It's not so mysterious -- glaciological principles are at play here. But it is intriguing nonetheless that one glacier can advance and retreat across the landscape leaving virtually no trace of its coming and going, while another (right next door) leaves quite a dramatic legacy of sediments and landforms.
As we all know, the term "bluestone" is used for any non-sarsen stone that pops up on Salisbury Plain, most often (but not always) in the vicinity of Stonehenge. As as we are also fully aware, there are around 30 different provenances included in the currently known Stonehenge bluestone assemblage. The bluestones recorded thus far are not all from the Mynydd Preseli - North Pembrokeshire area; and since the Altar Stone is apparently not from Pembrokeshire at all, and is in any case afforded the "bluestone" label, it is entirely logical to call any stones from the Cheviot area or elsewhere in Northern England bluestones as well.
As I have noted before, it is more and more apparent that bluestones are scattered over a wide area and that it is a mistake to label all of them as "STONEHENGE bluestones." The scatter of bluestones around Fargo Plantation is rather intriguing, and it looks as if there was an "independent" source of fragments somewhere near there. It has already been mooted by MPP and his colleagues that there may have been standing bluestones there, and maybe even a circle of rhyolite standing stones -- but there is no reason at all to assume that those were the same stones as we currently see at Stonehenge. See Chapter 4 of "Stonehenge for the Ancestors":
https://www.sidestone.com/books/stonehenge-for-the-ancestors-part-1
Then we have the highly controversial Boles Barrow site, which we have discussed at length. And now West Kennet and "Structure 5"..........
http://exploringavebury.com/book-notes-134-140
I still think that there may well be quite large bluestones that are as yet undiscovered. It is notoriously difficult to distinguish bluestones from sarsens in the field, since they have very similar colouring and similar shapes -- and it's only when you examine them closely that you can pick up the textural characteristics of dolerite, rhyolite or volcanic ash. As for the Palaeozoic sandstones -- telling them from sarsens is even more difficult.
It starts to get rather interesting. Who knows where it will all end?
One of the lumps of granidiorite found in the West Kennet excavation. From Josh Pollard's talk.
According to some posts on Facebook, quite a few people have known about this for quite a while, but now Josh Pollard has formally announced the finding of erratic material (a lot of it) from "Structure Five" at West Kennet, not far from Avebury. The material appears to be a very distinctive form of granidiorite from the eastern edge of Cheviot. According to Josh, the geologists (Ixer and Bevins) have provenanced the rock type to Cunyan Crags, near Dunmore. It's very crumbly and heavily weathered, and from the lumps of rock collected from various parts of the excavation, there are at least 130 kg of it -- and probably a lot more. Did the lumps of rock all come from a single erratic, or could there have been several in the vicinity? Josh -- of course -- assumes that the boulder or boulders might have been "direct or indirect" imports, but then he's an archaeologist who has an established preference for the human transport of large lumps of rock, and a reluctance to believe that ice is capable of carrying large stones over great distances and dumping them anywhere near Salisbury Plain or elsewhere in Wiltshire. The suggestion in the talk is that these lumps of rock (found mostly in post holes) are from a destroyed standing stone -- but there is currently no evidence to support that. He does note that no lumps of the granidiorite have been found on the surface -- and he assumes that any that did exist have simply been weathered away. Even the lumps that have been examined are more or less reduced to "grus" (the crumbly residue left when granitic rocks rot away) -- and that all suggests great age.But we can rest assured that the southward transport of igneous material from the far north was not just possible but probable, during the Anglian and earlier glacial episodes. In 1999 Olwen Williams-Thorpe and others described the occurrence of Whin sill quartz dolerite and many other far-travelled northern erratics in the glacial deposits of Hertfordshire and Buckinghamshire:
I discovered this very rare and historic photo showing the rescue of the Millennium Stone after it had slipped into the Eastern Cleddau river in the year 2000. This was taken a day or two after I had helped with the pulling of the stone on its sledge. It fell into the river when assorted volunteers tried -- using authentic techniques -- to transfer the stone from the river bank into a curragh that was afloat, round about high tide. Anyway, in order to recover the stone, authenticity had to be temporarily suspended, as it was on every single day of the ill-fated bluestone transport expedition. The full and exciting story is related in detail in the pages of "The Stonehenge Bluestones". Available from all good bookshops!
Next time those enthusiastic experimental archaeology people show you one of their photos demonstrating how easy it is to pull a bluestone across a nice flat college lawn or a grassy London park, show them this photo as well..........
Came across this very unusual photo. Brash ice (broken fragments of glacier ice from a floating ice edge) on the shore of an ice-dammed lake in Patagonia -- coming in very handy as cover for a hunting mountain lion. Otherwise known as a cougar, puma or panther.........
One of the chapters for my book "World of Ice" was about the wild life associated with glacial environments. Some of the adaptations are really rather splendid.
Here we go again. A big article in the Guardian, based on info fed to it by Vince Gaffney and relating to the supposed "mega-circle" of giant pits in the Durrington - Larkhill area. The "circle" is no more circular this year than it was last year.
It's here, in all its glory:
Other media outlets have picked up on the story as well, so as not to be outdone by the Guardian.
This is all based on third-hand information and speculation, issued now in order to drum up interest in a new programme to be shown on December 9th on Channel Five. No mention of flint mining or flint excavation pits or enlarged solution hollows for the purpose of finding flint nodules. No data, no evidence -- just excited hogwash which we are all expected to believe because there is no way to scrutinize what has actually been discovered. Maybe there is another paper somewhere in the pipeline, and maybe not. This is real megaphone archaeology, using the media and press releases as a substitute for sound academic research and peer review.
Programme title: Stonehenge: The New Revelations. This is a couple of miles away from Stonehenge -- but that's the word that pulls the viewers in, so what the hell.......I thought archaeology was in a bad way, having looked in detail at the working methods of our old friend MPP. This is now confirmed. And how.
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PS. This is what Gaffney et al said in the discussion at the end of their original paper:
Given the presumed later Neolithic date for the pit group, the size of the features, and the scale at which the circuit of pits has been implemented, it is difficult to identify directly comparable groups of features within the British Isles. In respect of clustering of large pits, those associated with, generally earlier, flint mines may invite consideration (Field and Barber 1998; Barber et al. 1999; Mercer 1981). In some instances, such as Cissbury hillfort, large pits associated with mining do form linear alignments; presumably following seams of flint within the boundary of the later Iron Age hillfort (Barber et al. 1999, 29). More locally, work by Booth and Stone (1952) and Stone (1958) record the presence of flint mines near Durrington. However, the illustrations provided by Stone demonstrate that these features are significantly narrower at the entrance than those described above (Figure 21). When considered spatially, Stone's features are also unlikely to be directly linked with the arcs of massive pits presented within this article. While it is not impossible that flint extracted from these pits may have been used on an ad hoc basis, the structural arrangement of the pit group around Durrington Walls, and their apparent link to the area of the henge monument, suggest that such a prosaic interpretation is not sufficient as an explanation for these features.
This was right at the end of the paper, the authors having previously studiously avoided any mention of consideration of flint mining or the excavation or enlargement of solution hollows for the purpose of flint nodule extraction. Occam's Razor appears to have been forgotten about. The authors are so keen on seeing their giant circle (which seems to me to be fanciful in the extreme) and on flagging up "the mystery of the giant pits" that the simplest and most logical explanation of these features has simply been shunted aside.........
Source:
Gaffney, V. et al. 2020 A Massive, Late Neolithic Pit Structure associated with Durrington Walls Henge, Internet Archaeology 55.
Starr Nunatak, Victoria Land, Antarctica. This nunatak has been left "high and dry" as glacier ice has wrapped itself around its flanks, escaping in order to infill all the available low points in the landscape.
And the result of glacial wrapping? Nunataks and ice-free enclaves, in every glaciated territory. Sometimes, plateaux may remain detached from ice-sheet glaciation, with the biggest outlet glaciers flowing around them in deep troughs, but if climatic conditions are cold and snowy enough for the biggest glaciers to be nourished and "kept alive", almost inevitably the plateaux will have ice caps of their own. We can see this on a grand scale in East Greenland today, with abundant small ice caps ranged around the edges of the Greenland ice sheet.
In glaciated landscapes where we see a mixture of major drainage routes (used by outlet glaciers) and smaller troughs used by glaciers draining from plateau ice caps, the most likely places for nunataks or unglaciated enclaves are the tips of the interfluves, where confluent troughs come together. I read an interesting article about this today, in a symposium on nunataks.
I have done a lot of posts already on nunataks and ice-free enclaves, and will not repeat them here. But the main point I want to make is this -- there are still many professional glacial geomorphologists to draw their hypothesised ice limits as straight lines, or taking no account at all of local topography. I have been on about this for years, criticising (for example) ice edges drawn across mid Wales regardless of the positions of mountain ridges and plateaux, and ice edges drawn in the Celtic Sea in positions that would have broken all the rules of physics. The rules relating to glacial wrapping are just as relevant in open areas (such as the floor of the Celtic Sea) as they are in glaciated uplands where there may be high peaks and glaciated troughs.
Readers of this blog may remember the spat I had with Prof James Scourse over the glaciation and ice edge positions in the Isles of Scilly. When I published my short paper on the glaciations of the islands, I provided evidence that Devensian ice had affected the west-facing coasts, as one would expect from glacier ice behaving normally. In published correspondence, he accused me, in rather intemperate language, of being incompetent -- but then he had to agree that I was right and he was wrong. Essentially, I was taking account of glacial wrapping, and he was not.
With regard to ice edge positions in and around Pembrokeshire, I have for years argued that ice edge positions cannot possibly have remained far off the western coast of the county if there was an ice edge pressing against the north face of Mynydd Preseli more than 350m above present sea level. Again, this was all about glacial wrapping. And at last, without any proper acknowledgement of my posts on this blog, the BRITICE team have acknowledged that I was right and they were wrong -- by showing on their latest maps that Devensian ice affected the coasts of south Pembrokeshire at least as far east as Caldey Island. As I have been trying to tell them for years, that's what the observations on the ground show, and that's what glaciological theory must have predicted.
We get there, gradually...........
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PS. By the way, glacial wrapping has nothing whatsoever to do with this latest trend for the inhabitants of high glacierised mountains (as in the Alps and parts of China) to cover snow-covered surfaces with vast swathes of special fabric in a forlorn attempt to reduce the rate of ablation and glacier wastage. I can understand why they are doing it, especially in areas where the skiing holiday industry is under threat -- but it is all really rather stupid. There is no technical fix for global warming -- people should stop these stunts (costing millions of pounds) and listen to what they are being told by the climate scientists and by Greta Thunberg and the younger generation.
The convoluted patterns are annual accumulation layers preserved in the ice and exposed as a result of surface ablation near the ice edge and further confused as a result of the internal deformation of ice as it moves from the ice centre out towards the edge. What makes these patterns so clear is the presence of hundreds if not thousands of ash layers, each one relating to an eruption somewhere in the vicinity. You can tell from the constitution and colour of the ash which eruption is responsible for each layer and when it occurred. So it all works rather like the recognition and dating of tree rings.
Another reason for the complexity of these patterns is the complexity of glaciological processes in and under this ice cap -- because there is geothermal heating under the ice, causing intermittent excessive melting and the creation of water bodies on the glacier bed, which occasionally escape as "jōkulhlaups" or catastrophic floods. So there are glacier surges too, on some of the outlet glaciers.
This is about as dynamic as a glacier gets.......
The BBC has just shown (for the 4th time) this excellent documentary dealing with ice on the surface of Planet Earth -- presented by Iain Stewart. Worth watching again -- especially the section showing graphically -- and with the use of satellite imagery -- how glaciers have been shrinking. I hate to think what has happened to some of the featured glaciers in the years since 2007..........
It all makes one feel distinctly uncomfortable, when we look at the manner in which the "findings" of MPP and his colleagues are presented to the world, and the extraordinary gullibility of those who take their fantasies on board and treat them as "astonishing discoveries".
On one of those ephemeral Facebook pages dealing the Neolithic matters, Giles Davies accuses me of shouting and screaming abuse whenever MPP is mentioned. Far be it from me ever to behave in such a fashion, but I will call a spade a spade. I will subject anything I read (or see in a TV documentary) to proper scrutiny, and I believe it is the duty of anybody who has a scientific training to do the same. Those who keep quiet just because they love a good story, or because they are too lazy to think seriously about what they are being asked to believe, do a disservice to themselves and to society at large. They facilitate the peddling of fantasies and lies dressed up as "facts" and disguised as "the truth." Anything for an easy life, maybe?
Just to make things clear, this is not an archaeological programme and it certainly isn't a science programme -- it is (like the BBC prog with Alice Roberts) a classic "hero narrative" about one man's quest, against all the odds, to find the Holy Grail. Should we blame Tomos TV, the BBC and PSB for that? To some extent. They do it all the time, perfectly cynically, since it resonates with the viewers. However, I think we might assume that MPP himself might have something to do with it......
To the programme itself. It is crammed with assumptions, speculations, outrageous claims, misreported scientific findings, evasions and downright nonsense. Just to home in on a few points. Contrary to what is claimed, it is not accepted that Stonehenge was a stone monument right from the very beginning. It is not accepted by all experts that the Aubrey Holes held a ring of bluestones. The bluestones were not "mined" and they were not even quarried. The geology work involving Richard Bevins and the geochemistry work involving Jane Evans has NOT established beyond any doubt that some of the bluestone monoliths at Stonehenge actually came from Carn Goedog and Craig Rhosyfelin. The "zircon research" is misrepresented, and it actually did nothing at all to pinpoint the sources of Stonehenge bluestones. The idea that there are "detached pillars ready to go" at Carn Goedog is fanciful in the extreme. The quarrying "evidence" at the two postulated quarry sites is, to put it mildly, hotly disputed. The idea that there are stone trestles, pillars, pivots, platforms and rails at the two "quarries" does not bear scrutiny.
In spite of yet another jolly piece of experimental archaeology, assisted by 30 or so willing schoolchildren, there is not a shred of real evidence to support the idea of overland transport of 80 or so bluestones from Preseli to Stonehenge. (In the programme the "heroic journey" is of course presented as fact....) It is admitted in the programme that all of the other known stone circles and Neolithic monuments in the UK are made from stones that were immediately accessible in the vicinity; in order to try and explain why Stonehenge is a bizarre anomaly takes a lot of nerve, a vivid imagination, and a lot of evidence fabrication.
The famous hazelnuts and their radiocarbon dates are flagged up as being involved in a "Eureka" moment, but the assemblage of radiocarbon dates from Rhosyfelin is so confusing that it "conclusively falsifies" the quarrying hypothesis. This was pointed out by Prof Danny McCarroll long ago, and I agree with him. All the dates show is that there was a very long history of use of the site; they tell us nothing at all about quarrying. There were indeed many prehistoric megalithic structures in the Preseli area, but we don't know how thick on the ground Neolithic features were, and there is no evidence that Preseli had an especially dense concentration of features, let alone a "special emphasis" on stone use.
As far as Waun Mawn is concerned, we see nice graphics but nothing that can seriously be referred to as evidence. Some chaps knocking their trowels on the ground and pronouncing hollows as "sockets" is not exactly convincing. As Pitts and Darvill have pointed out, the "stone sockets" are too shallow to have been used for standing stones. The use of the "110m diameter" circle as a means of making a link between Waun Mawn and Stonehenge is fanciful. There is no evidence of any monoliths from either Rhosyfelin or Carn Goedog ever having been used at Waun Mawn. The OSL "evidence" simply shows that there was occupation of this area around the time that Neolithic features were being created in the landscape -- that should surprise nobody. Other less convenient dates are simply ignored. The idea that one Stonehenge bluestone fits "like a key in a lock" into one of the shallow and irregular depressions in the ground surface is yet another fantasy which has caused much amusement.
The strontium isotope evidence presented by Jane Evans as showing that people from West Wales travelled to Stonehenge is not even supported by her own map shown in the programme. The solar alignment "evidence" is so vague as to be worthless. There is not a shred of evidence to link Waun Mawn with Stonehenge. And then we have the idea that the people of West Wales were attracted to Stonehenge because they liked the look of all those "periglacial stripes", reconstructed vividly with the use of computer graphics........oh dear.......enough said.
I could go on. I haven't even got to the spirits of the ancestors and mass migration yet, let alone all that portentious stuff at the end of the programme. I'm not shouting and screaming. I'm just feeling rather sad that serious scientists have allowed themselves to get caught up in this sorry business, and that the media have allowed themselves to be used for spreading it far and wide. We are now, I think, not just looking at a ruling hypothesis and its effect on the thought processes of otherwise intelligent human beings -- we are looking at something more akin to a pathological obsession afflicting a group of people who are in a very deep hole.
Maybe there is a feeling that the punters over the past few years have had enough of fantasies, and need something a bit more solid for a change? In any case, from what we have been able to discover, nothing of any interest was discovered at Waun Mawn in September, so I suspect that reality is beginning to kick in...... which means that MPP is best advised to keep a low profile for the time being.