Seahenge may be buried

Experts are undecided how to preserve ancient timbers

One of the most important Bronze Age sites to be excavated in Europe in recent years is likely to be reburied to preserve it for future generations.

It is extremely important that the timbers are preserved for future generations

Brian Ayers, Norfolk county archaeologist

The wooden circle - dubbed Seahenge - was uncovered by winter storms on the UK's Norfolk coast three years ago.

Despite heated opposition from some local people and druid groups, the decision was taken to excavate the timbers.

But now that experts have finished their investigations, the timbers could be put back in the ground to keep them for posterity.

Rites of passage

Seahenge consists of a central tree stump surrounded by a number of smaller posts, which 4,000 years ago would have formed an enclosure.

How Seahenge could have looked in 2050 BC

No records exist from the early Bronze Age so archaeologists can only guess at the site's function, but it could have been the focus of death rituals.

People of the period are thought to have practised "excarnation" in which bodies of the dead were left out in the open air to decay. Some archaeologists think the henge was seen as a "bridge" to the next world.

Scientists at English Heritage used dendrochronology (tree ring dating), carbon dating and statistical techniques to show that the timbers came from trees felled in the late spring or summer of the year 2050 BC and 2049 BC.

Major fire

"I'm no woodsman, but I would have thought if you were cutting a down an oak tree you would do it in winter," said Norfolk county archaeologist Brian Ayers.

"Quite clearly, these people were deliberately cutting these things down at a very difficult time of year.

"And then the central tree they were actually inverting and pushing down into the ground, so it raises whole questions about the spirituality of these people and how they were thinking," he told the BBC.

Since their excavation, the timbers have been kept at the Bronze Age research centre at Flag Fen near Peterborough where, ironically, they narrowly escaped being destroyed in a major fire last year.

When the henge was excavated, the plan was to transfer the remains to a purpose-built museum once they had been examined. But that idea has now been dropped on grounds of cost.

Long-term cost

"It is extremely important that the timbers are preserved for future generations," said Brian Ayers.

Preservatives may not retain fine detail

"One can either impregnate them with chemical solutions and keep them in an appropriate building with all the long-term cost that implies, or one can rebury them within appropriate deposits and use the natural environment to preserve them. In doing that, we won't lose track of them".

A key consideration in deciding the timbers' future is the reliability of the preservation process. If the circle was put back in the ground, the site chosen would probably be close to where the henge was originally discovered.

"Because the bottoms of the timbers were surrounded by fine silt, the detail of tool marks is excellent," said David Miles, Chief Archaeologist with English Heritage. "We can see that over three dozen different bronze tools were used.

"We're concerned that artificial preservation techniques like wax and freeze-drying might lose some of that detail." A final decision on the timbers' future will be taken at the end of January.