On Correcting 14C Ages of Gastropod Shell Carbonate for Fractionation
Issue Date
2002-01-01Keywords
uncertaintyextinct taxa
isotope fractionation
corrections
isotope ratios
living taxa
methods
C 14
carbon
isotopesradioactive isotopesshellsInvertebrataMolluscaC 13 C 12stable isotopesabsolute agecarbonatesGastropoda
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Pigati, J. S. (2002). On correcting 14C ages of gastropod shell carbonate for fractionation. Radiocarbon, 44(3), 755-760.Journal
RadiocarbonAdditional Links
http://radiocarbon.webhost.uits.arizona.edu/Abstract
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
Articletext
Language
enISSN
0033-8222Scopus Count
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