Machine work is part of
archaeological practice
Dear sir - In the recent past, some historians have made
highly publicised comments about the methods
archaeologists employ on sites discovered on foot of
National Roads Authority (NRA) road schemes.
Comments relating to the use of machinery betray a
misunderstanding of these methods and I would like to
clarify the issue and avoid future outbursts, which are
unhelpful in the current debate over roads schemes and
the National Development Plan.
It is the current practice on NRA road schemes to test a
proposed road route by means of machine cut centre-line
trenches with machine cut off-sets excavated at right
angles to the centre line. These off-sets are usually set
at 20m intervals and all testing is monitored by licensed
archaeologists.
The machines are fitted with broad-blade buckets because
the standard buckets with teeth can cause significant
damage to underlying archaeological deposits. The blade
can skim off the ploughsoil revealing underlying
archaeology without significant disturbance.
Once the surface extent of the deposits has been
revealed, machine work ceases in the area and qualified
archaeologists hand-excavate the exposed archaeology to
assess the nature and date of the remains.
The archaeology is recorded and surveyed according to
archaeological best practice, a report is written and
submitted to the heritage authorities for approval and as
a lasting record of the remains and the area highlighted
for further work.
It is possible that significant time delays can occur
between the initial testing phase and agreement being
reached on the archaeological mitigation strategy to be
employed. In these instances it may be deemed appropriate
to backfill the trenches.
If the archaeology uncovered during the testing is of
sufficient importance there may be a requirement to carry
out additional archaeological monitoring of this process.
This will ensure that the archaeology within the trenches
is appropriately protected and also that the
archaeologists have the opportunity to carry out
additional examination.
Occasionally, where appropriate and always under strict
archaeological supervision and with the assent of the
relevant heritage authorities, a metal detector may be
used to investigate the plough soil. This enables
archaeologists to retrieve any stray finds that may have
originated in the underlying site but became incorporated
into the topsoil as a result of more recent agricultural
activity.
It is possible that sites that have come to light in the
course of testing on road schemes, even those which were
subsequently found to be of national significance, may
have been observed with a number of tracked excavator
machines working in the vicinity.
It needs to be stressed, and this would appear to be the
root of some of the disquiet recently expressed, that
this is a normal part of internationally accepted
archaeological mitigation strategies; strategies that
have been agreed with all the relevant heritage
authorities, are carried out under licence to the
minister, monitored by the attending licensed
archaeologist and under the supervision of the NRA
project archaeologist. I trust this clears up some of the
confusion,
Yours sincerely,
EOIN HALPIN,
Chairman of the Institute of Archaeologists of
Ireland.
© The Meath Chronicle, 13th. August 2005.
