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On Correcting 14C Ages of Gastropod Shell Carbonate for Fractionation

Published online by Cambridge University Press:  18 July 2016

Jeffrey S Pigati
Jeffrey S Pigati*
Affiliation:
Desert Laboratory and Geosciences Department, University of Arizona, Tucson, Arizona 85721, USA. Email: jpigati@geo.arizona.edu.
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Abstract

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Correcting the 14C age of a sample for fractionation is straightforward if the measured carbon was derived entirely from the atmosphere, either directly or through chemical and/or biological reactions that originated with atmospheric carbon. This correction is complicated in the case of gastropods that incorporate carbon from limestone or secondary carbonate (e.g. soil carbonate) during shell formation. The carbon isotopic composition of such gastropod shells is determined by fractionation, as well as mixing of carbon from sources with different isotopic values. Only the component of shell carbonate derived from atmospheric carbon should be corrected for fractionation. In this paper, the author derives a new expression for correcting the measured 14C activity of gastropod shells for fractionation, and describe an iterative approach that allows the corrected 14C activity and the fraction of shell carbonate derived from atmospheric carbon to be determined simultaneously.

Type
Articles
Information
Radiocarbon , Volume 44 , Issue 3 , 2002 , pp. 755 - 760
Copyright
Copyright © The Arizona Board of Regents on behalf of the University of Arizona 

References

Clark, ID, Fritz, P. 1997. Environmental isotopes in hydro geology. CRC Press LLC, Boca Raton, FL, 328 pp.Google Scholar
Donahue, DJ, Linick, TW, Jull, AJT. 1990. Isotope-ratio and background corrections for accelerator mass spectrometry radiocarbon measurements. Radiocarbon 32(2):135–142.CrossRefGoogle Scholar
Goodfriend, GA, Hood, DG. 1983. Carbon isotope analysis of land snail shells: implications for carbon sources and radiocarbon dating. Radiocarbon 25(3):810–830.CrossRefGoogle Scholar
Linick, TW, Jull, AJT, Toolin, LJ, Donahue, DJ. 1986. Operation of the NSF-Arizona Accelerator Facility for radio-isotope analysis and results from selected collaborative research projects. Radiocarbon 28(2a): 522–533.CrossRefGoogle Scholar
Manning, MR, Lowe, DC, Melhuish, WH, Sparks, RJ, Wallace, G, Brenninkmeijer, CAM, McGill, RC. 1990. The use of radiocarbon measurements in atmospheric studies. Radiocarbon 32(l):37–58.CrossRefGoogle Scholar
Meijer, HAJ, van der Plicht, J, Gislefoss, JS, Nydal, R. 1995. Comparing long term atmospheric 14C and 3H records near Groningen, the Netherlands with Fruholmen, Norway and Izana, Canary Islands 14C stations. Radiocarbon 37(l):39–50.CrossRefGoogle Scholar
Pigati, JS, Shanahan, TM, Quade, J, Haynes, CV Jr. Radiocarbon dating of minute gastropods and new constraints on the timing of late Quaternary spring-discharge deposits in southern Arizona, USA. Palaeogeography, Palaeoclimatology, Palaeoecology, submitted.Google Scholar
Romanek, CS, Grossman, EL, Morse, JW. 1992. Carbon isotopic fractionation in synthetic aragonite and calcite: effects of temperature and precipitation rate. Geochimica et Cosmochimica Acta 56:419–430.CrossRefGoogle Scholar
Rubinson, M, Clayton, RN. 1969. Carbon-13 fractionation between aragonite and calcite. Geochimica et Cosmo chimica Acta 33:997–1002.CrossRefGoogle Scholar
Stott, LD. 2002. The influence of diet on the δ13C of shell carbon in the pulmonate snail Helix aspersa. Earth and Planetary Science Letters 195(3–4):249–259.CrossRefGoogle Scholar
Wigley, TML, Muller, AB. 1981. Fractionation corrections in radiocarbon dating. Radiocarbon 23(2):173–190.CrossRefGoogle Scholar