A grassroots gold discovery in eastern El Salvador is returning some encouraging numbers for
A series of hand trenches on a the prospect carry gold values averaging 0.72-3.55 grams per tonne across significant widths of up to 127 metres.
The company has used satellite imagery to zero-in on the prospective area, known as Oro Nuevo, situated in the northwestern corner of its San Cristobal property holdings.
Intrepid’s geologists felt the area offered the right ingredients for a favourable, deep-seated structural setting. A large circular feature greater than 2 km in diameter dominates the area. The southern rim of this feature is intersected by a 1.5-km-long north-south-striking lineament. Reconnaissance sampling along the linear structural corridor delivered gold values ranging from trace to 7.5 grams per tonne in 125 samples.
The extreme southern end of the linear feature is dotted with historic workings. Samples taken from the workings and dumps yielded between trace and up to 15 grams gold and upwards of 850 grams silver in 68 samples.
In the few months that have followed, Intrepid has carried out an aggressive program of geological mapping and hand-trenching. The structural corridor is believed to be a horst fault zone, flanked to the east and west by lithic tuffs and lacustrine sediments. The central core consists of dacite porphyry, which the company believes may represent a felsic dome complex.
Gold mineralization is found in the interior of the horst structure along the Guapinol fault and at the intersection of a secondary crosscutting feature. The company has tested a 325-metre strike length of the zone with eight hand trenches in a program spanning 1,500 metres. Results from the first four trenches have been reported; three trenches remain to be sampled.
Forty-five samples from the first trench averaged 1.84 grams gold and 4.33 grams silver across a width of 83.7 metres. The trenches generally were sampled on an interval of 1-2 metres. Some of these trenches have removed 750 tonnes by hand and are individually swept, says Intrepid’s President Laurence Curtis.
The second trench returned 127 metres grading 0.72 gram gold and 2.62 grams silver in 62 samples. Trench 3 averaged 2.22 grams gold and 3.55 grams silver across 106 metres for 53 samples, while the fourth trench showed 54 metres averaging 2.87 grams gold and 3.44 grams silver in 30 samples.
While gold values are described by Intrepid as consistent and in the range of 0.5-3 grams, higher-grade gold-bearing quartz veins assayed as high as 15.6 grams over 1.6 metres.
The trenching is sampling a wide sequence of saprolitic, oxidized and weathered dacite, silicified breccias, quartz veins, silicified tuffs and sediments. Fine veinlets of stockwork mineralization are common in the oxidized profile, says Curtis. “We are making sure the saprolite horizon, which appears to be a little nuggety in terms of assays, is being correctly sampled and is not blanketing our vision of the project,” he adds.
Intrepid brought in an independent consultant to audit its sampling protocol and collect duplicates, which have since been assayed at ALS Chemex Laboratories in Toronto. The data show considerable variability among pairs from selected sample sites, the widest variation being 0.48-2.2 grams. Taken as a group, the sample set assayed by ALS Chemex averaged 8% higher than previous samples. Sample variability is attributed to a coarser gold fraction in both the oxidized bedrock and saprolitic profiles.
Intrepid’s geologists have noted “boiling zone” textures right at surface, leading Curtis to suspect that the whole system is preserved underneath the sediments. The company intends to begin drilling at Oro Nuevo by late June, with 1,500 metres planned.
The San Cristobal projects cover 249 sq. km in the historic mining district of Jocoro, 20 km northeast of the city of San Miguel. A paved highway passes just south of the project. Intrepid’s property holdings include four historic mines, namely Encuentros, Hormiguero, Divisadero and Montecristo. The company has targeted extensive mineralized hydrobreccia zones surrounding, and along strike of, the former producers, in addition to deeper stockwork and high-grade vein systems below the mine workings. Intrepid first acquired ground in the area in 1997.
The Oro Nuevo discovery area is 15 km west of the Gigante project, where Intrepid has been carrying out multi-target drilling. The first of three holes designed to test the Gigante vein intersected close to 3 metres of 17.6 grams gold and 1,569 grams silver at a down-hole depth of 30 metres. Results from two additional holes, drilled at 500-metre stepouts along the vein structure, are pending.
The same rig was used to test Hormiguero, a high-level gold-silver target, a further 20 km away.
The Divisadero mine property was under option to
Meanwhile, in Argentina’s San Juan province, Intrepid is performing scoping work at the Casposo gold-silver project. A resource amenable to open-pit methods contains an indicated 271,000 tonnes of 7.07 grams gold and 97.1 grams silver, equivalent to 61,600 oz. gold and 846,000 oz. silver, along with an inferred 2.5 million tonnes grading 3.35 grams gold and 74.1 grams silver, for an additional 267,000 oz. gold and 5.9 million oz. silver.
Another 186,750 oz. gold and 3.5 million oz. silver are contained in deeper-lying mineralization, with an indicated portion estimated at 88,700 tonnes grading 14.2 grams gold and 181 grams silver, plus an inferred 384,700 tonnes of 11.8 grams gold and 239 grams silver.
Preliminary bottle-roll tests showed recoveries in the range of 89-93% for gold and anywhere from 75% to 83% for silver on minus 80 mesh. Initial gravity tests have recovered up to 25% of the gold alone. Curtis says metallurgy will be addressed in the upcoming scoping study.
Recent drilling at Casposo has confirmed bonanza grades of gold and silver at depths of up to 150 metres below the pit model.
Be the first to comment on "Intrepid’s Salvadoran prospect promising"