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Validity of Radiocarbon Dates on Terrestrial Snail Shells

Published online by Cambridge University Press:  20 January 2017

M. A. Tamers
M. A. Tamers*
Affiliation:
Instituto Venezolano de Investigaciones Científicas Caracas, Venezuela
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Abstract

Radiocarbon dating of terrestrial snail shells is examined. Three groups of samples, two from archaeological sites of Venezuela and one from the state of Texas, were taken as examples. The true ages were determined from radiocarbon dates on associated charcoal, and measurements on the snail shells allowed the errors to be determined. The groups showed completely different characteristics: 15 samples from Texas all had ages falsely old, 12 specimens of one Venezuelan group produced all correct dates, and another Venezuelan type with five samples gave dates all too recent. This study defines the directions and extents of errors for each group of snail shells, permitting them to be used as relatively reliable datable objectives in excavations where better materials are not available.

The possibility of correcting the radiocarbon dates using carbon-13 concentrations is considered, and 24 measurements are presented. It is concluded that more than one factor can influence the stable isotope concentrations in each case, and, therefore, carbon-13 is not useful for the improvement of the accuracy of snail shell dates.

Type
Research Article
Information
American Antiquity , Volume 35 , Issue 1 , January 1970 , pp. 94 - 100
Copyright
Copyright © Society for American Archaeology 1970

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References

Broecker, Wallace S. and Olson, Edwin A. 1959 Lamont Radiocarbon Measurements VI. American Journal of Science Radiocarbon Supplement, Vol. 1, pp. 111–32. New Haven.Google Scholar
Craig, Harmon 1953 The Geochemistry of the Stable Carbon Isotopes. Geochimica Cosmochimica Acta, Vol. 3, pp. 53–92. London.CrossRefGoogle Scholar
Epstein, J. F. 1963 Centipede and Damp Caves. Texas Archeology Society Bulletin, Vol. 33, pp. 1–129. Austin.Google Scholar
Jelks, Edward B. 1962 The Kyle Site. Department of Anthropology, University of Texas, Archaeology Series, No. 5. Austin.Google Scholar
Münnich, K. O., Roether, W., and Thilo, L. 1967 Dating of Groundwater with Tritium and C-14. In Isotopes in Hydrology, edited by the International Atomic Energy Agency, pp. 305–19. Vienna.Google Scholar
Pearson, F. J. Jr. 1965 Use of C-13/C-12 Ratios to Correct Radiocarbon Ages of Materials Initially Diluted by Limestone. United States Atomic Energy Commission Publication CONF-650652, pp. 357–66. Washington.Google Scholar
Rubin, Meyer, Likins, Robert C., and Berry, Elmer G. 1963 On the Validity of Radiocarbon Dates from Snail Shells. The Journal of Geology, Vol. 71, No. 1, pp. 84–9. Chicago.Google Scholar
Samos, George 1949 Some Observations on Exchange of CO2 between BaCOs and CO2 Gas. Science, Vol. 110, No. 2868, pp. 663–5. Washington.Google Scholar
Suhm, Dee Ann 1957 Excavations at the Smith Rockshelter, Travis County, Texas. Texas Journal of Science, Vol. 9, pp. 26–58. Austin.Google Scholar
Tamers, M. A. 1965a Routine Carbon-14 Dating Using Liquid Scintillation Techniques. Acta Cientifica Vene-zolana, Vol. 16, No. 5, pp. 156–62. Caracas.Google Scholar
Tamers, M. A. 1965b Instiruto Venezolano de Investigaciones Cientificas Natural Radiocarbon Measurements I. Radiocarbon, Vol. 7, pp. 54–65. New Haven.Google Scholar
Tamers, M. A., and Others 1964 University of Texas Radiocarbon Dates II. Radiocarbon, Vol. 6, pp. 138–59. New Haven.CrossRefGoogle Scholar
Waoner, Erika 1967 The Prehistory and Ethnohistory of the Carache Area in Western Venezuela. Yale University Publications in Anthropology, No. 71, pp. 1–107. New Haven.Google Scholar
Zucchi, Alberta 1965 Informe preliminar de las excavaciones del Yacimiento La Betania, Estado Barinas, Venezuela. Boletin Indigenista Venezolano, Vol. 10, pp. 155–68. Caracas.Google Scholar