Petrified Forest National Park, Arizona, USA

© Ian Shive/Tandem Stills + Motio

Info. Petrified Forest National Park

Here at Petrified Forest National Park in north-east Arizona, United States, these fallen trees are made of stone, not wood. They look similar on the outside but contain a core of colourful quartz crystals. More than 200 million years ago, trees and vegetation covered much of this area. But volcanic eruptions destroyed the forest, covering trees in a sediment comprised of volcanic ash and water, which turned the logs to stone. Millions of years later the rivers in the area dried up, revealing the fossilised wood.