Using laser scanning technology to study Europe’s most famous ancient monument, a team of computer experts and archaeologists has discovered carvings of two axe heads on Stonehenge. The most hi-tech investigation of the monument to date, the study was carried out between 2002 and earlier this year by a team from Wessex Archaeology and Archaeoptics Ltd.  
     Although similar carvings were first found at Stonehenge 50 years ago, they have never been fully surveyed or studied. "The laser scanning has opened up a whole new way of seeing Stonehenge," explained Tom Goskar of Wessex Archaeology. "We spent an hour recording the data at the stones and we were astounded to discover two new carvings as a result."  
     Both found on one stone, the axes, which date back to 1,800 BCE, are badly eroded and can’t be seen with the naked eye. But by sweeping low-powered laser beams at the stones and analysing the data closely, a picture emerged. The first newly-discovered carving is about 15 cm square and may possibly be two axes, one on top of the other, while the other is about 10 cm by eight.  
     Only a small part of three of the sarsen stones were scanned by the team and they believe that a full scan of the surviving 83 stones would reveal more ancient carvings. "With more time we could uncover many more and make plainer the outline of some known carvings that are difficult to see. This would give us a much better idea of the extent of the carvings and help us achieve a greater understanding of the monument. It is exactly 50 years since the carvings on Stonehenge were first documented, and the new laser scanner is a fascinating way of using state-of-the-art technology to shed light on an ancient wonder."
     Alistair Carty of Archaeoptics explained: "We have used 3D scanning previously to enhance badly weathered carvings on monuments, but never on details as fine as the Stonehenge axeheads. The possibility that other unknown carvings exist on the other stones is very exciting and may hopefully lead to a more complete interpretation of Stonehenge."
     The first recognised and best-known carvings at Stonehenge, a dagger and 14 axes, were found in 1953. They were followed by 26 axes, a possible trellis or lattice pattern, a shallow rectangle (sometimes described as a goddess), ribs and cup-marks. The team scanned some of these known carvings and compared their results with a photograph taken in 1953. They suspect the carvings may have eroded since they were first found, possibly because of people touching them.
     Stonehenge was created in several stages, from around 2,300 BCE, while the axes are of types made around 1,800 BCE, so the carvings are likely to be five centuries younger than the stones. However, the reason why they were created remains a mystery. Axe carvings on other monuments from this time are associated with burials, such as the ones found on a stone burial cist in Argyll, Scotland. This could indicate that Stonehenge was a place where the dead were commemorated, a theory backed by the many burial mounds found near the monument.  
     "It is extraordinary that these carvings, the most significant art gallery from ancient Britain, have still not been properly studied 50 years after their first discovery," added Mike Pitts, editor of British Archaeology and a leading expert on Stonehenge. "The laser scanning process makes recording and studying possible, and can be used to reveal the nearly invisible carvings for all."
     More about Archaeoptics and Wessex Archaeology laser scanning project on www.stonehengelaserscan.org website.

Sources: Article by David Prudames for 24 Hour Museum, BBC News (16 October 2003)