Tintina Mines Announces Commencement of Drilling at the Dos Amigos Project in Chile

TORONTO, ON AND SANTIAGO, CHILE / ACCESS Newswire / September 22, 2026 / Tintina Mines Limited (TSXV:TTS)(OTC PINK:TNNTF) ("Tintina" or the "Company") is pleased to announce the commencement of diamond drilling and field activities at its wholly owned Dos Amigos project ("Dos Amigos" or the "Project") in the Atacama Region of Chile. An initial approximately 40,000-metre ("m") program has been designed to support the conversion of Inferred Mineral Resources to the Indicated category, which is intended to form the basis for future feasibility study workstreams. Tintina intends to release drilling results on a regular basis throughout the program, with initial assays expected mid-November. In addition, the Tricolor target, a high-priority porphyry target located ~3km north of Dos Amigos, will be drill tested in Q4 2026. Previous drilling in 2018 at Tricolor returned 230m @ 0.56% copper ("Cu") and 0.33 g/t gold ("Au") from 18m to end-of-hole (SDDK 18-035). Infill Drilling Program The key near-term priority is approximately 40,000m of diamond drilling designed to support the conversion of existing Inferred Mineral Resources to the Indicated category. The Mineral Resource Estimate prepared by SRK Consulting (Chile) SpA ("SRK") and set out in the technical report titled "Technical Report NI 43-101 - PEA Domeyko Sulfuros" with an effective date of January 23, 2026 (the "Technical Report"), which supports the 2026 preliminary economic assessment ("PEA"), is as follows (see "Cautionary Note Regarding Mineral Resources" below): Measured & Indicated Mineral Resources - 100.8 million tonnes ("Mt") at 0.35% copper and 0.28 g/t gold (0.52% copper equivalent ("CuEq") at PEA base-case metal prices; 0.56% CuEq at current consensus long-term metal prices)1 Inferred Mineral Resources - 256.3 Mt at 0.34% copper and 0.24 g/t gold (0.49% CuEq at PEA base-case metal prices; 0.52% CuEq at current consensus long-term metal prices)1 1The Mineral Resource Estimate is reported within a conceptual open pit at a cut-off grade of 0.2% total copper, undiluted and without metallurgical deductions; tonnes and grades are rounded. Mineral resources that are not mineral reserves do not have demonstrated economic viability. The key assumptions, parameters and methods used to estimate the Mineral Resources, and the known legal, political, environmental and other risks that could materially affect the potential development of the Mineral Resources, are described in the Technical Report, available under the Company's profile on SEDAR+ at www.sedarplus.ca. CuEq grades are provided for comparison purposes only. They are calculated from the unrounded copper and gold grades in the Mineral Resource Estimate as CuEq (%) = Cu (%) + Au (g/t) × [(Au price ÷ 31.1035) × Au recovery] ÷ [(Cu price × 22.0462) × Cu recovery], using the PEA metallurgical recoveries of 88.2% for Cu and 64.6% for Au and (i) the PEA base-case long-term metal prices of US$4.30/lb Cu and US$2,500/oz, and (ii) current consensus long-term metal prices of US$5.03/lb Cu and US$3,570/oz Au as published by major banks and investment firms for September 2026. Payability, treatment and refining charges and other realization costs have not been applied. CuEq was not used in estimating, classifying or reporting the Mineral Resources or in determining the cut-off grade, and the CuEq grades do not represent a change to the Mineral Resource Estimate or to the results of the PEA. The majority of drilling will focus on the Dos Amigos porphyry deposit, with drill holes ranging between 300m and 800m depth. In addition, shallower drilling will be conducted at the Marisol breccia to the north of the Dos Amigos pit where a blanket of near-surface supergene mineralization has been identified. To date, approximately 28,900m and 19,300m have been drilled historically at Dos Amigos and Marisol, respectively. See Figure 1 for a plan view of historical and proposed drill holes. Drilling activities will gradually ramp up over the next month, and up to six (6) rigs are expected to operate on-site in Q4 2026 on a 24-hour basis until Q2 2027. Assay results will be released on a regular basis as they are received and validated, and the Company intends to publish an updated Mineral Resource Estimate in H2 2027 once all assays have been received. In addition to infill drilling, comprehensive geotechnical and hydrogeological investigations will be conducted throughout the course of the drilling program to support the feasibility study. Drill core will also provide sample material for metallurgical testwork, supplementing the testwork completed for the PEA and the metallurgical program currently under way. Figure 1: Plan view of proposed drilling, existing drilling (colored by Cu%) with aerial photo background Exploration Further to the infill drilling program, Tintina intends to embark on a systematic regional exploration campaign in H2 2027 comprising geophysics, surface geochemistry and mapping to explore the 10km-long trend of porphyry centres on Tintina's concessions. A review of the various geological, geophysical and geochemical databases is underway, and the Company will be formulating a long-term exploration strategy to support organic growth across the Tintina portfolio. Appointment of General Manager The Company is also pleased to announce the appointment of Mr. Richard Leclerc as General Manager of Andean Belt Resources SpA ("ABR"), the Company's wholly owned Chilean subsidiary, effective September 7, 2026. Based in Santiago and reporting to the Chief Executive Officer, Mr. Leclerc will lead ABR's operations, with overall responsibility for the Dos Amigos project, the ABR organization and relations with local authorities, communities and contractors in Chile. Mr. Leclerc brings more than four decades of experience in the copper and gold sector across Chile and the Americas. He joins ABR following a short retirement from Anglo American Copper, where he served from 2014 as Vice President, Technical and Sustainability in Santiago, and was previously President of Peregrine Metals Ltd., Vice President Operations of Andean Resources, Chief Operating Officer of Centenario Copper and Vice President Operations of Aur Resources. Mr. Leclerc also was involved in the development and implementation of the Operation Readiness program resulting in the successful commissioning and ramp-up of the Quellaveco Mine in Peru. He holds a bachelor's degree in mining and mineral engineering from Université Laval. Investor Relations Engagement The Company further announces that it has engaged 2608124 Ontario Inc. (dba Target IR & Communications) of Toronto, Ontario to provide investor relations services, including investor communications and disclosure materials, investor meetings, roadshows and conferences, shareholder targeting and liaison with the research and broker community. The agreement, dated as of September 22, 2026, is for an initial term of six months, renewable quarterly at the Company's option, and may be terminated by either party on 60 days' written notice. The Company will pay Target IR CAD$9,000 per month, plus applicable taxes; no securities of the Company have been issued or are issuable under the agreement. Target IR and its principal, Salisha Ilyas, are at arm's length to the Company, and neither Target IR nor Ms. Ilyas holds any securities of the Company. The engagement remains subject to acceptance by the Exchange. Additional Drill Hole Disclosure Table 1: Collar coordinates and details of 2018 drilling at Tricolor Drillhole ID X Y Z End Depth (m) Dip (degrees) Azimuth (degrees) SDDK 18-035 316863 6795545 810 250 -50 90 Notes: Coordinates are in PSAD56 UTM19S Table 2: Drilling intercepts at Tricolor Drillhole ID From (m) To (m) Cu (%) Au (g/t) SDDK 18-035 18.0 250.0 0.56 0.33 Notes: Drilling intercept has been calculated using a lower cut-off of 0.3% CuEq as defined by the equation CuEq = Cu% + (Au g/t x 0.7583) using September 2026 consensus commodity prices ($5.03/lb Cu and $3,570/oz Au) and recoveries presented in the PEA (88.2% for Cu and 64.6% for Au). The current orientation of mineralization is unknown therefore the intercept may not reflect true widths. A maximum of 4m of internal dilution has been allowed in the intercept, Quality Control & Quality Assurance Drill holes at Tricolor in 2018 were drilled using NQ diameter, with core extracted from drill tubes and sealed in core boxes with appropriate depth markers. Once transported from the drill rig to the on-site logging area, drill core was logged for lithology, alteration, veining, and structure, with magnetic susceptibility and geotechnical/recovery parameters also collected. Density data was also collected before the drill core is marked up for sampling at 2m intervals with breaks on significant geological boundaries. Drill core was cut in half using a core saw, with one half sent to an accredited laboratory (ALS) for analysis using an ore-grade 4-acid digest (Cu-AA62) and multi-element analysis (ME-ICP41). In addition, gold was analysed using a 30g fire assay method (Au-AA23) and weathered samples were selected for sequential copper leach test work. The Company employed a rigorous QAQC program involving certified standards, blank, ¼ core duplicates and coarse reject duplicates. The remaining ½ core was stored in racks at the Company's secure core warehouse in Domeyko. Qualified Person The Mineral Resource Estimate referred to in this news release was prepared by SRK under the supervision of Sophia Bascuñán Moraga, CCCRRM, and Joled Nur Paredes, CCCRRM, of SRK, each an independent "qualified person" for the purposes of NI 43-101, and is described in the Technical Report. All other scientific and technical information contained in this news release, including the restatement of the Mineral Resource Estimate, the calculation of CuEq grades and the work program and exploration targets described above, has been reviewed and approved by James Purchase, P.Geo., Vice President Exploration of the Company, a "qualified person" for the purposes of NI 43-101. Mr. Purchase is not independent of the Company. About Tintina Mines Limited Tintina Mines Limited is a TSXV-listed copper-gold exploration and development company advancing the wholly owned Dos Amigos Copper-Gold Project, formerly the Domeyko Sulfuros Project, in the Atacama Region of Chile through its wholly owned Chilean subsidiary, ABR. For more information, please visit www.tintinamines.com or refer to the Company's filings on SEDAR+ at www.sedarplus.ca. For Further Information, please contact: Claude Dufresne, P.Eng. Chief Executive Officer [email protected] +1 (416) 848-0106 Cautionary Statement Regarding Forward-Looking Information This news release contains "forward-looking information" within the meaning of applicable Canadian securities legislation that is based on current expectations, estimates, projections and interpretations about future events as at the date of this news release. Generally, forward-looking information can be identified by the use of forward-looking terminology such as "add" or "additional", "advance", "advancing" or "advancement", "anticipates" or "anticipated", "assumptions", "believes", "can be", "continue" or "continuing", "convert" or "conversion", "deliver" or "delivering", "estimates" or "estimated", "expect", "expected" or "expectations", "forward", "intends" or "intended", "may", "plans", "pending", "potential", "preliminary", "pro forma", "projections", "proposed", "reflects", "subject to", "support", "targeted", "update", "upside", "will" or "will be", "could", "would", "occur", or "achievements". Forward-looking information in this news release includes, but is not limited to, information with respect to: the scope, cost, metreage, sequencing, timing and anticipated outcomes of the work program described in this news release, including the resource-conversion drilling and the geotechnical, hydrogeological and metallurgical programs; the timing and outcome of an updated mineral resource estimate; the metal price and metallurgical recovery assumptions used to calculate CuEq grades; the decision to proceed directly to a feasibility study and the timing of the feasibility study; the intention to conduct a regional exploration campaign in the second half of 2027; the exploration potential of the Tricolor target and other targets within ABR's land package; the sufficiency of the Company's funding to complete the work program; the production, economic, capital and operating cost estimates set out in the Technical Report; and the potential of the Project to become a significant copper operation and a platform for future growth. Forward-looking information is based on the opinions and estimates of management at the date the information is made, and is based on a number of assumptions and is subject to known and unknown risks, uncertainties and other factors that may cause the actual results, level of activity, performance or achievements of Tintina to be materially different from those expressed or implied by such forward-looking information, including, without limitation: the assumption that drilling and study work will be completed within the metreage, budget and timeframes currently contemplated and will produce results supporting the conversion of Inferred mineral resources to the Indicated category; the assumption that a feasibility study will support a positive final investment decision; the availability of drill rigs, laboratory capacity, contractors and skilled personnel; assay turnaround times; the assumption that the environmental baseline program can be completed across a full seasonal cycle without material interruption and that the environmental impact assessment, the maritime concession and the further sectoral permits required for the Project will be obtained on the timelines contemplated; the risk that permitting timelines are longer than anticipated; the receipt and maintenance of all requisite regulatory approvals; future commodity prices, including copper and gold; changes in foreign exchange and interest rates; actual results of current exploration activities; government regulation; political or economic developments in Chile; community relations and stakeholder engagement; conflicts and their effect on supply chains; environmental risks; pandemic risks; capital and operating cost estimates; operating or technical difficulties in connection with exploration and development activities; employee relations; the speculative nature of copper and gold exploration and development, including the risks of diminishing quantities or grades of reserves; contests or uncertainties over title to properties; tax considerations and changes in tax law or the interpretation thereof; changes in project parameters as plans continue to be refined; as well as those risk factors discussed in Tintina's management's discussion and analysis and other continuous disclosure filings under its profile on SEDAR+ at www.sedarplus.ca. Tintina cautions that the foregoing list of material factors and assumptions is not exhaustive. Although Tintina has attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking information, there may be other factors that cause results not to be as anticipated, estimated or intended. Accordingly, readers should not place undue reliance on forward-looking information. Tintina does not undertake to update any forward-looking information, except in accordance with applicable securities laws. Cautionary Note Regarding Mineral Resources Until mineral deposits are actually mined and processed, mineral resources must be considered as estimates only. Mineral resource estimates are not mineral reserves and do not have demonstrated economic viability. The estimation of mineral resources is inherently uncertain, involves subjective judgement about many relevant factors and may be materially affected by, among other things, environmental, permitting, legal, title, taxation, socio-political, marketing or other relevant risks, uncertainties, contingencies and other factors described in Tintina's public disclosure available under its profile on SEDAR+ at www.sedarplus.ca. The quantity and grade of reported "Inferred" mineral resource estimates are uncertain in nature and there has been insufficient exploration to define such "Inferred" mineral resource estimates as an "Indicated" or "Measured" mineral resource, and it is uncertain if further exploration will result in upgrading "Inferred" mineral resource estimates to an "Indicated" or "Measured" mineral resource. It cannot be assumed that all or any part of an "Inferred" or "Indicated" mineral resource estimate will ever be upgraded to a higher category. The mineral resource estimates disclosed in this news release were reported using the Canadian Institute of Mining, Metallurgy and Petroleum Definition Standards for Mineral Resources and Mineral Reserves in accordance with NI 43-101. The PEA is preliminary in nature and includes Inferred mineral resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorised as mineral reserves. There is no certainty that the economic results described in the Technical Report will be realised. 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. SOURCE: Tintina Mines Limited View the original press release on ACCESS Newswire