Oligocene, Epoch. A division of geologic time that began about 37,000,000 years ago and lasted 14,000,000 years. The Oligocene is the third and latest division of the Paleogene Period. Most of the rock formed during the Oligocene is sedimentary-During this time some mountain building occurred in the northwestern United States. Petroleum and natural gas are found in commercial quantities in rocks of the Oligocene Epoch.
Everyone knows that once a bone has fossilized, it's hard as a rock, right? So how did scientists find soft tissue inside a broken dinosaur bone?
Earthquakes and volcanoes get all the press. But the landslides they trigger are often more devastating. What makes the ground suddenly rip downhill, taking trees and homes with it?