Geologic Map of the Lyman Quadrangle, Wayne County, Utah (M-288)

Summary:

The Lyman quadrangle lies astride the Thousand Lake fault zone in south-central Utah and includes the small towns of Lyman and Fremont in Rabbit Valley. Rabbit Valley, on the down-dropped side of the fault, contains an enormous landslide complex about 25 square miles (65 km2) in size shed off the west flank of Thousand Lake Mountain. The landslide is several hundred feet thick and traveled 4 miles (6.5 km) across the valley floor; it may be as young as about 500,000 years old. Younger landslides, parts of which are historically active, mantle the slopes of the mountain. The Fremont River, impounded at Mill Meadow Reservoir, runs through the northwest part of the quadrangle at the base of the northeast corner of the Awapa Plateau, which exposes resistant volcanic rocks of the Marysvale volcanic field.