Cobre Ridge caldera
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 of crystal-rich rhyodacite ignimbrite.
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 of crystal-rich rhyodacite ignimbrite.