Radiocarbon and dendrochronology

The radiocarbon dating method relies on calibration through an independent dating method. Dendrochronology is an ideal partner of radiocarbon, because tree-rings are close-to-perfect archives of the atmospheric 14C level, and the tree-ring time scale can be built beyond doubt with high replication. Over the past 30 years, several stages of 14C calibration data sets have been constructed from the work of tree-ring laboratories in Europe and North America. This process is outlined and the present state is documented. In turn, 14C age fluctuations, caused mainly by helio-magnetic changes, can be used to anchor floating tree-ring sections to the calendar scale with a precision of a few decades.