All scientists who study the late Quaternary are confronted by the problem of radiocarbon calibration. Since 1969, numerous high-frequency time series have been developed through the use of several stable isotopes (e.g., δ18O). Such time series are inefficient as dating methods because too many age possibilities are obtained for a given unique value. However, the Bayesian framework permits incorporation of these time series as a prior assumption on ages in order to improve calibrated ages obtained from a more precise absolute dating approach such as that using radiocarbon. The method is tested on data obtained from the Gigny cave (French Jura). Highly discontinuous posterior distributions are obtained with narrow highest posterior density regions. Thus, when the radiocarbon method alone gives large uncertainties, the incorporation of δ18O values of meteoric waters largely diminishes these uncertainties.