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A continuous 250,000 yr record of oxygen and carbon isotopes in ostracode and bulk-sediment carbonate from Bear Lake, Utah-Idaho

Quaternary Science Reviews
By: , , , and 
https://doi.org/10.1016/j.quascirev.2005.12.011

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Abstract

Oxygen and carbon isotopes from a continuous, 120-m-long, carbonate-rich core from Bear Lake, Utah-Idaho, document dramatic fluctuations in the hydrologic budget of the lake over the last 250,000 yr. Isotopic analyses of bulk sediment samples capture millennial-scale variability. Ostracode calcite was analyzed from 78 levels, mainly from the upper half of the core where valves are better preserved, to compare the isotopic value of purely endogenic carbonate with the bulk sediment, which comprises both endogenic and detrital components. The long core exhibits three relatively brief intervals with abundant endogenic aragonite (50±10%) and enriched δ18O and δ13C. These intervals are interpreted as warm/dry periods when the lake retracted into a topographically closed basin. We correlate these intervals with the interglacial periods of marine oxygen-isotope stages 1, 5e, and 7a, consistent with the presently available geochronological control. During most of the time represented by the core, the lake was fresher than the modern lake, as evidenced by depleted δ18O and δ13C in bulk-sediment carbonate.

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Publication type Article
Publication Subtype Journal Article
Title A continuous 250,000 yr record of oxygen and carbon isotopes in ostracode and bulk-sediment carbonate from Bear Lake, Utah-Idaho
Series title Quaternary Science Reviews
DOI 10.1016/j.quascirev.2005.12.011
Volume 25
Issue 17-18
Year Published 2006
Language English
Publisher Elsevier
Contributing office(s) Geosciences and Environmental Change Science Center
Description 13 p.
First page 2258
Last page 2270
Country United States
State Idaho, Utah
Other Geospatial Bear Lake
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