Radiocarbon Dating of Wood Using Different Pretreatment Procedures: Application to the Chronology of Rotoehu Ash, New Zealand
AuthorSantos, Guaciara M.
Bird, M. I.
Fifield, L. Keith
Alloway, B. V.
Hausladen, P. A.
accelerator mass spectroscopy
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CitationSantos, G. M., Bird, M. I., Pillans, B., Fifield, L. K., Alloway, B. V., Chappell, J., ... & Arneth, A. (2001). Radiocarbon dating of wood using different pretreatment procedures: Application to the chronology of Rotoehu Ash, New Zealand. Radiocarbon, 43(2A), 239-248.
DescriptionFrom the 17th International Radiocarbon Conference held in Jerusalem, Israel, June 18-23, 2000.
AbstractWe compare radiocarbon accelerator mass spectrometry (AMS) ages of wood samples subjected to a conventional acid-base-acid pretreatment with stepped combustion (ABA-SC) with results from the same samples subjected to an acid-base-wet oxidation pretreatment with stepped combustion (ABOX-SC) and cellulose extraction with stepped combustion (CE-SC). The ABOX-SC procedure has been shown previously to lead to lower backgrounds for old charcoal samples. Analyses of relatively uncontaminated " 14C-dead" samples of wood suggest that backgrounds of 0.11 +/0.04 pMC are obtainable for both the ABOX-SC and ABA-SC procedures. Where wood is significantly contaminated the ABOX-SC technique provides significantly better decontamination than either the ABA-SC technique or cellulose extraction alone, although CE-SC can produce comparably low backgrounds to the ABOX-SC procedure. We also report the application of the ABOX-SC, ABA-SC and CE-SC procedures to wood samples associated with the chronologically controversial Rotoehu Ash eruption, New Zealand. New 14C-AMS dates from wood sampled from below the Rotoehu Ash span an age range of 43-50 ka BP consistent with recently presented OSL dates of 42-44 ka obtained for palaeosols beneath the ash.