Mineralization consists of polymetallic, high-temperature, intrusion-related carbonate-replacement and minor skarn-hosted deposits. Mineralization occurs as tabular veins, mantos, massive lenses, breccia pipes, and irregular replacement zones.
The deposits were grouped into four geological zones: the Prieta complex, the San Javier–Milagros complex, the Vein systems, and Tailings Deposit No. 4.
Discordant, near-vertical deposits with irregular elongate shapes proximal to main intrusions are referred to as chimneys and breccia pipes. These include the San Javier, Milagros and Prieta breccia deposits.
Tabular sub-vertical replacement deposits are referred to as veins and can contain richer mineral shoots or small chimneys at the intersection of northwest-trending faults and fractures. Steeply dipping, tabular deposits of the Vein systems have a northeast orientation, and are commonly distal to main intrusions.
Massive lens replacement zones of the Prieta complex are proximal to a granodiorite source intrusion and formed adjacent to skarn alteration. Contact metamorphic features (recrystallization to marble, development of hornfels and skarnoid) normally occur peripheral to the skarn zone.
Mineralization consists of secondary oxide minerals including silver, iron, zinc, lead, copper oxides and native silver. Native silver and oxide minerals also occur with sulphides in skarn and carbonate replacementzones where sulphides ar ........
