High-Precision 14C Measurement of German and Irish Oaks to Show the Natural 14C Variations from 7890 to 5000 BC

Abstract

The availability of absolutely (dendrochronologically) dated German oak has allowed the Belfast laboratory to extend its published high-precision14C measurements of Irish oak (Pearsonet al.1986) by 2680 yr. The samples were selected at contiguous 20-yr intervals, following a precedent adopted and considered satisfactory in previous publications. All samples were measured for at least 200,000 counts within the14C channel. The statistical counting error, together with the error on standards, backgrounds and applied corrections, give a realistic precision quoted on each sample of ± 2.5‰ (± 20 yr). This error is considered high-precision for sample ages of 7000–8000 BP.