The Escalones deposit was discovered in the late 1990's by members of the current executive team at South American Silver, including Ralph Fitch, Executive Chairman, and Felipe Malbran, Vice President of Exploration.
The property lies within the well-known central Chilean porphyry copper belt that runs north-south through Chile in the central Andes Mountains. It is located approximately 100 km southeast of Santiago and 35 kilometers due east of El Teniente, the world's largest underground copper mine. The project has excellent infrastructure including road access and a gas pipeline that crosses the 70 square kilometer property
The Escalones project hosts a four-square-kilometer area of hydrothermal alteration with coincident geophysical anomalies that has demonstrated significant grades of copper, gold and silver in replacement-style "skarn” mineralization hosted in limestones and in porphyry related mineralization.
The exposed mineralization at Escalones occurs in limestones and interbedded shales that have been intruded by andesite and dacite porphyry bodies which are key ore hosts at El Teniente. Copper mineralization occurs primarily as chalcopyrite, as well as copper oxides near surface. The hydrothermal alteration exposed at surface includes intense zones of quartz-sericite, potassic, and calc-silicate alteration assemblages.
The 2013 drilling season ran from November of 2012 to May, 2013. A total of 9,070 metres of drilling were completed. An updated resource estimate was announcement on June 28, 2013 (View News Release 13-13 dated June 28, 2013).
Highlights of the estimate include:
- An Indicated resource of 232.6 million tonnes of mineralized material containing 1.6 billion lbs. of copper, 498,012 oz. of gold, 4.9 million oz. of silver, and 31.9 million lbs. of molybdenum, at a grade of 0.31% copper, 0.07 g/t gold, 0.66 g/t silver and 0.006% molybdenum
- An Inferred resource of 527.7 million tonnes of mineralized material containing 3.9 billion lbs. of copper, 609,437 oz. of gold, and 14.4 million oz. of silver, 79.5 million lbs. of molybdenum at a grade of 0.34% copper, 0.04 g/t gold, 0.85 g/t silver and 0.007% molybdenum
- A significant increase in pounds of copper and molybdenum and ounces of gold above assumed economic cut-off of 0.25% copper equivalent (CuEq*), compared to the initial resource dated December 19, 2011.
- Upgrading of approximately a third of the resource to Indicated from Inferred.
The Escalones deposit remains open to expansion laterally and down dip. Interpretation of ZTEM resistivity and aeromagnetic surveys show several large areas of untested conductivity and magnetic anomalies which may represent areas of potential additional mineralization. During the 2012 drilling season, 5 diamond drill holes were drilled on the project in the first half of 2012 totaling 3,205 metres. The results of these drill holes, which targeted both porphyry and replacement-style mineralized zones, and the interpretation of the ZTEM resistivity and aeromagnetic surveys, have been released to the public (Click here to see News Release 12-17 dated September 19, 2012).
A program of metallurgical testing on Escalones material was completed. The program is focused on the recovery of the copper, gold, silver and molybdenum by conventional flotation and conventional sulphuric acid leaching. The program also includes testing using the Company's patented chloride acid leach technology developed at Malku Khota in Bolivia to evaluate whether this technology can be used to recover the gallium and indium that occur in some of the Escalones mineralization.
The standard sulphuric acid leach metallurgical test achieved average copper extraction of 77% from mixed copper oxide/sulphide mineralization. Copper flotation was also successful and rougher/cleaner flotation testing of the porphyry material achieved 25-34% copper concentrate grades at high recovery. Further metallurgical testing is underway.
Read the latest news release on Escalones:
South American Silver Updated Resource at Escalones in Chile
View surface sampling and drill results highlights.