2008_09_18 Uinkaret Vocanic Field

The Uinkaret Volcanic Field, sited on the north side of the Grand Canyon's western reaches, looks like fresh tar poured over a birthday cake. Though active in the last millennium, most of the lava you see flowed about 73,000 years ago. That's nearly in the geologic present. The newest rocks over which it flowed are Kaibab Limestone (at the top of the canyon), about 290 million years old (in the Permian). The oldest, at the bottom of the canyon, are Vishnu Schist, which are about 2 billion years old.

40 photos | 295 views

items are from between 16 Feb 2008 & 18 Sep 2008.