Archaeologists studying Stonehenge have proposed a new theory on how one massive stone made its way across Britain to become part of the historical monument. The study focuses on the Altar Stone, a nearly 5,500kg sandstone megalith located at the center of Stonehenge.
Origin and transport
Previous research suggested the stone originated around 700 kilometres from Salisbury Plain, in northeast Scotland, making its feature in the monument a remarkable example of long-distance transport. However, the question long remained how exactly it got there.
The new study, carried out together by researchers from Australia's Curtin University and Sheffield Hallam University, suggests that ancient people, and not natural forces alone, were responsible for moving the heavy stone. The study builds on earlier research that ruled out glaciers as the primary means of transporting the stone.
Glaciers and human effort
Results from the investigation, which used a combination of mineral grain dating techniques with computer models of ancient ice sheets, show that glaciers may have moved the rock part way before help from people. It is believed that glaciers could have moved the rocks from Scotland, possibly to Dogger Bank in what is now the North Sea, but they could not have delivered the Altar Stone to southern England.
Co-lead of the study author Dr. Anthony Clarke, from the Timescales of Minerals Systems Group within Curtin's School of Earth and Planetary Sciences, said the evidence shows the stone was moved intentionally.
"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.
Implications for Neolithic communities
"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," he added. "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, the stone was likely moved in stages, potentially combining overland hauling with river or coastal transport where possible. This would have been an enormous undertaking for Neolithic communities and likely done in several stages.
Dr Clarke added that the levels of planning and cooperation may have been greater than previously thought. He said: "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."
The study demonstrates how combining geological analysis with computer modeling can help resolve long-standing questions about how Stonehenge was built.
