The Altar Stone at Stonehenge. Credit: English Heritage.
New research has revealed Stonehenge’s monumental six-tonne Altar Stone, long believed to originate from Wales, actually hails from Scotland.
Furthermore, the findings point to the existence of unexpectedly advanced transport methods and societal organisation at the time of the stone’s arrival at its current location in southern England about 5,000 years ago according to the study led by Curtin University, Australia.
Curtin researchers studied the age and chemistry of mineral grains within fragments of the Altar Stone, which is a 50cm thick sandstone block measuring 5 x 1 metres, that sits at the centre of Stonehenge’s iconic stone circle in Wiltshire.
Lead author, PhD student Anthony Clarke from the Timescales of Mineral Systems Group within Curtin’s School of Earth and Planetary Sciences, said analysis of the age and chemical composition of minerals within fragments of the Altar Stone matched it with rocks from northeast Scotland, while also clearly differentiating them from Welsh bedrock.
He 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 2,600 BC.”
Stonehenge. Credit: Public Domain.
Altar Stone’s origins
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 transportation methods.
“Our discovery of the Altar Stone’s origins highlights a significant level of societal co-ordination during the Neolithic period and helps paint a fascinating picture of prehistoric Britain.”
Professor Kirkland added: “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.”
Co-author Professor Richard Bevins from Aberystwyth University said the findings overturned what had been thought for the past century: “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.”
Dr Robert Ixer of the University College London Institute of Archaeology and also a co-author of the study, said the findings were genuinely shocking, but if plate tectonics and atomic physics were 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 full study titled ‘A Scottish Provenance for the Altar Stone of Stonehenge’ is published in the journal Nature.
