Multiple shallow sediment cores were obtained from Pilot Valley playa, a sub-basin located in the northwestern Bonneville basin. Analysis of stratigraphy, ostracodes, mineralogy, chemistry, total inorganic carbon (TIC), total organic carbon (TOC), and stable isotopes were performed to better place these sediments into proper context with respect to the Lake Bonneville cycle. Results showed Pilot Valley playa contains a nearly full sequence of Lake Bonneville deep-water marl in addition to sediments deposited before and after the Lake Bonneville cycle. Within the marl is a sequence of organic rich algal laminated marl correlated with the Stansbury oscillation. Four 14C ages ranging from ~22.4 k 14C years to ~15.8 k 14C years from preserved algae filaments in this sequence place it well within the time frame of the Stansbury oscillation. Oolitic sand found below this sequence indicates the existence of a shallow (<~5 m), saline lake in Pilot Valley prior to the transgression of Lake Bonneville. Analysis of sediments deposited during the late regressive phase of Lake Bonneville indicates the lake may have fallen to levels below that of Pilot Valley prior to transgressing to the Gilbert level.
College and Department
Physical and Mathematical Sciences; Geological Sciences
BYU ScholarsArchive Citation
Rey, Kevin A., "Insights into the Early Transgressive History of Lake Bonneville from Stratigraphic Investigation of Pilot Valley Playa, UT/NV, USA" (2012). Theses and Dissertations. 3803.
Lake Bonneville, Lake Bonneville marl, Stansbury oscillation, Pilot Valley playa, Pilot Valley stratigraphy