Thirty-five years after the first draft was begun, Petrified Forest National Park has its first published geological map.
Petrified Forest National Park, established as a national monument in 1906 and a national park in 1962, was set aside to protect scientific values of a 20 million year slice of Triassic Period deposits that include some of the earliest dinosaurs in the fossil record.
A project initiated in 2008 by park geology staff resulted in a completely revamped park stratigraphy that was published in the open access journal PLoS ONE in 2010. This study is the basis for the completed map, which covers 93,000 acres, was digitized in partnership by staff at Northern Arizona University with funding from the NPS Geological Resources Division.
The new map includes an eighteen page report summarizing the park’s geology, including a colorful cross section of the park geology and photographs of key rock outcrops. This new work provides a detailed breakdown of the park geology and demonstrates for the first time that the Chinle Formation is thicker in Petrified Forest than previously believed. This study also identified a specific layer where a sudden extinction of plants and animals is recorded, and provides foundation for continuing work studying possible causes of this major event.
The new map and accompanying report are freely available on-line through the Arizona Geological Survey website. For those interested in the more detailed study, the 2010 publication is also free on-line at the PLoS ONE website.
The new map is garnering lots of interest with the Arizona Geological Survey page, recording more than 1100 visits in one week. According to staff, this is best performance they have ever had for an online product.