Lake Bonneville — LLMpedia

Contents

Lake Bonneville was a vast pluvial lake that covered much of present-day Great Salt Lake Desert, Utah, Idaho, and Nevada during the Late Pleistocene. Scientists from institutions such as the United States Geological Survey, Smithsonian Institution, University of Utah, Brigham Young University, and Harvard University have reconstructed its history using methods developed by researchers including G. K. Gilbert and later studies by Milton W. Hamblin, J. R. Eardley, M. C. Gilbert, and teams from Scripps Institution of Oceanography and University of California, Berkeley. Interpretations of Lake Bonneville inform broader studies of the Pleistocene epoch, Last Glacial Maximum, Younger Dryas, and regional responses to climate events studied by NOAA, National Aeronautics and Space Administration, and paleoenvironmental groups.

Geology and Formation

The formation of Lake Bonneville is tied to regional tectonics of the Basin and Range Province, Quaternary volcanism near Yellowstone Caldera, and glaciohydrologic shifts during the Pleistocene epoch influenced by ice-sheet dynamics of the Cordilleran Ice Sheet and the Laurentide Ice Sheet. Early mapping by G. K. Gilbert and later geomorphologists from USGS and Geological Society of America used stratigraphy, radiocarbon dating from laboratories at Lawrence Livermore National Laboratory and tephrochronology comparing layers with eruptions from Mount St. Helens, Mount Mazama, and Mono Craters. Regional faulting along the Wasatch Fault and subsidence in the Bonneville Basin controlled accommodation space, while sedimentation patterns correlate with work by researchers from Oregon State University, University of Wyoming, and Montana State University.

At its maximum, Lake Bonneville inundated parts of modern Utah, Idaho, and Nevada, flooding basins near Great Salt Lake, Sevier Desert, Snake River Plain, and reaching shorelines now preserved at sites such as Bonneville Shoreline Trail and around the Provo Bench. Chronologies have been developed using radiocarbon labs at University of Arizona, cosmogenic nuclide dating by teams at Columbia University, and luminescence work from University of Oxford, correlating highstands with regional records from the Great Salt Lake, Lake Lahontan, and marine oxygen isotope stages like Marine Isotope Stage 2. Key episodes include the Bonneville highstand, the catastrophic breach at Red Rock Pass linked to Missoula Floods in comparative flood studies, and the subsequent Provo and Gilbert phases recognized by stratigraphers from USGS and University of Colorado.

Hydrologic reconstructions synthesize paleoclimate proxies from researchers at NOAA Paleoclimatology Program, isotope studies at Lawrence Berkeley National Laboratory, and pollen records analyzed by palynologists at Yale University and University of Cambridge. Forcing mechanisms include changes in atmospheric circulation tied to the North American Monsoon, shifts documented in Greenland ice cores from Greenland Ice Sheet Project and Antarctic records from Vostok, and teleconnections with events like the Younger Dryas and Holocene climatic optimum. Inflow sources such as the Provo River, Bear River, and Weber River were modulated by snowpack in the Rocky Mountains and runoff regimes affected by volcanic aerosol inputs from eruptions recorded by Krakatoa-era studies and regional tephra from Inyo Craters. Outflow controls involved the overflow at Red Rock Pass and spillways studied in comparative hydraulics with Missoula Floods research teams.

Lake Bonneville left prominent shorelines including the Bonneville, Provo, and Gilbert benches; geomorphologists from University of Utah and Brigham Young University documented strandlines, wave-cut terraces, and deltaic deposits near features such as the Bonneville Salt Flats, Antelope Island, and the Stansbury Mountains. Sedimentary facies and beach rock studied by sedimentologists from California Institute of Technology and coastal geomorphology groups at University of Washington reveal littoral structures, spits, and barrier systems analogous to Holocene coasts examined by Woods Hole Oceanographic Institution. Fluvial reworking produced alluvial fans at the mouths of the Provo Canyon and Weber Canyon documented by researchers from Idaho State University and University of Nevada, Reno.

Paleobiologists and archaeozoologists from Smithsonian Institution and University of Michigan have identified fossil assemblages of fishes related to modern cutthroat trout and endemic forms linked to post-Bonneville evolution in the Great Basin documented by ichthyologists at University of Kansas and Brigham Young University. Macrofossils, pollen, and charcoal records recovered by teams from Cornell University and Oregon State University indicate shifts from steppe and alpine parkland to sagebrush scrub characteristic of modern Great Basin National Park environs, with vertebrate remains of Bison antiquus, Mammuthus relatives, and Pleistocene rodents studied by paleontologists at American Museum of Natural History.

Archaeologists and anthropologists from University of Utah, University of California, Los Angeles, Peabody Museum, and Harvard University have documented Paleoindian and Archaic occupations along former shorelines, including artifacts comparable to assemblages at Clovis culture sites and later Fremont culture materials. Research integrates lithic sourcing studies connecting quarries at Obsidian Cliff and trade networks comparable to those documented in Ancestral Puebloans studies, with radiocarbon determinations calibrated against datasets from IntCal and labs such as Oxford Radiocarbon Accelerator Unit. Historic explorers including John C. Fremont and surveyors for the Transcontinental Railroad recorded remnants of Bonneville during 19th-century expeditions, informing later conservation efforts by entities like the National Park Service and state historic preservation offices.

Category:Pluvial lakes Category:Pleistocene geology of North America Category:Geography of Utah