Silver prospects attract interest — Metallica explores Mexican play

Metallica Resources (CDN) has defined two new precious metal occurrences at the Cerro San Pedro property in San Luis Potosi, Mexico.

The discovery follows the first 2,500 metres of a planned 10,000-metre program of reverse-circulation drilling.

Since its original discovery in the 1570s, the Cerro San Pedro has produced more than 2.5 million oz. gold and 30 million oz. silver. Most of this came from high-grade, oxidized bodies containing up to 20 grams gold and 200 grams silver per tonne.

Metallica’s new discoveries, known as the Abundancia and Barreno occurrences, are said to be amenable to open-pit mining and heap leaching. The mineralization, which overlies older, underground workings, is adjacent to the previously delineated Fresnillo open pit.

Twelve intersections were reported, with gold and silver assays ranging up to 1.97 grams gold and 142.8 grams silver, while widths ranged between 4 and 74 metres.

Previous work at the Fresnillo outlined a potentially open-pit, geological resource of 38.6 million tonnes averaging 0.8 gram gold and 24 grams silver, with a stripping ratio of less than 2-to-1. Oxidized mineralization was found to a depth of 300 metres below surface, and metallurgical tests by previous owners suggested that a heap-leach recovery of 70% was attainable.

Metallica’s new discoveries are expected to improve the economics at the Cerro San Pedro project, in particular by rendering the Fresnillo deposit more profitable as a potential open-pit mine.

In addition to completing 10,000 metres of drilling, Metallica will carry out check assays on earlier samples, as well as metallurgical tests, in anticipation of a prefeasibility study at year-end.