Abstract

There are eight main saline resource areas within the State of Utah. Of these, the saline areas found within or close to the boundaries established for this guidebook include, 1) the salt and potash deposits of the Bonneville Salt Flats (formerly the Salduro salt marsh), 2) the Miocene salts within the Sevier Desert basin, 3) the salts and brines in Sevier Lake, and 4) in the Jurassic salts in the Sevier-Sanpete Valley of central Utah. The salt and potash deposits of the Bonneville Salt Flats were first recognized in 1906 to 1907, and played an important and sometimes singular role of supplying the U.S. with fertilizer during the latter part of World War I. Today, they are an important contributor to potash production in the United States, and to the economic base of Tooele County and the State of Utah. The interception of 5000 feet of salt in the Sevier Desert basin was a surprise encountered while drilling the Argonaut No. 1 Federal oil exploration well north of Delta. To date, salt has been identified in four wells within a 55-mile-long, north-south-trending zone, but there has been no development of this resource to date. Sevier (Dry) Lake, is located in south-central Millard County, and covers an area of about 200 square miles. An extensive exploration program was started in 1979 that included augering over 700 20-foot-deep holes, drilling four deep holes, collecting brine samples for chemical analysis, determining sediment properties, and collecting weather data. Prior to the project’s termination in 1993, a six-mile-long brine collection canal and approximately 3000 acres of solar ponds had been constructed, and plans for the construction of sodium chloride and potassium sulfate production facilities were well under way. Within the Sevier-Sanpete Valley of central Utah, salt has been mined from both surface and shallow underground workings in the Redmond Hills area for more than 50 years. The salt is found in the Middle Jurassic Arapien Shale. The main salt-bearing geologic structure within this area is the Sevier-Sanpete Valley anticline. This is a very large, slightly sinuous anticline with a highly mobile shale core that trends in a north-south direction through Sanpete and Sevier Counties of central Utah. The syncline is 65-70 miles long and has structural relief perhaps as great as 20,000 feet.