Mr. Claude Dufresne reports

TINTINA MINES ANNOUNCES COMMENCEMENT OF DRILLING AT THE DOS AMIGOS PROJECT IN CHILE

Tintina Mines Ltd. has commenced diamond drilling and field activities at its wholly owned Dos Amigos project in the Atacama region of Chile. An initial approximately 40,000-metre 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 approximately three kilometres north of Dos Amigos, will be drill tested in Q4 2026. Previous drilling in 2018 at Tricolor returned 230 metres at 0.56 per cent copper and 0.33 gram per tonne gold from 18 metres to end of hole (SDDK 18-035).

Infill drilling program

The key near-term priority is approximately 40,000 metres 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 and set out in the technical report titled "Technical Report NI 43-101 -- PEA Domeyko Sulfuros," with an effective date of Jan. 23, 2026, which supports the 2026 preliminary economic assessment (PEA), is as follows:

• Measured and indicated mineral resources -- 100.8 million tonnes at 0.35 per cent copper and 0.28 gram per tonne gold (0.52 per cent copper equivalent at PEA base-case metal prices; 0.56 per cent CuEq at current consensus long-term metal prices);
• Inferred mineral resources -- 256.3 million tonnes at 0.34 per cent copper and 0.24 gram per tonne gold (0.49 per cent CuEq at PEA base-case metal prices; 0.52 per cent CuEq at current consensus long-term metal prices).

The majority of drilling will focus on the Dos Amigos porphyry deposit, with drill holes ranging between 300 m and 800 m 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 28,900 m and 19,300 m have been drilled historically at Dos Amigos and Marisol, respectively.

Drilling activities will gradually ramp up over the next month, and up to six 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 the second half of 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 test work, supplementing the test work completed for the PEA and the metallurgical program currently under way.

Exploration

Further to the infill drilling program, Tintina intends to embark on a systematic regional exploration campaign in the second half of 2027 comprising geophysics, surface geochemistry and mapping to explore the 10-kilometre-long trend of porphyry centres on Tintina's concessions. A review of the various geological, geophysical and geochemical databases is under way, 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 Richard Leclerc as general manager of Andean Belt Resources SpA (ABR), the company's wholly owned Chilean subsidiary, effective Sept. 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 Universite Laval.

Investor relations engagement

The company further announces that it has engaged 2608124 Ontario Inc. (doing business as Target IR & Communications) of Toronto, Ont., to provide investor relations services, including investor communications and disclosure materials, investor meetings, road shows and conferences, shareholder targeting, and liaison with the research and broker community.

The agreement, dated as of Sept. 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 of written notice. The company will pay Target IR $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.

Quality control and 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 were also collected before the drill core is marked up for sampling at two-metre 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 four-acid digest (Cu-AA62) and multielement analysis (ME-ICP41). In addition, gold was analyzed using a 30-gram fire assay method (Au-AA23) and weathered samples were selected for sequential copper leach test work. The company employed a rigorous QA/QC program involving certified standards, blank, one-fourth core duplicates and coarse reject duplicates. The remaining one-half 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 Bascunan Moraga, CCCRRM, and Joled Nur Paredes, CCCRRM, of SRK, each an independent qualified person for the purposes of National Instrument 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 copper equivalent grades, and the work program and exploration targets described above, has been reviewed and approved by James Purchase, PGeo, 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 Ltd.

Tintina Mines is a TSX Venture Exchange-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.

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