This picture of the scenery along the Blue Mesa Trail in Petrified Forest National Park, AZ, shows the detail that can be seen along this trail. The white layers are sandstone. The cap is clay. Darker layers are caused by high carbon content; dark reds are iron-stained siltstone. Reddish layers are caused by iron oxide, which is also called hematite (Source: NPS park brochure). Imaged in December 2009. This is the first of four SP images I shot during that hike (one, three and four).