Editing Painted Desert (Arizona) (section)

==Geology==
The desert is composed of stratified layers of [[siltstone]], [[mudstone]], and [[shale]] of the [[Triassic]] [[Chinle Formation]], which erode easily. These fine-grained rock layers contain abundant iron and manganese compounds, which provide the pigments for the various colors of the region. Thin, resistant [[Lake|lacustrine]] [[limestone]] layers and [[volcanic]] flows cap the [[mesa]]s. Numerous layers of [[Silica|silicic]] [[volcanic ash]] occur in the Chinle and provide the silica for the [[Petrified wood|petrified logs]] of the area. The erosion of these layers has resulted in the formation of the [[badlands]] topography of the region.<ref>Chronic, Halka, ''Pages of Stone: Geology of Grand Canyon & Plateau Country National Parks & Monuments,'' Mountaineers Books; 2nd ed., 2004, pp. 131–34 {{ISBN|978-0-89886-680-3}}</ref><ref>Baars, Donald L., ''Navajo Country,'' University of New Mexico Press, 1995 pp. 47–53 {{ISBN|0-8263-1587-9}}</ref><ref>Baars, Donald L., ''The Colorado Plateau: a Geologic History,'' University of New Mexico Press, 1983, pp. 163–68 {{ISBN|0-8263-0599-7}}</ref>

In the southern portions of the desert, the remains of a Triassic period [[coniferous]] forest have [[fossilized]] over millions of years. Wind, water and soil [[erosion]] continue to change the face of the landscape by shifting [[sediment]] and exposing layers of the Chinle Formation. An assortment of fossilized [[prehistoric]] plants and animals are found in the region, as well as ancient [[dinosaur]] tracks and evidence of early human habitation.