Sipapu Bridge, Natural Bridges National Monument, near Blanding, Utah, USA.

Desert varnish streaks Sipapu Bridge, in Natural Bridges National Monument, near Blanding, San Juan County, Utah, USA. White Canyon Creek has cut Sipapu Natural Bridge with a span of 225 feet (with a height of 144 feet, width of 41 feet, and thickness of 53 feet, says www.naturalarches.org) through a meander of white Permian sandstone of the Cedar Mesa Formation. Manganese-rich desert varnish requires thousands of years to coat a rock face 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 protected from wind. 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.

Add to Cart Add to Lightbox Download

Filename: 1503SW-0962_Sipapu-Natural-Bridge.jpg
Copyright: © Tom Dempsey / PhotoSeek.com
Image Size: 6000x4000 / 9.1MB; http://www.photoseek.com/; PhotoBest Plantae bridge desert landscape nature outdoor plants trees
Contained in galleries: 2015 Mar 3-Apr 8: favorites UT, CO hikes, USA: Utah favorites, Utah: Natural Bridges National Monument, 2015 Mar 3-Apr 8: all: Utah, Colorado hikes, USA: Southwest favorites (Arizona, Utah, New Mexico, Colorado, Nevada), Highlights 2015

Desert varnish streaks Sipapu Bridge, in Natural Bridges National Monument, near Blanding, San Juan County, Utah, USA. White Canyon Creek has cut Sipapu Natural Bridge with a span of 225 feet (with a height of 144 feet, width of 41 feet, and thickness of 53 feet, says www.naturalarches.org) through a meander of white Permian sandstone of the Cedar Mesa Formation. Manganese-rich desert varnish requires thousands of years to coat a rock face 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 protected from wind. 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.