Cobre Ridge caldera
Caldera in Arizona, U.S.
From Wikipedia, the free encyclopedia
The Cobre Ridge caldera is a large Jurassic volcano in the U.S. state of Arizona. It formed about 170 million years ago when a VEI-8 eruption ejected more than 1,000 km3 (240 mi3) of crystal-rich rhyodacite ignimbrite.[1]
