Some of the ideas discussed in this blog are published in my book called "The Bluestone Enigma" -- available by post and through good bookshops everywhere. Bad bookshops might not have it....
To order, click HERE
Some of the ideas discussed in this blog are published in my book called "The Bluestone Enigma" -- available by post and through good bookshops everywhere. Bad bookshops might not have it....
To order, click HERE
Thursday, 19 October 2017
There are few things on this planet more impressive than a big glacier in full flow. This is the Lambert Glacier in Antarctica. It flows into the Amery Ice Shelf. Click to see the image enlarged.
At the base of this NASA image, it is about 30 km wide, but at the big confluence with Fisher Glacier it is about 60 km wide. Across most of the area shown in the image, the glacier velocity is between 500 m and 800 m per year, but the velocity speeds up as the ice gets towards the ice shelf, with a flow rate of c 1 km per year. Surging glaciers sometimes move faster than that, but this is assumed to be the fastest-flowing big outlet glacier on the planet.
The streamlines or flowlines are shown here in extraordinary detail.
Here is another image -- this time from Google earth. You can see many of the same features.
Wednesday, 18 October 2017
On looking back at the literature over the past couple of years, I have been reassessing the following:
Parker Pearson, M., Pollard, J., Richards, C., Schlee, D., and Welham, K. (2016). "In search of the Stonehenge Quarries," British Archaeology, Jan/Feb 2016, pp 16-23.
Parker Pearson, M. (2016). "Secondhand Stonehenge? Welsh Origins of a Wiltshire monument." Current Archaeology 311 (2016), pp 18-22.
Both of these articles were published in the spring of 2016, about three months after the publication of the QN article by Dyfed Elis-Gruffydd, John Downes and me. That article, peer-reviewed and revised on the advice of referees and editor, described the landforms and stratigraphy at Rhosyfelin and made the point that there was no trace of a Neolithic bluestone quarry at the site, no matter what the geological affinities with Stonehenge might be. Parker Pearson, Pollard, Richards, Schlee and Welham (all senior archaeologists) must have known about the paper, and they must all have read it. They must also have been fully aware of the "media storm" that followed in December 2015 when their big Antiquity paper was published within a few days of our second paper in Archaeology in Wales. There were literally hundreds of write-ups in the press and in magazines, and on digital media as well. The great majority talked about the dispute. Assorted academics made comments on the record, flagging up the fundamental disagreement between one group of specialists and the other.
In spite of all this furore, the two articles mentioned above blithely promote the bluestone quarrying hypothesis and make no mention of any inconvenient evidence or academic dispute.
So there are two question here. Did the authors of the two articles mentioned above have time to react to the publication of our two articles in November and December ? And should they have changed their texts, even a proof stage, in order to inform their readers that their assumptions about bluestone quarrying were not universally accepted? The answer to the first question is undoubtedly "Yes". They had two months to make corrections and adjustments, and if they had requested relatively minor changes I am sure that the Editor would have agreed. And the answer to the second question is also "Yes" -- since a responsibility is always placed upon authors to provide reliable information and to avoid the pretence of certainty in cases where there is doubt. As mentioned in our earlier post
a deliberate failure to cite "inconvenient" publications or data is tantamount to falsification, fabrication and the intentional distortion of the research situation. That is rather a serious matter.
I haven't checked up on all the universities represented here, but MPP works at University College London, and all universities have Ethical Guidelines which staff and researchers are supposed to adhere to. The internal guidelines generally insist on publication of research results in a responsible and timely manner, in a form accessible to other interested parties, with research results preserved for future reference in cases where replication might be needed. It goes without saying that all academic authors must also adhere to COPE guidelines, which state:
Researchers should present their results honestly and without fabrication, falsification or inappropriate data manipulation.
Reports of research should be complete. They should not omit inconvenient, inconsistent or inexplicable findings or results that do not support the authors’ or sponsors’ hypothesis or interpretation.
Authors should cooperate with editors in issuing corrections or retractions when required.
Authors should represent the work of others accurately in citations and quotations.
New findings should be presented in the context of previous research. The work of others should be fairly represented. Scholarly reviews and syntheses of existing research should be complete, balanced, and should include findings regardless of whether they support the hypothesis or interpretation being proposed.
From COPE website: Wager E & Kleinert S (2011) Responsible research publication: international standards for authors. A position statement developed at the 2nd World Conference on Research Integrity, Singapore, July 22-24, 2010. Chapter 50 in: Mayer T & Steneck N (eds) Promoting Research Integrity in a Global Environment. Imperial College Press / World Scientific Publishing, Singapore (pp 309-16). (ISBN 978-981-4340-97-7)
Well, I have grumbled before about the complete lack of research diaries or field reports representing seven seasons of excavations in the field. Parker Pearson and his colleagues have behaved neither in a responsible nor a timely fashion. Nor is there a single paper which presents in a satisfactory and scientific manner the findings in the digs at Rhosyfelin, Carn Goedog and a number of other sites. (The paper published in Antiquity in December 2015 is far adrift of the standard required, and does not withstand scrutiny.)
Mike Parker Pearson, Richard Bevins, Rob Ixer, Joshua Pollard, Colin Richards, Kate Welham, Ben Chan, Kevan Edinborough, Derek Hamilton, Richard Macphail, Duncan Schlee, Jean-Luc Schwenninger, Ellen Simmons and Martin Smith (2015). Craig Rhos-y-felin: a Welsh bluestone megalith quarry for Stonehenge. Antiquity, 89 (348) (Dec 2015), pp 1331-1352.
The published material in the British Archaeology and Current Archaeology articles is examined in these two blog posts:
It's pretty clear that the COPE guidelines have been broken in both of the articles cited at the head of this post --since they have wilfully ignored two relevant -- but seriously inconvenient -- papers that should have been cited and discussed. This constitutes scientific misconduct. The only extenuating circumstance is the limited amount of "revision time" available to MPP and his colleagues between our publication dates and theirs.
So let's be forgiving for the moment. But if this pattern of behaviour (ie the wilful refusal to acknowledge the existence of "inconvenient" research) is repeated in future publications, I might start getting upset.
Tuesday, 17 October 2017
My favourite book of all time is "Molesworth", written by one genius (Geoffrey Willans) and illustrated by another (Ronald Searle). In one of the priceless episodes our hero Molesworth has a daydream in which he finds himself together with other "lusty skolars" in an Elizabethan college run by a psychopath called Doctor Kurdling.
Our hero argues with the evil doctor about the existence of America, and gets six of the best with the cane -- after which Kurdling says: "...that will teach you not to alter the ignorance of a lifetime!"
Here endeth the parable for today........
In the bad old days, before the enlightenment and before scientists had been invented, Jesus Christ went hoofing about in Palestine doing his preaching. Almost always he used similes, metaphors and especially parables to put his message across to his listeners, who were in general simple folk who had not had much in the way of education. Most good stories, whether for adults or very small children, are also parables or allegories, sending messages about ethical issues or about "the truth of things" in attractively packaged formats. I hesitate to compare myself with Christ, but I have found in the course of teaching university students and members of the public that there is no point in talking about landscape-forming processes involving glaciers or rivers or deserts if the listener does not have a mental picture of what these things actually look like. Nowadays the level of awareness of natural phenomena is much greater than it was 40 years ago, because images are thrown at us all the time via TV, cinema, computers, tablets and so forth. But the analogy still works, if I as a teacher want you, as a student, to understand what I am talking about.....
When I sit on a stone on a mountain top, looking down at a landscape below me, I instinctively recreate in my mind's eye what it might all have looked like when covered by ice, or partly submerged by the sea, or affected by tundra rather than deciduous forest conditions.
So I was rater chuffed the other day when I was idly scanning through (as one does) some NASA images from Antarctica, I came across an ice stream image in which showed two branches of an ice stream on the edge of the West Antarctic Ice Sheet. Between the two branches there was an ice-covered upland maybe 200 km long by about 50 km wide, and the western ice stream branch had a spectacular 90 degree bend in it as it swung around the outer edge of the upland. Immediately I thought "Irish Sea Glacier and the Welsh Ice Cap!"
So here we are. The top image is my latest recreation of the Anglian (?) glacial situation in SW Britain, and below it is something I created last night, involving image resizing, image superimposition, addition of colour, instant alpha, and adjustments in transparency. I had fun! The resultant image does not involve any horizontal distortion, so it is not a perfect match for that went on during that big glacial episode around half a million years ago. You seldom get perfect matches in nature. But it's near enough, with the main ice stream running down the western side of Wales and then swinging into the Bristol Channel, forced by powerful ice pressure from the west. To the east of the Welsh uplands there is another ice stream, replicating the ice stream that came in across the Cheshire Plain and into the west Midlands. And over Wales itself we see an undulating ice cap surface within which it is difficult to pick out individual glaciers or drainage routes. That is probably not far off the way it was........
Isn't nature wonderful?
Sunday, 15 October 2017
Many readers have apparently not realised that in association with the paper on Rhosyfelin, published in December 2015, we also published a glossary and photo gallery showing all of the features assumed by the archaeologists to have been man-made. We appended notes explaining why these features should NOT be considered to have anything to do with Neolithic quarrying activities.
I am increasingly struck by the fact that if we had not examined and photographed this dig site, while work was in progress, there would be nothing on the record in the way of evidence to contradict the fantastical interpretations of a group of archaeologists who were hell-bent on finding a quarry. Neither would there be any basis on which the question the interpretations of this site as published by Parker Pearson et al in December 2015. That was all down to a chance set of circumstances. First, there was open access to the site, adjacent to a public footpath. Second, a group of us were rather interested in this site and were more than a little worried about the high-profile "spin" that came from MPP and others. Third, we lived close enough to the site to visit it frequently, in spite of the fact that the diggers never invited us to take a look.
I hope that the scientific community is grateful to us for services rendered.
But it's a scary thought. How many other archaeological digs are opened up and then filled in again in conditions of great secrecy, without any independent scrutiny ever being brought to bear on the so-called "evidence" presented by the diggers themselves, and on the conclusions drawn?
Supplementary Information: Photo Gallery
Brian John, Dyfed Elis-Gruffydd and John Downes.
The paper itself:
OBSERVATIONS ON THE SUPPOSED “NEOLITHIC BLUESTONE QUARRY” AT
CRAIG RHOSYFELIN, PEMBROKESHIRE".
Archaeology in Wales 54, pp 139-148. (Publication 14th December 2015)
One of the Stonehenge sandstone lumps. Note how big it is -- about 45 cms long,
with a weight of 8.5 kg.
I think I forgot to mention this little note before. It has been posted on the Academia web site, but there is no citation or date. So it looks as if it has never been published. But the info contained is interesting!
Palynology, age and provenance of the Lower Paleozoic Sandstone of Stonehenge
Stewart Molyneux, Richard Bevins, Rob Ixer and Peter Turner
Shouldn't that be "Palaeozoic"??
The bluestones comprise a variety of volcanic, intrusive and tuffaceous igneous rocks, along with rarer sandstones. The last include the ‘Altar Stone’, two buried orthostats and a number of sandstone blocks in the debitage. The Altar Stone is petrographically similar to fine- to medium-grained calcareous sandstones in the Lower Devonian Senni Formation of South Wales. Sandstone fragments from the debitage, however, include specimens of greenish-grey, indurated, fine-grained, feldspathic sandstone that have been subjected to low-grade metamorphism, with a suggestion of a spaced cleavage. They are more deformed than the Devonian sandstones exposed in South Wales, form a coherent lithological group, now referred to as the ‘Lower Palaeozoic Sandstone’, and contain characteristic clasts of dark mudstone.
The palynological data, coupled with petrography, show that the Lower Palaeozoic Sandstone of Stonehenge is not older than Late Ordovician, and it is most probably from a Late Ordovician unit in the Welsh Basin. However, the possibility that it is from a Welsh Basin Silurian unit cannot be discounted without more information on acritarch assemblages from Silurian sandstones, including the nature of any recycling.
Saturday, 14 October 2017
Another geology paper on the bluestones, and another case of wilful negligence. That's the very least we can say about it -- and maybe we should be saying something a good deal stronger....
The paper in question is by Rob Ixer and Richard Bevins (2017), a feature article in "Geology Today" called "The Bluestones of Stonehenge." (Vol 33, No 5, Sept - Oct 2017, pp 184-187. You can see it (maybe) online here:
It's not a paper intended for archaeologists or the general public, but for people interested in geology. So we would expect something scientifically accurate, since geology is generally considered to be a science. It's also a feature article, meant to summarise the state of play in an entertaining way. And what have we got?
Well, it's nicely laid out and lavishly illustrated, as you would expect. Most of the text consists of an update from the geologists on the latest bluestone provenancing research -- so we have heard almost all of that before. The authors say that they consider a bluestone to be "any non-sarsen rock used as an ‘orthostat’ or standing stone" found in the inner circle and horseshoe at Stonehenge. They mention sarsens very briefly, and say they "may only have been moved dozens of kilometres" from their sources. On the other hand, they may all have come from the immediate vicinity, and it's careless of Ixer and Bevins not to mention that. Most of the geological core of the paper is uncontroversial, although they do claim that they corrected the interpretations of the OU team on the origins of the spotted dolerites, moving the likely source from Carn Meini to Carn Goedog and Cerrig Marchogion. I thought that the OU team said that long ago, and that the Ixer / Bevins work simply confirmed their suspicions? Then they move on to the 2 dacite and 2 rhyolite orthostats, and "go underground" in referring to the buried stumps which appear to be a mixture of tuffs and sandstones. After that, the references to rock types are all linked to the debitage, which is "dominated by a very distinctive, strongly foliated rhyolitic tuff and by more variable, well cleaved argillaceous tuffs, as well as with lesser amounts of an indurated Lower Palaeozoic sandstone which shows a poor fracture cleavage." There is a fundamental illogicality here, since according to the Ixer / Bevins definition anything that does not come from an orthostat should not be counted as a bluestone. It may be that the debitage is indeed made up of smashed-up standing stones -- but it may also be that the debris has nothing to do with standing stones and has come from smaller and inconvenient erratics found on the site. This possibility should at least be admitted.
There are a couple of paragraphs on the sandstones -- the Altar Stone and the Lower Palaeozoic (probably Upper Ordovician) sandstone. Mill Bay is eliminated as a source for the former, with the evidence now pointing to the Senni Beds somewhere or other. They don't speculate as to where the Lower Palaeozoic rocks might have come from, but the assumption is "somewhere in north Pembrokeshire", as we have seen in earlier publications. There is a mischievous hint that "Ice Age proponents" are rather careless when it comes to adventitious material at Stonehenge -- but the authors should know full well that Olwen Williams-Thorpe, Geoffrey Kellaway and I have always been very careful, when referring to a "wide range of rock types", to eliminate road stone and other rubbish carried onto the site. It's a bit silly to hint at our scientific incompetence -- especially in the light of the behaviour of the authors themselves............ Stones and greenhouses come to mind ...... so read on, dear reader.
In review or feature articles of this sort, the authors have to say something significant, so the last part of this one involves a discussion of the human transport routes for the bluestones, accompanied by the usual map which we have all seen a thousand times before. (Yes, they are assuming, in all of this, the correctness of the human transport hypothesis, and yes, that is bad science, but we have got used to it by now.) Because the "new" provenances for bluestone orthostats and debitage happen to be on the northern flank of Preseli, Ixer and Bevins say that rules out Milford Haven and sea transport, and so they promote the MPP hypothesis of the overland or A40 route instead. They throw in a reference to the Steep Holm glacial erratics here as well, which I find quite mystifying, since they have nothing whatsoever to do with the matter in hand, and since nobody, as far as I know, has argued in print that they were "abandoned bluestones" dropped by Neolithic seafarers. They are simply taking pleasure in putting up an Aunt Sally in order to knock it down.
Rhosyfelin -- the rock face, carefully cleaned and presented for public approval.....
So -- inevitably -- we come to Rhosyfelin and the source of some of the rhyolite debitage. This is where the science goes seriously cockeyed. The authors refer to "a north-west facing planar face". It is nothing of the sort, as I have frequently shown on this blog. The rock face reveals multiple planar surfaces, not just one. It is broken up by multiple fractures, and some bits of the rock face project more than 1.5 m out beyond other bits. They say the face "does not look natural" -- that's a highly subjective judgment with which I and many other visitors to the site disagree. One small blessing is that the authors do not say in this article that they have provenanced foliated rhyolite fragments to "within a few square metres."
But Ixer and Bevins say this: "Subsequent archaeological excavations have shown features consistent with ancient quarrying." That's for Rhosyfelin. A little earlier in the paper, with reference to Carn Goedog, they say this: "......very recent excavations at Carn Goedog have revealed evidence for Neolithic working of the outcrop (Parker Pearson and others, in press)". The implication is that a new paper is on the way, which will enumerate the evidence. But there is no such reference in the "suggestions for further reading", and from what I can gather the only paper to which we can all look forward is another general one from MPP which might not even be peer reviewed. Perhaps Ixer and Bevins will enlighten us as to the nature of this paper, and tell us when and where it will be published. Until then, we will treat this as a false citation.
Now let's get serious. Ixer and Bevins have told the readers that there are "features" and "evidence" pointing to Neolithic quarrying or working, at Rhosyfelin and Carn Goedog. That, as we all know, is just part of the story, and the authors have known, ever since 2015, that there are two peer-reviewed papers in the literature which have analysed all of the cited "evidence" and have concluded that the described features are entirely natural. Not only that, but the papers both suggest that some of the evidence cited by the MPP team (including Ixer and Bevins as senior authors) may actually be best described as artifices created by the diggers themselves during their ongoing excavations. Just in case anybody has failed to encounter them, here are the papers:
Brian John, Dyfed Elis-Gruffydd and John Downes (2015). "Quaternary Events at Craig Rhosyfelin, Pembrokeshire." Quaternary Newsletter, October 2015 (No 137), pp 16-32.
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)
To the best of our knowledge, not one of the 14 authors in the MPP team has cited these easily available and much-read papers in any of the "bluestone" papers published over the past two years. So are they terrible papers? Well, they are quite short, but they are also detailed, and they were submitted through the normal channels to two journal editors, peer-reviewed blind, revised appropriately, and then published under strict editorial control. People might not like them, but they are there, on the record. Not one of our pieces of evidence has been challenged, and not one of our deductions or conclusions has been disputed in print or even off the record. So have 14 authors simply chosen to ignore them, in the hope that they will go away? So it would appear. I can understand why archaeologists might not want to cite the two papers, since they are not scientists, and our papers are seriously "inconvenient" -- but for two senior earth scientists to do the same is unforgivable. They have read the papers in detail. They understand exactly what we are presenting in the way of evidence, and they know the full implications of our conclusions. And yet they have chosen to live in a state of denial, refusing to cite and refusing to engage. Why? Maybe because there are no bluestone erratics scattered around on Salisbury Plain? I just cannot understand the twisted logic that leads senior scientists from that particular issue to a refusal to analyse so-called "quarrying" evidence at two rocky outcrops in west Wales. Or maybe this has to do with "corporate responsibility", with Ixer and Bevins, having been involved in that infamous paper on Rhosyfelin, now refusing to break ranks because it would be unsporting or disloyal to do so? I have looked at that issue in a previous post:
Now let's get even more serious. The most serious crime that can be committed by a scientist is to falsify evidence, with a view to promoting a particular conclusion that might be at fault. Scientific misconduct or malpractice comes in many different forms, but here are two definitions cited by COPE:
Danish definition: "Intention or gross negligence leading to fabrication of the scientific message or a false credit or emphasis given to a scientist"
Swedish definition: "Intentional distortion of the research process by fabrication of data, text, hypothesis, or methods from another researcher's manuscript form or publication; or distortion of the research process in other ways."
We can't accuse the two geologists here of "gross negligence", since we know that they know all about the two "ignored" papers and that they have discussed them in detail. They have simply chosen not to cite them, with the object of promoting the quarrying hypothesis. But if we were to be sitting on a university ethics committee I think we might see clear signs of an intention to fabricate a message or to give a false emphasis through the selective citation of sources. We might also see a distortion of the research process or a misrepresentation of the work of other scientists.
According to the US National Science Foundation, "falsification" is a very serious matter. They give one of the definitions as follows: ".....omitting data or results such that the research is not accurately represented in the research record." That could not be clearer. If you fail to cite "inconvenient" material you are in trouble, and your reputation is on the line. In another study, this is called "suppression" -- a failure to publish significant findings due to the results being adverse to the interests and prior claims of the researcher.
Then we have things called "bare assertions". It is generally not a good idea to make entirely unsubstantiated claims. The archaeologists do this all the time, since they are seriously into storytelling, but geologists need to be more careful, especially when promoting a quarrying thesis after being told -- in two peer-reviewed papers -- that the claim is unsubstantiated.
So Ixer and Bevins have used selective citation and carefully selected evidence (which they know is disputed) in a paper designed for a knowledgeable geological readership. At the same time they have wilfully ignored peer-reviewed material that happens to be relevant but inconvenient.
Disrespectful, biased and careless, or something much more serious? I leave it to the reader to judge.
Postscript 1There is rather bizarre postscript to this sorry tale. As all readers of this blog will know, ever since 2011 and the sudden rise to prominence of Rhosyfelin, we have been discussing with Rob in one post after another how the features at the site should be interpreted. It is to his great credit that he has been prepared to engage in the process of debate. But over and again he said: "Don't just argue on this blog. Get your material written up, and get in published in the peer-reviewed literature!" He even, if I recall correctly, suggested Archaeology in Wales as a reputable journal worth approaching. So we gratefully followed his advice, wrote up our material, and submitted it to two journals -- one specialising in Quaternary stratigraphy etc, and the other in the field of archaeology. In due course, in November and December 2015, the two articles were published, to the accompaniment of much excitement in the media. From that point on, the articles have been systematically ignored by the two geologists. Really most peculiar.
Postscript 2This is not the first time that Bevins and Ixer have knowingly promoted the quarrying hypothesis, in the process ignoring "inconvenient" peer-reviewed material already on the academic record. The following article was submitted in April 2016, ie 4 months after publication of one the two papers by BJ, DEG and JD, and 6 months after the other. No excuses.
Richard Bevins, Nicola Atkinson, Rob Ixer & Jane Evans (2016) "U– Pb zircon age constraints for the Ordovician Fishguard Volcanic Group and further evidence for the provenance of the Stonehenge bluestones”, Jnl Geol Soc 174, 14-17, 3 November 2016, https://doi.org/10.1144/jgs2016-042
Quote: “……….the age obtained in this study supports the findings on the basis of petrography and geochemistry that its source is not Craig Rhos-y-felin. Nevertheless, this region provides an obvious target to search for further Neolithic quarry sites to add to those identified most recently by Parker Pearson et al. (2015)."And here is another short paper published by the same authors in February 2016:
Rob Ixer and Richard Bevins (2016) “Go West: the search for the bluestone quarries”. Current Archaeology 311 (Feb 2016), pp 23-24.
Quote: "There is clearly still much to learn here, but as work on the Preseli quarries continues, we hope that our detailed petrology will help to resolve the ongoing debate about how the bluestones arrived at Stonehenge and from exactly where."
This was published three months after our QN paper, and if the authors had chosen to adapt their text and recognize the existence of a "quarrying dispute" they could have done so, even at proof stage. They chose instead to ignore our peer-reviewed article and to maintain the pretence that the existence of the Neolithic quarries was established fact.
Friday, 13 October 2017
Thought I'd share this -- it's a very beautiful map made from LANDSAT imagery -- published by the Geological Survey. It's effective because of low level light, dense shadows and false-colour adjustments, which show up uplands as green, full forest or well-wooded areas as dark red, urban areas as grey, and orange for everything else.
The distribution of uplands is particularly impressive. Click to enlarge. There is extraordinarily fine definition. If you imagine the Welsh Ice Cap sitting over these uplands, with an axis running more or less N-S, you can see how and why the Irish Sea Glacier was unable (for most of the time) to penetrate into the west-facing coasts of Cardigan Bay and was pushed southwards, where it flowed NW-SE across the Pembrokeshire peninsula and up the Bristol Channel, driven by ice from the west, in Southern Ireland. It all makes good sense......
Wednesday, 4 October 2017
This is an image I took yesterday -- Carn Goedog, on the northern flank of the Preseli ridge, looking pretty well SSE. I was standing at SN120351. Carn Goedog is c 2km away. (We are not very far from Pensarn, where the diggers have been at work this year.)
I have been troubled for a long time by the frequent occurrence of spotted dolerite boulders in places where they should not be........... I am not talking here about gateposts or pillars, which could have been collected from Carn Goedog by the local farmers, but big rounded boulders which are clearly heavily abraded glacial erratics. The nearest known source for spotted dolerites would be Carn Goedog, but to get them dumped in a big morainic spread at this location would involve a substantial flow of glacier ice from the south towards the north -- and that can only have involved an active Preseli ice cap.
The other option is that there are other sources for spotted dolerite to the north or north-west of this location, which we do not know about. The dolerites on Carnedd Meibion Owen are not spotted, and there are some very peculiar rocks that look like ashflow tuffs or ignimbrites in Tycanol Wood. There are rhyolites at Sychpant, not far from Nevern, and there are dolerite dykes on my own land in Cilgwyn. The geological map is clearly inadequate in this area.......
That being the case, I wonder how reliable the provenancing of the spotted dolerites at Stonehenge actually is? Rob Ixer and Richard Bevins tell us that the "best match" is at Carn Goedog and Cerrig Marchogion, but the matches are not perfect, and could it be that some at least of the Stonehenge spotted dolerites could have come from sources as yet unidentified, to the north of the location I examined yesterday?
That would put the cat among the pigeons -- but the geologists really need to check this out.........
Here are some of the pics taken of the surfaces of some spotted dolerite boulders. The whitish mineral clusters are quite spectacular in some cases, and they actually stand proud of the surface, having resisted weathering processes better than the "matrix" in which they are set.
The erratic assemblage here includes unspotted dolerites, foliated rhyolites, ignimbrites and quartz boulders. Some of the boulders are heavily weathered and have clearly been exposed for a very long time -- others are quite fresh in appearance, having been dragged out of the ground by a JCB during a building project next to the track.
Monday, 2 October 2017
Every now and then I throw out some comment or other about one or other of the tors on Preseli, forgetting that not everybody is familiar with the local geography. Thanks to the wonders of Apple Maps, here is an annotated satellite image showing how the tors are related.
Below is another image -- a closer zoom in on the Carn Meini tors. Enjoy! If you click on the images, you should be able to enlarge substantially.
Saturday, 30 September 2017
Well, blow me down! Bing Maps has recently put up some new imagery of North Pembs, showing a winter landscape with a low sun.
In the centre of this image is the Cot Llwyd "roundhouse" -- with a diameter of about 10m. It's on the edge of the common, on the northern slope of Carningli. Generally this is assumed to be one of the better preserved of the Bronze age dwelling sites in this area. Grid ref: SN056380.
I have never seen this before, on other satellite images, but suddenly we can see that there is a much bigger circular structure, with the roundhouse in the middle. I estimate that the diameter of the big circle is about 70m. The shape is that of a reversed capital D -- very strange. Maybe the planned circular feature was not completed, and was finished off later with a straight wall on its eastern flank? Was it a henge? There does not seem to be an associated ditch either outside or inside the wall or embankment.
There is another mysterious uncompleted feature near Carn Llwyd, maybe 500m to the east. There is a curving section of ditch and embankment about 50m long. That looks as if it might have started off as an ambitious project for a circular feature with a diameter of at least 200m. That's truly enormous. The bank section is in the centre of this image:
Friday, 29 September 2017
This is a topic to which we have returned many times, and will no doubt return again.......
I have been taking a fresh look at the highly influential paper by Patton et al (2016) which applies a more sophistcated modelling technique than ever before to the Eurasian ice sheet complex -- including the Celtic Ice Sheet (otherwise called the British / Irish Ice Sheet or BIIS). Although the work relates to the climatic and other conditions for the Late Weichselian (let's say 40,000 BP to 15,000 BP as being relevant to SW Britain) the modelling is in some respects more applicable to the earlier glaciations, since ground truthing suggests that the Celtic Ice Sheet never did develop to the full extent as predicted by the model.
The map above shows the most commonly assumed Devensian ice limit (red line) for the British Isles, which is clearly inadequate in many respects. The area defined by the wavy dark blue line shows the maximum extent of the modelled ice sheet, based on an analysis of a vast range of different parameters. The orange areas are the areas of assumed highest erosion -- the dark blue area shows the ice shed location, stretching from the Lake District across to the Isle of Man and thence towards SW Ireland. Note that the ice is shown impinging well into the counties of Devon, Cornwall and Somerset, onto Salisbury Plain, and across the Midlands towards The Wash, incorporating a large area to the north of the Thames Basin assumed to have been unglaciated in the Devensian.
Take a look at these maps as well:
The similarity between these maps is remarkable, given that my map is based largely on ground evidence, and theirs is based on computer-based glacier modelling.
So far so good -- but the intriguing thing is that my map shows my assumed Anglian glacial scenario, and theirs shows a theoretical Late Weichselian scenario! I need advice from the experts. Watch this space........
Henry Patton, Alun Hubbard, Karin Andreassen, Monica Winsborrow, Arjen P. Stroeven. 2016.
The build-up, configuration, and dynamical sensitivity of the Eurasian ice-sheet complex to Late Weichselian climatic and oceanic forcing. Quaternary Science Reviews, Volume 153, 1 December 2016, Pages 97–121
Note: Late Weichselian = Late Devensian
The Eurasian ice-sheet complex (EISC) was the third largest ice mass during the Last Glacial Maximum (LGM), after the Antarctic and North American ice sheets. Despite its global significance, a comprehensive account of its evolution from independent nucleation centres to its maximum extent is conspicuously lacking. Here, a first-order, thermomechanical model, robustly constrained by empirical evidence, is used to investigate the dynamics of the EISC throughout its build-up to its maximum configuration. The ice flow model is coupled to a reference climate and applied at 10 km spatial resolution across a domain that includes the three main spreading centres of the Celtic, Fennoscandian and Barents Sea ice sheets. The model is forced with the NGRIP palaeo-isotope curve from 37 ka BP onwards and model skill is assessed against collated flowsets, marginal moraines, exposure ages and relative sea-level history. The evolution of the EISC to its LGM configuration was complex and asynchronous; the western, maritime margins of the Fennoscandian and Celtic ice sheets responded rapidly and advanced across their continental shelves by 29 ka BP, yet the maximum aerial extent (5.48 × 106 km2) and volume (7.18 × 106 km3) of the ice complex was attained some 6 ka later at c. 22.7 ka BP. This maximum stand was short-lived as the North Sea and Atlantic margins were already in retreat whilst eastern margins were still advancing up until c. 20 ka BP. High rates of basal erosion are modelled beneath ice streams and outlet glaciers draining the Celtic and Fennoscandian ice sheets with extensive preservation elsewhere due to frozen subglacial conditions, including much of the Barents and Kara seas. Here, and elsewhere across the Norwegian shelf and North Sea, high pressure subglacial conditions would have promoted localised gas hydrate formation.
Thursday, 28 September 2017
Late Devensian Glaciation of South-western Britain and the Celtic Sea
Here is my latest attempt to summarise what is currently known about the extent of ice in the Late Devensian, around 25,000 years ago (see Note). The maximum ice positions may have occurred at different times in different parts of the glaciated area, as a result of surges or pulsing behaviour. Also, the boundary between Irish Sea ice and ice from the Welsh and Irish Ice Caps must have oscillated in a fashion not currently fully established.
Note the following:
1. The ice movement directions shown for the Celtic Sea Piedmont Glacier are approx 90 degrees away from the directions assumed by most glacial geomorphologists in their maps. This is because ice marginal deposits at more or less the same levels (ie just a few metres above present sea level) in western Pembrokeshire, on Caldey Island and in the Isles of Scilly cannot be explained by a glacier with a gradient running from NE towards SW. Ice must always move perpendicular to the ice edge except in troughs and other tightly constrained situations. That means the ice gradient must have run from NW towards SE, as shown on the map, driven from a dynamic and vary large ice dome over Ireland.
2. If, as I believe, glacier ice over-rode Lundy Island and impinged against the coastline of Devon and Cornwall, there is a possibility of a large meltwater lake being trapped within the Bristol Channel.
3. I have shown local ice caps over the uplands of Devon and Cornwall, and assume that in the Late Devensian they did not come into contact with ice coming in from the NE.
Note added 29.9.2017: recent papers are suggesting that the glacial maximum occurred around 25,000 years ago -- this pushes the date back by about 5,000 as compared with the widespread assumptions of a few years ago. Partly this adjustment is related to the advent of new dating techniques, which have supplemented -- and sometimes -- supplanted evidence based solely on radiocarbon dates on organivc materials.
Note added 29.9.2017: recent papers are suggesting that the glacial maximum occurred around 25,000 years ago -- this pushes the date back by about 5,000 as compared with the widespread assumptions of a few years ago. Partly this adjustment is related to the advent of new dating techniques, which have supplemented -- and sometimes -- supplanted evidence based solely on radiocarbon dates on organivc materials.
The extent of the "Greatest British Glaciation" in the south-western quadrant of the Celtic Ice Sheet (sometimes called the British and Irish Ice Sheet)
This is my latest attempt to map the greatest-ever Pleistocene extent of ice in this area, bearing in mind evidence from a wide variety of sources. I'll be happy to discuss modifications if anybody has any doubts about what the evidence on the ground actually shows.
When was this? The jury is still out. The most common assumption nowadays is that the glaciation was very ancient indeed -- the Anglian Glaciation (MIS 12) conventionally dated to c 450,000 years ago. However, Phil Gibbard is suggesting nowadays that maybe this was the Wolstonian, which used to be called the Riss or Saalian glaciation on the continent, and which occurred around 200,000 years ago (MIS 6). Maybe the ice edge shown is a composite one, but this will need to be established by cosmogenic dating such as that undertaken by the BRITICE project over the past few years.
Please note the following:
1. The ice direction arrows shown are approximate only -- one must bear in mind that there are considerable swings as ice masses wax and wane. For example, before the Irish Sea Glacier became prominent, the Welsh Ice Cap would have been more extensive, pushing ice further out from the core of the Welsh uplands. Individual outlet glaciers at such a time would also have been more topographically controlled. Something similar might well have happened at the end of the glaciation, as the Irish Sea Glacier waned and retreated from its maximim position. We do not know at present how many phases or pulses of glacier expansion there may have been -- the evidence on the ground is very patchy.
2. South-central England is shown as a permafrost zone, but there must have bee extensive areas of perennial or semi-permanent snowfields.
3. It is assumed that the ice extended to the south of the Isles of Scilly and that there may well have been a large calving bay at the ice grounding position, in the Celtiv=c Sea and off the bottom left corner of the map.
4. I'm assuming that moving ice pressed onto the Cotswolds, into the Bristol and Bath area, over the Mendips, and across most of the Somerset Levels. I believe that there us reasonable evidence to support the position of the ice limit as shown.
5. In Devon and Cornwall, it is reasonable to assume that there were small discrete ice caps over Exmoor, Dartmoor, Bodmin Moor and some of the other uplands. These ice caps might have coalesced, and they would have been in contact with the Irish sea ice somewhere near the position of the present coastline.
6. Note that the coastline is shown here for guidance only. In reality, at the time of this very large glaciation, sea-level must have been at least 120m lower than it is today.
Over the last week or two I have spoken to many people -- including archaeologists -- about the recent archaeological work on the northern flank of Preseli, and I am intrigued by the fact that NOBODY has even mentioned bluestones or quarries. There now appears to be widespread scepticism about the existence of the Neolithic quarries so beloved by MPP and his friends, and an acceptance that the evidence they have unearthed during their mad quarry hunt has been so equivocal and unconvincing that the whole idea is best dropped. For example, the radiocarbon dates and organic remains from Carn Goedog and Rhosyfelin do nothing at all to support the idea of bluestone monolith quarrying, but simply demonstrate the intermittent occupation of hunting and gathering sites.
In contrast, a number of people have said to me that the archaeologists are getting back to the normal practice of their trade by subjecting a smallish area to intense scrutiny (using geophysics, aerial surveys and LIDAR) and finding some rather interesting cultural features from the Neolithic, Bronze Age, Iron Age and Roman times. This shows a long history of settlement in an area with quite positive environmental attributes. Essentially this is a random process -- and a number of experienced archaeologists have said that MPP and his team could probably have subjected almost any part of North Pembrokeshire to a similar level of technical scrutiny and manpower investment, and would have obtained quite similar results. We knew already from the excellent work done by Dyfed Archaeological Trust and other university groups over the years, that there are widespread cultural traces across the landscape and that a large proportion of them have survived because the level of agricultural and other development here has been lower than it has been across much of south Pembrokeshire.
Many of the relevant records are in the Coflein and Archwilio databases, and some are contained in this Report:
It's a bit out of date now, but is very valuable nonetheless.
So the feeling seems to be that the digs at Pensarn (three excavations), Parc y Gaer (one excavation) and Waun Mawn (six pits opened) represent a welcome return to normal service -- involving a lot of students, who will have obtained valuable training in how a good dig should be run.
No additional significance can be attached to these digs. There is nothing "special" about the areas investigated, and I hope that the archaeologists will resist the temptation to pretend that there is. A location does not become special or significant just because MPP and his colleagues have dug there. And as I have noted before, and as many others have noticed, there is nothing in any of these recent digs that has anything to do with bluestones, quarries, Stonehenge, Carn Goedog, Rhosyfelin, or Stonehenge. It would be quite preposterous for MPP and his team to pretend otherwise.
So a gentle request to the teams who have been at work on these sites in 2017 -- please add your records to the database of prehistoric sites for North Pembrokeshire, and follow the unassuming and efficient practices of the Dyfed Archaeological Trust. Write and publish your peer-reviewed papers if you will. Please resist the temptation to speculate and to tell elaborate stories. Place your dig diaries and excavation records into the public domain as quickly as you can, and spare us any additional hype.......
Wednesday, 27 September 2017
On this blog we know and love geologists Richard Bevins and Rob Ixer, since they feature in a vast number of posts and have made amazing contributions to our understanding of the geology of the bluestones. And Rob personally has been prepared to get involved in good knockabout debates on a wide range of issues, and to explore the pros and cons of many theories of geological, geomorphological and archaeological interest. In the comments sections following a myriad of posts, he is a prominent and learned contributor. For that, he deserves enormous respect.
But one thing has been puzzling me greatly for the past seven years or to -- why is it that two reputable geologists have turned into evangelists for the Neolithic quarrying thesis so enthusiastically advocated by Mike Parker Pearson and his team? They claim, whenever you ask them, that they are entirely neutral in their utterances, and that they maintain a certain academic detachment from the grubby business of archaeological disputes, but the evidence is rather strong that they are fully signed up to the quarrying idea -- and indeed we have speculated on previous posts that as long ago as 2011 they actually pushed our friend MPP into some of his more effusive and picturesque statements about Pompeii, smoking guns and proto-orthostats. Consider the following statements made by Drs Ixer and Bevins, from their recent published output:
"There is clearly still much to learn here, but as work on the Preseli quarries continues, we hope that our detailed petrology will help to resolve the ongoing debate about how the bluestones arrived at Stonehenge and from exactly where."
"So the contents of a 60-year-old box led to the discovery of the first secure Stonehenge-related quarry site, confirming that man moved the bluestones.”
“.......very recent excavations at Carn Goedog have revealed evidence for Neolithic working of the outcrop.”
“........ archaeological excavations have shown features consistent with ancient quarrying.”
“The best that can be hoped for is that a number of undisputed Neolithic quarry sites can be found.”
"It's like an IKEA. You just walk up to it, take what you want and take it away."
“The discovery of a megalithic bluestone quarry at Craig Rhos-y-felin in 2011 marked a turning point in this research. Subsequent excavations have provided details of the quarrying process......”
“Colluvium has buried and protected the remains of prehistoric quarrying from subsequent stone removal and disturbance in the medieval and modern era.”
“Six megalith-quarrying features have been discovered at Craig Rhos-y-felin.”
“There is relatively little debris within the quarry to indicate the methods used for detaching monoliths from the rock face.”
“It is possible that the bluestone monoliths were taken directly from their quarries to Salisbury Plain.”
I know that all of these statements are taken out of context, but they do not contain many signs of neutrality or impartiality, as I think readers might agree. But how can it be that two senior earth scientists are apparently prepared to ignore the evidence of earth surface processes that various people have presented for Rhosyfelin, Carn Goedog and many other Pembrokeshire sites, and have decided instead that assorted natural features and sediments are not natural, but are man-made?
One reason might be that many of their papers are published in archaeological journals, and that they have been seduced away from pure geology into saying things that the archaeologists (or maybe just some of them) would quite like to hear? There have been some strong personalities in the ranks of senior archaeologists who have been arguing for Neolithic quarries for many years now -- think of Darvill, Wainwright, Parker Pearson, Pollard, Richards, Welham, Pitts etc. Their research agendas and projects, and their hypotheses, pull in other people -- and when joint peer-reviewed papers or popular magazine articles appear with multiple authorships, the principle of corporate responsibility applies. For example, the big 2015 Antiquity paper on Rhosyfelin (which I still think of as one of the worst I have ever read) had no less than 14 authors, and whatever nonsense there is within that paper now has to be defended by all of them. Nobody can break ranks and say "Well, actually, I never did agree with what was said on page fifteen......" I still think that Rob Ixer and Richard Bevins made a grave mistake by ever agreeing to contribute to jointly authored papers like this one -- the millstone that hangs around Mike Parker Pearson's neck hangs round their necks as well.
Another reason why the geologists have been signed up as supporters of this Neolithic quarrying business is, I believe, that they have just not been able to do adequate fieldwork in the area that they are writing about. Richard Bevins knows the area well, having wandered about all over the outcrops of Fishguard Volcanics over many years, and having collected hundreds of geological samples from useful exposures. But how much time has he spent in the company of glaciologists or geomorphologists on these field visits? I just don't know, but I'll hazard a guess that the answer is "Not very much." He is Keeper of Geology at the National Museum of Wales in Cardiff, with vast responsibilities, so it's a miracle that he is able to do any fieldwork at all, and to maintain an incredible flow of research publications. I am lost in admiration for his dedication and his commitment to research. As for Rob, he lives a very long way away from Pembrokeshire, and is involved in such detailed lab-based petrography, and across such a wide range of topics, that it would be not far short of another miracle if he has ever managed to find the time to wander across north Pembs and simply look at the landscape and the processes that have fashioned it.
And thirdly, I think the geologists have gone with quarrying because they (like everybody else) are attracted by the spectacular, which is always more interesting than the mundane. Although they are earth scientists, they probably quite like the idea of our heroic ancestors doing wondrous things. And from an academic standpoint, they probably quite like the idea of fame and notoriety. You just have to look at the string of press releases to which their names are attached -- in those, caution is thrown to the winds, and IMPACT is everything. They can't blame university or museum press officers for the purple prose -- they are the ones ultimately responsible. And hey -- they might even appear in National Geographic documentary one day. And how exciting is that?
Finally, I have become convinced that the geologists have gone along with the quarrying idea -- and have ended up promoting it -- because they think that the evidence for glacial bluestone transport is in some way deficient. They have, I assume, taken on board the idea that "glacial transport was impossible" because, at some stage, James Scourse and Chris Green said so. So by default they have to accept that human transport WAS possible, and that the quarrying of the bluestones was possible too. As I have said many times before, that is not very scientific, because it conflates various issues. There are three issues under debate -- stone entrainment, stone transport, and stone dumping. If we are trying to be good scientists, we need to examine the evidence for each one of these issues independently, without allowing assumptions about the other two to influence our interpretation of the evidence on the ground. What the geologists have done, I fear, is to assume that there are quarries at Carn Goedog and Rhosyfelin because there are not enough bluestones scattered about on Salisbury Plain. Hmm --- how logical is that?
I write this post not in anger but in sadness -- since I have enormous respect for the two geologists involved, and the great work they have done. So if I was to write a press release about all of this I would put on top of it the title: "The sad case of two good geologists led astray".
Monday, 25 September 2017
It's rather interesting that work has resumed at Waun Mawn at grid ref SN083341. Apparently work started there very late in the digging season, maybe because the archaeologists were frustrated at having found no trace of proto-Stonehenge at either Pensarn or Parc y Gaer! Anyway, there are signs of great activity up there, and some seriously heavy plant has been used. It's all a bit of a mess at the moment, but it will no doubt settle down again over the winter..........
I'm quite pleased to see that this new work is going on, because the Waun Mawn - Tafarn y Bwlch - Cnwc yr Hydd area is extremely interesting. Hummocky morainic topography, standing stones, old stone walls, ancient trackways, and even traces of an old deer park......... Use the search box to find previous posts. If there is a Neolithic quarry anywhere in this part of North Pembs, it is here, at the top of the hill -- but there are other pock-marks lower down as well, from which rhyolite and metamorphosed shales appear to have been taken. Goodness knows why. (Maybe the quarries are quite modern, having been used for road material for the trackway up to Gernos Fach?)
On the platform halfway up the hill there are 4 big stones that appear to have been used in a stone setting. They are all dolerites picked up in the vicinity, all very heavily abraded and weathered. They are certainly not freshly quarried from anywhere -- they are classic glacial erratics, although they have probably not travelled far from their places of origin. (But who knows? They could have come from Cilgwyn or Carningli.) Only one of the stones is standing, and there are two very big recumbent stones and one smaller recumbent stone which is just visible above the turf. One can't see the full dimensions of the stones, but I reckon the two big ones each weigh between 6 and 8 tonnes.
The archaeologists have opened up six pits and closed them again. These are the locations:
Two of the pits have been dug adjacent to recumbent stones, and four very extensive exploratory pits have been opened up -- two to the west and two to the east of the visible stones. The stones may have been placed in the ground about 10m apart. Rumour has it that two sockets have been found -- I'm not sure whether these relate to stones that are still there and have fallen over, or to stones that have gone missing........ I hope the archaeologists will publish a field report soon and give us the info on that.
Recumbent stone number one -- the westernmost stone in the series. You can see the traces of the dig around the stone, and at top left you can see the position of one of the exploratory digs.
Recumbent stone number two -- there has been no dig adjacent to this stone
Recumbent stone number three -- apparently the smallest of the three. There has been excavation on all sides of this stone
I'm a bit more convinced than I was that the stones may lie on the circumference of a very large circle. If so, it must have had a diameter of around 140 m -- that is enormous, and much larger than the footprint of Stonehenge. On the other hand, Avebury outer circle has a diameter of 331m, and Stanton Drew is 113m in diameter -- so who knows what might have happened here?
I still think that on balance this is a rather wonky stone alignment. My reason for thinking that is that a circle with a diameter of 140 m would not have fitted onto this little step on the hillside-- it would have spilled over onto the steeper slope below, so that parts of the circle would have been quite invisible from other parts. That would not have made any sense at all..........
Anyway, all very interesting, and we look forward to hearing what the archaeologists have to say about this site in due course.
Without breaking any confidences, here is a brief summary of what has been placed in the public domain, arising from the 2017 digging season involving Mike Parker Pearson and his colleagues. This was all under the auspices of the "Stones of Stonehenge" project. The dig lasted about 3 weeks, ending around 20th September. This very day the holes in the ground are being filled in.....
The focus of attention was again Pensarn, not far from Brynberian and Crosswell, on the south side of the B4329 road. The minor road leads down to Pensarn, Droifa and Glanyrafon-Uchaf and other delightful cottages on the northern edge of Brynberian Moor. It's where the annual Ras Beca cross-country races are held every August -- not that that's strictly relevant! What's more relevant is the presence of abundant interesting landforms, sediments and Neolithic and Bronze Age features on the moor itself -- as noted in some earlier posts:
This is the key report which gives the regional context:
To return to the matter in hand. What we now know is as follows:
1. In 2016 the dig at location SN123358, on a low mound in the middle of the field, revealed a Bronze Age cist burial site, details of which are still to be published. I summarised what we know here:
2. Another field about 500m to the east of the Pensarn lane is referred to as Parc y Gaer (field of the fort). Here there is a rectangular feature with two sub-rectangular boundaries, a square feature and irregular ditched enclosures to the south (all identified last year by the geophysics). These are now investigated, and are apparently confirmed as the remains of a Roman villa. This is exciting, since it would be the westernmost Roman villa recorded in Wales. Kate Welham and her Bournemouth University team will have been working on this one.
Just a word of caution: some years ago there was great excitement when a supposed "Roman Villa" was found at Wolfscastle. When it was investigated by Duncan Schlee and others, it was found to be nothing of the sort.........
Apologies for getting the location wrong in a previous post. I have now done an edit to correct the mistake.
In the hedge to the west of the"villa dig" there is a large stone with "prehistoric rock art engravings" which were identified (correctly?) in 2016. No doubt more work will have been done on this stone.
3. In 2017 there were two new excavations near Pensarn Farm, in another field, on the western side of the lane, at the following grid refs: SN123357 and SN 122357.
(a) In the eastern pit (the one with the bucket, the trowel and the beer bottle) there is only a very thin layer of sediments (c 60 cms) over broken bedrock, but there is evidence of assorted features dating from the Iron Age. It looks as if it might be an Iron Age defended homestead -- there is something that might be a defensive embankment. Traces of walls have also been found, and in the dig there is a series of pits which may be post holes. Some interesting domestic and decorative artifacts have been found, and organic materials are going off for C14 dating.
(b) In the western Pensarn pit there are apparently traces of a Neolithic embanked enclosure of some sort -- a very subtle feature, since the sediments are very thin here and no sign of it could be seen on the ground surface. It was picked up in 2016 by geophysical work including LIDAR. Apparently there are some "very unusual features" showing up, which are not commonly seen in the British Neolithic. It may be a henge of some sort. Organic materials have been recovered, and these will go off for C14 dating.
4. Further work has been done at Waun Mawn, close to Tafarn y Bwlch, where all those standing stones and recumbent stones are located.
Apparently work was not started there until almost the end of the digging season, but on Tuesday 19th Sept the diggers found what appears to be a stone socket with some organic material within it, and rumour has it that another socket has also been found. Samples sent for C14 dating might show when the stones were in position and when they were removed or fell over. Nobody should be surprised by any of this -- there are two very large recumbent stones and a smaller one visible on the surface at Waun Mawn, which might well have been upright at some stage. So there will be sockets and there will be organic materials within them. There is also a very fine standing stone. As pointed out in previous posts, the stones might be on the circumference of a very large circle. Grid ref SN084340 approx.
(I have also heard rumours of a "worked" stone somewhere, which has been removed from its socket and taken away -- but I have no idea whether that rumour relates to one of the stones referred to above.......... We know already that there are other standing stones in the area, and other stones incorporated into hedgerows. Both dolerite and foliated rhyolite. I had a look at some of these last year, in the company of Chris. )
That's all we know at the moment, from what Mike PP has been saying on his guided tours and evening lectures over the past few days. My informants are not always 100% attentive, and might misunderstand some things too. If I have misreported anything, apologies -- no doubt somebody will correct me, and I will adjust the text accordingly.
Anyway, there is cause for pleasure all round, I think, since our knowledge of prehistoric north Pembs has been significantly advanced. So congratulations to all the diggers for what they have come up with. It confirms what we already knew from the unsung work of Dyfed Archaeological Trust over the years -- that there is a very long history of early settlement here, stretching from the Mesolithic through Bronze Age and Iron Age to Roman times, with a range of settlement and ritual features under the turf and out on the moor. Some of the new sites will no doubt become scheduled ancient monuments, which is right and proper.
Observant readers might have noticed that none of the above information has anything whatsoever to do with quarrying, bluestones, Stonehenge, Proto-Stonehenge, Rhosyfelin, Carn Goedog, Carn Meini or the transport of monoliths.........
Saturday, 23 September 2017
Sometimes I sits and ponders, and sometimes I just sits. So goes the old saying. Anyway, I was pondering a bit today, out in the garden, and I got to asking myself this question. Why is it that certain archaeologists are so obsessed with the idea of Neolithic bluestone quarries in north Pembrokeshire that they continue to try and sell them to all and sundry, in spite of the fact that their "evidence" does not stand up under scrutiny? Not only that, but why to they exist in a state of denial about contrary opinions, to the extent that they refuse even to acknowledge the existence of two peer-reviewed papers that show that their cited "quarrying features" are in fact entirely natural?
The answer, I have concluded, is that Mike Parker Pearson's book called "Stonehenge: exploring the greatest Stone Age mystery" came at exactly the wrong time. At the time Mike thought it was the right time, and a wonderful opportunity to enhance his academic reputation. Let me explain. The book was published in June 2012. That means it was probably in production between January and June 2012 -- and that means that Mike had to complete the manuscript probably by Christmas 2011. Going back a bit further, in August 2011 Richard Bevins contacted MPP to say that he and Rob Ixer had "pinpointed" a match for one of the Stonehenge foliated rhyolite samples to the outcrop called Rhosyfelin. (Before that, they had published a paper flagging up the Pont Saeson area as a good match for some of the material in the rhyolite collection.) The archaeologists had planned to dig at Carn Goedog, again after guidance from the geologists that that was a likely source for Stonehenge spotted dolerite samples, and at Waun Mawn, where they thought there might be the remnants of a large stone circle. But because of this piece of supposed high-precision provenancing, MPP and his colleagues decided to concentrate on Rhosyfelin.
They seem to have decided, even before they dug the first turf, that this was a Neolithic monolith quarry. In no time at all they found an "ancient ground surface", so-called hammerstones (which all turned out, of course, to be fluvioglacial cobbles), the big rhyolite block (claimed to weigh about 4 tonnes, whereas it is actually over 8 tonnes) and "rails of elongated stones" set on edge beneath it. News spread about this amazing discovery, although when I visited the site with friends I could see nothing at all that demonstrated human occupation, let alone quarrying activity. Anyway, at the end of the September digging season Mike hoofed around, announcing to the world that the "Pompeii of prehistoric stone quarries" had been found. The first talk was at Newport Memorial Hall on 15th September. The detailed Rhosyfelin petrography paper came from Ixer and Bevins in December 2011, and there were then press releases from the geologists, followed by a media feeding frenzy featuring "the bluestone quarry" just before Christmas 2011. There was no need for the geologists to push the quarrying hypothesis, but they chose to do it, presumably because they were convinced of its correctness........... and even geologists just love media attention and fame. Don't we all?
By this time Mike must have finished the manuscript for his book. The purple prose is there for all to see, between pages 286 and 291. After the bit about Pompeii, MPP said: "We could hardly believe our luck. This was a smoking gun; the game was up for anyone still trying to argue that the bluestones were not quarries in Preseli during the Neolithic, and then taken to Wiltshire." And then in June 2012 it was in print, between hard covers, there for everybody to read. Set in stone, as it were.
The trouble with books is that they are so wretchedly permanent and are deemed by readers to contain well-considered views on this and that. They are not like scientific research reports, or field diaries, or journal articles, or press releases. These latter forms of communication are all ephemeral by comparison, and although press reports are read by millions of people, they are soon forgotten. And the things that you might have said in them can be quietly dropped, or changed, without many people noticing......
So there was MPP's extremely premature description of the 2011 dig and his conclusions on it, written before any field reports or journal articles had been worked on, and rushed out on the basis of completely inadequate field evidence. Act in haste and repent at leisure. Since June 2012 Mike has been stuck with the quarrying ruling hypothesis, and I think it is now a millstone round his neck. He can't or won't change his mind about the quarry, and he has persisted in the promotion of it in spite of the fact that no evidence has emerged over six subsequent digging seasons to confirm the hypothesis. In fact, many people will have noticed that the radiocarbon and stratigraphic information presented for the Rhosyfelin dig in the Antiquity paper of December 2015 is extremely inconvenient, and tends if anything to mitigate AGAINST the quarrying hypothesis. But still MPP (and his colleagues) trundle on, refusing to admit that the thesis is wrong. Instead, they have simply modified the theory, claiming now that the quarrying went on several centuries earlier than they would have liked, and that there must have been a Proto-Stonehenge somewhere, which they WILL find, come hell or high water.....
It's all becoming more than a little absurd.
By the way, my review of the MPP book is in the Antiquaries Journal, and is reproduced here: