The physical and tectonic setting of Andean high-sulfidation epithermal gold-silver deposits and what it means for mineralizing processes and exploration targeting

Gold and silver mineralization in the vast majority of Andean high-sulfidation epithermal Au-Ag deposits occurs at high elevations and typically 200-500 m below low-relief landforms situated at 3500 to 5200 m a.s.l. present day elevation. Stratovolcanoes, in contrast, are uncommon ore hosts. Most deposits are middle Miocene and younger and include (among others), El Indio, Tambo, Pascua-Lama, Veladero (El Indio belt, Chile/Argentina), Cerro de Pasco (Central Peru), Pierina, Lagunas Norte, Yanacocha (northern Peru), Quimsacocha (Ecuador), and the California-Vetas mining district (Santander, Colombia), jointly accounting for> 140 Moz Au resources. Slightly older examples are preserved in the Atacama Desert and include the middle Eocene El Guanaco and El Hueso and the late Oligocene/early Miocene La Coipa deposits. Mineralization coincides with transpressional tectonics and pronounced surface uplift, predominantly in segments of shallow angle subduction of the Nazca or Caribbean plate below the South American continent. However, near neutral stress regimes and syn-orogenic extension typically influence the structural style at the high elevations where epithermal mineralization is located.