Myris asks for more info on the radiocarbon dates. It's interesting that he says he has heard nothing about them at all, except from this blog. Even more interesting that a good friend of his is actually a partner in this project, and if he knew anything, he would certainly have passed it on......
From my report of the 2013 MPP lecture in Moylgrove: Then Mike moved on to talk about the latest discoveries associated with C14 dating. He gave no actual dates, did not tell us where they had come from, and gave us no idea how many dates there are from the past and present excavations. Secrecy prevails. So we were forced to take everything on trust. Anyway, he claimed to have a sequence of dates ranging from the Neolithic to the Iron Age, some of which were associated with a series of hearths near the position of the Iron Age hearth discovered last year. I assume that they have found charcoal or other organic materials that have been dated. It looked as if the hearths were in more or less the same place, in a nice sheltered position beneath the crag, just above the grassy floor of the valley. Perfect camping places for hunting groups, or for quarrymen, or for jolly family barbeques on a summers evening, depending on your preferences........ That was all quite interesting. There was no mention of the big pit or stone hole which got so much attention last year. Wonder why?
As far as I can recall, this sort of statement has been repeated several times, in other contexts -- presumably referring to radiocarbon dates from the 2011 and 2012 digging seasons. So it's on the record that there are Neolithic and Iron Age dates which presumably support the MPP hypothesis in some way. So to the rumours, which I have picked up on from two different directions. Where there is an obsession with secrecy, rumours proliferate......
One rumour is that certain samples collected last year, which were assumed to be of Neolithic date, have actually given radiocarbon dates which place them in the Mesolithic or early part of the Holocene. The other rumour is that this has caused some internal difficulty regarding the "Neolithic Quarry" hypothesis, and for that reason the dates have been withheld pending further investigations. I assume somebody has gone back to the lab and said "Surely these dates can't be right? Might there be some mistake?" and that the lab has said "We stand by the results. No contamination, as far as we can see." (It happens all the time. I have been involved in this process myself, when the radiocarbon date from a rhinoceros scapula from Caldey Island proved to be very "inconvenient" to certain people....... and when C14 shell dates I obtained from fluvio-glacial deposits in Pembrokeshire were similarly disbelieved by people who should have known better.)
As I have said many times before on this blog, if the sediments beneath the famous "proto-orthostat" at Rhosyfelin contain charcoal or other organic materials which can be dated to the Neolithic, c 5,000 BP, that would support the MPP thesis of a Neolithic "quarrying floor" or surface on which the heroic quarrymen went about their business. As for the sediments in contact with the flanks of the big stone, or overlying it, these would of course have to be later Neolithic, Bronze Age or later for the quarrying hypothesis to stand up to scrutiny. My own guess is that there may have been quite young deposits on top of the stone, because its upper flattish surface was not buried very deeply beneath the present ground surface.
If, on the other hand, the material on the flanks of the stone and on top of the stone proves to be Mesolithic or substantially older than 5,000 BP, the Rhosyfelin diggers have a problem, because the hypothesis collapses. They might try and argue that the sediments are disturbed, and that older organic materials have been incorporated into younger sediments, but from what I have seen of the sedimentary layers, there doesn't seem to be any sign of disturbance. To repeat my old mantra -- it all looks perfectly natural to me, and is therefore nothing to get excited about.
I may be totally up the creek on all of this, and dates may shortly be released which support everything the quarrymen have said in public -- in which case I will eat humble pie. But until then, I will continue to ask for less speculation and more evidence. And, of course, for the immediate publication of the dates.