An expanded radiocarbon age calibration procedure to correct for the marine reservoir effect in mixed marine and terrestrial samples

Recently, the importance of statistical and probabilistic analysis to derive accurate 14C data has been recognized. This paper discusses a 14C calibration procedure to correct marine reservoir effect using the marine source contribution estimated as a probability distribution. In addition, we also developed the marine source estimation with δ13C and δ15N for the 14C calibration in order to cover a complex mixture of terrestrial and marine carbon such as a human. In our calibration procedure, the 14C date is weighted with the probability distribution of marine source contribution and the calibrated date depended on the marine 14C intake can be evaluated. The age range calibrated by our procedure can be also reduced more than by conventional calibration methods. We illustrated the character of our calibration procedure by the example of human bones found from the archaeological shell mounds in Japan.