Radiocarbon: Calibration to Absolute Time Scale

Radiocarbon ages require correction due to fluctuations of atmospheric 14 C content. Research during the last 60 years has allowed construction of an experimental calibration curve for the last 50 000 years. Absolute and radiocarbon chronologies of various natural archives, such as trees (dendrochronology), provided a basis for the radiocarbon calibration curve. An overview of the historical background and construction of the calibration curve shows development in dating techniques. Calibration programs are available to all users allowing calibration of 14 C ages. A few examples from archaeology given in this chapter illustrate some problems of the calibration process. Tools such as the Bayesian modeling of calibration programs can help to reduce the effect of natural variability of 14 C, which resulted in wiggles of the calibration curve.