Petrology of Lake Bonneville Gravels Salt Lake County, Utah

A study of sand and gravel deposits associated with Pleistocene Lake Bonneville was made from October 1961 to July 1962 in lower Jordan Valley, Salt Lake County, Utah. The sand and gravel deposits were mapped, and existing and potential reserves of sand and gravel were estimated. Pebble counts were taken to determine the mineralogical composition and geologic origin of the different deposits. Representative samples of the deposits were tested in the laboratory for grading, liquid-limit and plasticity index, absorption, optimum moisture and dry density, and abrasion. The sand and gravel deposits of lower Jordan Valley are derived almost entirely from the rocks that make up the mountains surrounding the valley and includes (1) Deposits associated with the Alpine, Provo, and post- Provo stages of Lake Bonneville; (2) stream terraces, formed by streams breaching and redepositing the shore gravels of the lake; (3) sand dunes associated with some of the Provo spits; and (4) mud-rock flow deposits and alluvial fans.