Stonehenge has been a place of myth and mystery for centuries, and theories abound on whether it was a Druid temple, an astronomical calendar or an alien creation.
A new study by a team of researchers, including a Canadian archeologist, has answered some of the questions of who likely built the imposing stone circle. The team used a novel technique – examining chemical markers on cremated material – to analyze bones from 25 bodies that were buried at the site around 3,000 years ago. They found that most of the bodies had come from western Wales, about 250 kilometres away. It’s the clearest indication yet that the early phase of Stonehenge was probably a monument for people living farther away than many experts had previously thought. It’s also a sign that Neolithic people travelled much greater distances than most other research had shown.
The discovery could change the course of research at Stonehenge and it’s the first time the new test has been used on a large scale. The technology was developed by a graduate student at Oxford University and is set to revolutionize archeology and open up thousands of years of history to new research. The Stonehenge project was so successful the technique is now being utilized at dozens of ancient burial sites across Europe.
“The advances in scientific archeology are really quite exciting,” said one of the study’s lead authors, Rick Schulting, a Canadian who is an associate professor in scientific and prehistoric archeology at Oxford.
Scientists have long thought that most of the smaller rocks at Stonehenge, known as the “bluestones,” had come from the Preseli Hills on the west coast of Wales. But they weren’t sure how the rocks got there or who brought them. The new study shows that the people buried at Stonehenge came from the same region in Wales and that they may have transported the stones, most of which are nearly four metres long and weigh almost four tons.
“Being able to link not only the stones but the people, just gives us an added level of information about the site that we never had before,” Dr. Schulting said. ”We now know that part of the reason the monument was built there was probably to serve as a marker or memorial to some kind of long-standing connection between west Wales and Wessex.”
The connection between the two communities isn’t clear and it’s not known why these people travelled so far, he added. More than 50 bodies were buried at Stonehenge, making it the largest Neolithic burial site in Britain.
“With both the stones and the people, we have the sense that this marks almost the beginnings of an international outlook for prehistoric Neolithic people,” he said. “We have had evidence of people moving around but nothing on the scale at Stonehenge where people were coming together to build a monument that persisted for over 1,000 years. We think of Stonehenge in its final form but this was a long-term project, and we’re seeing the very start of it and that connection [between Wales and Wessex] might have been one of the things that kicked it off, even though we can’t really understand the reason for that particular relationship between these two places.”
The innovative test used in the study was developed by Christophe Snoeck, one of Dr. Schulting’s former doctoral students. Dr. Snoeck, who is from Belgium, had a background in chemical engineering and a keen interest in archeology. When he began his doctorate in the science at Oxford in 2012, Dr. Schulting offered him a challenge: find a way to analyze cremated bones.
It wouldn’t be an easy task. The issue had dogged archeologists for years and had limited the study of ancient history in places where cremation had been a common way to dispose of the dead. Archeologists had developed a test for non-cremated bones and teeth that involved searching for traces of strontium isotopes, a kind of biological marker. Strontium is a common chemical element that’s found in rocks and soil, and it gets into the food chain through plants and animals. Once inside humans the chemical acts much like calcium and attaches to bones and teeth. Two strontium isotopes, which are variations on the element and contain a different number of neutrons, can be detected in bones and teeth for centuries. And since different geologies and plants have different strontium markers, the isotopes act as a kind of homing device to track where the person lived.
The problem was that archeologists hadn’t figured out how to use the technique on cremated bones. Cremation destroys tooth enamel where strontium is typically found and it damages bones.
“Rick stumbled on this question: Is cremation really a dead end or not?” Dr. Snoeck recalled. Few professors gave him much hope of finding the answer. “When I started, many professors told me it could be that at the end of your PhD, you’ll find that nothing works and you will be quite disappointed. I was ready to take the risk.”
After several years of research, Dr. Snoeck discovered that the strontium isotopes were better preserved in cremated bones because the heating process locked in the chemical. He developed a test to find the isotopes and tried it out on a few sites in Ireland before approaching researchers at Oxford who had just excavated a collection of bones from Stonehenge. They agreed to give it shot and the results proved stunning. “Strontium worked beautifully,” he said.
Dr. Snoeck is now working on a project in Belgium to apply the technology to 3,000 years of cremated remains across the country. He’s also involved in another project in Ireland and Crete, and could soon be working in Austria and Slovenia. Dr. Snoeck said cremation was prevalent in Europe from the Bronze Age, which started around 2000 BC, to the rule of the Catholic Church. The technology will provide new insights into the makeup of populations and how people moved around. “It’s really growing and it’s nice to see people are picking up the method and want to use it.”