Llangynfelyn Dig Diary
A MEDIEVAL TIMBER TRACKWAY AND INDUSTRIAL COMPLEX AT LLANGYNFELYN,
CORS FOCHNO
During June 2004 Cambria undertook the partial
excavation of a medieval timber trackway crossing Cors Fochno (Borth
Bog) in Ceredigion. The trackway was visible on the surface as a
low bank running across a pasture field. Recent land drainage and
other agricultural improvements presented a severe threat to the
survival of the timber elements of the feature and a decision was
taken to undertake a rescue excavation with funding support from
Cadw. The excavation also provided a training opportunity for students
from the Institute of Archaeology and Antiquity at the University
of Birmingham.
The timbers formed a walkway about 1.5m wide and
the whole structure was supported by a series of wooden pegs or
stakes hammered into the peat. The trackway had then been covered
in layers of gravel effectively forming a roadway across the bog.
Two 10th - 11th Century AD radiocarbon dates were obtained from
two of the timbers and dendrochonological dates suggest that three
of the timbers are from trees that were felled between AD1080 and
AD1120.
At the southern terminus of the visible causeway,
the trackway was found to overlie an extensive area of burning and
industrial debris. A preliminary examination of the samples from
this waste indicate a very high proportion of lead waste suggesting
that lead ore may have been smelted in the immediate vicinity. We
have just obtained two radiocarbon dates of 60 BC-AD90 and AD20-220
for charcoal from these industrial deposits, suggesting a late Iron
Age or Roman date.
How does this industrial activity relate to the
trackway? The dates are suggesting that there is a long time gap
between the two. However, the charcoal that provided the radiocarbon
dates may be from old or reused timbers. Another possibility is
that the industrial activity continued well after the Roman period
and that the trackway dates to the later stages of its use, perhaps
even linking it with quarrying activity on the ‘island’
of Llangynfelyn to the north.
A further season of excavation will be undertaken
at the site in June 2005 to allow a more thorough investigation
of the industrial activity associated with the southern end of the
trackway. Once again we intend to ensure that local community interaction
will be at the heart of the project with regular updates on our
website.
Llangynfelyn Excavation Open Day
There will be a public open day on our excavation
of the timber trackway and industrial complex at Llangynfelyn, near
Talybont, Ceredigion on Saturday 11th June. Visitors will have the
opportunity to see the excavation of this outstanding discovery
in progress between 11.00am and 4.00pm with free guided tours and
display.
Map showing location
of dig
Llangynfelyn Dig Diary 2004
Page
Day
1 (May 31st) - The machining has got underway
with bright sunny weather. We have decided to look again
at the southern end of the Trackway to examine its relationship
with the industrial deposits that were identified in
June 2004. Following the removal of the topsoil, this
new Trench (Trench 6) has already exposed large areas
of burning and waste material. Previous examination
of this material indicates a high lead waste content
suggesting that it might be from the smelting of lead
ore. The radiocarbon dates hint at a Roman date.
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Site Director, Nigel Page, guides Eifion Jenkins
who is driving the digger
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Day 2 (June
1st) – The weather has taken a turn for
the worse. The Birmingham students spend their first
day on the site in the pouring rain or sheltering from
the downpours! However, good progress is made and the
excavation trench begins to take shape. |
The excavation attracts its first visitors
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The students taking shelter in the portacabin
during a heavy shower
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Cleaning the upper surface of the industrial
deposits
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Day
3 (June 2nd) – We continue to make
good progress with cleaning the site. The timbers
of the trackway are now starting to show and appear
to be very well preserved in this area. |
Cleaning the timbers of the trackway
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The excavation taken from the field to the
south. It is possible that the smelting furnaces
are located in this field.
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Day 4 (June
3rd) – Work begins on making a scale
plan of the trench before excavation. We are keen to
record and remove the trackway as quickly as possible
so that we can investigate the earlier industrial deposits
that lie underneath.
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Preparing a scale plan of the Trench 6
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Day 5 (June
6th) – We are also beginning work on
a series of small test excavations in the adjacent field
where we think there may be platforms for metal smelting
furnaces. This is much to the amusement of our neighbours! |
Excavating one of the Test Trenches in the neighbouring
field
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Our neighbours remain fascinated
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Day
6 (June 7th) – We have continued to
open a series of test pits to determine the extent
of the industrial activity. It is clear that it cover
a very large area within several fields. In one of
the test pits we have found several pieces of burnt
stone with glazed surfaces – almost certainly
part of the smelting furnaces – and bits of
metal slag. Even more exciting was finding some fragments
of glass. We are almost certain that this is Roman
glass and it seems to tie in with the radiocarbon
dates from the industrial deposits. |
Spraying the timbers of the trackway to prevent
them from drying out
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A fragment of the furnace lining
and the metal slag |
The possible Roman glass from one of the Test
Pits
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Day
7 (June 8th) – Our first visit from
a local school – Ysgol Llangynfelyn. More of
the Test Pits are producing fragments of furnace lining.
It seems possible that there were many small furnaces
in a number of different areas of the site. |
Richard Jones showing around visitors from
Ysgol Llangynfelyn
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Excavating one of the Test Pits
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Day 8 (June
9th) – The area of the Trackway in Trench
6 has now been fully cleaned and recorded. It is very
well preserved in this area and it appears to be constructed
of branches split into two with the flat sides down.
We suspect that most of the timbers are either alder
or oak. The bark is still visible on the upper surface
of the individual timbers. The lack of wear and the
rough surface suggests that this was not the original
walking surface of the trackway. Both in this area and
elsewhere we have observed that the timbers were covered
with gravel suggesting that the actual walking surface
was a gravel track not a timber boardwalk. The timber
structure seems to be intended to prevent the gravel
track from sinking into the bog – essentially
a ‘floating road’. |
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Details of the timber surface |
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Day 9 (June 10th) - We still have
not identified the exact locations of any of the former
smelting furnaces. However, we have found many more
fragments of the burnt furnace lining. The industrial
deposits are also very deep in several of the Test
Pits. We received further school visits – this
time from Craig yr Wylfa school, Borth and Talybont
school.
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Section of one of the Test Pits showing the charcoal
and industrial debris overlying the brown peat of
the bog
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Day
10 (June 11th) – we had a very successful
Open Day with well over a hundred visitors being given
a guided tour of the excavation. Visitors included local
councillors and members of the local Young Archaeologist
Club. |
A general view of the excavation showing some
of the visitors during the Open Day
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Day
11 (June 13th) – most of the day has
been spent recording and lifting the timbers from the
main trench and collecting environmental samples. We
were assisted by specialists from the University of
Lampeter including Nigel Nayling and Astrid Caseldine. |
Surveying in the area of the main trench
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Nigel Nayling from the University of Lampeter
collecting samples of timber from the trackway
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Day
12 (June 14th) – The majority of the
trackway has now been lifted and the morning was spent
cleaning the underlying industrial deposits for general
photographs. Work began on the excavation of these deposits
in the afternoon. Meanwhile specialists from the University
of Lampeter returned to the site to carry out several
cores of the peat next to the trackway. They hope to
use pollen from these cores to chart vegetation and
landscape change through time. |
The Birmingham students proudly displaying some
of the timber samples collected from the trackway
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Several of the vertical stakes hammered into
the peat either side of the trackway have sharpened
ends
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Day 13 (June 15th)
– Finally we have got some evidence for the actual
site of a smelting furnace. This was located in one
of the Trial Pits and was represented by intense burning
of the surrounding soil. This Trial Pit also produced
large quantities of furnace lining. Meanwhile, work
continued on the investigation of the industrial deposits
under the timber trackway. |
Cleaning the industrial deposits under the timber
trackway
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Hannah working in the area of the possible smelting
furnace
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Day 14 (June
16th) – the last full day of the excavation.
Tomorrow the students will be returning to Birmingham.
The day was spent sampling the deposits under the trackway
and completing the final recording of the site.
The results of the excavation have
been very pleasing. We have now clarified the nature
of the industrial activity. It still seems likely that
the complex represents lead-smelting dating to the Roman
period. Further dating work and other analysis now needs
to be undertaken on all the samples collected to confirm
this interpretation. The Test Pits have now also indicated
the size of the complex and it is much larger than we
originally thought. It runs for at least 200m along
the edge of the bog and is at least 50m wide.
We have also obtained new information
on the nature of the later trackway. It now seems likely
that the timber elements provided a foundation for a
gravel track and prevented the track from sinking into
the bog.
Now that we have located a possible
furnace site, we are now keen to examine this feature
in more detail. Hopefully, we will be able to raise
the funds to carry out another season of work next year.
In the meantime we would like to thank both Cadw and
the University of Birmingham for their financial support
for this year and an especial thanks to all the Cambria
and Lampeter staff, the Birmingham students and the
other volunteers for making this season of work such
a success.
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Catherine completing a final plan
of one of the trenches
A final group photograph of the
Birmingham students |
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The following page is copied (with their permission) from Cambrian Archaeology.
