Researchers at the University of Bern have successfully pinpointed a prehistoric settlement of early farmers in northern Greece dating back over 7,000 years to 5259 BC by combining annual growth ring measurements on wooden building elements with the sudden spike of cosmogenic radiocarbon. This discovery provides a reliable chronological reference point for many other archaeological sites in Southeast Europe. Dating finds is crucial in archaeology, and while determining the age of prehistoric finds was once challenging, methods like dendrochronology and radiocarbon dating have made it possible to accurately date objects.
A team led by the Institute of Archaeological Sciences at the University of Bern has dated timber from the archaeological site of Dispilio in northern Greece to different building activities between 5328 and 5140 BC. Previously, dating to the year had not been possible at this site. By utilizing high-energy particles from space that can be reliably dated to 5259 BC, the researchers were able to establish a precise timeline for the construction phases at Dispilio. Their findings have been published in Nature Communications, shedding new light on the settlement’s history and contributing to the broader understanding of prehistoric societies in the region.
Dendrochronology uses patterns of annual growth rings in wood to date objects, but its applicability is limited by the availability of regional chronologies. Radiocarbon dating, on the other hand, relies on the decay rate of the radioactive carbon isotope 14C to estimate the age of finds. While dendrochronological dating in the Mediterranean region is considered ‘floating’ due to the lack of consistent chronologies, the discovery of cosmic ray-induced spikes in 14C content by Japanese physicist Fusa Miyake in 2012 provided a new method for dating archaeological sites without established chronologies. These spikes serve as important anchor points for dating.
The Miyake event in 5259 BC has enabled researchers to date the settlement phases at Dispilio and connect them to a global event that can be accurately dated using long tree-ring chronologies. By analyzing timber samples from Dispilio, the research team was able to establish an annual growth ring chronology dating back to 5140 BC, aligning it with the known spike in radiocarbon content in 5259 BC. This breakthrough has allowed archaeologists to establish a precise timeline for the settlement’s construction activities, providing a valuable reference point for dating other sites in the region.
The success of dating the Dispilio site independently of a consistent regional calendar marks a significant advancement in prehistoric archaeology, particularly in the Balkans. This paradigm shift opens up the possibility of developing a regional dendrochronology for the southern Balkans, linking other chronologies from the period to the newly established ‘Dispilio Chronology.’ As the oldest lakeside settlements in Europe, the Balkans have played a key role in the spread of agriculture on the continent, making the accurate dating of sites in this region crucial for understanding the development of early farming societies in Europe.