A new study has offered a fresh explanation for one of Stonehenge's enduring mysteries: how its so-called altar stone travelled hundreds of miles to reach the famous monument. According to Sky News, researchers at Curtin University in Australia conducted the work to uncover how the stone seemingly journeyed around 435 miles. The findings were discussed with Remy Vaness, a lecturer in glaciology at Sheffield Hallam University and co-lead author of the paper.
As explained on Sky News, the altar stone is what experts call a blue stone, one of the component stones that make up Stonehenge. What makes it especially intriguing is its origin, because it comes from north-east Scotland. That makes it the most far-travelled not only of the blue stones but of any of the stones at Stonehenge, a distance that has long puzzled researchers trying to understand how it arrived.
According to Sky News, there have been many theories about how the stone reached the site in southern England. Some have suggested that people used rollers to haul it overland, while others have proposed that it came by water or across the sea. The new research set out to test a different possibility, namely that nature, rather than human effort alone, did much of the early heavy lifting.
Vaness, a glaciologist, told Sky News that her contribution involved modelling the potential for ice to transport the altar stone toward Stonehenge. The work concluded that it was not possible for ice to move the stone the entire way. However, it found that glaciers did move rocks to an area known as Doggerland, or Doggerbank, off the coast of the North Sea, which roughly halved the total distance that humans would later have needed to cover.
Explaining the mechanism, Vaness said that Britain, as an island, was once covered by a massive body of ice, and that this ice flowed much like a river. According to Sky News, she compared it to throwing a stick into a river and watching it be carried along. In much the same way, the altar stone is thought to have been picked up as a single rock and transported all the way to Doggerland.
According to Sky News, the stone was then deposited on a hill, a topographic rise described as a moraine. Doggerland, an area many people may recognise from its mention in the shipping forecast, is now underwater. That detail raises the question of how the stone completed the remainder of its journey from there to its final position at Stonehenge.
According to Sky News, that final stretch would have had to be carried out by humans, and the researchers believe it happened in multiple stages. Vaness said people likely moved the stone first as sea levels rose, and then moved it again to its final resting point. The study therefore points to a combination of natural ice movement and human effort behind the journey of one of Stonehenge's most travelled stones.