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Press Release

First released by Wessex Archaeology on
Thursday October 16 2003

Hi-tech lasers throw light on Stonehenge secrets

The latest hi-tech laser equipment has unlocked more secrets of Europe’s best-known ancient monument, Stonehenge.

A team of computer experts and archaeologists used laser scanning on the stones for the first time and discovered carvings of two bronze axe heads.

The most hi-tech investigation of the monument to date was carried out in 2002-3 by a team from Wessex Archaeology of Salisbury, near Stonehenge, and Archaeoptics Ltd of Glasgow. A full account of their work is featured in today’s (Thursday) edition of British Archaeology.

The axes, both on one stone, are badly eroded and can not 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 (6 inches) square and may possibly be two axes, one on top of the other; the other is about 10 cm (4 inches) by 8 cm (3 inches).

The team scanned only part of three of the sarsen stones and believe that a full scan of all the surviving 83 stones would reveal more ancient carvings.

Carvings of axes and a dagger were first found at Stonehenge 50 years ago, but they have never been fully surveyed or studied. The team scanned some of these known carvings and by comparing visually 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.

The stones at Stonehenge were put up in about 2,300 BC. The axes are of types made around 1,800 BC, so the carvings are likely to be five centuries younger than the stones. Their purpose is a mystery.

Axe carvings on other monuments from this time are associated with burials, such as the seven axes found on a stone burial cist (a box shaped stone structure) 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.

“The laser scanning has opened up a whole new way of seeing Stonehenge,” said 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. 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 said: “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.”

Mike Pitts, editor of British Archaeology and a leading expert on Stonehenge, said: “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. The laser scanning process makes recording and studying possible, and can be used to reveal the nearly invisible carvings for all”.

Note to Editors

1. Archaeoptics used a Minolta VI-900 scanner capable of capturing 300,000 points in three seconds. At Stonehenge they acquired nine million 3D points on the stones in 30 minutes. They then took two days to create highly accurate 3D models from these points. The raw data captured by the scanner are in the form of “point clouds”, unconnected 3-dimensional points. To be more useful for visualisation and analysis, these were converted into “solid” surfaces formed from millions of triangles. The models are then manipulated in a software package called Demon developed by Archaeoptics. Various lighting techniques were developed at Wessex Archaeology to further enhance the images.

2. The first recognised and best-known carvings at Stonehenge, a dagger and 14 axes, were found by Richard Atkinson in 1953, on the inner face of Sarsen number 53. About 26 axes were found soon after on the outer face of Sarsen stone 4, and three on the outer face of stone 3. These axes vary from 8 to 36 cm long (3-14 inches). There are also a possible trellis or lattice pattern on stone 3, and hollows, a shallow rectangle (sometimes described as a goddess), ribs and cup-marks on other stones. The significance of these putative carvings, never accurately surveyed, is debated by archaeologists.

In 1967 a team from University College, London used a stereometric camera to produce a very fine contour plot of the dagger and adjacent axe on stone 53. English Heritage’s Survey Team completed the first metric survey of all the stone surfaces, published in 1996.

3. Other stone carvings from this period include:
• seven axe shapes found at Ri Cruin in the Kilmartin valley, Argyll, on one end of a stone burial cist, covered with a cairn.
• close by, the cairn of Nether Largie north has another 14 axes on a stone cist.
• another nearby cairns has another axe.
• a barrow at Badbury Rings, Dorset, had a stone bearing two dagger shapes and two axe-like triangles and five cup-marks.
• a stone cist inside a barrow at Pool Farm, Somerset, contained a slab decorated with seven feet and about ten cup-marks
• another foot-shaped carving was found on a cist slab at Harbottle Peels, Northumberland
• ten foot-carvings were found at a Late Neolithic barrow know as the Calderstones in Liverpool

4. Wessex Archaeology is a firm of commercial archaeologists based near Salisbury, Wiltshire. It employs 170 staff and works across the country.

Archaeoptics is a 3D laser-scanning bureau based in the UK and operating worldwide, mainly in the archaeology and heritage sector

5. British Archaeology is the UK’s only retail archaeology magazine, available in larger W H Smiths and Borders. Editor Mike Pitts has excavated at Stonehenge and was responsible for the recent discovery of the decapitated Anglo-Saxon man.

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