Soft Sediment Deformation at Coyote Buttes

March 09, 2010

20100309 – Tuesday - Soft Sediment Deformation at Coyote Buttes

Photographer: Roger Hopkins
Summary Author: Roger Hopkins

March 2010 Earth Science Picture of the Day Viewer's ChoiceThe photo above showing a wavy, orange-colored rock face was taken in the Coyote Buttes area of the Paria Canyon-Vermilion Cliffs Wilderness in Grand Staircase-Escalante National Monument. It’s located on the border of Arizona and Utah. About 150 million years ago this rock was a giant sand dune. The movement of the sand in the wind caused the layering, called cross-bedding, that remained long after the dunes were covered and eventually consolidated into sandstone. However, a portion of the dune collapsed while it was still unconsolidated, probably due to water turning the sand into a mud-like slurry. Geologists refer to this process as soft sediment deformation. After the porous sandstone was fully formed, water carrying mineral salts (primarily iron and manganese) seeped in and left behind the fantastic coloration. Note that a permit is required to visit this area. Photo taken on November 20, 2008.