Ground-breaking laser scanning is
offering a unique insight into the creation of Seahenge
by a "highly developed" Norfolk community. Results
of the research are already being hailed as a huge
leap forward in the study of the Bronze Age period.
SUE SKINNER reports.
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| 1.
A timber entrance post from the Seahenge circle
is scanned using a laser scanner linked to a laptop
computer. |
2.
The laser is able to record every rise and fall
of the wood's surface. The data is then transformed
into a 3-dimensional image which appears on the
computer screen. |
3.
The image can be moved and turned as a 3D object
in order to study the timber's properties more closely.
This laser scan shows the evidence of bronze axe
marks. |
It was the spiritual
focal point for a community which appears to have been
at the cutting edge of Bronze Age technology.
The people who built a timber circle close to the
North Norfolk coast more than 4000 years ago were probably
farmers engaged in a wide variety of specialised tasks.
They grew crops, fished, kept animals and managed woods
- but have also emerged as highly-skilled tool-makers.
| Seahenge
Q&A
 Who
built it?
With the help of the Norfolk Archaeological Unit,
we try to see through the mists of prehistory.
Digging
into the past
What was life like
for the Bronze Age people who are presumed to
have built Seahenge?
Last
stop for pilgrims?
Seahenge is linked with
Stonehenge and Avebury by ancient roads - and
could have been the final stop on a pilgrimage.
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A digital scan of the 55 oak posts and central tree
stump, which began at the Flag Fen Bronze Age centre
near Peterborough last month, produces three-dimensional
and computer images.
Impossible to achieve with ordinary recording methods,
these have revealed cut marks left by at least 38 different
bronze axes, at a time when bronze technology had only
recently arrived from the Continent.
They are also the earliest metal tool marks on wood
ever found in Britain - and confirm that the community
responsible for Seahenge was much more highly developed
and organised than envisaged.
Francis Pryor, director of archaeology at Flag Fen,
where the timbers have been stored since their controversial
excavation from the beach at Holme, near Hunstanton,
two years ago, said: "The widely different 'fingerprints'
of each of the axes show up clearly in the high-resolution
images.
"It is remarkable that this tiny community was able
to lay hands on such a large number of tools only about
100 years after the knowledge of how to make bronze
arrived in the country.
"The scan will enable us to examine other features
of the timbers, such as the insides of the 'tow holes'
in the central stump, through which honeysuckle ropes
were threaded to haul it into position."
The process, which is being carried out for English
Heritage by Alistair Carty and Dr Carolyn Sleith
of the specialist laser-scanning company, Archaeoptics,
is regarded as a major advance in archaeological research.
Due to continue for another four weeks, it will enable
the fragile axe marks to be captured and preserved in
their optimum condition.
As well as providing a permanent and accurate record,
it will allow archaeologists to monitor the future condition
of the timbers.
Preserved by an accident of nature
Seahenge, made from trees cut down in the spring of
2049BC and built on a site which was then inland, was
by no means the only timber circle in existence at the
time.
The key to its survival, which is what makes it so
unusual, was its long immersion in wet ground before
the shifting sands at Holme finally brought it to light.
"What ultimately preserves wood is lack of oxygen
and lack of light," explained Maisie Taylor, an expert
in prehistoric wood-working.
"If wood is wet and then dry, it rots - anybody who
has ever put up a wooden fence knows that. Wooden fences
rot off and break but if they are in wet ground you
will find the wood is still there underground. It just
changes.
"We don't know a great deal about this period so to
get something with this huge amount of data is such
a huge leap forward. It's like we've got a big jigsaw
with lots of pieces missing. There are sites like this
where the wood hasn't been preserved but there are metal
tools and we don't know what they did with them - so
this has brought it all together."
It is gradually becoming clear how the circle was
set out. The central stump went in first before a back
panel and an entrance opposite were set out, followed
by marker timbers in an arc.
Associated with burial rites?
The spaces between the markers were then filled in.
Debris left from dragging the timbers reveals that a
stockpile of wood was kept to one side of the circle,
while woodworking was undertaken on the other.
"One of the things that happened at the end of the
Stone Age was that they started building earthworks
and stoneworks and woodworks," said Ms Taylor. "It's
obviously something in the development of human beings."
Seahenge represents a large communal outlay of energy
and resources and would undoubtedly have had great spiritual
significance. Most structures of its type were associated
with burial rites.
"I think that's what we might call the best feel at
the moment," continued Ms Taylor. "There are various
things which are surprising. One is the wide variety
of tools they were using early on in the Bronze Age
and the number of people involved in a relatively small
monument. There seemed to be at least three or four
dozen people building this.
"It's about the time that people started living in
what we would call tribes or clans."
While later religious edifices, such as churches, would
occupy a central position in their communities, the
circles tended to be placed on the edges - almost like
markers for where the territory of one tribe ended and
another began.
Seahenge has been hailed as "a new window into the
Bronze Age" and one of the most important discoveries
of recent years for British archaeology. The information
it has revealed so far has surpassed all expectations.
English Heritage now maintains that conservation for
future generations is the best way forward for what
is regarded as a unique prehistoric structure, of international
importance.
Ms Taylor said: "When you get something like
this you are immediately very excited by the possibilities
- your mind goes into wild extremes. But this site
has produced everything that I ever thought it could.
It has literally lived up to my wildest dreams - it's
brilliant."
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