Quaternary geology of part of the Sevier Desert, Millard County, Utah (SS-70)

By: C. G. Oviatt

This report describes the Quaternary geology and Quaternary geologic history of part of the Sevier Desert in east-central Millard County, Utah. Surficial deposits in the map area consist of fine-grained lacustrine deposits of Lake Bonneville and of pre-Bonneville lakes, vast areas of fine-grained alluvium deposited by the Sevier and Beaver Rivers, and coarser grained lacustrine and alluvial deposits in piedmont areas. Thin deposits of eolian sand or silt and clay are present throughout the map area but are concentrated in dunes in favorable localities. The map area also contains Quaternary basalt flows and volcanic vents; Quaternary faults cut deposits of all ages. The Sevier Desert basin has been periodically occupied by lakes throughout the Quaternary Period, and the geologic record of these lakes is exceptionally good. The lake deposits have been dated by interbedded volcanic ashes, lava flows, and various geochronometric methods. This report is one of the first attempts to map in a systematic way the Quaternary deposits and landforms in a large area of the Basin and Range physiographic province of western Utah.

The purpose of this report is to describe the Quaternary geology, and to outline the Quaternary history, of part of the Sevier Desert. With a few exceptions, the Quaternary geology of western Utah has not been mapped in as much detail as the pre-Cenozoic rocks in the region. Quaternary geology in western Utah is important in studies of Lake Bonneville and other Quaternary lakes, earthquake, volcanic, and other geologic hazards, and ground water. Geologic mapping provides basic data for these and other investigations.

Other Information:
Published: 1989
Pages: 41 p.
Plates: 1 pl.
Scale: 1:100,000
Location: Millard County
Media Type: Paper Publication