Vancouver, British Columbia--(Newsfile Corp. - July 21, 2025) - Transatlantic Mining Corp. (TSXV: TCO) (the "Company") is pleased to provide an update on its exploration activities at the Anvil prospect, key target within the larger Monitor Copper-Gold Project. The project is located approximately 8 kilometers south of Taft, Idaho, USA and continues to demonstrate prospectivity.
Highlights of the Exploration Program:
High-Grade Underground samples at Anvil: An outcrop sample returned 3.1% copper (Cu) over 0.3 metres.
Anvil Prospect Potential: Recent underground samples at Anvil indicate multiple copper fissure veins within a complex system that are anomalous in copper and support larger Copper Fissure System in the district.
"Samples underground and confirmation of 2 orientations with copper mineralisation are encouraging for further follow up," said Bernie Sostak, CEO of Transatlantic Mining. "This supports multiple high grade copper mineralisation veins in the region. We look forward to uncovering more copper in the district with updated geophysical techniques along strike and down dip."
Geology and Mineralization
At the Anvil prospect, copper mineralization is found within steeply dipping fissure veins that form along second-order structures within a prominent shear zone, trending approximately N40W to N70W. These veins, typically can be up to 1.8 metres wide, are characteristic of the broader Coeur d'Alene mining district. In this eastern and southeastern part of the district, where the Monitor Project is situated, veins are typically copper-rich with reduced silver, lead, and zinc content, suggesting formation under higher-temperature conditions or closer proximity to the hydrothermal source. These copper-rich veins are generally less than 5 meters wide, extend to significant depths, and primarily contain chalcopyrite, pyrite, calcite, siderite, and quartz. Hydrothermal alteration, notably pervasive siderite zoning and bleaching, is a defining characteristic of the mineralized zones, with disseminated siderite sometimes extending hundreds of meters into the wall rocks.
Exploration Results
Building on this geological understanding, the Company conducted a systematic exploration program, implementing industry best practices to confirm the property's geological and mineralogical characteristics.
Initial underground sampling at the Anvil prospect yielded encouraging copper results. An underground adit returned samples up to 3.1% Cu over 0.3 metres (see Figure 1,2) ( *See also historical reports).
The historical workings at the Anvil prospect were explored, mapped, and sampled. These workings were developed along a northeast-trending mineralized structure. The workings and this northeast-trending structure intersect a distinct northwest-trending structure. All of these structures were sampled as part of the program. Samples collected were subsequently sent to Christofferson Labs, LLC. in Smelterville, Idaho, USA for analysis of gold and then to American Analytical Laboratories in Osburn, Idaho for an ICP analysis.
Figure 1: Map of the Big Elk Prospect, a subset of the Monitor Project
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Figure 2: Map of the Anvil Prospect, an underground subset of the Monitor Project (Table 1)
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Overall, the Company's exploration efforts confirmed the strike and dip of the vein mined along the Big Elk workings. Surface samples indicate the veins contain copper mineralization. Furthermore, through mapping and sampling of the Anvil working, the Company has identified additional veins within the claim block. Both the Big Elk and Anvil prospects represent historical workings on fissure veins within the larger shear zone, confirming the presence of multiple veins within the shear zone that encompasses the entire project.
Sampling, Analysis, and Quality Assurance/Quality Control (QA/QC)
All samples, are those from chip samples underground in the Anvil Adit across strike of the vein. The samples were up to 5 kilograms and were sent to Christofferson Labs, LLC in Smelterville, Idaho, USA for gold analysis. Subsequent ICP analysis was performed at American Analytical Laboratories in Osburn, ID. All sampling results for the Anvil prospect are detailed in Table 1. All analytical procedures adhered to industry-standard protocols, and results have passed internal QA/QC checks.
Table 1: Sampling across Anvil Prospect Underground Vein
| Sample ID | Sample Type | From (m) | To (m) | Length (m) | True Width (m) | Cu % | Au g/t | Ag g/t | Description |
| MON_ 241016_01 | Chip | 0 | 0.4 | 0.4 | 0.4 | 0.1 | 0.20 | 2.72 | Siderite vein dip 50 degrees |
| MON_ 241016_02 | Chip | 0 | 0.4 | 0.4 | 0.4 | 0.1 | 0.75 | 3.40 | Siderite vein dip 50 degrees |
| MON_ 241016_03 | Chip | 0 | 0.3 | 0.3 | 0.3 | 1.5 | 1.05 | 11.90 | Copper mineralised vein dip 80 degrees |
| MON_ 241016_04 | Chip | 0 | 0.3 | 0.3 | 0.3 | 3.1 | 0.20 | 1.70 | Copper mineralised vein dip 80 degrees |
| MON_ 241016_05 | Chip | 0 | 0.3 | 0.3 | 0.3 | 0.7 | 0.10 | 2.72 | Copper mineralised vein dip 80 degrees |
*Underground rockchip samples, such as those described herein, are selective by nature and are not necessarily indicative of the total average grade of mineralisation
See also,
*NI43-101: Copper-Gold-Silver Mineralization at the Monitor Mine Property, Eastern Coeur d'Alene Mining District, Shoshone County, Idaho, USA, (Ray July 2013), and
* New Release May 14, 2025
About the Monitor Claim Group:
Transatlantic Mining has numerous prospects within the greater Monitor Copper-Gold Project. At the historical Monitor mine, historical grades of up to 15% Copper and 8 g/t Gold were achieved. Surface samples of other prospects have returned grades of up to 30% copper, which have been reported previously.
Qualified Person Review:
The technical information contained in this news release has been reviewed and approved by Zachary J. Black, SME-RM, a Principal for Ethos Geological Inc., who is a Qualified Person pursuant to National Instrument 43-101.
About Transatlantic Mining Corp.
Transatlantic Mining (TSX-V: TCO) is an emerging precious and base metal explorer. The Company has a focus on converting projects into mines within stable mining jurisdictions. The Company currently holds property interests including an 80% Joint Venture position on the Monitor Copper-Gold project in Montana-Idaho (USA) and 100% of the Golden Jubilee Gold Project with its associated mining rights. The Company also has an extended lease, right to mine, and purchase arrangement for the Miller Gold Mine in Montana, moving towards 100% ownership by way of a payment royalty.
Cautionary Statement Regarding Forward-Looking Statements
This news release contains "forward-looking statements" within the meaning of Canadian securities legislation. These forward-looking statements include, but are not limited to, statements regarding the Company's future exploration plans, geophysical programs, and the potential for mineralization. Forward-looking statements are subject to known and unknown risks, uncertainties, and other factors that may cause the actual results, level of activity, performance, or achievements of the Company to be materially different from those expressed or implied by such forward-looking statements. These factors include, but are not limited to, risks associated with the exploration and development of mineral properties, the Company's ability to obtain necessary permits, and the availability of financing. Readers are cautioned not to place undue reliance on forward-looking statements. The Company undertakes no obligation to update or revise any forward-looking statements, except as required by law.
For further information, please contact: Bernie Sostak: bsostak@transatlanticminingcorp.com , +61 (0) 439 904 044.
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 release.
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SOURCE: Transatlantic Mining Corp.
