Callyoma is located approximately 225 kilometers northwest of Arequipa, Peru at an elevation of 4,500 meters (Latitude: 15° 12’ 15” S, Longitude: 71° 51’ 40” W). The mine, processing plant and related infrastructure are located in the Caylloma Mining District, 14 kilometers northwest of the town of Caylloma. The mine is connected to the national power grid and water is locally available.
Geology and Mineralization
The silver-base metal rich epithermal vein deposits of the Caylloma Mining District are hosted by Tertiary calc-alkaline andesitic pyroclastic tuffs and tuff breccias, flows and laharic deposits that unconformably overlie a folded marine sequence of quartzite, shale and limestone of the Jurassic Yura Group. More than 15 major mineralized veins have been identified within the district with the veins typically trending northeasterly and dipping moderately to steeply to the southeast or northwest.
The veins range from 1 to 25 meters in width and range up to 4 kilometers in length. Ore grade shoots are generally subvertical in orientation within the plane of the vein, having lengths of tens to hundreds of meters and extending to more than 300 meters in a downdip direction. Principal ore minerals include sphalerite, galena, chalcopyrite and tetrahedrite with subordinate polybasite, stephanite, argentite, native silver, pyrargyrite, miargyrite, chalcocite, native gold, and other Pb and Ag sulfosalts. Principal gangue minerals are quartz, manganese-rich silicates (dominantly rhodonite), rhodocrosite, and calcite with variable quantities of adularia, illite and barite present locally (Echavarria et al, 2006)