The sedimentology and sequence architecture of the Cathedral Bluffs Tongue of the Wasatch Formation, South Pass, Wyoming

The early Eocene (Gardnerbuttean) Cathedral Bluffs Tongue of the Wasatch Formation near South Pass, Wyoming preserves a succession of continental fluvial deposits, which interfinger with lacustrine strata of the Green River Formation in a basinward direction. This thesis focuses on the sedimentology of the Cathedral Bluffs Tongue and identifies the dominant influences on sediment accumulation. Previous studies focused primarily on the regional (basin-scale) lithostratigraphic architecture of Eocene strata in the Green River Basin. Detailed sedimentological analyses of the study interval have not previously been completed. Using whole-rock geochemistry, gamma spectrometry, outcrop description and petrography, fine-scale correlations were made through the study interval. As climate remained constant throughout the ∼ 1. 5 million year study interval, and syndepositional structural influences can be demonstrated in the study area, it is shown that movement of the Wind River Thrust Fault, played a dominant role in Early Eocene sediment accumulation at South Pass.