Wednesday I crossed into Arizona to visit the Petrified Forest National Park. The Petrified Forest occupies a portion of the Painted Desert in Arizona. As in all National Parks there is much to see and many diverse elements covered. I experienced the beauty of the stratified layers of various sandstone as sediments were deposited over eons and saw how water can build, shape and erode. I was reminded of all the early travelers to this park as I walked through the Painted Desert Inn and saw the original alignment of Route 66. I was also reminded of a people that have been here tens of thousands of years as I explored the ruins of the Puerco River Pueblo and tried to puzzle out the messages left on “Newspaper Rock”. And I saw the phenomenon of a once living organism that under the proper conditions was changed to stone. I feel so fortunate that that the land in this National Park was set aside years ago to be preserved as unique and important so future generations, such as me, can enjoy and learn from it.
Wood becomes petrified when it is buried under sediment and protected from decay due to oxygen and organisms. Water laden with various minerals will flow through the protective covering sediment and all the organic material in the tree is replaced with minerals (usually a silicate such as quartz) turning the tree to stone while retaining the shape of the original tree. Different types of trees and the presence of different minerals during the process will result in different looks in the petrified specimen. For example, the presence of carbon results in black coloring; the presence of copper will result in green tones and iron oxides will leave red or yellow coloring. Once wood is petrified it will become as heavy as the stone replacing it. Petrified wood is apparently not as rare as I had assumed. It can be found around the world and has been found in all 50 states in the US.
In areas such as here in the Painted Desert, where trees were not available and stone would have to be quarried and cut to be used, petrified trees were used to construct houses and other structures. There is a ruin of one in the park but it is a hike to get to it.