New theory on how six‑tonne Stonehenge rock was transported from Scotland thousands of years ago: On a glacier
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Built from stones weighing between 2 and 25 tonnes (2 to 28 tons), the structure of Stonehenge demonstrates a scale of construction hard to imagine before the invention of the wheel. The mystery deepens when you consider that the stones are not from the local bedrock. So why these stones, and how did they get there?
Recent work I carried out with geochemist Anthony Clarke from Curtin University in Australia might have an answer to these two questions for Stonehenge's most far-traveled stone—the Altar Stone.
The Altar Stone was sourced from 700 km (435 miles) away in northeast Scotland, from a region of bedrock geology known as the Orcadian Basin that was once a lake called Lake Ocradie. The sandstone of the Altar Stone was formed from these lake sediments. Now, new work by our international team has tested the possibility that it was transported by glaciers.
It is the largest and heaviest of the so-called bluestones (Stonehenge's traveled rocks), weighing 6 tonnes (6.6 tons) and measuring 4 meters (13 feet) long. The bluestones were the first stones at Stonehenge, predating the larger stones that form the arches by 2,000 years.
We know the north of the UK was covered by ice until approximately 15,000 years ago, at the end of the last ice age. This ice was so thick and persistent that it flowed like a slow-moving river, picking up and carrying rock and debris with it. The team tested whether rocks from the Orcadian Basin could have traveled closer to Stonehenge if transported by this body of ice.
We studied this using a new numerical model, which I have been developing over the past five years to predict the possible deposit locations of glacially transported rocks (known as erratics). This showed that rocks transported from the Orcadian Basin could have been carried to a region off England's east coast called Dogger Bank.
Although today Dogger Bank is known for cod fishing and wind farms, it is thought to have once been a Neolithic site of significance as early humans moved from southern Europe north and west into the UK as the climate warmed at the end of the last ice age approximately 12,000 years ago. Dogger Bank represented a local topographic high point within the Doggerland region, rich in archaeological evidence.
What is interesting about Dogger Bank is that it is formed in part by a large glacial moraine (a ridge of rock and debris deposited by a glacier). This moraine marks the end of a glacial "conveyor belt," where a range of glacially transported rocks and boulders from the north would have been deposited during the last ice age.
To someone walking around Dogger Bank at the time, the site would probably have looked like something between a building demolition site and an interesting rock museum. We know Neolithic people were highly knowledgeable about rocks and selective about the stones they chose for tools. This suggests they might have deliberately chosen the Altar Stone for some of its attributes.
More recently, there are countless examples of people realizing that the landscape's glacial erratics were out of place. The Victorians in Britain, for example, chose the name "erratic" because of the rocks' unusual locations (at the time, they were thought to be the result of the biblical flood).
On the other side of the North Sea, Scandinavians know erratics as "troll stones," having realized these boulders came from the upland mountains. They used to think the only explanation was that they had been thrown hundreds of kilometers by playful trolls, with the early Swedish term for erratics (jättekast) literally translating to "giant throw." It's hard to say exactly what made the Neolithic people of Dogger Bank choose the Altar Stone. But if it was transported by ice to Dogger Bank, they would have needed to move it at least once before taking it 400 km (250 miles) to Stonehenge.
Doggerland was gradually flooded as large ice sheets around the world melted at the end of the last ice age. We know it stayed above sea level until around 8,000–9,000 years ago (perhaps even as late as 7,000 years ago). However, throughout that time, the landscape saw dramatic change. It transitioned from a land bridge connecting Europe to Britain to a small island, where the Altar Stone stood. This island eventually slipped below the sea, too.
This is interesting because Doggerland was inundated before the construction of Stonehenge. Therefore, the Altar Stone would have had to be transported to at least one intermediate site before finally being incorporated into Stonehenge.
Once the Altar Stone was safely on England's east coast, the idea that it was moved by humans to Salisbury Plain becomes more plausible. This distance would be roughly the same as that of the other bluestones, the next most far-traveled stones, but still 10 times the distance of the more locally sourced larger Sarsen Stones. Around the time of Stonehenge's construction, we know east-west travel was happening along the Berkshire Ridgeway, a Neolithic high route often touted as the oldest road in Europe, leading directly to Salisbury Plain.
Our recent study opens up a new hypothesis for how the Altar Stone could have traveled south to Stonehenge, and why people might have been motivated to first move the stone in response to rising sea levels threatening its initial site.
This work suggests that Neolithic people not only had the agency and coordination to move a large rock hundreds of kilometers, but also potentially realized that their landscape was changing and that they needed to act.
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Citation: New theory on how six‑tonne Stonehenge rock was transported from Scotland thousands of years ago: On a glacier (2026, July 28) retrieved 28 July 2026 from https://phys.org/news/2026-07-theory-sixtonne-stonehenge-scotland-thousands.html
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