Almost 15 years ago, archaeologists studied an island burial ground on Łańskie Lake (north-eastern Poland). Artefacts found in the graves indicated that the dead belonged to a farming community dating to around the third millennium BC. However, the C14 dates obtained from the bone, suggested that these people were 1,000 years older than the archaeologists had supposed.
After several years of investigation, the mystery was finally solved by Łukasz Pospieszny from the Institute of Archaeology and Ethnology PAS in Poznań.
The researcher focused on the grave of a young child whose bone was shown to be approx. 5600 years old, according to C14 dating.
“The method of burial and grave goods indicate that the community was part of the Corded Ware culture, who appeared in many parts of Europe 5,000 years ago at the earliest. They were mainly involved in animal husbandry, some scholars also consider them the oldest Indo-Europeans” said Dr. Pospieszny.
The reservoir effect
The researcher worked out that the C14 date was inconsistent with prior archaeological knowledge because of the so-called reservoir effect, associated with freshwater lakes.
“The C14 method is based on the carbon isotope analysis, the content of which in the atmosphere is quite stable and predictable. The situation is different in an aqueous environment, where old carbon can be present” explained Dr. Pospieszny.
According to the researcher, it was the diet of the deceased that influenced the surprising result – animals that exist in the water absorb old carbon atoms, and this transfers into humans after consumption. During the excavations, researchers from the Institute of Archaeology UW discovered large quantities of mussel shells and bones, which may lend credibility to this explanation.
In the child’s grave, intricately decorated artefacts made from deer antlers were discovered. Dr. Pospieszny decided to carry out C14 dating from one of them in order to compare it with the bone results. Deer do not eat food derived from the aquatic environment, so it would provide a good comparison. The result was within the expected range of approx. 4700 years, which was also consistent with the dating of similar finds from other archaeological sites.
However, the identity of the people buried in the cemetery still remains a mystery. Members of the Corded Ware culture did not fish, as demonstrated by isotopic analyses of bones found in other parts of Europe.
“In this respect, the people buried by Łańskie Lake are puzzling. Objects found in the graves indicate that the inhabitants of the island belonged to herder communities, but their diet was different” said Dr. Pospieszny.
The archaeologist thinks that these people may have been hunter gatherers living in this region for thousands of years, who only adopted some elements of agriculture.
“Mazury lakes were perfect for the old methods of obtaining food. Agriculture in the area was still limited over the next few centuries” Dr. Pospieszny concluded.
It may be possible to find out more about the people buried on the Łańskie Lake island when scientists complete DNA testing of the remains excavated from graves.
Above article written from materials provided by PAP
Freshwater reservoir effect and the radiocarbon chronology of the cemetery in Ząbie, Poland, has been published in the Journal of Archaeological Science.