Diamond drilling by
The new core drilling followed up on a reverse-circulation (RC) program Intrepid ran in 1999, which tested a barite stockwork system with silver and zinc mineralization in a dacite-porphyry hill called Cerro Colorado III. In that program, four RC holes intersected silver mineralization with some gold and zinc values over lengths ranging from 7.5 to 55 metres. Silver grades in those intersections ranged from 95 to 449 grams per tonne.
In the present round of drilling, seven drill holes tested at depth, below the intersections the RC holes had encountered in 1999. Five intersected continuous lengths of silver and zinc mineralization.
Hole CC3-1 cut a 77.2-metre core length that graded an average of 81 grams silver per tonne, and included intervals of 29.8 metres grading 142 grams and 2 metres grading 342 grams. Hole CC3-3 cut 22 metres grading 64 grams silver and 0.22 gram gold, with 1.05% zinc. Farther down-hole, CC3-3 cut another 30 metres grading 57 grams silver, with 2.22% zinc.
Hole CC3-4 intersected 19 metres grading 128 grams silver and 0.35 gram gold, with 0.55% zinc, while CC3-5 cut 53 metres with average grades of 100 grams silver, 0.41 grams gold and 1.79% zinc.
Assays from another hole, CC3-6, are not yet complete, but a 45-metre interval shows a grade of 21 grams silver based on results currently in hand.
Hole CC3-7, aimed to twin the results of a 1999 RC hole, intersected mineralization over 55 metres, like its predecessor. Samples from the last 33 metres are still being assayed, but the average grade over the first 22 metres was 204 grams silver and 0.05 gram gold, comparable to the grades found in the 1999 hole.
In aggregate, the results indicate a possible silver- and zinc-rich feeder zone, about 50 metres thick, beneath the silver-rich barite stockwork. The feeder zone is a siliceous breccia developed in the Cerro Colorado III dacite porphyry, and the breccia grades at depth into another barite-silver stockwork.
Surface showings dot a 1-km corridor leading north from Cerro Colorado III to another prospect, called San Casimiro, marked by old Spanish mine workings. Five channel samples at San Casimiro showed a style of mineralization similar to that found at Cerro Colorado III.
In one zone on the western side of the prospect, a 25-metre channel sample ran an average of 236 grams silver and 0.1 gram gold, with 0.12% zinc and 0.56% lead. On the eastern side, a 25-metre channel graded 129 grams silver and 0.4 gram gold, and carried 1.36% zinc and 0.52% lead.
Underground in the old Spanish workings, a 16-metre sample turned up grades of 410 grams silver and 0.08 gram gold, plus 1.88% zinc and 1.09% lead.
Adding to the evidence that the two occurrences are part of a single mineralized system, magnetic data show a 700-metre-long anomaly coinciding with both Cerro Colorado III and San Casimiro. Intrepid now plans an induced-polarization survey to trace the structure hosting the Cerro Colorado III mineralization toward the north.
The IP crew will also be testing the Carolina target, 1.5 km southeast of Cerro Colorado III, where recent sampling indicated surface mineralization in an area singled out in a geochemical survey by the United Nations Development Program in the 1970s. There, grab samples showed grades of 117 to 763 grams silver, with gold, zinc and lead values.
Intrepid and joint-venture partner
The arrangement gives Intrepid full ownership of Aldea Zapote and two other exploration properties in El Salvador, and enables High River, already a major shareholder in Intrepid, to increase its holding in the company to 19.8%. The agreement has yet to be approved by regulators.
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