Calibration of the C-14 time scale: towards the complete dating range

Radiocarbon calibration based on dendro-chronology and U-series dated corals yield a calibration curve (INTCAL98) well into the Late Glacial, back to ca. 15,600 calendar years ago. Beyond this limit, various calibration curves are produced, mainly based on laminated sediments and various carbonates dated by U-series isotopes. Such calibration curves now cover the complete C-14 dating range of about 45,000 years, but are not consistent with each other. Each calibration method (other than dendro-chronology) has its own assumptions and pitfalls. Thus far, the calibration curve obtained from Lake Suigetsu laminated sediments is the only terrestrial (atmospheric) one