Nov 29, 2012 2:14 PM by Associated Press
LOS ANGELES (AP) - It's the most common question visitors to the Grand Canyon ask: "How old is it?"
A provocative new study suggests the natural wonder is much older than commonly believed. Using a new tool to date the age of rocks, a team of researchers contends the western section of the Grand Canyon may be 70 million years old. That would put it during the era when dinosaurs roamed.
Their research was published online Thursday in the journal Science.
The new age goes against the prevailing theory that the Grand Canyon is geologically young. Many scientists believe much of the gorge was carved by the Colorado River 5 million to 6 million years ago.