Problems encountered with the 14c dating of peat
Four fen peat sequences in northern Finland were dated by the accelerator mass spectrometry (AMS) radiocarbon method in order to study past peatland dynamics and carbon accumulation patterns.
Initially, plant macrofossils were used for dating.
For each slice the remaining peat was then split into humic acid, humin and fulvic acid fractions and radiocarbon dated.
This research demonstrates that significant variations can occur in the radiocarbon content of discrete chemically defined fractions of peat. The results from the four columns of peat are highly variable and mutually inconsistent.
Following these unreliable results, a few bulk peat samples were dated to help assess if any of the plant macrofossil-derived dates were reliable. This study evaluates the possible sources of error but is unable to single out one clear cause.