The following page is copied (with their permission) from Cambrian Archaeology.
   

 

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

Cadw logo
Welsh Assembly Government logo
University of Birmingham logo

 

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.

Site Director, Nigel Page, guides Eifion Jenkins who is driving the digger

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

The excavation attracts its first visitors

The students taking shelter in the portacabin during a heavy shower

The students taking shelter in the portacabin during a heavy shower

Cleaning the upper surface of the industrial deposits

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

Cleaning the timbers of the trackway

 

The excavation taken from the field to the south. It is possible that the smelting furnaces are located in this field.

The excavation taken from the field to the south. It is possible that the smelting furnaces are located in this field.

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.

Preparing a scale plan of the Trench 6

Preparing a scale plan of the Trench 6

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

Excavating one of the Test Trenches in the neighbouring field

 

Our neighbours remain fascinated

Our neighbours remain fascinated

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

Spraying the timbers of the trackway to prevent them from drying out

 

A fragment of the furnace lining and the metal slag

A fragment of the furnace lining and the metal slag

The possible Roman glass from one of the Test Pits

The possible Roman glass from one of the Test Pits

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

Richard Jones showing around visitors from Ysgol Llangynfelyn

 

Excavating one of the Test Pits

Excavating one of the Test Pits

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’.

Details of the timber surface
 

Details of the timber surface

Details of the timber surface

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.

Section of one of the Test Pits showing the charcoal and industrial debris overlying the brown peat of the bog

Section of one of the Test Pits showing the charcoal and industrial debris overlying the brown peat of the bog

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

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

Surveying in the area of the main trench

 

 

Nigel Nayling from the University of Lampeter collecting samples of timber from the trackway

Nigel Nayling from the University of Lampeter collecting samples of timber from the trackway

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

The Birmingham students proudly displaying some of the timber samples collected from the trackway

 

Several of the vertical stakes hammered into the peat either side of the trackway have sharpened ends

Several of the vertical stakes hammered into the peat either side of the trackway have sharpened ends

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

Cleaning the industrial deposits under the timber trackway

 

Hannah working in the area of the possible smelting furnace

Hannah working in the area of the possible smelting furnace

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.

Catherine completing a final plan of one of the trenches

Catherine completing a final plan of one of the trenches

A final group photograph of the Birmingham students

A final group photograph of the Birmingham students