Ancient societies may have carved ‘sun stones’ to end volcanic winters

Hundreds of mysterious carved “sun stones” excavated in Denmark may have been ritually buried after the sun disappeared in a volcanic eruption around 2900 BC.

A total of 614 stone tablets and fragments inscribed with decorative motifs of the sun and plants were recently unearthed at the ruins of Basagal West on the Danish island of Bornholm. They were discovered in geological formations dating back some 4,900 years, when Neolithic people were farming the region and building enclosures surrounded by earthworks of banks and ditches.

Most of the carved sun stones were found in ditches around these enclosures, which were covered with cobblestones containing pottery shards and other items. This pottery is typical of the Late Funnel Beaker culture, which existed in the area from about 2900 to 2800 BC.

It was originally proposed that the stone carving of the Sun was buried to ensure a good harvest. According to Rune Iversen of the University of Copenhagen in Denmark, the early agricultural culture of Northern Europe was centered around the sun.

“But why did they store all these images at the same time?” Iversen asks. “What they basically ended up doing here was depositing these sun stones and covering them with animal bone fragments and all kinds of artifacts and stuff like that. And then it went from trench to trench. You can see it being repeated. So it’s some sort of action or event.”

Now he and his colleagues have found the answer. They looked at data from ice cores taken in Greenland and Antarctica and found that high concentrations of sulfate were deposited in the years following volcanic eruptions around 2900 BC.

The relative proportions of sulfate deposits in Greenland and Antarctica suggest that the eruption was somewhere close to the equator, and its effects appear to have spread over a vast area, the researchers said. Ash clouds may have blocked the sun and cooled temperatures for years.

A severe cold period around 2900 B.C. is supported by sources such as preserved wood rings from the Main River Valley in Germany and long-lived rock pine tree rings from the western United States.

This eruption would have had a devastating impact on the Neolithic peoples of northern Europe. “If we don’t have a harvest and the crop is not accepted, we won’t be able to sow anything next year,” Iversen says. “They must have felt quite punished at the time, because endless catastrophe was just going to befall them.”

He and his colleagues say burying the sculptures may have been an attempt to bring back the sun, or a celebration after the skies finally cleared.

“This is a good explanation,” says Jens Winter Johansen of Denmark’s Roskilde Museum. “There is no doubt that our staunchly agricultural society must trust the sun.”

Lars Larsson from Sweden’s Lund University wonders why, if climate impacts are widespread, evidence of such behavior is found only on Bornholm and not elsewhere in southern Scandinavia. I have doubts.

That may be because the people there had an abundance of slate, a hard stone with which to carve statues of the sun, whereas much of the rest of southern Scandinavia is mostly clay and has fewer stones suitable for carving. The body, Iversen says. “They may have carved wood or leather from other locations,” he says, but these would not normally have been preserved.

Or it may reflect cultural differences, Johansen says. “These societies are not isolated, but they are more isolated on the islands. That may be why they developed their own customs and culture.”