~(14)C AGES OF 43 CONSECUTIVE SINGLE-YEAR TREE RINGS BETWEEN 2710 AND 2655 CAL BP USING ACCELERATOR MASS SPECTROMETRY

摘要

We have measured the radiocarbon ages of 43 consecutive single-year tree rings using accelerator mass spec-trometry (AMS) with a statistical accuracy of approx 2.3 per thousand. AMS ~(14)C ages of the 36 viable samples are between 2708 and 2666 cal BP, a period in which the DELTA ~(14)C of the IntCal04 curve (Reimer et al. 2004) shows an enhancement. The ~(14)C ages of the samples are scattered with a Gaussian distribution around the interpolated IntCal04 calibration curve. The time profile of the deviations of the 36 ~(14)C ages from the interpolated IntCal04 calibration curve indicates a linear trend and a characteristic variability rather than a random fluctuation around the curve. The trend indicates a higher gradient than that of the interpolated IntCal04 calibration curve. The profile implies a periodic variation of approximately 11 yr and an amplitude of roughly 18 ~(14)C yr.