Stonehenge has been a part of our history for centuries now, but the more we explore the more mysteries appear. Even when we think we have solved all the mysteries surrounding its construction, we always find something that does not fit and the questions are once again reopened. The last piece of the puzzle that has stopped making sense once again is the origin story of the Altar Stone, which was previously believed to have come from Wales but now evidence suggests it may have come from Scotland.
Let us rewind for a bit and look at the big picture. The current Stonehenge consists of more than 80 stones but we know that there are many missing from the original circle. These stones are classified into 11 categories, some of which only have one stone, that says something about where the stone was found or where it sits relative to others. There have been thorough investigations performed on all these stones over the decades finding their origins, purpose, weight and material, as contrary to popular belief not all stones used are the same type.
The current Stonehenge mystery, the Altar Stone
While we will never truly know the original purpose of any of the stones that make up Stonehenge, after all the origins of the circle itself are dubius to this day, the Altar Stone is one of the few that are not sarsen stones. It is instead a large slab of greenish Old Red Sandstone, which makes it quite different from the rest. It was found lying partially buried beneath two of the fallen stones of the largest trilithon and so we do not know if it was originally upright or of its position has always been laying down.
This impressive six-ton block of sandstone that measures 16 feet by 3 feet and is now situated in the center of the iconic Wiltshire circle, which made it quite easy to study, but it seems like despite the ease of access there is still a lot to learn.
A research team from Curtin University was the one responsible for reviving this particular mystery. The team studied the age and chemistry of mineral grains within fragments of the stone and managed to create a chemical fingerprint of the stone. This was done to once and for all determine the origine of the stone, as it is a unique fingerprint that all materials have depending on their composition and even the force of the magnetic field when they were created.
This chemical analysis proved that the stone matched that of rocks from northeast Scotland and not those from the Welsh bedrock, which is the origin that it had previously been attributed.
Anthony Clarke, lead author and Ph.D. student from the Timescales of Mineral Systems Group at Curtin’s School of Earth and Planetary Sciences gushed about the new discovery “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 kilometers [466 miles] away from Stonehenge.”
Richard Bevins, study co-author and professor at Aberystwyth University remarked that this discovery is only the beginning, as now the hunt for the exact location of the origin of the stone has begun. And the fun does not end there. Because of how far the origin is, the mode of transportation must have been vastly different than the ones previously proposed, which, once again, opens up a can of worms.
Chris Kirkland, study co-author and Curtin professor explains the significance of this discovery and problem “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 organization than is widely understood to have existed during the Neolithic period in Britain.”