HBCO Correction: Its Impact on Archaeological Absolute Dating

Abstract

When constructing absolute chronologies in archaeology, the aim is to detect archaeological events. In this respect, we draw attention to the relation between the radiocarbon ages of human bone collagen samples and the absolute dating evidence on the age at death. In recent material, Mebus Geyh (2001a,b) described the offset between the former and the latter, and suggested the relevant correction. The corrected 14C ages pertain to the age of the individual at death.We have developed an application of Geyh's original observation, which we term the human bone collagen offset (HBCO) correction, to apply to archaeological 14C dates. If the death and interment of individuals are identical, the corrected 14C date reliably informs us about the deposition of the body and accompanying grave goods. In archaeology, the concrete correction value is determined by the anthropologically estimated age of the individual, which we model by a normal (Gaussian) distribution. The eventual impact of the HBCO correction on archaeological chronology depends on the portion of the calibration curve through which the HBCO-corrected date is calibrated. At a certain level of 14C measurement precision, the difference between the HBCO-corrected and non-corrected calendar dates can be considerable.

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