(Dept. of Geosciences, University of Arizona, 2005)
Ohkouchi, Naohiko; Eglinton, Timothy I.; Hughen, Konrad A.; Roosen, Ellen; Keigwin, Lloyd D.
As a result of the growing use of multiple geochemical proxies to reconstruct ocean and climate changes in the
past, there is an increasing need to establish temporal relationships between proxies derived from the same marine sediment
record and ideally from the same core sections. Coupled proxy records of surface ocean properties, such as those based on
lipid biomarkers (e.g. alkenone-derived sea surface temperature) and planktonic foraminiferal carbonate (oxygen isotopes),
are a key example. Here, we assess whether 2 different solvent extraction procedures used for isolation of molecular biomarkers
influence the radiocarbon contents of planktonic foraminiferal carbonate recovered from the corresponding residues
of Bermuda Rise and Cariaco Basin sediments. Although minor Δ14C differences were observed between solvent-extracted
and unextracted samples, no substantial or systematic offsets were evident. Overall, these data suggest that, in a practical
sense, foraminiferal shells from a solvent-extracted residue can be reliably used for 14C dating to determine the age of sediment
deposition and to examine age relationships with other sedimentary constituents (e.g. alkenones).