From Monday 10th until Thursday 20th July the Bancbryn stone alignment was examined by excavation. Four trenches were cut across the row revealing that the stones are within a thin peaty soil. The excavation confirmed that the area had never been subjected to ploughing and indeed the only evidence of human activity was the stone row itself. No dating evidence was found but the position of the stones within the profile was consistent with a prehistoric or early historic date. A much earlier natural flood water channel was found in the vicinity of one of the stones. A draft report has been produced and will appear here in the near future. In the meantime a few photographs will hopefully illustrate what was found.
Plan showing the position of the stones and the excavation trenches
All the stones were within a shallow peaty soil that overlay a hard compacted subsoil (Scales 1m and 250mm).
There was no trace of any socket hole or propping stones, but given the relatively small size of the stones they could have been either placed directly on the ground or more probably inserted into a small cut in the contemporary turf and topsoil. Both scenarios are consistent with the evidence. The position of the stones may at face value suggest a more recent date, however, frost heave has almost certainly artificially raised the stones. Stone conducts cold more than the surrounding peat and every winter (perhaps on several occasions) an ice wedge will have developed under the stones pushing them upwards. Following the thaw the stones would descend, but each time a few grains of soil will have settled under the stones resulting in very gradual upward movement. The evidence is therefore entirely consistent with the stones being placed in shallow sockets in the prehistoric period and as the soil profile has developed the stones have migrated upwards. The appearance of the stone alignment today may therefore be very similar to its original form, although it is likely that some of the stones have fallen from their original position. The depth of the stones is not consistent with the early 20th century suggested by the Cotswold Archaeology report (Wright, J. 2012, 31) unless the stones had been inserted into sockets. It is of course not possible to dismiss the idea that they were placed here much earlier in the historic period since their position within the stratigraphy would be similar. There is however no known context for such arrangements of stones within the medieval period in this type of environment. A date earlier than the post-medieval period is consistent with the evidence although the lack of finds or any environmental data to support this conclusion introduces an element of uncertainty. Ironically the lack of dating evidence provides a modicum of support for the prehistoric interpretation since previous work at stone alignments has indicated a paucity of artefacts (e.g. Cholwichtown on Dartmoor where despite total excavation no artefacts or dating material was recovered (Butler, 1994, 109)).
A cut identified next to one of the excavated stones was initially identified as a possible quarry. Further work revealed that it formed part of a natural flood water channel. View from north east (Scale 250mm).
Butler, J., 1994, Dartmoor Atlas of Antiquities, Volume Three, The South-West, Devon Books, Tiverton