Old wood effect radiocarbon dating
I think that I shall never see, a sample of a plain old tree, a tree that's not been carved or painted, calcified, burned or otherwise tainted, But bones and shells and peat I get; preparing them all day I sweat.Won't someone please take pity on me, and send in just one plain old tree. A Rafter in Procs 6th international Radiocarbon Conf, Pullman, 1965. The quote given above illustrates the preference that radiocarbon daters have had with dating wood and wood charcoal materials.
In the late 1950's, the issue of presample age was identified as a causal factor in the difficulties encountered in accurately cross-dating the Julian calendar with that of the Yucatan Maya of Lowland Mexico.Charcoal and wood possess a high molecular weight, so rigorous pretreatments are able to be implemented without losing large amounts of sample.Its major source of error has been 'inbuilt', or 'presample' age (Mc Fadgen, 1982).Charcoal and wood are two of the most widely used materials for accelerator mass spectrometry (AMS) radiocarbon dating.
AMS labs prefer to carbon date charcoal and wood because these materials do not need complex pretreatment.The possibility that something (organic) was already in situ must always be considered, especially if the results appear suspiciously early.