August 23, 2005

The Utah Geological Survey (UGS) recently released Special Study 115 entitled “The Origin and Extent of Earth Fissures in Escalante Valley, Southern Escalante Desert, Iron County, Utah,” by William R. Lund, Christopher B. DuRoss, Stefan M. Kirby, Greg N. McDonald, Gary Hunt, and Garrett S. Vice.

The special study presents the results of a UGS investigation of five recently discovered earth fissures in southwestern Utah. The Escalante Valley earth fissures were discovered in January 2005 after floodwater infiltrated into and enlarged the previously hairline cracks near Beryl Junction.

Locally the infiltrating floodwater formed linear depressions over 10 feet wide and 6.5 feet deep. Individual fissures are 300 to 1300 feet long, and together form a discontinuous north-south trending zone about 6.5 miles long in western Escalante Valley.

The UGS concluded that the most likely explanation for the formation of the earth fissures is a significant drop in the ground-water level in the Escalante Valley due to agricultural pumping, which led to compaction of the dewatered portion of the ground-water aquifer. Compaction of the aquifer resulted in ground subsidence and the formation of hairline cracks, or earth fissures.

The UGS special study discusses the geology and hydrology of Escalante Valley, where the earth fissures formed, includes maps of the fissure traces, discusses the most probable cause of fissure formation, and presents recommendations for future study.

Special Study 115 is available for $19.95 at the Department of Natural Resources Map & Bookstore, located at 1594 West North Temple in Salt Lake City, http://mapstore.utah.gov.

For more information, please contact William Lund (435-865-9034; billlund@utah.gov) or Christopher DuRoss (801-537-3348; christopherduross@utah.gov).