The state of Arizona and its picturesque landscapes have been shaped by a geological history of volcano eruptions across the region. Some of the oldest volcanic rocks in the state are 1.8 billion ...

FLAGSTAFF — Just 30 minutes from downtown Flagstaff, Sunset Crater Volcano National Monument offers a striking look at northern Arizona’s explosive past. The cinder cone, now standing over 8,000 feet ...

Volcanoes and contact metamorphism (existing rocks exposed to magma) have played an important role in the geologic history and diverse mineral composition of Arizona. From 1.8 billion years ago during ...