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

The availability of absolutely (dendrochronologically) dated German oak has allowed the Belfast laboratory to extend its published high-precision 14 C measurements of Irish oak (Pearson et 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 the 14 C 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.