CHILE – Vancouver-based QUADRA MINING released an independent resource estimate for its Sierra Gorda project northeast of Antofagasta in the Atacama Desert. The indicated resource is 215 million tonnes at 0.38% Cu and 0.066% Mo (0.71% CuEq). An additional inferred resource of 182 million tonnes at 0.34% Cu and 0.024% Mo (0.46% CuEq) was also noted. The deposit contains oxide, supergene and hypogene copper resources and hypogene molybdenum resources. Detailed numbers for the various types of mineralization are available at www.QuadraMining.com.
Quadra began its Sierra Gorda program in April 2004. Since then, it has spent approximately $2.6 million on work that includes a 50-hole, 10,712-m reverse circulation drill program, geophysical surveys, detailed mapping and geological modeling. Exploration to date has determined that copper oxide mineralization continues from near surface to depths ranging from 150 m to 200 m below the surface. This would imply that mining might begin with copper oxide leaching, followed by conventional sulphide flotation open pit mining. Some of the strongest molybdenum mineralization identified to date occurs locally at the oxide-sulphide copper interface. This is economically significant as it would allow for the extraction of high-grade Cu-Mo sulphide mineralization early in a Cu-Mo sulphide mine plan.