Radiocarbon dating of recent water samples, aquatic plants, and animals, shows that age differences of up to 2000 14C years can occur within one river. Here, freshwater influence causes reservoir ages to vary between 250 and 700 14C years during the period 5400 BC - AD 700.

What happens in carbon dating?

Radiocarbon dating works by comparing the three different isotopes of carbon. Over time 14C decays to nitrogen (14N). Most 14C is produced in the upper atmosphere where neutrons, which are produced by cosmic rays, react with 14N atoms.