These massive stones, each typically weighing an astonishing 20 tonnes and soaring up to 7 meters in height. (CREDIT: Creative Commons)
In a groundbreaking discovery chronicled in the prestigious journal Science Direct, a team of researchers led by geomorphologist Professor David Nash has unraveled the centuries-old mystery of Stonehenge's colossal sarsen stones.
These massive stones, each typically weighing an astonishing 20 tonnes and soaring up to 7 meters in height, have long shrouded their origins in enigma. Now, thanks to modern scientific techniques and a serendipitous return of a core drilled from Stonehenge's 'Stone 58' during repair work in the 1950s, the veil of uncertainty has been lifted.
Sarsen stones are the architectural backbone of Stonehenge, constituting all fifteen stones of the central horseshoe, including the uprights and lintels of the outer circle, as well as several outlying stones like the Heel Stone, the Slaughter Stone, and the Station Stones.
While the monument's smaller bluestones have previously been traced back to specific locations in the Preseli Hills of Wales, the sarsens, characterized by their more uniform composition, had remained stubbornly untraceable until now.
The pivotal moment in this quest for origins came when the long-forgotten core, retrieved during the 1950s repair work and residing in Florida for decades, made its journey back to English Heritage at the behest of Mr. Robert Phillips. This serendipitous event offered Professor Nash and his colleagues a unique opportunity to delve into the interior of one of Stonehenge's grand sarsen stones.
Embarking on a mission funded by the British Academy, Professor Nash's team commenced their exploration with non-destructive testing of all the remaining sarsens at the Stonehenge site. The results were nothing short of astonishing, as they revealed that most of these ancient stones, including Stone 58, shared a strikingly similar chemical makeup, strongly suggesting a common origin.
To confirm their findings, the researchers ventured beyond the Stonehenge boundaries, analyzing sarsen outcrops from as far afield as Norfolk to Devon. Comparing the chemical composition of these outcrops with the retrieved core's chemistry was the next step in this scientific odyssey.
New research reveals the origin of Stonehenge’s giant sarsen stones as West Woods, on the edge of Wiltshire’s Marlborough Downs. (CREDIT: Creative Commons)
The breakthrough, however, arrived when the team conducted a destructive test on the core itself. This analysis unequivocally demonstrated that the composition of Stone 58 matched the chemistry of sarsen stones found in West Woods, nestled just south of Marlborough, approximately a 40-minute drive from the Stonehenge site today.
English Heritage Senior Properties Historian Susan Greaney expressed her excitement at the revelation, stating, "To be able to pinpoint the area that Stonehenge's builders used to source their materials around 2500 BC is a real thrill. Now we can start to understand the route they might have traveled and add another piece to the puzzle." She went on to emphasize that the primary objective in selecting these sarsen stones was their size – Stonehenge's builders aimed for the biggest, most substantial stones they could find, preferably from the nearby vicinity.
Plan of Stonehenge, showing locations of STH08 and SAV08 (trenches TR44 and TR45) from which the sarsen debitage analyzed in this study was excavated. (CREDIT: Science Direct)
In stark contrast, the bluestones used in the monument's construction seem to have been selected for different reasons, perhaps due to a sacred connection to the Preseli Hills in Wales. Susan Greaney's reflections on these findings underscored the meticulous planning and deliberate choices made by the ancient architects of Stonehenge.
Professor David Nash of the University of Brighton, who led this scientific voyage into the Neolithic past, remarked, "It has been really exciting to harness 21st-century science to understand the Neolithic past and finally answer a question that archaeologists have been debating for centuries."
Photograph of refitted sarsen sample SAV08 TR44 006 74/1 from trench TR44. B – Schematic, showing principal fractures and delineation into parts A and B (dashed line). The join between the two parts was weathered, suggesting that the flake was fragmented in prehistory. (CREDIT: Science Direct)
He explained that X-ray fluorescence, a non-destructive technique, was instrumental in revealing the shared chemistry of most sarsen stones at Stonehenge. Mass spectroscopy, a specialized method, was then employed to analyze samples from sarsen outcrops across southern England and, crucially, the tiny pieces of the Phillips' Core.
Each outcrop's unique geochemical signature provided valuable data, but it was the return of the core that ultimately enabled the researchers to pinpoint the source area for the Stonehenge sarsens. Professor Nash expressed immense gratitude to the Phillips family for their role in this groundbreaking discovery.
With this revelation, the puzzle of Stonehenge's origin grows clearer, shedding new light on the remarkable engineering and intentionality of its Neolithic builders. The journey into the past continues, offering tantalizing glimpses into the mysteries that still linger within this ancient and iconic monument.
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