If you have a 200 year-old tree that is living today, a date on the bark represents today and a date on the centermost ring represents 200 years ago even though the tree is still alive. You only need to include the confirmation code in the package.
Therefore, the accuracy of the radiocarbon date depends upon where the wood came from within the tree.
Beta Analytic’s radiocarbon dating fees are inclusive of δ13C measurements by Isotope Ratio Mass Spectrometry (IRMS) and calendar calibration when applicable, δ18O for carbonates, and δD (deuterium) and δ18O for water.
The lab also offers C: N, %C and %N measurements on collagen extracted from non-cremated bones in addition to δ15N and δ13C at no additional cost for samples sent for radiocarbon dating.
Otherwise, it will be discarded upon completion of the analysis.
More details can be found on the Sample Retention and Return of Excess Materials page.
However, it may be actually somewhat older if recent organic materials have been incorporated into the pot due to mobilized humic acids.3 – Date the extractable tempering agents Dating organic tempering agents is possible when the organic material is either charred or the temperature of the firing process was not hot enough to burn it away.
Shell temper will be unaffected for firing temperatures less than 600°C.
Depending on the consistency of the soot, the pretreatments may be varied allowing for either acid or acid and alkali.
Accuracy relative to the time of use of the fires will depend upon the source of the soot.
NOTE – If you are not sure what might be dated for your pottery sherd, please contact us prior to sending your sample to the lab.