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Radiocarbon Dating of Alkenones from Marine Sediments: II. Assessment of Carbon Process Blanks

Published online by Cambridge University Press:  18 July 2016

Gesine Mollenhauer ,
Daniel Montluçon  and
Timothy I Eglinton
Gesine Mollenhauer*
Affiliation:
Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543–1543, USA
Daniel Montluçon
Affiliation:
Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543–1543, USA
Timothy I Eglinton
Affiliation:
Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543–1543, USA
*
Corresponding author. Email: gmollenhauer@whoi.edu.
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Abstract

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We evaluate potential process blanks associated with radiocarbon measurement of microgram to milligram quantities of alkenones at the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility. Two strategies to constrain the contribution of blanks to alkenone 14C dates were followed: 1) dating of samples of known age and 2) multiple measurements of identical samples. We show that the potential contamination associated with the procedure does not lead to a systematic bias of the results of alkenone dating to either younger or older ages. Our results indicate that alkenones record Δ14C of ambient DIC with an accuracy of approximately 10‰. A conservative estimate of measurement precision is 17‰ for modern samples. Alkenone 14C ages are expected to be reliable within 500 yr for samples younger than 10,500 14C yr.

Type
Articles
Information
Radiocarbon , Volume 47 , Issue 3 , 2005 , pp. 413 - 424
Copyright
Copyright © 2005 by the Arizona Board of Regents on behalf of the University of Arizona 

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