Sunset Crater, located in north-central Arizona, is the youngest volcano found on the 130,000-square-mile (337,000 square kilometers) Colorado Plateau. In 1930, the Sunset Crater Volcano National ...

Volcanic cones are among the simplest volcano formations. They are built by fragments (called ejecta) thrown up (ejected) from a volcanic vent, piling up around the vent in the shape of a cone with a ...