The Tucson Mountain caldera is one of several Late Cretaceous calderas that crop out in southern and southeastern Arizona. Some calderas, e.g., Silver Bell Mountains, are associated with massive porphyry copper deposits that make up the foundation of Arizona's copper industry. Copper mineralization occurs in the Tucson Mountains, but not to the extent seen elsewhere. Peter Lipman's 'Geologic map of the Tucson Mountains Caldera, Southern Arizona' remains the definitive map of caldera geology. https://ngmdb.usgs.gov/Prodesc/proddesc_10186.htm
Photographer: Peter Lipman
Photo Date: 1993
Photo Location Accuracy: Known Location
Photo Tags: Tucson caldera, volcanism, Tucson Mountains, geotourism, Saguaro National Park, Amole pluton, ignimbrite, Late Cretaceous, geologic hazard