Petrified Forest National Park


Petrified Forest National Park
The Petrified Forest National Park in north-eastern Arizona was formed over 225 million years ago the area, was once a vast floodplain criss-crossed by many streams, alongside which tall conifer trees grew. The trees, which included Araucarioxylon, Woodworthia and Schilderia fell into swollen streams and were washed into adjacent floodplains. They were buried under sediment formed from silt, mud and volcanic ash which cut off oxygen and prevented their decay. Then over time silica-laden water seeped into the logs and replaced the original wood tissue with silica deposits. This silica eventually crystallised into quartz, and the logs were preserved as petrified wood. The continents shifted in to their present positions, the region uplifted, the climate changed and the tropical environment became the grassland that we see today. Finally, over time the elements eroded the layers of rock and exposed fossilised ancient plants, trees and animals.The famous petrified forests occur in a colourful banded sequence of rocks known as the Chinle Formation - widely exposed in the south-western USA and visible in the Grand Canyon National Park and the Canyon de Chelly National Monument. The Chinle Formation consists of a variety of sedimentary rock types - mainly soft, siltstone, claystone and fine-grained mudstone, although it also contains beds of coarser, much harder sandstone. The amazing colours of the petrified wood came from minerals in the silica-saturated water that seeped into the logs while they were trapped by the sediment. Carbon, iron, manganese, cobalt and chromium produced stunning patterns and blends of red, yellow, black, blue, brown, pink and white. Although over the years the process has resulted in petrified wood being deposited all over the planet, nowhere is it more prevalent than in Arizona's Petrified Forest National Park.

The Petrified Forest was discovered thousands of years ago by the ancient ancestors of today's Native Americans. Spanish explorers found no one living in the area in 1540, however documentary evidence recounts bands of Navajo, Zuni and Hopi roamed the area after that date. Sites throughout the Park reveal evidence of humans in the area for more than 10,000 years. It's unsure whether any of these ancient peoples recognised that some of the stone they fashioned into tools had originally been wood, but John Wesley Powell, one of the early explorers of the Southwest reported that the modern Paiute of southern Utah, believed the petrified logs to be the arrow shafts of their thunder god, Shinuav. This may or may not suggest that they had noticed the similarity of the petrified logs to the trunks of living trees. In the mid 1800s United States government surveyors and mappers explored the area and carried stories back east of the "remarkable Painted Desert and its trees turned to stone" which resulted in a large number of pioneers, ranchers and sightseers coming to the area. Inevitably much of the wood disappeared for souvenirs and other commercial ventures and it was recognised that the supply was not endless. In 1906 President Theodore Roosevelt set aside selected collections of petrified trees as the Petrified Forest National Monument. In 1932 a further 53,200 more acres of the Painted Desert were bought and added to the Monument and in 162 Congress designated it a national park. Finally, in 1970 Congress designated 50,000 acres in the park as one of America’s first National Park System wilderness areas and research continues to reveal a wealth of geological and paleontological information. View images of the Petrified Forest and Painted Desert by Richard Lumb here. Read about the Painted Desert by Jacquie Lumb here wildlife, trees,

National Parks: Grand Canyon, Grand Canyon Info, Grand Canyon Map, Walnut Canyon, Walnut Canyon Info, Sunset Crater and Wutapki Monument, Sunset Crater Info, Wupatki Monument Info, Montezuma Castle and Well, Montezuma Castle Info, Montezuma Well Info, Petrified Forest, Painted Desert Info. Attractions: Apache Trail, Apache Trail Info, Apache Trail Map, Phoenix Desert Botanical Garden, Desert Botanical Garden Info, Meteor Crater, Meteor Crater Info, Monument Valley Tribal Park, Monument Valley Info, Oak Creek Canyon, Oak Creek Info, Slide Rocks State Park, Slide Rocks Info, Taliesin West, Taliesin West, Arboretum at Flagstaff, Arboretum at Flagstaff Info. and Towns and Cities: Flagstaff and envrions, Flagstaff Info, Prescott, Prescott Info, Route 66 Info.



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