Shafer Canyon Overlook

From left to right: Desert Varnish: These dark, glossy streaks of manganese and iron form when airborne minerals become concentrated on the surface of desert rocks.           Chinle Formation: Water-deposited sandstone, siltstone and wind-deposited volcanic ash form the talus slopes at the base of the Wingate cliffs. Mines in this layer have yielded uranium.          Fallen Slab: When undercut by erosion, sections of the cliff that cannot carry their own weight will collapse. These fallen rocks become part of the eroding rubble on the talus slope below.       Douglas Fir: These tall Douglas fir trees are remnants of a past climate what was much cooler and wetter. They can survive in this location because the cliff offers shade and a small spring at its base provides water.             Kayenta Formation: Ancient streams deposited sediment in many thin layers, forming red and gray tinted sandstone and shale. Eroding ledges expose dinosaur tracks in this meandering river environment.            Wingate Sandstone: A vast desert of massive sand dunes formed the majestic cliffs - some as high as 500 feet - that surround the Island in the Sky.            Pinyons & Junipers: Pinyon and Utah juniper grow wherever their roots find a crack that stores water. These hardy, slow-growing trees form a "pygmy" forest over much of the park.               Navajo Sandstone: The crossbedding of ancient sand dunes patterns this white, red and brown sandstone. Round and domed on top, the cliffs collect water at the base, promoting plant growth.       Joints: These vertical cracks in the sandstone set the pattern for erosion. Water, ice and roots invade the cracks, then slowly wear or break the rocks apart.           "Slickrock": Smooth, colorful sandstone is found throughout the canyon country. Loose sand and gravel on slopes create "slick" conditions, a hazard for early travelers' metal-shod horses.