PROBLEMS ENCOUNTERED WITH THE C-14 DATING OF PEAT

Pairs of neighbouring short columns of peat from two sites in Northern England were divided into contiguous 1 cm thick slices that were sub- sampled for pollen and plant macro fossil analysis. For each slice the remaining peat was then split into humic acid, humin and fulvic acid fractions and radiocarbon dated. This research demonstrates that signi ficant variations can occur in the radiocarbon content of discrete che mically defined fractions of peat. A total of 127 radiocarbon dates wa s obtained. The results from the four columns of peat are highly varia ble and mutually inconsistent. The fulvic acid fraction, although norm ally younger than the corresponding humic acid and humin fractions, ha s very little effect on a combined date in these samples. However, it is removed from all samples prior to dating in order to remove any car bonates which could contaminate samples. The variations in the ages ob tained for the humic acid and corresponding humin fractions range from the humin fraction being 630 years older than the humic acid (SRR-402 9) to the humic acid being 1210 years older than the humin fraction (S RR-4007), even when a two sigma confidence is allowed. No correlation was apparent between pollen concentration, C-13 enrichment, degree of humification and the conventional radiocarbon ages.