Desert varnish patterns, Lower Emerald Pool, Zion National Park, Springdale, Utah, USA.
Patterns of desert varnish coat canyon walls near Lower Emerald Pool waterfall in Zion National Park, Springdale, Utah, USA. Manganese-rich desert varnish requires thousands of years to coat a rock face that is protected from precipitation and wind erosion. The varnish likely originates from airborne dust and external surface runoff, including: clay minerals, oxides and hydroxides of manganese (Mn) and/or iron (Fe), sand grains, trace elements, and usually organic matter. Streaks of black varnish often occur where water cascades over cliffs, but wind doesn't sculpt its shape. Varnish color varies from shades of brown to black. Manganese-poor, iron-rich varnishes are red to orange, and intermediate concentrations are shaded brown. Manganese-oxidizing microbes may explain the unusually high concentration of manganese in black desert varnish, which can be smooth and shiny where densest. More about Zion: The North Fork of the Virgin River carved spectacular Zion Canyon through reddish and tan-colored Navajo Sandstone up to half a mile (800 m) deep and 15 miles (24 km) long. Uplift associated with the creation of the Colorado Plateaus lifted the region 10,000 feet (3000 m) starting 13 million years ago. Zion and Kolob canyon geology includes 9 formations covering 150 million years of mostly Mesozoic-aged sedimentation, from warm, shallow seas, streams, lakes, vast deserts, and dry near-shore environments. Mormons discovered the canyon in 1858 and settled in the early 1860s. U.S. President Taft declared it Mukuntuweap National Monument in 1909. In 1918, the name changed to Zion (an ancient Hebrew name for Jerusalem), which became a National Park in 1919. The Kolob section (a 1937 National Monument) was added to Zion National Park in 1956. Unusually diverse plants and animals congregate here where the Colorado Plateau, Great Basin, and Mojave Desert meet.Add to Cart Add to Lightbox Download