Quote from Ixer and Bevins 2011:
"This is the first time that any lithics from Stonehenge have been unequivocally assigned to an area of a few square metres, namely to within a very small single outcrop or couple of outcrops......"
Article: "CRAIG RHOS-Y-FELIN, PONT SAESON IS THE DOMINANT SOURCE OF THE STONEHENGE RHYOLITIC ‘DEBITAGE’
Rob Ixer and Richard Bevins, Archaeology in Wales 50, 2011, pp 21-31
How many times have we heard the claim that geologists Richard Bevins and Rob Ixer have identified the source of certain foliated rhyolites in the Stonehenge debitage to "within a few square metres" on the Rhosyfelin rock face? Too many -- and as we have pointed out very often, the claim was unreliable when it was first made, and it remains unreliable today since no new evidence has been published to support it. Other geomorphologists who have visited Rhosyfelin are just as sceptical as the three of us who wrote the papers questioning the reliability of the "bluestone quarry" hypothesis:
Brian John, Dyfed Elis-Gruffydd and John Downes. 2015. OBSERVATIONS ON THE SUPPOSED “NEOLITHIC BLUESTONE QUARRY” AT CRAIG RHOSYFELIN, PEMBROKESHIRE". Archaeology in Wales 54, pp 139-148. (Publication 14th December 2015)
Brian John, Dyfed Elis-Gruffydd and John Downes (2015a). "Quaternary Events at Craig Rhosyfelin, Pembrokeshire." Quaternary Newsletter, October 2015 (No 137), pp 16-32.
There have been a number of posts on this blog on this subject, including the following:
The trouble is that the claim, having been prematurely and incautiously made, has been accepted as the truth by archaeologists who cannot realistically be expected to know any better -- and so the myth, having been manufactured, continues to roll. One of the most absurd byproducts of it is the claim by Prof MPP that he now has the precise location of an "extraction point" from which one of the Stonehenge bluestone monoliths was taken. He says that he knows this because the geologists have told him it is true....... it's always a good trick to avoid responsibility for a statement by pretending that you have it on the good authority of somebody who is more expert than you are.......
So why is the "few square metres" claim unreliable?
Firstly, none of the thin sections from the foliated rhyolite debitage at Stonehenge precisely matches the published thin section from locality 8 near the tip of the Rhosyfelin spur. There is quite a lot of variation in the "jovian fabric" of the samples from Stonehenge and in the samples from the Rhosyfelin - Pont Saeson area. It's all very well for the geologists to say "We are the experts. trust us. We know what we are talking about." In that case, show us the colour of your evidence, and we might believe you.
Secondly, we have received no answer to this point: if the jovian fabric shown in the Location 8 thin section is typical of one particular foliation layer on one particular fracture plane, surely that "signature" will also exist wherever else that foliation / fracture plane relationship occurs? By my reckoning, similar if not identical samples might also have been taken from approximately 40 sq metres of the currently exposed rock face, and also from any number of outcrops within and outside the Brynberian river valley, and also from parts of the crag subsequently removed by glacial erosion and other processes. The geologists cannot prove that the "similar" or "related" samples found in the Stonehenge rhyolitic debitage have not come from hundreds of metres or even kilometres away. It is no argument to say that all of the other samples taken in the Pont Season / Rhosyfelin area are different from that taken from Location 8. Of course they are different, since they came from different positions in the rhyolitic sequence, some from above the "special" foliation plane and some from below it. You would expect them to be different -- some very different indeed, and others just slightly so............
Thirdly, we must question the claim by Ixer and Bevins that in excess of 99.9% of of the Stonehenge rhyolitic ‘debitage’ can be petrographically matched to the rhyolitic rocks found around Craig Rhosyfelin and Pont Saeson. It is largely because of that statement that the media have become obsessed with the idea that the source of at least some of the bluestones has now been found. However, as I have pointed out before on this blog, the 99.9% figure is meaningless, since we have no idea how many rhyolite fragments have been examined, how they were distributed in the Stonehenge Layer, how close together the collection points were, and what degree of selection was employed in the collection of samples during the respective digs. Percentage figures like this should never be used without a full presentation of the numerical data from which they are supposedly derived. In any case, we have no idea which rhyolites occur in the Stonehenge Layer in those large segments of Stonehenge that have not been excavated, and in the soils of the area around Stonehenge, and what their frequency may be.
Abundant over-egging of the pudding going on here. I'm not questioning for a moment the competence of the geologists concerned. Just their tendency to go off-topic. They have a lot to answer for, since they are the ones who set this whole quarrying wild goose chase going when they would have been far wiser to simply present their evidence without seeking to over-emphasise its archaeological importance.
Will the geologists now please retract the "few square metres" claim, and allow common sense to prevail?