John Wesley Powell A professor of geology at Illinois Wesleyan ... and sponges. Known as the Grand Canyon Supergroup, these layers of rock lie at an angle relative to the layers of rock above.

The Grand Canyon is a breathtaking geologic wonder located in the northern part of the state of Arizona, USA, with its rock layers dating back a million years laid bare before the eye. Scientists ...

Oregon is a great place for geology geeks. Enormous lava flows, Ice Age megafloods, massive volcanic eruptions —we bear ...

Visitors hoping to take in the spectacular sights of the Grand Canyon ... fog filled the vast canyon. The phenomenon, known as "total cloud inversion," happens when a layer of cold air at the ...

Relative dating puts geologic events in chronological order ... it is possible to work out the relative ages of rocks. In the Grand Canyon, the layers of strata are nearly horizontal.

Relative dating puts geologic events in chronological order ... it is possible to work out the relative ages of rocks. In the Grand Canyon, the layers of strata are nearly horizontal.