We’ve finally figured out where Stonehenge’s giant boulders came from

By Donna Lu

Andre Pattenden (English Heritag

The origins of the giant boulders at Stonehenge have long been a thriller – but now we have now uncovered where they got here from.

David Nash at the University of Brighton within the UK and his colleagues have known the source of 50 of the 52 gigantic boulders, veritably called sarsens, that salvage up the monument’s iconic stone circle.

By analysing the stones’ chemical composition, the team has traced their origins to 25 kilometres a long way off from the monument, within the West Woods in Wiltshire.

The sarsens comprise Stonehenge’s outer circle as successfully as a horseshoe-fashioned inner ring. Many are in trilithons: two vertical stones topped with a horizontal lintel.

Stonehenge furthermore accommodates smaller rocks, veritably called bluestones, end to its centre, the origins of which have previously been traced to Wales.

The researchers analysed the chemistry of the sarsens thru a strategy called transportable X-ray fluorescence spectrometry, truly a handheld X-ray gun. With this, they took five readings at assorted positions for every stone.

This published that 50 sarsens shared a overall chemistry, containing bigger than 99 per cent silica, with hint formula including aluminium, calcium and iron.

“Two, unheard of to our surprise, were assorted to that most well-known cluster, but furthermore assorted to every assorted,” says Nash. This suggests they have gotten two separate origins.

Next, the researchers analysed a fraction of stone, taken from a collapsed sarsen when it used to be re-erected in 1958, to carry out a geochemical breakdown of the rock. They mild this to sample areas of comparable stone across southern Britain.

The site within the West Woods, one in every of six the team sampled within the Marlborough Downs, turned up with a match. “We didn’t quiz we would ever catch the distinctive source field,” says Nash.

Identifying the origins of the sarsens opens up the most likely of future archaeological review into the routes they are able to even were transported to Stonehenge, says Nash.

The origins of the assorted two sarsens have but to be known.

Journal reference: science Advances, DOI: 10.1126/sciadv.abc0133