Radiocarbon calibration by means of mass spectrometric 230Th/234U and 14C ages of corals:: An updated database including samples from Barbados, Mururoa and Tahiti

As first shown by Bard et al. (1990a), high-precision Th-230-U-234 ages can be used successfully to calibrate the radiocarbon time scale beyond the high-precision tree-ring calibration that now reaches 11,900 cal sp (Kromer and Spurk 1998). Using mass spectrometric techniques, we measured C-14 and Th-230 ages on new samples collected from boreholes drilled off the islands of Tahiti and Mururoa (French Polynesia) in order to complement the database previously obtained on Barbados corals (Bard ct nl. 1990a, 1993).