimate establishes a strong foundation for advancing the Sudbury Basin Project," said Matthew Gollat, President and CEO of Errington Metals. "We have defined a significant increase in tonnes at similar grades compared to the previous estimates with more than 80% of the resources classified as Measured and Indicated, demonstrating the potential value created by the extensive historical database and our disciplined technical work. To build on this momentum, and with all three deposits open for expansion, a fully funded drill program is underway focused on further increasing the resource base, advancing metallurgical studies and defining the path toward future development." Table 1: Global Mineral Resource Table Grade Contained Metal Material Tonnes Cu Zn Pb Au Ag CuEq Cu Zn Pb Au Ag % % % g/t g/t % t t t oz oz Errington Measured 7,652,664 1.13 3.61 0.99 0.81 46.08 2.54 86,175 275,910 76,089 198,143 11,337,846 Indicated 2,968,518 1.13 4.55 1.30 0.81 54.58 2.79 33,572 134,936 38,475 77,051 5,209,514 Vermilion Measured 2,000,962 1.33 4.53 1.24 0.90 56.75 3.05 26,621 90,724 24,804 58,087 3,650,558 Indicated 1,582,181 1.56 4.40 1.11 0.91 54.05 3.23 24,665 69,665 17,605 46,364 2,749,567 M+I Total 14,204,325 1.20 4.02 1.11 0.83 50.25 2.74 171,032 571,235 156,972 379,644 22,947,485 Inferred Grade Contained Metal Deposit Tonnes Cu Zn Pb Au Ag CuEq Cu Zn Pb Au Ag % % % g/t g/t % t t t oz oz Errington 804,289 1.24 4.30 1.20 0.79 51.79 2.81 10,011 34,614 9,646 20,363 1,339,190 Vermilion 357,339 1.11 4.92 1.24 1.08 58.15 3.00 3,975 17,571 4,428 12,400 668,051 Balfour 2,274,831 0.93 4.68 1.99 0.41 73.08 2.57 21,126 106,548 45,207 29,982 5,345,239 Total 3,436,459 1.02 4.62 1.73 0.57 66.55 2.67 35,113 158,733 59,282 62,745 7,352,480 Notes: The Mineral Resource Estimate has been estimated using the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Definitions and Standards for Mineral Resource and Mineral Reserve in accordance with National Instrument 43-101 - Standards of Disclosure for Mineral Projects ("NI 43-101"). Mineral Resources which are not Mineral Reserves do not have demonstrated economic viability. An Inferred Mineral Resource has a lower level of confidence than that applied to an Indicated Mineral Resource and must not be converted to a Mineral Reserve. There is no certainty that Inferred Mineral Resources will be converted to Indicated Mineral Resources through continued exploration. Inferred Mineral Resources are exclusive of the Measured and Indicated Resources. Underground mining stope optimization was performed using DeswikTM (v.2026.1.2159). Stope shapes were developed using a break-even cut-off grade of 1.5% CuEq which considers metal prices of USD 5.80/lb Cu (USD 12,787/t), USD 1.30/lb Zn (USD 2,866/t), USD 0.90/lb Pb (USD 1,984/t), USD 4100/oz Au and USD 50/oz Ag; metal recoveries of 72% for Cu, 45% for Pb, 78% for Zn, 70% for Au and 70% for Ag; a mining cost of USD 75.00/t RoM (Run-of-Mine, mineralized material); processing cost of USD 35/RoM, and G&A cost of USD 10/t RoM. The total operating costs of producing the concentrates is USD 120/t RoM. Allowance has been made for payability, smelter terms, refining charges, penalties, or deleterious elements where applicable. The transportation, treatment, and refining costs of the concentrates are estimated at approximately USD 34/t RoM. CuEq% = 1 * %Cu + 0.1804 * %Zn + 0.0731 * %Pb + 0.5321 * g/t Au + 0.006124 * g/t Ag. Underground resources were estimated using stope shapes optimized from a break-even cut-off grade of 1.5% CuEq; however, the reported in-situ figures include low-grade 'must take' material estimated within the underground reporting shapes (though largely above a marginal cut-off grade of 0.5% CuEq). The estimate of Mineral Resources may be materially affected by technical, environmental, permitting, legal, title, taxation, socio-political, marketing, or other relevant issues. The effective date of the Mineral Resource Estimate is September 20, 2026. Figures have been rounded to an appropriate level of precision for the reporting of Mineral Resources. As a result, totals may not compute exactly as shown. The resource estimate was prepared by Ryan Wilson, Ph.D., P. Geo, of DRA Americas Incorporated in accordance with NI 43-101. Mr.Wilson is an independent qualified person ("QP") as defined by NI 43-101. The technical report in support of the above noted Mineral Resource estimate will be filed by the Company within 45 days of this news release. Geology and Mineralization The Sudbury Basin Project area contains three massive sulphide deposits, Vermilion, Errington and Balfour. All three are hosted by a chert-carbonate lithological unit interlayered with argillite which is underlain by a thick, estimated at 1.4 km, volcanic pyroclastic sequence. The mineralized sequence is folded and faulted such that the massive sulphide horizon is repeated in a configuration where mineralization zones are up to 50 m thick. The overall geological setting for mineralization is considered as a Volcanogenic Massive Sulphide style, analogous to copper-zinc-lead-gold-silver deposits in the Iberian Pyrite Belt in Spain and Portugal, the Zinkgruvan deposits in Sweden and some of the massive sulphide deposits in the Bathurst District in Canada. Errington Deposit The Errington deposit accounts for approximately 70% of the Sudbury Basin Project's M&I Resource inventory. Its tabular geometry reflects the continuity of the mineralized horizon over 1.2 kilometres, while structural stacking increases the mineralized thickness locally to as much as 50 metres. Distinct higher-grade copper and zinc zones reflect the metal zonation commonly observed in VMS style deposits, and higher-grade gold zones also occur within an otherwise broadly consistent grade distribution. Errington remains open at depth, including on the eastern portion of the deposit where massive sulphide intersections were recently reported (see press release dated Sept 03, 2026). At higher cutoff grades, the Errington deposit retains continuity. The 1500 Zone is specifically open along the dip extensions toward surface and to depth. A new structural interpretation is planned for the 1500 Zone to further improve drill targeting. Vermilion Deposit The Vermilion deposit is more compact compared to Errington owing to the nature of faulting at Vermilion. Grades are somewhat higher overall than Errington; most notably gold grades are consistently higher, particularly at higher cutoff grades (see Table 2). The distribution of Measured versus Indicated Resources at Vermilion largely reflects the proportion of more recent (i.e., 2011–2013) drilling to older historic programs. The strike extensions of the mineralized horizons have not been fully drilled and have been targeted for drilling Fall 2026. Balfour Deposit The Balfour deposit is currently all considered as Inferred Resources. Balfour had previously been drilled, but the drill holes had been widely spaced and were not amenable to resource modelling. Errington Metals has completed over 13,000 m of drilling as well as developed a 3D geological model guiding the resource estimate. Mineralization at Balfour is zinc- and silver-rich compared to Vermilion and Errington; specifically at higher cutoff grades (see Table 2). Folding is also more prominent at Balfour with the main hinge zone interpreted to depth and not yet drilled. Mineral Resource Sensitivities  An underground stope shape sensitivity analysis was completed to assess the robustness of the mineralized zones in response to varied cut-off grades as a function of metal prices, associated costs and other modifying factors. The analysis is inclusive of the current MRE update and provided only to show the effect of cut-off grade assumptions on potential future underground resource shapes; results are provided in Table 2. Table 2. Sensitivity Table for Resources using multiple grade cutoffs Description of all parameters used for calculations is given in the footnotes of Table 1. Resource Estimate Parameters  Mineralization wireframe boundaries for Errington, Vermilion and Balfour were initially defined using individual metal grade distributions of copper, zinc, gold, silver and lead. The block models were calculated using a copper equivalent grade combining all five metals – refer to footnote 5, Table 1. Metal recoveries used in the resource estimate are based on available historical metallurgical testwork and relevant comparable polymetallic projects. Errington Metals is conducting an ongoing metallurgical testwork program to evaluate and optimize metal recoveries, concentrate grades and potential flowsheet configurations. Results from this program remain preliminary and have not yet been incorporated into the resource estimate. The estimation method used for the estimates was Inverse Distance Weighting squared (IDW2) although other methods, including IDW3, Ordinary Kriging (OK) and Nearest Neighbour (NN), were also run to validate continuity and consistency of the block modelling. Cutoff grades were determined using benchmark economic grades and tonnes from comparable deposits to be mined underground. In general, Measured Resources are definable by approximately 25 m spaced drilling, Indicated by 50 m spacing and Inferred to 100 m spacing. The database for the mineral resource estimate consists of over 450,000 m of historic drilling; most recently over 75,000 m were completed in 2011–2013 validating previous programs and results. In addition, Errington Metals has completed over 40,000 m of drilling since July 2025. The resources were constrained by potential mining shapes for reporting purposes. Optimization was carried out using DeswikTM software (version 2026.1.2159). The shapes created were 10 m long by 10 m high by 1.5 m true thickness (minimum mining width). Future Plans The Company has initiated its Phase 2 drill campaign of approximately 55,000 m with initial drilling focused on testing the extensions of the Vermilion deposit and some infill drilling to continue to improve the resource model. The program will extend to test target areas identified in the Errington and Balfour mineral resource models to further understand their expansion potential. Regional targets based on geological and geophysical data interpretation have been identified and will also be tested. Additional geophysical surveys have been completed to refine resource expansion targets as well to recognize new areas of mineralization. Further drilling to collect a bulk sample at Errington will be conducted this Fall in preparation of a mini-pilot metallurgical study next year. About Errington Metals Errington Metals Corp. is a Canadian exploration and development company focused on critical and precious metals. The Company is advancing its wholly owned Sudbury Basin Project, which hosts high-grade volcanogenic massive sulphide ("VMS")-style mineralization in the world-renowned Sudbury mining district. Through systematic drilling and disciplined technical work, Errington Metals is positioning the Sudbury Basin Project as a high-quality exploration and development opportunity. The Company is advancing a Phase 2 planned 55,000 m drill program designed to grow resources and advance the Property. Several regional targets throughout the recently consolidated property will also be tested. For further information about the Company please visit www.erringtonmetals.com and sign up for email updates.  www.erringtonmetals.com Qualified Persons The mineral resource estimation was conducted by Ryan Wilson, Ph.D., P. Geo, of DRA Americas Inc. in accordance with NI 43-101. Mr. Wilson is an independent qualified person ("QP") as defined by NI 43-101. Other scientific and technical information in this press release has been reviewed and approved by Frank Santaguida, Ph.D., P. Geo. Mr. Santaguida is Vice President, Exploration for Errington Metals Corp. and is a qualified person under NI 43-101. QA/QC Procedures Core samples are collected and handled using typical industry standards. Sampling, core-cutting and submission to the assay labs were conducted and supervised by Errington Metals personnel. Assay lab results have been verified by Errington Metals via Certified Reference Material standards, blanks and field duplicates. Samples were submitted to either ALS Canada in Sudbury Ontario, Activation Labs in North Bay or MSALABS in Timmins, Ontario who all meet the guidelines of ISO17025 accreditation and ISO9001, ISO14001 and ISO45001 certification. Analyses of internal reference material standards were concurrently analysed by the labs are also reported and certified. Samples are digested using a four-acid solution and analysed using a combination of ICP-MS and ICP-AES methods. Gold is independently analysed using a 30 g aliquot by fire assay methods. Cautionary Note Regarding Forward-Looking Information This news release contains forward-looking statements and forward-looking information (collectively, "forward-looking statements") within the meaning of applicable securities laws. Any statements that are contained in this news release that are not statements of historical fact may be deemed to be forward-looking statements. Forward-looking statements are often identified by terms such as "may", "should", "anticipate", "will", "estimates", "believes", "intends", "expects" and similar expressions which are intended to identify forward-looking statements. More particularly and without limitation, this news release contains forward-looking statements that include, but are not limited to, statements regarding the Company's planned 2026 drill program, the timing of completion of the technical report in support of the Mineral Resource estimate, the exploration potential of the Sudbury Basin Project, the ability to grow the resource base of the Project and advance metallurgical studies and defining the path toward future development of the Sudbury Basin Project, exploration targets, geological interpretations, metallurgical studies, and the potential advancement of the Sudbury Basin Project. Forward-looking statements are inherently uncertain, and the actual performance may be affected by a number of material factors, assumptions and expectations, many of which are beyond the control of the Company, including expectations and assumptions concerning the Company and its Sudbury Basin Project. Readers are cautioned that assumptions used in the preparation of any forward-looking statements may prove to be incorrect. Events or circumstances may cause actual results to differ materially from those predicted as a result of numerous known and unknown risks, uncertainties and other factors, many of which are beyond the control of the Company. Readers are further cautioned not to place undue reliance on any forward-looking statements, as such information, although considered reasonable by the management of the Company at the time of preparation, may prove to be incorrect and actual results may differ materially from those anticipated. The forward-looking statements contained in this news release are made as of the date of this news release and are expressly qualified by the foregoing cautionary statement. Except as expressly required by securities law, the Company does not undertake any obligation to update publicly or to revise any of the included forward-looking statements, whether as a result of new information, future events or otherwise. 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. No stock exchange, securities commission or other regulatory authority has approved or disapproved the information contained herein. SOURCE Errington Metals Corp. View original content to download multimedia: http://www.newswire.ca/en/releases/archive/September2026/22/c4763.html Contact: For Further Information Please Contact: Matthew Gollat, President & CEO, Errington Metals Corp., Toll-free: 1-888-279-1157, Direct: 1-807-577-5785, [email protected]