Stonehenge is partly Scottish, scientists have revealed, after investigations found the mysterious Altar Stone at the heart of the stone circle originated near Orkney.
Archaeologists already knew that the smaller bluestones in the Neolithic monument were mined in Welsh quarries 140 miles away, but new testing has shown the Altar Stone was brought 460 miles to Salisbury Plain from north-eastern Scotland.
And it is suspected the stone, which weighs six tons and is 6ft long, may have been shipped along the coast or up rivers to avoid having to drag it across the mountains and forests of Neolithic Britain.
Prof Richard Bevins, of the department of geography at Aberystwyth University, said: “These findings are truly remarkable – they overturn what had been thought for the past century. We can now say that this iconic rock is Scottish and not Welsh.
“The thing that is unique is the distance that the stones have been transported. Usually stones in stone circles are sourced locally, perhaps one mile or less, so Stonehenge is very different.”
Experts have known for some time that Stonehenge’s bluestones were brought from the Preseli Mountains in Wales, while the larger, more well-known sandstones come from within 15 miles of the 5,000-year-old monument.
It was assumed that the Altar Stone must also be Welsh, but scientists struggled to find a match for its geology in any outcrops.
After years of searching, they sought the help of experts in Australia, who used mineral and uranium readings to create a geological fingerprint which matched the red sandstone beds of the Orcadian Basin in northeast Scotland.
Finding the ‘perfect rock’
Anthony Clarke, from the timescales of mineral systems group at Curtin University, Australia, said: “Considering the technological constraints of the Neolithic, our findings raise fascinating questions about how such a massive stone was able to be transported over the vast distance implied.
“Given major overland barriers en route from north-east Scotland to Salisbury Plain, marine transport is one feasible option.
“I guess millionaires today adorn their mansions of marble from Italy. People have always had a fascination with finding the perfect rock and maybe the Neolithic people were the same, but their motivations are lost to time.”
The team has ruled out the theory that the stone could have been deposited by a glacier, because the ice sheets which covered the Orcadian Basin flowed northwards during the last Ice Age.
Dr Clarke added: “We know why the pyramids were built, but the purpose of Stonehenge will always be unknown so we have to turn to the rocks of the megaliths and the chemical insights that we can glean.
“The great unanswerable question of this work is why. It really is a mysterious endeavour that Neolithic humans undertook. It raises a lot more questions than it answers.”
The purpose of the Altar Stone is unknown, and archaeologists are unsure whether it always lay flat, or would have once stood erect.
Archaeologists have noted that as the sun set on Midwinter’s Day, the last rays of light would have fallen on the stone, perhaps marking the turning of the year and the return of lighter, warmer days.
It is also unclear when exactly the Altar Stone arrived at Stonehenge, but experts think it may have been placed within the central horseshoe of stones during the second construction phase around 2620 to 2480 BC.
Nick Pearce, professor of geochemistry at Aberystwyth University, said: “Hopefully, people will now start to look at the Altar Stone in a slightly different context in terms of how and when it got to Stonehenge, and where it came from.
“I am sure this will lead to some new thinking about the development of Stonehenge and its links to the rest of Neolithic Britain.
“There’s no doubt that this Scottish source shows a high level of societal organisation in the British Isles during the period. These findings will have huge ramifications for understanding communities in Neolithic times, their levels of connectivity and their transport systems.”
The origins of Stonehenge have baffled historians for many hundreds of years. In 1100, Geoffrey of Monmouth, the Catholic cleric and historian, wrote that Merlin had constructed the monument, while in 1640, John Aubrey, the philosopher, declared it the work of the druids.
In 1655, John Webb, the architect, claimed Stonehenge was a Roman temple to Caelus, the sky god, and it was not until the advent of radiocarbon dating that it was proven to be far older – dating from 3100 BC and constructed by early farmers who had migrated from Central Europe.
Recent isotope analysis of the skulls of people buried at Stonehenge show unmistakable Welsh origins. But the new research now shows there was a Scottish connection.
Dr Robert Ixer, of the UCL Institute of Archaeology, said: “This is a genuinely shocking result, but if plate tectonics and atomic physics are correct, then the Altar Stone is Scottish.
“The work prompts two important questions: why and exactly how was the Altar Stone transported from the very north of Scotland, a distance of more than 700 kilometres, to Stonehenge?”
The research was published in the journal Nature.
