Geology of the Mount Aetna Volcanic Center, Chaffee and Gunnison Counties, Colorado

Presents some results of a study of an assemblage of middle Tertiary igneous rocks in the southern Sawatch Range of central Colorado. The study, which began in the early 1960's as a part of a multidisciplinary field and laboratory study of the chemical and petrologic relations between "classic" base- and preciousmetal hydrothermal mineralization and the differentiation processes exhibited by a complex suite of calc-alkaline intrusive rocks, led to the recognition of a deeply eroded, highly altered eruptive center that may have been the source of widespread volcanic deposits in the region.