J2 Metals Identifies Three New Historic Mining Workings at Its Sierra Plata Project, Zacualpan-Taxco District, Mexico

Executive Summary

• J2 Metals Inc. identified three historic mine workings (El Samano, El Chinicuil, and El Cedro Rojo) at its Sierra Plata Project in Mexico during its initial field program, bringing the total discoveries to six.
• The company collected 53 rock samples from the newly identified workings and surface exposures, while completing geological mapping on 250 of the project's 2,200 hectares.
• Next steps include re-assessing covered workings for safe access, dewatering the El Sabino mine, and awaiting geochemical assay results from the submitted samples.

Key Details

• Historic Workings Identified: El Samano (UTM 421723E / 2058377N), El Chinicuil (UTM 421193E / 2058179N), and El Cedro Rojo (UTM 421562E / 2056410N) were located during the May 19–31, 2026 field program under Country Manager Carlos Cham.
• El Samano: ~5m of underground development hosted in black shale; float sample contains white quartz, calcite, amethyst quartz, and visible polymetallic sulfides.
• El Chinicuil: Collapsed mine; hand sample reveals quartz-calcite vein with polymetallic sulfides; company plans to reassess the structure for safe re-entry in future programs.
• El Cedro Rojo: Capped with overburden and currently inaccessible; company will evaluate feasibility of uncovering and sampling at a subsequent time.
• Sampling & Assays: 53 rock samples collected from six historic workings and surface exposures; four quartz veins with iron oxide mineralization identified on surface. Laboratory results are pending.
• Mapping Progress: 250 of 2,200 hectares mapped, identifying limestone, sandstone, and black shale lithological units. Oxidation zones mapped and correlated with historic workings and surface vein occurrences.
• Next Steps: Systematic location and sampling of historic mining structures, geological-structural mapping, alteration studies, dewatering the second level at El Sabino mine, and interpretation of geochemical assay results.
• Project Context: Sierra Plata is a 2,203-hectare silver-gold-antimony epithermal project in Zacualpan, Guerrero State, Mexico. Recent waste dump sampling returned grades up to 3,932 g/t AgEq. Mineralization is hosted in quartz-dominant vein systems reflecting a low to intermediate epithermal system.

Notable Quotes

• CEO Thomas Lamb: "The pace of discovery at Sierra Plata is exactly what we expected from a district with this much historical production and so little systemic modern exploration: six long-forgotten mining workings identified in the first two weeks of fieldwork. With 53 samples now at the lab and only 250 of 2,200 hectares mapped, we're still in the very early innings of understanding Sierra Plata."