A collection of giant calderas ("super volcanoes") from the beginning of New Mexico's "Age of Volcanoes".
Rhyolite, quartz latite
These are older volcanoes and volcanic rocks dating from the Neogene. They represent part of the great ignimbrite flare-up that occurred throughout the Southwest at this time. Many of these eruptions resulted in large calderas similar to the modern Vallis Caldera. However, 20 to 35 million years of erosion and faulting have erased most of the morphology of large calderas. Today this area is dominated by masssive cliffs of ash flow tuffs and exposures of shallow batholiths consisting of granitic and intermediate volcanic rocks.°
View Datl-Mogollon Volcanic Field in a larger map