Zacatecas Silver Identifies High-Grade Vein System at Oso Negro
Event summary
- Zacatecas Silver completed a 5-day surface sampling program at Oso Negro in March 2026, collecting 156 rock-chip samples from 2 km of low-sulphidation veins.
- Samples show brecciated veins up to 3 m wide with iron oxides, suggesting potential for precious metal mineralization at depth.
- Historical sampling by Heliostar returned grades up to 5.15 g/t Au and 953 g/t Ag over 1.2 m.
- CEO Eric Vanderleeuw positions Oso Negro as a high-priority target within Zacatecas Silver's expanded portfolio.
The big picture
Zacatecas Silver's systematic advancement of Oso Negro reflects a strategic shift toward multi-asset exploration in proven Mexican mining districts. The focus on underexplored, high-grade targets aligns with broader industry trends of resource scarcity driving exploration in historic mining belts. With two existing resources and an expanded portfolio, the company aims to generate consistent discovery news flow while managing execution risk across multiple projects.
What we're watching
- Drill Target Definition
- How quickly Zacatecas Silver can translate surface sampling results into drill-ready targets at Oso Negro.
- Portfolio Integration
- Whether the company can sustain parallel exploration momentum across its multiple assets.
- Mineralization Depth
- The extent to which high-grade mineralization extends below the identified upper-level veins.
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