The Rockhounder: Oolitic Sand on Stansbury Island, Tooele County

By Christine M. Wilkerson

Geologic information:

Oolitic sand is an unusual sediment that is found in and around the Great Salt Lake. Instead of forming from grains of mineral fragments washed down from higher ground, this sand formed within the Great Salt Lake. It is composed of tiny, lightbrown, rounded oolites. An oolite has a shell of concentric layers of calcium carbonate that precipitated around a nucleus or central core. The nucleus is usually a tiny brine shrimp fecal pellet or a mineral fragment. Oolites form in shallow, wave-agitated water, rolling along the lake bottom and gradually accumulating more and more layers. In addition to the Great Salt Lake, oolites also form in Baffin Bay (Texas), the eastern Mediterranean Sea, the Persian Gulf, and the waters surrounding the Bahamas. Although oolitic sand is collected for its uniqueness, it has also been used to dry flowers and as flux in mining operations.

How to get there:

Travel approximately 36 miles west of Salt Lake City on Interstate 80 until you reach the second Grantsville exit. Exit and turn west (left) onto the road to Stansbury Island (do not turn south to Grantsville). Travel about 6 miles on this main road until you reach an intersection with a stop sign on the west side of Stansbury Island. Turn west (left) and travel 0.5 miles to a sandy dune area adjacent to the road. Stop here and park on the edge of the road. Be careful not to get your vehicle stuck in the sand and watch out for the large trucks that use this road.

Where to collect:

Oolitic sand dunes are adjacent to the road and easily accessible in this area. Use a plastic bag or a bucket to collect the sand. Be careful not to disturb the vegetation that stabilizes the dunes.

Useful maps:

Tooele 1:100,000-scale topographic map, Corral Canyon 7.5- minute topographic map, and a Utah highway map. Topographic maps can be obtained from the Utah Geological Survey, 2363 South Foothill Drive, Salt Lake City, UT 84109-1491, (801) 467- 0401.

Land ownership:

Bureau of Land Management (BLM) public lands.

Miscellaneous:

A hat and water are recommended. Watch out for the large trucks that travel on the Stansbury Island roads. Respect private property and do not trespass. Please carry out your trash. Have fun collecting!

Extra fun:

You can also enjoy mountain biking while visiting the island. The BLM Stansbury Island Mountain Bike Trailhead is located about 1 mile north of the intersection with the stop sign on the west side of Stansbury Island. The trail is approximately 3 miles one-way and is steep in places. For more information contact the BLM Salt Lake District office at (801) 977-4300.

Survey Notes, v. 28 no. 2, April 1996