Geology of Cu-Mo Sierra Gorda Deposit, North Chile

Abstract

Samples collected during the KGHM PM S.A. program Go Global Internship were used in these work to develop a mineralogical model of all zones in the Sierra Gorda deposit. Reflected light microscope observation and quantitative microchemical analyses show that thedeposit is characterized by high variability of all parameters. The major mineral within the oxides zone is atacamite. The following other minerals have been identified: malachite, brochantite, chryzocolla, sampleite, paratacamite, brushite, antlerite, aubertite, montmorillonite and kaolinite. The major minerals in the sulphide zone are chalcopyrite, covellite, molybdenite and pyrite. The minor and accessory minerals are bornite, arsenopyrite, pyrrhotite, sphalerite and galena. Substitution of Cu in rock-forming minerals as well as inclusions of Cu and Mo sulphides within silicates will play an important role in the recovery of both metals.