Stonehenge’s Altar Stone 'came from Scotland - not Wales'

It may have been transported around the coast by sea - implying that long-distance trade networks existed during the Neolithic period in Britain around 5,000 years ago, say scientists.

Previous geological research suggested that the six-tonne slab probably originated from the Brecon Beacons in south east Wales.

But the new study, led by Australian scientists, concluded that the monumental Altar Stone actually hails over 460 miles from Salisbury Plain in north east Scotland.

The Australian team used state-of-the-art equipment, including specialist mass spectrometers, to examine the composition of the Altar Stone.

View of Stonehenge showing the position of the buried 'Altar stone' (Image: Oli Scarff / SWNS)

Their findings, published in the journal Nature, also point to the existence of "unexpectedly advanced" transport methods and organisation at the time of the stone’s arrival in Wiltshire around 5,000 years ago.

Researchers from Curtin University in Perth, Western Australia, studied the age and chemistry of mineral grains within fragments of the Altar Stone, which is a 50 cm (19.6 ins) thick sandstone block measuring five metres by one metre (16 ft x 3ft), that sits at the centre of Stonehenge’s iconic stone circle.

Study lead author Anthony Clarke explained that analysis of the age and chemical composition of minerals within fragments of the Altar Stone matched it with rocks from Scotland, while also clearly differentiating them from Welsh bedrock.

Mr Clarke said: “Our analysis found specific mineral grains in the Altar Stone are mostly between 1,000 to 2,000 million-years-old, while other minerals are around 450 million years old.

“This provides a distinct chemical fingerprint suggesting the stone came from rocks in the Orcadian Basin, Scotland, at least 750 kilometres away from Stonehenge.

“Given its Scottish origins, the findings raise fascinating questions, considering the technological constraints of the Neolithic era, as to how such a massive stone was transported over vast distances around 2600 BC."

Mr Clarke, a PhD student within Curtin’s School of Earth and Planetary Sciences, added: “This discovery also holds personal significance for me. 

"I grew up in the Mynydd Preseli, Wales, where some of Stonehenge’s stones came from. 

"I first visited Stonehenge when I was one year old and now at 25, I returned from Australia to help make this scientific discovery – you could say I’ve come full circle at the stone circle.”

Study co-author Professor Chris Kirkland, also from the Timescales of Mineral Systems Group at Curtin, said the findings had "significant" implications for understanding ancient communities, their connections, and their transport methods.

Prof Kirkland said: "Our discovery of the Altar Stone’s origins highlights a significant level of societal coordination during the Neolithic period and helps paint a fascinating picture of prehistoric Britain.

“Transporting such massive cargo overland from Scotland to southern England would have been extremely challenging, indicating a likely marine shipping route along the coast of Britain.

“This implies long-distance trade networks and a higher level of societal organisation than is widely understood to have existed during the Neolithic period in Britain.”

The study was conducted in collaboration with Aberystwyth University in Wales, The University of Adelaide and University College London (UCL).

Co-author Professor Richard Bevins, of Aberystwyth University, said the findings overturned what had been thought for the past century.

He said: “We have succeeded in working out, if you like, the age and chemical fingerprints of perhaps one of the most famous of stones in the world-renowned ancient monument.

“While we can now say that this iconic rock is Scottish and not Welsh, the hunt will still very much be on to pin down where exactly in the north east of Scotland the Altar Stone came from.”

Co-author Dr Robert Ixer, of UCL's Institute of Archaeology, said the findings were "genuinely shocking" - but if plate tectonics and atomic physics were correct, then the Altar Stone is Scottish.

He added: “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?”