The focus of the research is the Altar Stone, a six-ton sandstone megalith located at the center of Stonehenge. Previous work suggested the stone originated in northeast Scotland, roughly 700 kilometers (435 miles) from Salisbury Plain, making its presence at Stonehenge one of the most remarkable examples of long-distance transport in prehistoric Europe.

The latest findings strengthen the idea that ancient people, not natural forces, were responsible for moving the enormous stone across challenging terrain.

Tracing the Altar Stone's Ancient Journey

The study builds on earlier research that ruled out glaciers as the primary means of transporting the stone. To further investigate, scientists combined mineral grain dating techniques with computer models of ancient ice sheets. Their goal was to determine exactly where the stone came from and whether glaciers could have carried it southward during the last Ice Age.

According to the results, glaciers may have moved rocks from Scotland part of the way, possibly reaching Dogger Bank in what is now the North Sea. However, the models show there was no realistic glacial route that could have delivered the Altar Stone directly to southern England.

That leaves a significant portion of the journey unexplained by natural processes alone.

Evidence Points to Human Transport

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 indicates the stone's movement was intentional rather than accidental.

"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 Feat of Neolithic Organization

Moving a six-ton stone over such a vast distance would have been an enormous undertaking for Neolithic communities. Researchers believe the journey likely involved multiple stages and required careful coordination among groups living across different regions.

Dr. Clarke said the findings highlight a level of planning and cooperation that may have been greater than previously recognized.

"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 plan to continue investigating the Altar Stone's origins by identifying its precise source location in northeast Scotland and exploring the routes prehistoric people may have used to transport it.

The study involved collaboration between researchers from Curtin University, Sheffield Hallam University, the University of Sheffield, Wessex Archaeology, and the University of Bristol.