DELTA-C-13 MEASUREMENTS FROM THE IRISH OAK CHRONOLOGY

Measurements of the stable isotope ratio C-13/C-12, relative to PDB, were made for fractionation correction purposes on all oak samples used in the Irish oak C-14 calibration curve. Stable isotope data have not been published previously. We have collated the stable isotope data from the calibration work, carried out some further measurements to investigate anomalies in the original results, and generated tables of data that include site and tree information pertaining to both stable isotopes and source material for C-14 calibration measurements. The data suggest that land-grown trees tend to be isotopically lighter than bog-grown wood, and that the Irish trees used in the calibration exercise tend to. be isotopically heavier than those from Scotland and England. Preliminary analysis of the data is given.