Researchers studying the origins of Stonehenge’s Altar Stone have proposed a new possibility for how the enormous rock began its journey from Scotland to southern England.
A team from Sheffield Hallam University and Curtin University, Australia, analyzed ancient ice movement and found that glaciers during Britain’s last ice age may have transported the stone from Scotland’s Orcadian Basin as far as Dogger Bank in the North Sea. From there, however, people would still have had to move it hundreds of kilometers to Salisbury Plain.
Stonehenge’s central Altar Stone is a six-tonne sandstone megalith that researchers now believe came from northeast Scotland, roughly 700 km (435 miles) from Stonehenge. Its distant origin has raised one of the monument’s most intriguing questions: how did such an enormous stone travel so far?
Tracing the Altar Stone From Scotland
To reconstruct the possible route, researchers combined mineral grain dating with computer models of ancient ice sheets. This allowed them to investigate both where the stone originated and whether glaciers could realistically have carried it south.
Dr. Remy Veness, co-lead author of the paper from Sheffield Hallam University, said: “We recently discovered that the origin of the Altar Stone is northeast Scotland, but how it traveled 700 km to Salisbury Plain is widely debated.
“Our research gives a new plausible explanation for part of the journey to Salisbury Plain.
“What is exciting about these findings is that they could imply that the people of Doggerland attached cultural significance to the Altar Stone long before it was incorporated into Stonehenge. Hypothetically, the Altar Stone could have been significant enough to be willing to move the stone at least twice; First to potentially save it from being submerged by rising sea levels at the end of the last ice age and then again to its final resting place on Salisbury Plains.”
A Possible Stop in Lost Doggerland
Doggerland was a Neolithic landscape off the east coast of England that is now submerged beneath the North Sea. Because the area had no natural rock outcrops, any large stones found there would have had to arrive from somewhere else, potentially carried by glaciers.
The researchers suggest the Altar Stone could have been deposited in the Dogger Bank region by ice. People living in the area may then have moved it again as the landscape changed and sea levels rose.
From Doggerland, the stone could eventually have been transported toward the Berkshire Ridgeway, regarded as the oldest road in Europe. The route was in use around the time Stonehenge was built and may have provided an important corridor toward Salisbury Plain.
Glaciers Could Only Explain Part of the Journey
Co-lead author Dr. Anthony Clarke, from the Timescales of Minerals Systems Group within Curtin’s School of Earth and Planetary Sciences, said the evidence points toward a complicated journey involving multiple stages rather than one simple route.
“Rather than being carried naturally by ice, the evidence points to a deliberate, carefully planned movement across a challenging and varied landscape,” Dr. Clarke said.
“Our modeling shows glaciers may have transported rocks part of the way during the last Ice Age — potentially as far as Dogger Bank in the North Sea — but not into southern England, meaning the stone would still have needed to be moved hundreds of kilometers by people.
“The research indicates there were no viable glacial pathways linking the source region directly to Stonehenge, reinforcing the conclusion that human transport was required.
“Instead, this suggests the stone was likely moved in stages, potentially combining overland hauling with river or coastal transport where possible.”
A Remarkable Neolithic Transport Effort
If the proposed route is correct, moving the Altar Stone to Stonehenge would have demanded significant cooperation among Neolithic communities. Transporting such a large rock through different landscapes over hundreds of kilometers would have required careful organization and detailed knowledge of possible routes.
Dr. Clarke said the findings point to a level of planning and coordination that may not have been fully appreciated before.
“Transporting a stone of this size over such a long distance would have required planning, coordination and a deep understanding of the landscape — not to mention tremendous determination,” Dr. Clarke said.
“The study demonstrates how combining geological analysis with computer modeling can help resolve long-standing questions about how Stonehenge was built.”
Researchers now hope to narrow down the Altar Stone’s precise source in northeast Scotland and investigate in greater detail the routes prehistoric communities may have used to move it south.
The research was co-led by Sheffield Hallam University and Curtin University, in collaboration with experts from the University of Sheffield, Wessex Archaeology, and the University of Bristol.