Scientists are closer to solving the mystery of where the massive Altar Stone at Stonehenge originated, with new research suggesting it may have come from northern England. For decades, experts debated whether the six-tonne sandstone slab was transported from west Wales or, more recently, from northeast Scotland.
A new investigation, led by Professor Duncan Pirrie from the University of South Wales, has focused on the geological unit known as the 'Old Red Sandstone.' The team's findings, published in the Journal of the Geological Society, indicate that the Altar Stone does not match geological samples from the Orcadian Basin in northeast Scotland, a previously favored location.
Instead, the research has narrowed the potential origins to a broad area encompassing southern Scotland and northern England. The Altar Stone is unique among Stonehenge's megaliths, distinguished by its sandstone composition, calcite cement, and the mineral baryte.
"Our work has suggested that we can rule out Wales," Professor Pirrie stated. "There are still some areas in the far north-east of Scotland that we need to check, so perhaps we cannot entirely rule out this area, although we haven't found anywhere yet in this region. So we are focusing on southern Scotland and northern England."
Identifying the stone's source could provide further insights into the capabilities of Neolithic people. "I think that we have perhaps rather lost sight of just how capable Neolithic people were," Professor Pirrie added. "Clearly moving a six–tonne stone significant distances is a testament to their engineering and organisational ability."
Professor Richard Bevins of Aberystwyth University noted that the latest study significantly refines the search by pinpointing specific geological characteristics. This allows future investigations to be more targeted, moving researchers closer to solving one of Stonehenge's enduring enigmas. The bluestones at Stonehenge are known to have come from the Preseli Hills in Pembrokeshire, approximately 140 miles away, while the larger sarsen stones are believed to be more locally sourced from the Marlborough Downs.