10. Meteor Crater, Arizona, United States
The origin of this classic, simple meteorite impact crater was long the subject of controversy. The discovery of fragments of the Canyon Diablo meteorite, including fragments within the breccia deposits that partially fill the structure, and the presence of a range of shock-metamorphic features in the target sandstone, confirmed its impact origin. Target rocks include Paleozoic carbonates and sandstones; these rocks have been overturned just outside the rim during ejection. The hummocky deposits just beyond the rim are remnants of the ejecta blanket. This aerial view shows the dramatic expression of the crater in the arid landscape.
Aerial image courtesy of D. Roddy.