The porphyry molybdenum deposit of Compaccha,Peru, and its geologic setting

Compaccha, in Peru, is a zoned molybdenum, copper, zinc, lead, antimonyarsenic district which has historically been important because of tungsten production derived from all zones. Wolframite, the principal tungsten mineral, is zoned compatibly with the sulfides. Manganese tungstate occurs in the molybdenum zone, while iron replaces the manganese increasingly importantly as distance is gained away from this zone. The alteration zoning in and around the molybdenum zone is typical of that of a porphyry copper deposit, in that fluorite, topaz or other fluorine rich silicates are not common. The molybdenum zone does include a porphyry molybdenum deposit, however, and this is characterized by intense silicification and quartz veining (stockworks). Within the area of the deposit, east of the coastal batholith, no Mesozoic arc type or basic volcanics can be inferred. A cratonic setting is postulated for the deposit.