A new study has ruled out a theory that the six-tonne Altar Stone at Stonehenge originated in north-east Scotland. The 4.9-metre sandstone slab was previously believed to have come from Wales, before a more recent study suggested a north-east Scotland origin.
Scientific tests conducted in the Orcadian Basin area of Scotland failed to find a location matching the stone's characteristics. Professor Duncan Pirrie from the University of South Wales, who led the latest investigation, stated the team is now "far better equipped to focus on the areas most likely to yield an answer."
Professor Nick Pearce from Aberystwyth University, who worked on previous research, noted that "ruling out potential source areas is just as important as identifying new ones." He added that eliminating locations narrows the search and brings researchers closer to discovering the Altar Stone's origin, which would provide insights into its journey to Salisbury Plain.
The study, published in the Journal of the Geological Society, combined new observations with examinations of stone fragments in museum collections, focusing on structure, minerals, and composition.