A high resolution record of strontium and calcium isotopes over the Paleocene Eocene boundary from marine barite

Author(s): Griffith, E. M.; Paytan, A.; Bullen, T. D.
Author Affiliation(s): Primary:
Stanford University, Department of Geological and Environmental Sciences, Stanford, CA, United States
Other:
U. S. Geological Survey, United States
Volume Title: AGU 2006 fall meeting
Source: Eos, Transactions, American Geophysical Union, 87( Fall Meeting Suppl.); American Geophysical Union 2006 fall meeting, San Francisco, CA, Dec. 11-15, 2006. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0096-3941 CODEN: EOSTAJ
Note: In English
Summary: A high resolution record of strontium and calcium isotopes over the Paleocene Eocene boundary will be presented from marine barite extracted from sediments collected by ODP Leg 199, at Site 1221 in the equatorial Pacific. Global weathering rates are thought to have been elevated during the P/E boundary (Os isotope record; Ravizza et al., 2001), which potentially will be recorded in the strontium and/or calcium records. This will be the first attempt at recovering a high resolution record of Ca isotopes over this interval. Although radiogenic strontium isotopes appear to be stable over the P/E boundary, a high resolution record (less than 100 ky) has not been established. Because the residence time of Sr in the ocean today is approximately two million years, it is assumed that it could not record such a short perturbation in silicate weathering as the P/E. The variations in previously published Sr isotopes over this interval have been attributed to diagenesis of the recording phase. Marine barite is an inorganic phase precipitated in the water column and is stable in stable in non-sulfate- reducing sediments. It provides a valuable record of variations in seawater chemistry at high resolution. Our record will test assumptions that Sr and Ca concentrations are stable over this interval, providing valuable information for other proxies (e.g. coccolith Sr/Ca and foraminiferal Mg/Ca). It will also provide limits for proposed mechanisms of changes in weathering and carbonate deposition over this interval.
Year of Publication: 2006
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Alkaline earth metals; Barite; Calcium; Cenozoic; Chemostratigraphy; Cores; Diagenesis; Eocene; Equatorial Pacific; High-resolution methods; Isotopes; Leg 199; Lower Eocene; Marine environment; Marine sediments; Metals; ODP Site 1221; Ocean Drilling Program; Pacific Ocean; Paleo-oceanography; Paleocene; Paleocene-Eocene boundary; Paleogene; Sediments; Stratigraphic boundary; Strontium; Sulfates; Tertiary; Upper Paleocene; Weathering
Coordinates: N120200 N120200 W1434200 W1434200
Record ID: 2007079976
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