Inherited age of floating charcoal fragments in a sand-bed stream, Macdonald River, NSW, Australia: Implications for radiocarbon dating of sediments

Radiocarbon dates on multiple individual charcoal fragments floating together down the Macdonald River, New South Wales, Australia, have calibrated ages spanning >1700 years. Partial explanations of this range of inherited ages can be attributed to the inbuilt age of living biomass, charcoalisation conditions, hillslope transport and storage and/or valley floor (fluvial) transport and storage, but the contribution of each of these components can be constrained only rarely. These results caution against using radiocarbon dating of charcoal as the sole dating technique to interpret Late-Holocene sedimentary histories. These findings also show that it is unlikely that deposit age has a dependable relationship to charcoal age.

Automated summary

Radiocarbon dating of charcoal from the Macdonald River in Australia revealed calibrated ages spanning over 1700 years. The varying ages can be attributed to factors such as the age of living biomass, charcoalisation conditions, and transportation and storage processes. These findings caution against relying solely on radiocarbon dating of charcoal to interpret sedimentary histories and suggest that deposit age may not be reliably determined by charcoal age.