Scientists say they’ve finally pinpointed the origin of the megaliths in the 5,000-year-old Stonehenge monument.
Fifty of the 52 massive sandstone sarsens, as they’re called, used in the monument were quarried about 15 miles away from the West Woods in Wiltshire, researchers announced Wednesday after using Geochemical testing to trace back their origins.
The sarsens were erected at Stonehenge in 2500 B.C., with the tallest reaching 30 feet high and the heaviest weighing 30 tons.
Stonehenge’s smaller bluestones have a different origin story. Those stones have already been traced back to Pembrokeshire in Wales — about 150 miles away. But the source of the sarsens has until now eluded scientists.
“The sarsen stones make up the iconic outer circle and central trilithon horseshoe at Stonehenge. They are enormous,” said David Nash, a University of Brighton geomorphologist who led the study.
Researchers will now attempt to understand how the sarsens were moved from Wiltshire to Stonehenge. It’s believed they were pulled on a sled-like system.
“How they were moved to the site is still really the subject of speculation,” Nash went on. “Given the size of the stones, they must have either been dragged or moved on rollers to Stonehenge. We don’t know the exact route but at least we now have a starting point and an endpoint.”
Nash and his team’s discovery is based on the analysis of a sarsen stone fragment that was removed from Stonehenge in the late 1950s during a conservation effort. The piece was extracted when conservators installed metal rods to stabilize a cracked megalith.
That fragment was originally gifted as a souvenir to Robert Phillips, a man who worked for the company that carried out the stabilization effort. Phillips had carried the rock with him when he emigrated to the US. He then returned the stone to Britain for research in 2018, before passing away earlier this year.
With authorities barring destructive testing on the Stonehenge site, the old souvenir was a crucial sample for researchers, giving them an opportunity to shape the sarsen’s geochemical fingerprint.
“I hope that what we have found out,” Nash said, “will allow people to understand more about the enormous endeavor involved in constructing Stonehenge.”