Yamana discovers copper sulphides in Chile

Exploration by Yamana Resources (YRI-T) has uncovered disseminated copper sulphide mineralization in drill cuttings and hydrothermal alteration assemblages at two of the company’s eight porphyry copper properties in northern Chile.

At the Inca property, south of the El Salvador copper mine, three of five widely spaced holes encountered anomalous copper and zinc values, including up to 0.47% copper. The size of the property was recently expanded to more than 16,000 ha.

Meanwhile, drilling at the 6,300-ha Elvira prospect encountered trace amounts of copper in a zone of disseminated pyrite associated with a large magnetic anomaly. Crosscutting the anomaly is West Fissure fault zone, a major north-south structure that parallels the Chilean coast.

Yamana believes the magnetic anomaly overlapping the West Fissure is a “geologic aberration that warrants further investigation for its mineral potential.”

The recent drilling is part of a regional program that has spanned two and a half years. Remote sensing and geophysical techniques preceded the reconnaissance drilling, which consisted of 37 reverse-circulation holes and nearly 9,500 metres.

During the program, Yamana geologists found that many remote-sensing techniques, such as enzyme leach geochemical surveys, transient electromagnetics and induced-polarization surveys, generated false anomalies and were ineffective in identifying mineralization. The company considers widely spaced systematic drilling to be its best method of exploring for porphyry deposits in the region.

Yamana plans to abandon the prospects that failed to return economic mineralization and to continue exploring Inca and Elvira.