The desert southwest hardly seems a likely candidate for a forest of any size. Granted, there are some juniper trees and other dwarf species, but nothing like the stately timbers seen in more temperate environments.
Such was not always the case. A visit to the Petrified Forest National Park in northeast Arizona permits viewing of the fossilized remains of what were once vast tracts of very respectably-sized trees.
The park is easily accessed off I-40 and runs through the hilly terrain with many switchbacks and very few straight stretches of roadway. It is also adjacent to the Painted Desert.
The official estimate is the rocks that were once trees are about 200 million years old. That would put them in the category of providing shade for dinosaurs.
Multi-ton sections of petrified trees are scattered over the landscape. Even a few logs are evident, but most pieces are under seven feet in length.
While no dinosaur fossils, petrified or otherwise, were evident, there were some aquatic fossils. Many believe, and there is evidence, that the area was then covered by a large inland sea.
The trees may have grown on islands and/or in shallows that ebbed and flowed. The now siliconized timbers were submerged rapidly, some even being buried beneath muddy soil.
If left in the likely humid atmosphere, rot and decay would have occurred along with insect damage. Fossil records have indicated insects did exist during this time period.
Those that have red mineralization are reflecting the exposure to iron in the soil and oxygen. Those with green and/or blue coloration indicated iron, but in anaerobic conditions lacking oxygen.
The differences in hues indicate the possibility of traumatic events such as floods and/or seismic activity over an extended period of time. Less than 100 miles from the Petrified Forest there is evidence of volcanic activity in Arizona.
The long-expired volcanoes still have lava flows on the surface. Volcanoes are also associated with earthquakes.
The area’s early residents left evidence of their visits. Petroglyphs are present in several locations easily viewed by tourists.
Whatever the cause, the tree’s colors are brilliant even after 200 million years. While most of the examples are in chunks, there are some logs evident in the now dry and arid landscape with only a few plants evident.
Souvenir hunting is strictly forbidden under penalty of law. Signs at the exits indicate park staff can look inside vehicles for any stray rocks that found their way into the trunk or glovebox.
Polished and raw specimens are available in the souvenir shop, along with stuffed animals and tee shirts made China. Some things never change.
For the adventurous there are hiking trails. Well-fitting shoes, a broadbrimmed hat, and plenty of water are advised. During the summer midday walks should be undertaken with caution.
The area’s early residents left evidence of their visits. Petroglyphs are present in several locations easily viewed by tourists.
Their meaning is open to interpretation, but it would not be much of a stretch to think the men of the day visited to pick up a colorful rock for their lady friends…and, like today, it was a smart move.
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