Responses of sediment geochemistry to climate change in Owens Lake sediment: An 800-k.y. record of saline/fresh cycles in core OL-92

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Abstract

Geochemical parameters of sediments from drill hole OL-92 indicate that Owens Lake was saline, alkaline, and highly productive during interglacial periods, and was hydrologically open and relatively unproductive during glacial periods. Abundance of CaCO3, organic carbon, and cation-exchange capacity of the clay fraction show cyclic variation down the core. Six minima in these components during the past 500 k.y. are interpreted as caused by intensive overflow that occurred during Sierran glacial advances. Maxima in these components indicate closed-lake conditions, reflecting warmer and more arid interglacial climates. The pattern of CaCO3 abundance suggests that closed lake conditions predominated over the past 500 k.y. The absence of gaylussite and gypsum in the sediments, however, indicates lake salinity never exceeded about 15 wt %, a limit which requires flushing of accumulated salts every 10 k.y.

Oscillations of CaCO3 generally indicate a 100-k.y. dominant cycle, a characteristic of the marine δ18O record. Four of the last five marine isotope terminations are clearly shown in the Owens Lake record. The last interglacial at Owens Lake appears to have occurred between 120 ka and 50 ka. The roughly 10-k.y. offset between this interval and marine oxygen-isotope stage 5 reflects either error in the age-depth model, or alternatively, a time lag between changes in Northern Hemisphere ice volumes and the manifestation of local climate change in lake geochemistry and sedimentology.

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Publication type Book chapter
Publication Subtype Book Chapter
Title Responses of sediment geochemistry to climate change in Owens Lake sediment: An 800-k.y. record of saline/fresh cycles in core OL-92
DOI 10.1130/0-8137-2317-5.37
Volume 317
Year Published 1997
Language English
Publisher Geological Society of America
Description 11 p.
Larger Work Type Book
Larger Work Subtype Monograph
Larger Work Title An 800,000-year paleoclimatic record from core OL-92, Owens Lake, Southeast California
First page 37
Last page 47
Country United States
State California
Other Geospatial Owens Lake
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