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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: [email protected].
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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 

References

Brown, TA, Southon, J. 1997. Corrections for contamination background in AMS 14C measurements. Nuclear Instruments and Methods in Physics Research B 123:208–13.Google Scholar
Eglinton, TI, Aluwihare, LI, Bauer, JE, Druffel, ERM, McNichol, AP. 1996. Gas chromatographic isolation of individual compounds from complex matrices for radiocarbon dating. Analytical Chemistry 68:904–12.Google Scholar
Eglinton, TI, Benitez-Nelson, BC, Pearson, A, McNichol, AP, Bauer, JE, Druffel, ERM. 1997. Variability in radiocarbon ages of individual organic compounds from marine sediments. Science 277:796–9.CrossRefGoogle Scholar
Engel, A, Zondervan, I, Aerts, K, Beaufort, L, Benthien, A, Chou, L, Delille, B, Gattuso, J, Harlay, J, Heemann, C, Hoffmann, L, Jacquet, S, Nejstgaard, J, Pizay, M, Rochelle-Newall, E, Schneider, U, Terbrueggen, A, Riebesell, U. 2005. Testing the direct effect of CO2 concentration on a bloom of the coccolithophorid Emiliania huxleyi in mesocosm experiments. Limnology and Oceanography 50:493–507.Google Scholar
Ingalls, A, Anderson, RF, Pearson, A. 2004. Radiocarbon dating of diatom-bound organic compounds. Marine Chemistry 92:91–105.Google Scholar
McNichol, AP, Osborne, EA, Gagnon, AR, Fry, B, Jones, GA. 1994. TIC, TOC, DIC, DOC, PIC, POC - unique aspects in the preparation of oceanographic samples for 14C-AMS. Nuclear Instruments and Methods in Physics Research B 92:162–5.Google Scholar
McNichol, AP, Jull, AJT, Burr, GS. 2001. Converting AMS data to radiocarbon values: considerations and conventions. Radiocarbon 43(2A):313–20.Google Scholar
Mollenhauer, G, Eglinton, TI, Ohkouchi, N, Schneider, RR, Müller, PJ, Grootes, PM, Rullkötter, J. 2003. Asynchronous alkenone and foraminifera records from the Benguela Upwelling System. Geochimica et Cosmochimica Acta 67:2157–71.Google Scholar
Mollenhauer, G, Kienast, M, Lamy, F, Meggers, H, Schneider, RR, Hayes, JM, Eglinton, TI. 2005. An evaluation of 14C age relationships between co-occurring foraminifera, alkenones, and total organic carbon in continental margin sediments. Paleoceanography 20: PA1016; doi:10.1029/2004PA001103.Google Scholar
Ohkouchi, N, Eglinton, TI, Keigwin, LD, Hayes, JM. 2002. Spatial and temporal offsets between proxy records in a sediment drift. Science 298:1224–7.Google Scholar
Ohkouchi, N, Eglinton, TI, Hayes, JM. 2003. Radiocarbon dating of individual fatty acids as a tool for refining Antarctic margin sediment chronologies. Radiocarbon 45(1):17–24.Google Scholar
Ohkouchi, N, Xu, L, Reddy, CM, Montluçon, D, Eglinton, TI. 2005. Radiocarbon dating of alkenones from marine sediments: I. Isolation protocol. Radiocarbon , this issue, p 401–12.Google Scholar
Pearson, A, Eglinton, TI. 2000. The origin of n-alkanes in Santa Monica Basin surface sediment: a model based on compound-specific Δ14C and δ13C. Organic Geochemistry 31:1103–16.Google Scholar
Pearson, A, McNichol, A, Schneider, RJ, von Reden, KF, Zheng, Y. 1998. Microscale AMS 14C measurement at NOSAMS. Radiocarbon 40(1):61–75.Google Scholar
Pearson, A, Eglinton, TI, McNichol, A. 2000. An organic tracer for surface ocean radiocarbon. Paleoceanography 15:541–50.Google Scholar
Prahl, FG, Wolfe, GV, Sparrow, MA. 2003. Physiological impacts on alkenone paleothermometry. Paleoceanography 18: doi:10.1029/2002PA000803.Google Scholar
Reddy, CM, Pearson, A, Xu, L, McNichol, AP, Benner, BA, Wise, SA, Klouda, GA, Currie, LA, Eglinton, TI. 2002. Radiocarbon as a tool to apportion the sources of poly-cyclic aromatic hydrocarbons and black carbon in environmental samples. Environmental Science and Technology 36:1774–82.Google Scholar
Smittenberg, RH, Hopmans, EC, Schouten, S, Hayes, JM, Eglinton, TI, Sinninghe Damsté, JS. 2004. Compound-specific radiocarbon dating of the varved Holocene sedimentary record of Saanich Inlet, Canada. Paleoceanography 19: doi:10.1029/2003PA000927.Google Scholar
Teuten, EL, Xu, L, Reddy, CM. 2005. Two abundant bio-accumulated halogenated compounds are natural products. Science 307:917–20.Google Scholar
von Reden, K, McNichol, A, Pearson, A, Schneider, RJ. 1998. 14C AMS measurements of <100μg samples with a high-current system. Radiocarbon 40(1):247–53.Google Scholar