Radiocarbon dating belfast
But levels of carbon-14 in the atmosphere vary from year to year, so scientists need to calibrate their estimates using long-running records of radiocarbon levels.
Researchers from the School of Natural and Built Environment at Queen's have discovered that the monument is actually over 300 years older, dating from the 13th or 14th centuries, and is most likely the remains of a "lost" monastic round tower.
By providing a more precise record of this element in the atmosphere, the new data will make the process of carbon-dating more accurate, refining estimates by hundreds of years.
The data will allow archaeologists to better gauge the age of their samples and estimate the timing of important events such as the extinction of Neanderthals or the spread of modern humans through Europe.
“This dataset is the only continuous atmospheric record beyond the end of the tree rings,” said Paula Reimer, an archaeologist from Queen’s University Belfast in Northern Ireland who was not involved in the study.
It extends over virtually the entire timespan for which carbon-dating is used—as far back as 60,000 years or so, when the the carbon-14 in the sample has decayed to unreliable levels.