Blue Stones

George Carter not only researched the archaeology, local history and folklore of the Pebblebeds, and more widely, that of Devon but hewas also very knowledgeable about the local geology. He was the first to find rare radioactive nodules that occur in the red sandstones underlying the Budleigh Salterton Pebblebeds which he found on the beach as water worn specimens (Carter 1931; Perutz 1939). During his archaeological excavations of pebble mounds Carter recognized a particular type of stone that was different from all the others that he termed blue stones. The use of this term by him is particularly interesting as only a few years prior to Carter starting his excavations the geologist Herbert Thomas had published his findings that the bluestones of Stonehenge were derived from the Preseli mountains of Pembrokeshire, south Wales (Thomas 1923). Carter, then had his own blue stones but in comparison with those at Stonehenge they were tiny.
Prior to the 2008 excavations undertaken by the Pebblebeds Project Chris Tilley had been looking out for blue stones while carrying out field research on the heathlands. He never found any- not helped by the fact that he didn’t know what they looked like. Carter had not published photographs of any of his blue stones nor drawn any of them, and he did not seem to have kept any from his excavations. The blue stones that he found were probably primarily significant to him because of their blue colour- sacred in Indo-Ayran mythologies and associated with Indra the great father-god whose horse was blue. (see George Carter and the archaeology of east Devon). However, he had consistently recorded their presence and suggested that they were incorporated into geometrical patterns of pebbles on the surface, in and under pebble mounds. Notably they were present in the pebble cairn he excavated on Woodbury Common (see Background to the Project) and they were directly associated with what was in all probability a Beaker cremation burial and we know that the bluestones at Stonehenge were erected in association with its use as a Beaker cremation cemetery.
In a footnote to his paper ‘Pebbled Mounds’ he states that ‘these pebbles [those of the Budleigh Salterton pebble beds] are mainly a pale quartzite but occasional pebbles (1: 1000) are of dark or coloured igneous rock’ (Carter 1934: 4). Elsewhere he states ‘blue stones of various shades of colour and petrological nature (though of igeneous origin) occur locally…in the Bunter Pebble Beds” (1936: 2). In an unpublished book manuscript Carter states: ‘The regular use of the darker stones of the Budleigh Salterton Pebble Beds (other than black stones), which show colours ranging through many shades of blue from purple to grey, seems to indicate an insistent idea of the importance of this colour’ (Cater, ISCA ms, p. 95). Elsewhere Carter informs us that ‘some of the stones of Woodbury Common are rhyolites: most of the igneous rocks at Stonehenge are imported rhyolite” (ISCA: ms note p. 13).
At the start of the excavations of the Pebblebed Project in 2008 one important research question was whether we could identify the blue stones that Carter had reported and recorded. Once more Carter proved to be right! Once the surface vegetation and soil had been removed from the cairn surface we immediately found blue stones on the cairn surface in the south-east quadrant and elsewhere in the north-west and north-east quadrants. We recorded the presence of these blue stones by excavated metre square and pebble layer. Small numbers were recorded throughout the pebble layers of the cairn in the excavated south-east quadrant. On our plans these stones were recorded as CBS (Carter Blue Stone) and all these blue stones were collected as ‘special pebbles’ (see Poetics of Pebbles and Excavations 2008).

Figure 1. Smooth axe-blade shaped Carter blue
stone from the surface of the SE
quadrant of Tor barrow

Figure 2. A selection of Carter blue stones from
the 2008 Tor barrow excavations

There are a number of specific features of these blue stones that Carter does not mention which are potentially very important indeed in their interpretation. None of these blue-stones are pebbles. They differ from the pebbles in terms of (i) shape- they are all very irregular in form about 10-15 cm in size and the majority have at least one broken face the others being relatively smooth (ii) wetting the pebbles always brings out or activates their colours. By contrast these blue stones loose their blueness when wet becoming much darker. Their blueness is intensified when dry.
If the Stonehenge bluestones were transported to Wiltshire along the sea coast of southern England from south Wales they would be passing beneath the cliffs at Budleigh Salterton where the Pebblebeds were exposed. Might the local populations have seen this transportation of stones and been inspired to collect and use their own local blue stones that although tiny in comparison looked similar? Roger Taylor (project geologist) has examined the blue stones recovered from Tor barrow and has reported that they are quartzite, just like the other pebbles, but that they are highly unusual because they have not been subjected to the same weathering processes and have a different transport history. Their source, in contrast to that of the other pebbles, may be quite close to East Devon, perhaps from rock outcrops submerged under the English Channel or from Brittany or Normandy. As a consequence the rocks have not been rolled and ground down into pebble forms so much as the other stone material by the ancient Triassic river. This accounts for the irregular shape and form of these blue stones- they are not pebbles. What was the importance of these stones? First of all we need to emphasize that these stones were significant because of the manner in which they were noticeably different from all the other pebbles in form, colour and the manner in which they react to water.
Imagine the following scenario: bluestones are passing by Budleigh Salterton from south Wales on the way to Stonehenge. The local populations witnessed this (or these) events and perhaps those moving the stones sheltered in the mouth of the river Otter. The people of the Pebblebeds would have instantly recognized the similarity in colour, texture and composition of their blue stones to some of those being transported to Stonehenge. Of course their local blue stones were tiny in comparison but no less symbolically powerful so they incorporated them in their cairns. Carter mentions finding granite chunks from Darmoor and manganese ore, another non-local material, in some of his excavations.
• The Pebblebeds Project intends to identify possible non-local stones during excavations and investigate the possibility that some of the stones found in the pebble cairns might be derived from Dartmoor or even more distant places.

References
Carter, G. (1931) ‘An occurrence of vandiferous nodules in the Permian beds of South Devon’, Mineralogical Magazine Vol XXII. No 134: 609-13
Carter, G. 1936 ‘Unreported mounds on Woodbury Common’, Proceedings of the Devon Archaeological Exploration Society Vol II: 1-13.
Perutz, M. (1939) ‘Radioactive nodules from Devonshire, England, Mineralogische und Petrographische Mitteilunge 51: 141-61
Thomas, H. (1923) ‘The source of the stones of Stonehenge, Antiquaries Journal 3: 239-60