Stonehenge, a monument embodying somberness, stillness, and antiquity, holds a prominent place in human lore – an ancient edifice of mystery that has vigilantly guarded southern England for eons.
The identities of its builders and their motivations have remained subjects of intense speculation for centuries.
And in the year 2024, the enigma surrounding this 5,000-year-old structure became even more profound.
Researchers disclosed that Stonehenge’s Altar Stone, a predominantly submerged 6.6-ton block of grayish-green sandstone, originated from the extreme north of Scotland, a distance of approximately 700 kilometers (435 miles) from its present position on Salisbury Plain.
The feat of traversing such a considerable span has led some to theorize that glacial ice might have facilitated its movement.
However, a recent analysis indicates that at least a portion of this arduous journey was undoubtedly facilitated by human intervention.
“Rather than being transported passively by ice, empirical evidence strongly suggests a deliberate, meticulously orchestrated relocation across a challenging and varied terrain,” stated geologist Anthony Clarke, affiliated with Curtin University in Australia.
“Our simulations indicate that glaciers might have conveyed rocks part of the way during the last Ice Age – possibly as far as Dogger Bank in the North Sea – but not into southern England, implying that the stone would still have required extensive human effort for hundreds of kilometers.”
While the original purpose of Stonehenge remains a subject of conjecture, the stones themselves offer valuable insights.
They are primarily composed of two distinct types: immense local sandstone blocks, referred to as sarsens, and the bluestones forming the inner horseshoe, quarried from Wales, situated 230 kilometers away.
The Altar Stone, designated as Stone 80, is singular among the monument’s components. It lies nearly concealed at the center, partially obscured by two toppled sarsen stones, and is fashioned from a rock type unrepresented elsewhere in the formation.
In 2024, Clarke and his associates examined microscopic zircon crystals embedded within the Altar Stone, tracing its provenance to the Orcadian Basin, precisely at the northeastern extremity of Scotland – a location almost maximally distant from Salisbury Plain on the British mainland.
Subsequently, earlier this year, Clarke, in collaboration with fellow geologist Christopher Kirkland of Curtin University, unveiled supplementary findings.
Through diligent scrutiny of Salisbury Plain’s geological composition, the duo ascertained that this area had not experienced glaciation during the temporal window necessary for the Altar Stone’s transport. Their conclusion was that regardless of its journey, the rock could not have been directly deposited by glacial activity.
This new research represents the culmination of the investigative process.
The initial phase involved accurately pinpointing the Altar Stone’s origin. The zircon crystals bore the closest resemblance to those found in Caithness, situated at the very edge of mainland Scotland.
Subsequently, the researchers simulated the movement patterns of the British-Irish Ice Sheet during the Last Glacial Maximum, approximately 27,000 years ago.
Their findings were consistent with their prior observations: they concluded with certainty that ice could not have transported the stone from Caithness all the way to Salisbury.
However, an intermediate scenario might have been possible.
The results suggested that the stone could have been conveyed on glacial ice as far as Dogger Bank, a region now submerged beneath the North Sea but which comprised dry land during the Ice Age.
This would have effectively halved the journey to Salisbury Plain, reducing the distance from 700 kilometers to 400.
The significant impediment to this particular theory, however, is that Dogger Bank was inundated by rising sea levels millennia before Stonehenge was constructed. Consequently, if the Altar Stone had been located there, humans would have had to retrieve it prior to sea level rise, relocate it elsewhere, store it for a period, and then utilize it in the construction of Stonehenge thousands of years later.
This chain of events is complex, yet it may represent a more plausible explanation than the exertion required to haul a six-ton rock over 700 kilometers.
“The investigation indicates the absence of any viable glacial routes connecting the region of origin directly to Stonehenge, thus reinforcing the conclusion that human transportation was essential,” asserts Clarke.
“Instead, this points to the stone likely being moved in sequential stages, potentially combining overland hauling with riverine or coastal transportation where feasible.”
The precise details of this monumental journey may forever remain elusive.
Nevertheless, these silent monoliths continue to narrate a compelling account of extraordinary human ingenuity.
“The transportation of a stone of this magnitude over such an extensive distance would have necessitated meticulous planning, coordinated efforts, and a profound comprehension of the topography – not to mention immense perseverance,” states Clarke.
“This study effectively demonstrates how the fusion of geological analysis with computational modeling can contribute to resolving age-old questions regarding the construction of Stonehenge.”
The findings were published in the Journal of Quaternary Science.
