Another bluestone source identified

This is getting more and more interesting. There's an important revision to the article recently published by Mike Pitts in British Archaeology -- arising from the discovery of a rock outcrop at Pont Saeson, between Brynberian and Crosswell, which matches up with one or more fragments found in the Stonehenge digs. The authors refer to "rocks from undistinguished outcrops in the low ground north of Mynydd Preseli, close to Pont Saeson." This is important for a number of reasons:

1. It provides yet another example of entrainment from a very narrow zone (it seems to be about 3 km wide) which runs from Dinas Head SE towards Carningli, then to Carnedd Meibion Owen, Brynberian, Carngoedog and Foeldrygarn. This seems to confirm the thesis put forward by Lionel Jackson and myself in EARTH magazine at the beginning of this year -- namely that the entrainment of erratics has occurred along a very narrow contact zone, probably between Irish Sea ice and Welsh ice. Very soon I shall plot all these known sources on a map.

2. The authors stress that this bluestone source is not at all prominent -- just an undistinguished outcrop in a valley on the north flank of Preseli. This appears to be another nail in the coffin for the idea that stones were collected by Neolithic stone collectors from prominent hill masses that were "auspicious" or prominent in the landscape. Carn Clust-y-ci and Carn Llwyd, on the flank of Carningli, two other bluestone sources, are pretty unimpressive too. We must be talking here of glacial entrainment, not human collection.

3. The idea that some of the bluestones might have come from North Wales now appears to be unpopular again! Again, this makes glaciological sense -- if the stones at Stonehenge really are glacial erratics, then they should come from one source area or maybe from a number of sources approx on the same line, which was the route followed by the moving glacier.


Details:
British Archaeology
http://www.britarch.ac.uk/ba/ba109/interim.shtml
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Important revision to Stonehenge bluestone theory
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Rob Ixer and Richard Bevins