Errors in the radiocarbon dating of deposits in Finland from the time of deglaciation

Some radiocarbon dates of sediments from the area of the Salpausselkä moraines, and north of them in the area deglaciated after c. 10200 B.P., are too old and at variance with a number of radiocarbon dates for the regional pollen assemblage zones. Redeposited organic material is mainly responsible for the dates being too old, but an inliuence of the hard-water effect and of graphite can also be demonstrated. The age of the deglaciation is therefore likely to be in agreement with that suggested by the varve chronology and supported by most radiocarbon dates from organic deposits.