Showing posts with label Petrified Forest National Park. Show all posts
Showing posts with label Petrified Forest National Park. Show all posts

Thursday, May 31, 2012

Arizona Road Trip - Part 3 - Petrified Forest

The Petrified Forest National Park was not at all like I had imagined - there wasn't a tree in sight! Just miles and miles of desert.  Studded throughout the park though were the remains of an ancient forest - fallen and broken trees that had been transformed to quartz ridden petrified wood.

A large petrified log with a smaller broken off piece


Here is what the guidebook says about it.

"...The trees fell, and swollen streams washed them into adjacent floodplains.  a mix of silt, mud and volcanic ash buried the logs. This sediment cut off oxygen and slowed the logs' decay.  Silica-laden groundwater seeped through the logs and replaced the original wood tissues with silica deposits.  Eventually the silica crystallized into quartz, and the logs were preserved as petrified wood.  Over the 225 million years since the trees lived, the continents moved to their present positions, and this region was uplifted.  As a result the climate changed and the tropical environment became today's grassland.  Over time, wind and water wore away the rock layers and exposed fossilized ancient plants and animals.  The hills will yield more fossils as weathering sculpts the Painted Desert's soft sedimentary rock."  National Park Service. U.S. Department of the Interior

It is against the law to collect even the smallest piece of petrified wood from the park to maintain the integrity of the park.  However, there is some to be found outside the park boundries and enterprising residents collect and sell pieces outside of the park itself.

A large log on a cliff at center left, with fallen logs below

A piece of petrified wood with the colored quartz visible

The logfall in the center looks like people hiding in the rocks


A cluster of petrified logs

Another type of old fossils with petrified wood on the ground in the background

A field of mineral-rich petrified logs

The petrified wood is just one aspect of the Petrified Forest National Park.  Next time I'll post pictures of the Painted Desert portion - a beautiful park for exploring and learning about the prehistoric past.