Dendrochronology at Belfast as a Background to High-Precision Calibration

Abstract

The tree-ring program at Belfast originally aimed at the construction of a 6000-year oak chronology. The stimulus for this work came from the large numbers of sub-fossil oaks uncovered in Northern Ireland during land drainage and motorway construction in the late 1960's (Pilcher et al 1977). It became clear that any attempt to build such a long chronology would break naturally into two distinct units. One unit related to the construction of a prehistoric (BC era) chronology dependent on the sampling of large numbers of essentially random sub-fossil timbers. For this unit to be successful, timbers would have to survive relatively uniformly through time. The second chronology building unit was related principally to the AD era, with a natural extension into the first millennium BC at least. This unit was envisaged as the link between the present day and the necessarily floating sub-fossil chronologies. This AD chronology was based on modern, historic, and archaeologic timbers.