DELTA-C-13 MEASUREMENTS FROM THE IRISH OAK CHRONOLOGY

Measurements of the stable isotope ratio C-13/C-12, relative to PDB, w ere 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 f rom the calibration work, carried out some further measurements to inv estigate anomalies in the original results, and generated tables of da ta that include site and tree information pertaining to both stable is otopes and source material for C-14 calibration measurements. The data suggest that land-grown trees tend to be isotopically lighter than bo g-grown wood, and that the Irish trees used in the calibration exercis e tend to. be isotopically heavier than those from Scotland and Englan d. Preliminary analysis of the data is given.