This is Throwback Thursday #175. In these, we look back into the past at ESCONI specifically and Earth Science in general. If you have any contributions, (science, pictures, stories, etc ...), please sent them to [email protected]. Thanks!
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The Petrified Forest National Park is a beautiful place, located in Arizona. If you get a chance to visit, you won't be disappointed. There's an official website for the park, with many beautiful photos and videos of both the Petrified Forest and the Painted Desert.
Blue Mesa Memberm Chinle Formation NPS
The Tepees in Petrified Forest National Park in northeastern Arizona, United States. View is toward the northwest from the main park road. According to a National Park Service (NPS) document, rock strata exposed in the Tepees area of the park belong to the Blue Mesa Member of the Chinle Formation and are about 220 to 225 million years old. The colorful bands of mudstone and sandstone were laid down during the Triassic, when the area was part of a huge tropical floodplain
Exhibit commemorating U.S. Route 66, a historic transcontinental highway that passed through the park
History of the park (More on Wikipedia)
The Petrified Forest is known for its fossils, especially fallen trees that lived in the Late Triassic Epoch, about 225 million years ago. The sediments containing the fossil logs are part of the widespread and colorful Chinle Formation, from which the Painted Desert gets its name. Beginning about 60 million years ago, the Colorado Plateau, of which the park is part, was pushed upward by tectonic forces and exposed to increased erosion. All of the park's rock layers above the Chinle, except geologically recent ones found in parts of the park, have been removed by wind and water. In addition to petrified logs, fossils found in the park have included Late Triassic ferns, cycads, ginkgoes, and many other plants as well as fauna including giant reptiles called phytosaurs, large amphibians, and early dinosaurs. Paleontologists have been unearthing and studying the park's fossils since the early 20th century.
The history of Petrified Forest National park began with the documentation of fossil wood in the 1850s (NPS, 2007b). As the region developed, pioneers, ranchers, sightseers, and eventually commercial ventures came to collect fossils wood. In 1906, President Theodore Roosevelt created Petrified Forest National Monument. The early monument only encompassed selected stands of fossil trees (NPS, 2006c). Over 53,000 acres in the Painted Desert were added to the monument in 1932. Lands associated with Painted Desert Inn were added in 1936 (the Inn became a National Historic Landmark in 1987) (NPS, 2007b). Congress elevated the National Monument to National Park status in 1962. In 1970, Congress designated over 50,000 acres of the park as wilderness, part of the first wilderness designation in the National Park System ((NPS, 2006c; NPS, 2007b).
They've had a problem with erosion over the years.... Erosion caused by the weather and erosion of a human kind... People walk off with rocks, petrified wood, fossils, etc. Please respect the rules and let everyone enjoy the beauty for years to come!
Here's an article from the ESCONI newsletter in 1972. It was a partial reprint from the Chicago Sun Times on November 26th, 1972.
Piece by Piece, They Carry Away the Petrified Forest - Chicago Sun Times, Sunday, November 26, 1972
Petrified Forest National Park, Arizona
A new kind of erosion has struck the Petrified Forest - the Public. They are carrying away the park, piece by piece.
Rangers give warnings to all visitors entering the park: "Federal law prohibits removal of any petrified wood from this park, no matter how small the piece. If you violate this law, you will be subject to a fine or imprisonment or both." The maximum fine is $500, the Maximum sentence is six months in jail. So far this year $1850 in fines have been paid by wood thieves.
Polished petrified wood items may be purchased in two stores within the park boundaries. The law requires the wood be obtained and polished outside the park.
Northeastern Arizona 200 million years ago was a low-lying swampy area, a basin where logs were carried by streams and rivers innundated with sediments from ancient mountain ranges and turned into stone by nature. President Theodore Roosevelt set aside the area as the nation's second national monument in 1906. It was designated a national park in 1962. "It was set aside to preserve petrified wood for posterity." said Harvey Sorenson, a park ranger. "I would not be surprised if the day may come when this will be the only national park locked tighter than a drum to protect it from the people."
