Los Gatos is interpreted as an intermediate sulfidation epithermal vein.
Veins in the Cerro Los Gatos deposit show textures and gangue mineralogy (local chalcedony and calcite, and quartz-replaced lattice texture calcite) that indicate a relatively high-level hydrothermal system in the boiling environment. Breccia with clasts of vein quartz indicates a protracted hydrothermal system during multiple faulting events.
Mineralization at Cerro Los Gatos is characterized by silver, lead, zinc, and copper sulfides and their corresponding oxides, along with fluorite, manganese, barite, and traces of gold associated with quartz and calcite veins.
The veins vary in orientation from West-Northwest to Northwest to North-Northwest and vary in thickness from 20 cm to 30 m in the mine operation. Study of the veins in hand specimens and thin sections suggest they are epithermal in origin and are likely of intermediate sulfidation composition.
The Los Gatos District hosts a series of quartz, quartz-calcite, and calcite veins in at least fifteen separate vein systems that are exposed along a strike length of approximately 30 km and an outcrop belt width of approximately 5 km.
The veins containing silver, lead and zinc at Los Gatos are hosted primarily by the Andesite rocks immediately above the contact with the dacitic lithic tuff. Vein thickness is variable. Figure 7.7 shows an isometric view of the dacite lithic tuff unit (pink) which ma ........
