Hamburg, 02/11/2021 | Story | Industrial Solutions Olympus Sheds Light on the Origins of Stonehenge

For centuries, researchers have puzzled over the origin of Stonehenge's stones, which weigh up to 30 tons. Thanks to new research findings and advanced technology from Olympus, the question has finally been answered.

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Stonehenge_image_2 credit Andre Pattenden_English Heritage

The sun beats down. The coarse rope cuts deeper into your hands. Thirty tons of rough-hewed stone sit in front of you, and you’ve got to drag it across uneven terrain. You don’t have any heavy machinery. You don’t even have wheels—the stone sits on a wooden sled that digs into the earth each time you pull.

It’s backbreaking work, which begs the question: how much farther do I have to go?

About 4,500 years ago, the early inhabitants of what is today England dragged 30-ton stones from the area they quarried them to the Salisbury Plain, and then erected them to create the world-famous monument now known as Stonehenge.

For centuries, explorers and archaeologists have speculated about where these stones came from. About the only thing most people agreed on is that they didn’t come from the Salisbury Plain. It would take hundreds of years, but the mystery of their origin is now being solved thanks to new research and advanced technology.

Analyzing the Architecture of Stonehenge: From Bluestones to Sarsens

While studies have traced the smaller stones near the center of Stonehenge, known as bluestones, to the Preseli Hills in Pembrokeshire, over 200 km (124 miles) away, the origin of the site’s largest stones, known as sarsens, has remained a mystery.

But new research from four UK universities (Brighton, Bournemouth, Reading, and UCL) and English Heritage, the organization that cares for Stonehenge, reveals a likely source. The research team used a novel geochemical approach with X-ray fluorescence (XRF) technology to determine the location.

The results show the large sarsen stones came from a much more local area—the West Woods, Wiltshire, just 25 km (15 miles) north of the monument.

Overview of Stonehenge (Picture: Andre Pattenden, English Heritage)

Tracing the Source of Giant Sarsen Stones Using XRF Technology

First, the researchers analyzed the 52 sarsens at the Stonehenge monument using our Olympus DELTA™ handheld XRF analyzers. XRF analyzers use a nondestructive technique called X-ray fluorescence to determine the elemental composition of a material without damaging it. It works like this: when you run a test, the analyzer emits X-rays that hit the sample, causing the elements in the sample to fluoresce and send X-rays back to the analyzer’s X-ray detector. The analyzer then measures the energy spectrum and provides the chemistry result on the screen. All of this happens in seconds.

Jake Ciborowski (University of Brighton) analysing the sarsen core extracted from Stone 58 at Stonehenge using a portable x-ray fluorescence spectrometer. (Picture: Sam Frost, English Heritage)

As fast, portable instruments, XRF analyzers enable archeologists to analyze large, heavy samples (like sarsens) without needing to bring them into the lab. As a result, researchers can get immediate, lab-quality results in the field.

The XRF results, now published in the journal Science Advances, show that 50 of the sarsens share a similar geochemistry. This meant they originated from one common source.

But where?

While Stonehenge scholars long suspected the sarsens came from nearby Marlborough Downs, an area with the largest concentration of sarsen in the UK, the scientists needed a way to confirm the source and pinpoint a more exact location. After all, the Marlborough Downs covers a wide area, and other regions with sarsens, such as Kent, Dorset, and Oxfordshire, could have supplied the stones.

The answer came to them when something unexpected happened—a missing part of Stonehenge was returned to the UK.

An Old Relic Returns—and New Research Begins

In 1958, drilling work was completed at Stonehenge to help re-erect a fallen trilithon, a structure made of two upright sarsens covered by a sarsen lintel stone. During the process, the workers removed three one-meter-long (3 ft) drilled-out cylinders, known as cores, from one sarsen stone (Stone 58) to stabilize it with metal rods. All three cores went missing and for 60 years, the whereabouts of the cores remained a mystery.

Drilling work at Stonehenge in 1958. Robert Phillips, who returned one of the cores to the UK in 2018, is pictured left. (Picture: Robin Phillips)

In 2018, that all changed. Englishman Robert Phillips, one of the restorers involved in the drilling work and later moved to Florida, returned one of the cores to the UK right before his 90th birthday. He had been given the core as a souvenir of the conservation work and had kept it first at his UK office and later at his home in Florida. A year later, part of the second core turned up at the Salisbury Museum.

Solving the Stonehenge Mystery with Geochemical Fingerprinting

With the “Phillips’ Core” returned, researchers could get back to work. The goal was to determine the unique geochemistry of the sarsen core and match it to the geochemical fingerprint of sarsens across southern Britain. With permission from English Heritage, scientists at the University of Brighton first cut three small samples from a section in the middle of the Phillips’ Core. When the fingerprint was compared to sarsen samples in 20 regions across southern England, it matched the West Woods in the southeast Marlborough Downs.

Jake Ciborowski (University of Brighton) analysing the sarsen core extracted from Stone 58 at Stonehenge using a portable x-ray fluorescence spectrometer. (Picture: Sam Frost, English Heritage).

Mysteries Remain

This discovery provides some additional insight into the historic monument, but it also brings up new questions:

  • Why did the early inhabitants choose the West Woods area as the primary source for the Stonehenge sarsens?
  • Where were the sarsens extracted from in the West Woods?
  • Why were two of the 52 sarsens taken from a different source, and where did they come from?

To answer them, archaeologists will need to continue their research using advanced technologies like XRF.

To learn more about the role of Olympus XRF analyzers in this breakthrough and other discoveries, read more about the research project and explore the applications of our newest handheld XRF instrument, the Vanta analyzer.

Plan of Stonehenge by W.M. Flinders Petrie in the late 19th century (left) and Map showing the locations of Stonehenge and West Woods with possible transport routes. (David Nash, University of Brighton)