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Refining Background Corrections for Radiocarbon Dating of Bone Collagen at Orau

Published online by Cambridge University Press:  18 July 2016

R E Wood*
Affiliation:
Oxford Radiocarbon Accelerator Unit, Research Laboratory for Archaeology and the History of Art, University of Oxford, Oxford, United Kingdom
C Bronk Ramsey
Affiliation:
Oxford Radiocarbon Accelerator Unit, Research Laboratory for Archaeology and the History of Art, University of Oxford, Oxford, United Kingdom
T F G Higham
Affiliation:
Oxford Radiocarbon Accelerator Unit, Research Laboratory for Archaeology and the History of Art, University of Oxford, Oxford, United Kingdom
*
Corresponding author. Email: [email protected]
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Abstract

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During the laboratory pretreatment of samples for radiocarbon dating, small amounts of carbon may be added to a sample. Contamination can be incorporated at any stage: during chemical pretreatment, combustion to CO2, graphitization, or accelerator mass spectrometry (AMS) measurement. Such carbon contamination is often modern in age, and so can have an especially severe effect on samples older than ∼25 ka BP. During the extraction of collagen from bone using the ultrafiltration protocol at the Oxford Radiocarbon Accelerator Unit (ORAU), small amounts of young carbon are added to the sample. Currently, this contamination is poorly characterized when less than 10 mg of collagen is extracted from a bone. Demand to date small collagen samples with 14C concentrations that approach the detection limit of AMS measurement has increased recently with the growing interest in, for example, directly dating Neanderthal remains and Upper Paleolithic bone artifacts. This paper aims to reduce the minimum collagen sample size required to produce a reliable date from 10 to 5 mg by re-examining the combustion background and subsequently the pretreatment background for bone. The average of 136 measurements of directly combusted nylon suggests that 0.0007 ± 0.001 mg of modern carbon is added to each sample, although the distribution is positively skewed. Regression analysis of the measurements of 52 collagen samples extracted from a bone of background age results in a background of just less than 50,000 BP for bone treated at ORAU.

Type
Bone Dating and Paleodiet Studies
Copyright
Copyright © 2010 by the Arizona Board of Regents on behalf of the University of Arizona 

References

Brock, F, Bronk Ramsey, C, Higham, TFG. 2007. Quality assurance of ultrafiltered bone dating. Radiocarbon 49(2):187–92.Google Scholar
Brock, F, Higham, TFG, Ditchfield, P, Bronk Ramsey, C. 2010. Current pretreatment methods for AMS radiocarbon dating at the Oxford Radiocarbon Accelerator Unit (ORAU). Radiocarbon 52(1):103–12.Google Scholar
Bronk Ramsey, C. 1995. Radiocarbon calibration and analysis of stratigraphy: the OxCal program. Radiocarbon 37(2):425–30.CrossRefGoogle Scholar
Bronk Ramsey, C. 2001. Development of the radiocarbon calibration program. Radiocarbon 43(2A):355–63.Google Scholar
Bronk Ramsey, C, Higham, T, Bowles, A, Hedges, R. 2004a. Improvements to the pretreatment of bone at Oxford. Radiocarbon 46(1):155–63.Google Scholar
Bronk Ramsey, C, Higham, TFG, Leach, P. 2004b. Towards high-precision AMS: progress and limitations. Radiocarbon 46(1):1724.CrossRefGoogle Scholar
Brown, TA, Nelson, DE, Vogel, JS, Southon, JR. 1988. Improved collagen extraction by the modified Longin method. Radiocarbon 30(2):171–7.Google Scholar
de Rooij, M, van der Plicht, J, Meijer, HA. 2008. Sample dilution for AMS 14C analysis of small samples (20–150 μg C). Radiocarbon 50(3):413–36.CrossRefGoogle Scholar
Dee, M, Bronk Ramsey, C. 2000. Refinement of graphite target production at ORAU. Nuclear Instruments and Methods in Physics Research B 172(1–4):449–53.Google Scholar
Gupta, SK, Polach, HA. 1985. Radiocarbon Dating Practices at ANU. Handbook , Radiocarbon Dating laboratory Research School of Pacific Studies, ANU. Canberra. 173 p.Google Scholar
Higham, TFG, Jacobi, RM, Bronk Ramsey, C. 2006a. AMS radiocarbon dating of ancient bone using ultrafiltration. Radiocarbon 48(2):179–95.Google Scholar
Higham, T, Bronk Ramsey, C, Karavanic, I, Smith, FH, Trinkaus, E. 2006b. Revised direct radiocarbon dating of the Vindija G1 Upper Paleolithic Neandertals. Proceedings of the National Academy of Sciences of the United States of America 103(3):553–7.Google Scholar
Hüls, CM, Grootes, PM, Nadeau, M-J. 2009. Ultrafiltration: Boon or bane? Radiocarbon 51(2):613–26.CrossRefGoogle Scholar
Jacobi, RM, Higham, TFG, Bronk Ramsey, C. 2006. AMS radiocarbon dating of Middle and Upper Palaeolithic bone in the British Isles: improved reliability using ultrafiltration. Journal of Quaternary Science 21(5):557–73.CrossRefGoogle Scholar
Jacobi, RM, Higham, TFG. 2008. The “Red Lady” ages gracefully: new ultrafiltration AMS determinations from Paviland. Journal of Human Evolution 55(5):898907.Google Scholar
Jacobi, RM, Higham, TFG. 2009. The early Lateglacial recolonization of Britain: new radiocarbon evidence from Gough's Cave. Quaternary Science Reviews 28(19–20):1895–913.Google Scholar
Jöris, O, Álavarez Fernández, A, Weninger, B. 2003. Radiocarbon evidence of the Middle to Upper Palaeolithic transition in southwestern Europe. Trabajos de Prehistoria 60(2):1538.Google Scholar
Kirner, DL, Taylor, RE, Southon, JR. 1995. Reduction in backgrounds of microsamples for AMS 14C dating radiocarbon. Radiocarbon 37(2):697704.CrossRefGoogle Scholar
Staff, R, Brock, F, Chivall, D, Ditchfield, P, Humm, M, Leach, P, Bronk Ramsey, C. 2009. Method development for very small mass samples at the Oxford Radiocarbon Accelerator Unit [abstract #92]. 20th International Radiocarbon Conference, 31 May-5 June 2009, Kona, Hawaii, USA.Google Scholar
Tisnérat-Laborde, N, Valladas, H, Kaltnecker, E, Arnold, M. 2003. AMS radiocarbon dating of bones at LSCE. Radiocarbon 45(3):409–19.Google Scholar
van Klinken, GJ. 1999. Bone collagen quality indicators for palaeodietary and radiocarbon measurements. Journal of Archaeological Science 26(6):687–95.Google Scholar
Vogel, JS, Nelson, DE, Southon, J. 1987. 14C background levels in an AMS system. Radiocarbon 29(3):323–33.CrossRefGoogle Scholar
Waterbolk, HT. 1971. Working with radiocarbon dates. Proceedings of the Prehistoric Society 37:1533.Google Scholar
Westgate, JA, Preece, SJ, Froese, DG, Pearce, NJG, Roberts, RG, Demuro, M, Hart, WK, Perkins, W. 2008. Changing ideas on the identity and stratigraphic significance of the Sheep Creek tephra beds in Alaska and the Yukon Territory, northwestern North America. Quaternary International 178(1):183209.CrossRefGoogle Scholar