The San Francisco volcanic field is a vast area covering more than 10,000 km22 containing cinder cones, lava fields, lava domes and the majestic (extinct) San Francisco Peaks, the highest of all mountains in Arizona, rising 5,000 feet above the surrounding plateau. The area prese... [more]
Sunset Crater in northern Arizona is one of the youngest volcanoes in the USA. It is named for its brilliantly colored scoria deposits on the cone and only one of more than 550 vents of the vast San Francisco volcanic field.
Snow-mantled Sunset Crater (left-center), seen from O'Leary Peak to the NW, is the youngest volcanic feature of the San Francisco Mountain volcanic field, which covers a vast area of northern Arizona between Flagstaff and the Grand Canyon. The Sunset Crater eruption began about 1100 AD from a chain of cinder cones and vents trending NW-SE, the largest of which is Sunset Crater. Three lava flows were erupted, the longest of which traveled 11 km to the NE. Photo by Ed Wolfe, 1973 (U.S. Geological Survey)
The last eruption took place sometime between abo... [more]
The Uinkaret volcanic field is located at the north rim of the Grand Canyon in Arizona. It contains cinder cones that have produced lava flows that repeatedly cascaded into the Grand Canyon, forming temporary lava dams up to 200 m high. In one of these lava flows, known as the Li... [more]