Researchers seek origin of Stonehenge Altar Stone

In hopes of solving one of the enduring mysteries about the iconic monolith, Geologists have redirected the search for the origins of Stonehenge’s central Altar Stone to Scotland after recent research shifted the search away from Wales.

But in a surprising twist, new analysis suggests the stone did not originate in Orkney, an archipelago off the northeast coast of Scotland that is home to 5,000-year-old Neolithic sites.

The findings, published September 5 in the Journal of Archaeological Science: Reportscame shortly after a study released in August that pointed to northeastern Scotland as the likely origin of the Altar Stone. That research, published in the journal Natureoverturned a centuries-old idea that the stone came from the region that is now Wales.

The Altar Stone, the largest of the bluestones used to build Stonehenge, lies at the heart of the ancient monument in southern England. The 6-tonne block was likely transported more than 700 kilometres from north-east Scotland nearly 5,000 years ago, possibly by sea.

However, the purpose of the stone still remains a mystery.

A team of geologists, including many of the same authors as the Nature study, examined Neolithic-era stones at two well-known landmarks on Mainland Island, the largest in the Orkney archipelago, that were similar in size and rock type to the Altar Stone. However, the analysis did not detect a connection.

“The mystery of the stone’s origin is becoming increasingly clear as we begin to rule out specific areas in northeastern Scotland,” Richard Bevins, lead author of the study and an honorary professor in the department of geography and earth sciences at Aberystwyth University in the United Kingdom, said in a statement.

“This research is radically changing our thinking about the origins of the Altar Stone. It is exciting to know that our chemical analysis and dating work are gradually unravelling this great mystery.”

Putting together an ancient puzzle

Construction of Stonehenge began around 3000 BC and occurred in several phases, according to previous research, and the Altar Stone is believed to have been placed within the central horseshoe during the second phase of construction, between 2620 BC and 2480 BC.

Substantial research over the years has focused on the types of stone used to construct the iconic circle in Wiltshire, England. Previous analysis has shown that bluestone, a type of fine-grained sandstone, and blocks of silicified sandstone called sarsens were used in the construction of the monument. The landmark is located on the southern edge of Salisbury Plain, which was inhabited around 5,000 to 6,000 years ago.

The sarsens came from the West Woods near Marlborough, about 25 kilometres away, while some of the bluestones originated in the Preseli Hills area of ​​west Wales and are thought to be the first to be placed there.

“The Altar Stone is anomalous in many ways relative to both the bluestones and sarsens at Stonehenge,” Bevins said. “It is in an unusual position in the monument, occupying an almost central location and not within the Bluestone Circle or the Bluestone Horseshoe. Furthermore, it is a greenish-grey sandstone, unlike any other type of bluestone block.”

Bevins has been investigating Stonehenge for 15 years, and his quest to understand the origins of the stones has taken him all over England and Wales. However, discovering that Wales was probably not the location of the Altar Stone’s origin was a turning point, Bevins said.

“Suddenly, we were free to think about where the Altar Stone could have come from, opening up completely new avenues of investigation and exploration,” Bevins said in an email.

Seeking answers in Scotland

The search took researchers to Mainland Island, where they conducted fieldwork in June 2023.

“There is evidence of long-distance links between Orkney and Stonehenge, in part related to the exchange of certain styles of material culture,” said Bevins.

The enduring link between Stonehenge and Orkney includes decorated pottery styles and similar architecture of ancient dwellings found at both sites, Bevins explained.

The team took portable X-ray machines to Orkney to carry out a chemical analysis of minerals contained in rocks exposed at the Stones of Stenness and the Ring of Brodgar, two ancient remains of stone monuments.

The Ring of Brodgar is a large ceremonial stone circle dating from the third millennium BC, and the Stones of Stenness was once a circle of 12 stones with a central hearth, built over 5,000 years ago, and is one of the earliest monuments in the British Isles.

The researchers compared their findings with samples from the Altar Stone and found no mineralogical connection between the rocks.

However, the study suggests it is still likely that the Altar Stone came from another region in north-east Scotland, presenting a vast area of ​​research for the team to investigate in the future. The origin of the rock could lie anywhere from “Orkney and Shetland, down through parts of Caithness and Sutherland, to Inverness, and then eastwards to Aberdeenshire,” Bevins said.

This content was originally published in Researchers seek the origin of the Stonehenge Altar Stone on the CNN Brasil website.

Source: CNN Brasil