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Excavations 2008 Preliminary notes on Tor Barrow, Colaton Raleigh Common, East Devon After removing surface vegetation and soil this proved to be a perfectly circular pebble cairn 6m in diameter and about 0.7 m high in the centre (Figs. 1 & 2).
Figure 1. The barrow prior to excavation after
Figure 2. The cairn after removing surface vegetation This and a smaller cairn 2.5m to the south-east appear to be aligned to the rising sun on the midwinter solstice. The cairn did not have a kerb of larger pebbles. The perimeter was marked out by a series of large pebbles set with their long axis in a vertical plane at c. 0.5 m intervals. Within the cairn structure other larger pebbles were similarly set perhaps acting as internal revetments. The smaller pebbles comprising the majority of the cairn were horizontally laid. In all from the quarter section excavated so far 14 large pebbles were found. These almost certainly came from the bed of the nearby stream since such large pebbles are rarely found exposed elsewhere on the Pebblebed heathlands. In the centre of the cairn ten distinct layers of pebbles were exposed in the section (Fig 3).
Figure 3. Part of the section through the centre of The old ground surface has not yet been reached here in the excavation and there may be as many as twelve or more layers of pebbles. These pebble layers were stabilized by placing thin lenses of sandy soil between them before the next layer of pebbles was laid down. The pebbles were carefully placed horizontally across the cairn surface. The material was not dumped or thrown. The pebbles are of a fairly uniform (baking potato) size around 7-10 cm in length. About 30-40% are broken which varies between layers. Most are oval in shape, a few are round. About 20% are irregular in form. The source of the majority of the material was probably local although special pebbles may have been brought from a considerable distance away. There may also be exotic non-local stone including granite from Dartmoor. The pebbles in the cairn differ substantially from those found on the beach at Budleigh Salterton below the pebble bed exposure in the cliffs. Wave action has altered the beach pebbles which are generally thinner and flatter so it appears that only special pebbles might have been collected from the beach. A 2x 2 m test trench was dug to examine pebbles in the natural (Fig 4).
Figure 4. Test trench in natural This showed: a) that there were far fewer pebbles; b) they were much smaller; c) that their spatial distribution was random or unstructured compared with the cairn layers; d) there were no or only a few special (i.e, beautiful multi coloured and interesting pebbles with quartz veins and a mottled surface).
Figure 5. The extent of the 2008 excavations
Figure 6. Cairn plan and grid system Of these the old ground surface under the cairn has been exposed over an area of 5 sq m. The lowest pebble layers in the cairn centre have yet to be removed. The cairn was excavated by pebble layer of which there were two on the edge and so far ten in the middle. Each pebble layer was photographically recorded in metre squares. Each pebble was then colour coded according to basic colour categories (red, brown, yellow, grey etc.) and whether it had a multi coloured or mottled surface or had quartz stripes, veins or other inclusions on the plan. All broken pebbles were recorded on a separate plan by metre square. The pebbles were then removed and the length of each whole pebble was measured and each pebble was weighed and classified according to whether it was broken, oblong, round, oval or irregular in form. The pebbles were washed and special pebbles kept and bagged up by metre square. After analysis we will know how many different coloured pebbles there are by m sq and layer, their spatial distribution and the size, weight, morphology and the frequency of special pebbles. Exactly the same recording methodology was used for the test trench so we will have precise statistics to compare. The sections were photographed and drawn and drawings made of various pebble levels in the cairn. Four Firs, Woodbury, Devon A small section which had been cut into the NE barrow at Four Firs by an unknown party was cleaned up, recorded and back filled. The section was approximately 80cm in length and 80cm in depth. On cleaning it became apparent that the barrow was composed of at least two layers of deposited soil. The lowest layer (context 012) is a reddish-orange colour typical of this region. It is possible this constitutes a heaped up ploughsoil. It could not be determined if this was the natural sub-soil at the base of the barrow in the section. The natural was not reached, as the remit of the excavation was simply to clean up the existing section and record it. However the natural at Four Firs as elsewhere across the Pebble Bed heathlands is grey gritty sand and pebbles. This layer was followed by context 0011, a mid-brown friable soil layer, and by a further reddish-orange soil (context 0010), interpreted as re-deposited ploughsoil. The soil from the original excavation of the hole, and from the archaeological excavation was sieved. No finds came from the hole.
Figure 7. Section through the north-east mound at Four Firs The barrow was surveyed by EDM, and it was noted that the barrow is surrounded by a bank, which encircles the barrow in an arc on one side, effectively delimiting the area between the two roads in the cross-road. A comparable feature was noted at two other barrows at Four Firs. Notably the composition of the barrow, on the basis of this section, is completely different from the heathland barrows which are largely composed of pebbles derived from the pebble bed deposits. Coupled with the bank features described above which are unknown in prehistory, everything points to this barrow being an ornamental landscape feature of the 18th or 19th century rather than a prehistoric monument. The material to make up this mound must have been carted up from the lowland surrounding the Pebble Bed heaths. A likely source is soil taken away whilst digging the ornamental lake in Bicton Park |
