Outcrop doubles inferred silver at Santa Ana: resource and mine design notes for engineers
Reviewed by Joe Ashwell

First reported on MINING.com
30 Second Briefing
Outcrop Silver & Gold has more than doubled inferred silver resources and lifted indicated silver by 23% at its Santa Ana project in Colombia, now totalling 1.8 Mt indicated at 376 g/t Ag and 1.8 g/t Au (21.7 Moz Ag, 104,000 oz Au) plus 2.3 Mt inferred at 266 g/t Ag and 1.29 g/t Au (20.1 Moz Ag, 98,000 oz Au). The update incorporates 130,006 m of drilling in 646 holes, models 46 domains across 13 vein systems including new Guadual, Aguilar and Los Mangos zones, and constrains resources within potentially mineable underground shapes. Mineralisation is largely within 300 m of surface along a 17 km corridor, with a further 35,000 m drill campaign targeting depth extensions and at least 12 undrilled vein systems.
Technical Brief
- Classification now demands ≥3 drill holes for indicated and ≥2 for inferred within search ellipsoids.
- Resource model expanded to 46 mineralised domains across 13 discrete vein systems.
- Drilling input increased to 130,006 m in 646 holes, adding 71,094 m since 2023.
- Los Mangos indicated: 170,000 t at 397 g/t Ag and 1.62 g/t Au (2.2 Moz Ag, 9,000 oz Au).
- Los Mangos inferred: 78,000 t at 488 g/t Ag and 0.76 g/t Au (1.2 Moz Ag, 2,000 oz Au).
- Mineralisation footprint now spans from Los Naranjos in the north to Los Mangos in the south.
Our Take
The 17 km mineralised corridor and at least 12 known vein systems still outside the current resource suggest that the 646-hole dataset is far from exhaustive, implying that successive resource updates could continue to trade grade for tonnage as drilling steps out along strike and at depth.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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