Badlands at the Painted Desert. Painted Desert is composed of stratified layers of easily erodible siltstone, mudstone, and shale of the Triassic Chinle Formation. The rock layers contain abundant iron and manganese compounds which provide the pigments for the beautiful colors of the region. Navajo Nation, Arizona, USA..© febr. 26 2007 Marco van Middelkoop/Aerophoto-Schiphol