As readers of this blog will know, we have often discussed sampling bias, the caveman effect, and artificial significance. Here we are again, at the end of another dig, in the MPP lecture season, where everybody prepared to listen will be told yet again that Carn Goedog and Rhosyfelin are of earth-shaking significance. They are the great bluestone quarries, now mythologized in much the same way as Stonehenge, with high pressure PR work and judiciously placed articles in the archaeological magazines. This, of course, in spite of the fact that the EVIDENCE for quarrying just does not stand up to scrutiny.
As readers will know, my thinking about Rhosyfelin is that this site has nothing whatsoever to do with either monolith extraction or with the human transport of big stones to Stonehenge -- but that it might have been used intermittently during the Mesolithic, Neolithic and Bronze Age for the fabrication of cutting or slicing implements, given the lovely sharp edges which this rhyolite gives. So in that sense, the rock might have been used opportunistically. But maybe not. Maybe the good old folks just liked being there in the woods, doing a bit of fishing, gathering berries, listening to the birds, and sheltering from the wind. Later on, some Iron Age people used this sheltered site against a craggy rock face in a wooded valley as an encampment -- maybe just over the winter months.
My thinking about Carn Goedog is that there is no prehistoric quarry there either, and that there was not actually any need for Neolithic quarrying activity on the tor, given the readily available spotted dolerite slabs, pillars and boulders scattered as glacial erratics across the Preseli landscape. If tribesmen had wanted monoliths for building into cromlechs, or for use as standing stones, they could have just picked them up, very close to the places where they were needed. People camped in the vicinity, and in that sense used the site, but bits of charcoal, ancient soils and radiocarbon dates do emphatically NOT indicate quarrying activity.
We cannot avoid talking about artificial significance. Archaeologists don't think about it often enough. We could also call it sampling bias. It is pretty clear that MPP and his colleagues have invested these two sites with significance because (a) they have decided in advance that they were Neolithic quarrying sites, and (b) simply because that is where they have dug. It is perfectly reasonable to think that if they had visited almost any sheltered craggy site in a north Pembrokeshire valley (and there are many of them) and subjected that site to the same level of scrutiny as applied to Rhosyfelin, they would have found virtually the same assortment of features -- including charcoal, hazel nuts and fireplace traces. I have made this point here:
The same is true of Carn Goedog. There is nothing exceptional about it, apart from its close proximity to a droving route. If the archaeologists had dug at Carn Bica, Carn Breseb, Carn Arthur or any of the other Preseli tors, the strong probability is that they would have found traces of occupation. After all, some of these tors have prehistoric enclosures built against their rocky flanks. The diggers would have found a litter of large blocks and slabs partly buried in the turf, traces of temporary encampments, charcoal and assorted other organic and dateable materials. If they had bothered to check, they would have found a similar Pleistocene stratigraphy too.
The point is that the archaeologists have never even tried to demonstrate that these two so-called quarrying sites are exceptional or unique. There have been no control digs at any other sites with similar physical and locational characteristics -- and the sampling bias is very strong indeed.
(I have directed exactly the same sort of criticism at the geomorphologists who recently published a set of cosmogenic dates for the northern fringes of the Isles of Scilly, in support of their assumed ice limit. All of the dates were obtained from inside the assumed limit, and none of them were from outside it -- so there were no controls in the sampling programme. I still cannot believe that such an elementary error in field sampling design was made by a group of experienced researchers.......)
As noted by Darvill and Wainwright in the recent Pembrokeshire County History volume, the distribution of recorded sites is not necessarily the same as the pattern of prehistoric activity. A site does not become significant simply because it has been worked on. I agree with that, and it's a point made by other archaeologists as well. In any investigation, especially if you are seeking to demonstrate something quite exceptional (such as Neolithic monolith quarrying), you have to show that other similar places are unexceptional. Do Rhosyfelin and Carn Goedog show features that are not normal? The archaeologists have not even bothered to try to demonstrate that. That's bad science.
To come back to Hitchens's Razor, the onus is on MPP and his colleagues. Their quarrying thesis is simply rejected out of hand, until the archaeologists can come up with something more convincing.