Late Cenozoic Drainage History of the Southwestern Great Basin and Lower Colorado River Region: Geologic and Biotic Perspectives
Late Pleistocene shorelines of Owens Lake, California, and their hydroclimatic and tectonic implications
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Published:January 01, 2008
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CiteCitation
Antony R. Orme, Amalie Jo Orme, 2008. "Late Pleistocene shorelines of Owens Lake, California, and their hydroclimatic and tectonic implications", Late Cenozoic Drainage History of the Southwestern Great Basin and Lower Colorado River Region: Geologic and Biotic Perspectives, Marith C. Reheis, Robert Hershler, David M. Miller
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Owens Lake has existed for most of the past 800,000 yr, but the sequence of interconnected lakes and streams of which it was often part, the Owens River cascade, last flourished during late Pleistocene time. A fluctuating, increasingly saline, terminal lake survived into the late Holocene until upstream water diversions to the Los Angeles Aqueduct began in 1913. Shoreline fragments and beach stratigraphy indicate that the lake reached its highest late Pleistocene level around 23.5 ka, during the Last Glacial Maximum, when it was fed by meltwaters from Sierra Nevada glaciers and spilled southward to Searles Lake and beyond. The lake then fell to relatively low levels after 16.5 ka before experiencing terminal Pleistocene oscillations related to hydroclimatic forcing, which involved changing regional precipitation regimes rather than major inputs from Sierra Nevada glaciers. Two major transgressions occurred. The first culminated around 14.3 ka and was probably related to a cooler, wetter regional climate. The second culminated around 12.8 ka and was linked to the earlier wetter phase of the Younger Dryas cold event. However, the high late Pleistocene shoreline is deformed, and the highest beach ranges in elevation from 1140 m to 1167 m above sea level. If the terminal Pleistocene lake overflowed, as suggested here, then its outlet has also been raised since 12.8 ka. This deformation appears to have involved uplift of the Coso Range magmatic complex relative to subsidence and faulting within the Owens Lake graben between the Sierra Nevada and Inyo Mountains frontal faults. Such deformation confounds simple hydroclimatic explanations of lake behavior and must be incorporated into models that seek to interpret the changing form and geochemistry of Owens Lake and the frequency of its spillage southward to Searles Lake.
- California
- Cenozoic
- Coso Range
- drainage basins
- faults
- fluctuations
- geomorphology
- grabens
- hydrology
- igneous rocks
- intrusions
- Inyo County California
- lake-level changes
- last glacial maximum
- lithostratigraphy
- meltwater
- neotectonics
- Owens Lake
- Owens Valley
- paleoclimatology
- paleoenvironment
- paleohydrology
- Pleistocene
- Quaternary
- rainfall
- Searles Lake
- shorelines
- Sierra Nevada
- stratigraphic units
- subsidence
- systems
- tectonics
- United States
- uplifts
- upper Pleistocene
- upper Weichselian
- Weichselian
- Younger Dryas