Outcrop Silver & Gold (TSXV: OCG; US-OTC: OCGSF) has reported more than twice the inferred and almost a quarter more indicated silver at its Santa Ana project in Colombia than in its 2023 resource.
The new resource shows about 1.8 million indicated tonnes grading 376 grams silver per tonne and 1.8 grams gold, containing 21.7 million oz. silver and 104,000 oz. gold, Outcrop said this week. Inferred resources add 2.3 million tonnes grading 266 grams silver and 1.29 grams gold for 20.1 million oz. silver and 98,000 oz. gold. See a 3-D map of drilling.
“Mineralization at Santa Ana continues to impress with its high grades, continuity and scale,” CEO Rob Bruggeman said in a release. “New vein systems like Guadual and Aguilar have added substantial resources to the updated resource, with another dozen veins still to be adequately drill tested and more veins likely to be discovered as exploration continues.”
Santa Ana lies near Falan in Tolima Department, about 190 km west of Bogotá. The advanced exploration project covers part of the historic Mariquita silver district, where mining dates to the 16th century.
More drilling
The initial 2023 resource modelled 1.23 million indicated tonnes grading 446 grams silver and 2.3 grams gold for 17.6 million oz. silver and 88,800 oz. gold. Inferred resources were 966,000 tonnes at 312 grams silver and 1.6 grams gold for 9.7 million oz. silver and 50,900 oz. gold.
That means indicated contained silver has risen 23%, while inferred silver has increased about 107%. Across the two categories, contained silver has grown to 41.8 million oz. from 27.2 million oz., while gold has increased to 202,000 oz. from 139,700 oz.
The update incorporates 130,006 metres of drilling in 646 holes, 71,094 metres more than in the initial estimate. It defines mineralization across 46 domains in 13 vein systems.
Outcrop also tightened its classification criteria. The 2023 estimate classified indicated material largely according to distance from drill samples, while the new model requires support from at least three drill holes within a defined search area. Inferred material requires support from two holes. Resources were also constrained within potentially mineable underground shapes.
The company said the stricter approach partly explains why indicated resources grew less sharply despite the large increase in drilling.
New veins
The resource now extends across a much broader stretch of Santa Ana, from Los Naranjos in the north to Los Mangos in the south.
Last year, Los Mangos was still more than 8 km south of the resource area when drilling returned some of Santa Ana’s strongest intersections. The system is now included in the estimate, with indicated resources of 170,000 tonnes grading 397 grams silver and 1.62 grams gold, containing 2.2 million oz. silver and 9,000 oz. gold. Inferred resources add 78,000 tonnes at 488 grams silver and 0.76 gram gold, containing 1.2 million oz. silver and 2,000 oz. gold.
Outcrop says at least 12 known vein systems remain outside the resource because they haven’t been drilled sufficiently. Most of the currently defined mineralization lies within about 300 metres of surface, while the company says shoots and feeder structures remain open at depth.
An ongoing 35,000-metre drill campaign is targeting extensions of known resources as well as new vein systems along the project’s 17-km mineralized corridor.
Outcrop shares closed Tuesday 3.1% higher at 33.5¢ in Toronto, valuing the company at about $165 million. The shares have traded between 24.5¢ and 65¢ over the past year.
Source: https://www.mining.com/outcrop-doubles-inferred-silver-at-santa-ana-in-colombia/
