A powerful cosmic ray dramatically increased the levels of radioactive carbon in a region of Greece around 5259 BCE.
According to SciTech Daily, a research team from the University of Bern (Switzerland) utilized a method of measuring spikes in radioactive carbon in tree rings caused by cosmic rays to date a prehistoric Greek settlement to over 7,000 years ago.
This new method promises to open a gateway for accurately dating many other archaeological sites in Southeastern Europe.
The wooden stilt field at Dispilio with 800 wooden posts from the ancient settlement. The logs used as wooden posts inadvertently recorded details of the cosmic ray impact over 7,000 years ago – (Photo: UNIVERSITY OF BERN).
The aforementioned Greek village – named Dispilio – has been discovered for quite some time and provides evidence of one of the oldest agricultural settlements in the region.
However, when the people here began to farm in a manner similar to how we do today remains an intriguing mystery.
In Europe, some sites can be dated using tree rings, which reflect changes in climate patterns, but not all can, according to lead author Andrej Maczkowski from the Archaeological Science Institute at the University of Bern.
However, there is another aspect that tree rings can record, which is the carbon isotope 14C from cosmic rays. Trees absorb this while alive and cease to absorb it upon death.
Searching for tree rings that are “saturated” with this isotope and examining how it decays over time can help pinpoint when the cosmic rays struck the Earth.
By cross-referencing the lifespan of the trees and how they were used in wooden structures, researchers can determine the age of the settlement.
The research team from the EXPLO project, led by the University of Bern, successfully established the dating of annual growth rings spanning 303 years, ending in 5140 BCE, by analyzing 787 wooden fragments from the archaeological site of Dispilio on Lake Orestida in Northern Greece.
The identified phases of settlement indicate various building activities over more than 188 years, from 5328 to 5140 BCE.
The basis for this data is a significant geomagnetic event – caused by the impact of cosmic rays – occurring in 5259 BCE.
“We hope that other dates in the region from this period can now be quickly linked to the Dispilio Chronology. This paves the way for regional dating studies for the southern Balkan region,” the authors stated.
In the Balkans, there are some of the oldest lakeside settlements in Europe, with dates just after 6000 BCE. This area played a crucial role in the expansion of agriculture in prehistoric Europe, contributing to the foundation of modern civilization.
