In addition to underpinning core site selection and the comparison of piston core records of paleoclimate from the Lake Bonneville basin, seismic profiling provides evidence of recent faulting and relative movements of importance to the regional tectonics and basinal history.
Several faults displace the uppermost sediments and the lake floor.
Bioherm structures are present above some faults and fractures, suggesting that the faults served as conduits for sublacustrine discharge of fresh water. A shallow ridge between Carrington Island and Promontory Point, underlain by a well-cemented pavement, separates the south arm of the lake into two basins. The ridge is fault controlled, and younger sediments lap on to it from both sides. Onlap-offlap relationships and morphology of the lake floor indicate a former shoreline of an extremely low lake, well below the present level. This low stand, dated as early Holocene from evidence in cores, is represented by irregular reflections in seismic profiles from the deepest part of the basin.