Wednesday, 18 December 2019

Stonehenge Bluestone Glaciation Pontification

Dr Brian John takes aim on his blog at a mystery man who raises doubts about John's theory that glaciers brought the bluestones to Stonehenge, or at least somewhere near by, by answering some questions put to him. He claims "there is not a shred of hard evidence in support of the idea of long-distance human transport of bluestones from Wales to Stonehenge, either by land or sea." Taking absence of evidence as evidence of absence he declares it must obviously be glaciers then. has the full question and answer but briefly, the questions put first, the meat of Dr John's answers for brevity's sake next in italics and my own short thoughts afterwards.

1)Where's all the other bluestones on the Salisbury Plain? Surely a glacier wouldn't have brought only the precise number of them required at Stonehenge...?

Response: this is an absurd point, and I cannot for the life of me understand why people are still making it, after all the advances of recent years. Forget the "immaculate Stonehenge" with 82 bluestones and 82 sarsens. There is no evidence that Stonehenge was ever completed.....It is far more logical to suggest that there never were enough bluestones to finish "the Stonehenge project", and that after playing around with assorted stone settings over many centuries, the builders (maybe the descendants of the originators) just gave up and walked away...... This argues for the use of glacially transported erratics which were systematically collected up and used -- until there were none left in the Stonehenge landscape.

So not a single bluestone left unfound in a till deposit? Really? No little ones that weren't big enough to be erected? No pebbles? That is stretching the bounds of believability.

2. While sampling the various types of stone isn't allowed at the site, the volume of chips found in the wide area would easily correspond with the presumed number of present and missing stones. There's lots of visual evidence that points to stone-bashing throughout the life of the monument. See also the 'Stonehenge Layer'.

Response: The suggestion that the "volume of chips" somehow corresponds with the presumed number of missing stones does not survive a moment's scrutiny. Some mathematics please!...

OK. Roughly to get order of magnitude, 30 two tonne stones missing (above ground). 60 Tonnes of Bluestone. Stonehenge layer covers roughly 120 square meters. Stonehenge layer is the debitage from making trinkets so assume wastage at a quarter the of weight, but if trinkets are made elsewhere, as bluestone debitage found elsewhere might suggest, halve that. So the expected weight would be in the order of 1/8 tonne per square meter - 125kg per square meter (1/8 of 60 tonnes spread over 120 square meters) . The layer is 350mm thick of which a large proportion is bluestone, say equivalent to 50mm of it. Which would be 130kg of bluestone at a 2.6 tonne cubic meter density. Very, very rough maths but as a first pass to get an idea of magnitude not too far off.

3. The vacant stone-pipe at Rhosefellin more than suggests it was removed by humans -- no glacier would select a single example from that face and leave the others intact. Despite what Dr Johns says, the site was a well-used quarry from as far back as the Mesolithic. The petro-chemistry of that pipe matches Bluestone-44, that stone having been sampled before the present rules applied.

Response: Ah -- Rhosyfelin! A lovely spot. Right on my doorstep. Now we are seriously into the realms of fantasy. "The vacant stone pipe" or "monolith extraction point" (as MPP likes to call it) does not exist....

You say, he says. Shall we just say the jury is out on whether the monolith was levered out or fell out? But that doesn't tell us much about how it made the rest of the journey. The question of the quarrying is a different one to the transport and conflating the two is unhelpful.

4. In the 1920s HH Thomas was wrong about a possible source being Carn Meini -- they are now known to include Carn Goedog and probably Bedd Arthur. There is a lot of archaeological evidence surrounding these sources.

...most definitely not Bedd Arthur. The latter is not a rock outcrop but a stone setting including small locally-derived monoliths; nobody has ever claimed that it was a source for Stonehenge monoliths. More care, please.

No comment to the archaeology around Carn Goedog I note.

5. There is a marked difference in size and shape between the outer bluestone ring and the inner horseshoe. This strongly suggests they arrived at different times -- the outer ring almost certainly near-original, with the taller versions being installed after the Trilithons went up, much much later. How likely is it these were collected from deposits of the near-environs in such precise order?

...I strongly disagree that the stones arrived at different times, as a result of two distinct stone-collecting expeditions. There is no evidence to support that contention. There was no "precise order." I agree that the stones have been rearranged many times, and my reading of the evidence is that in the last re-setting the "best" of the bluestone assemblage (including the tallest and most elegant pillars) were selected for the horseshoe, and some of them were carefully worked and embellished.

Sorry, having spent many hours in close communion with them they are an as obvious two different sets of stones as one could wish for. There are no intermediate members of the sets.

7. Show me evidence of a glacially entrained Welsh Bluestone south of Bristol.
The idea of glacial transport has been thoroughly examined and found to be implausible. It's not the conspiracy of prevailing thought -- it's very well established.

Response: If you don't mind me saying so, that is an arrogant and dismissive statement put out by somebody who does not know the literature. Can Mr X please tell us which experts have found the glacial transport idea to be implausible?....Mr X needs to do some enlightening Christmas reading. On the matter of glacially entrained bluestones south of Bristol, he just needs to buy a copy of my book...

So no answer to the key point: "Show me evidence of a glacially entrained Welsh Bluestone south of Bristol"

So still no evidence of bluestones being brought by glaciers to the English side of the River Severn, and once you accept, which he does, that the builders of Stonehenge could manoeuvre the stones a short distance then it is logical that could have moved them hundreds of miles. It is just a question of time.

I think we have moved on from Atkinson's view that the builders of Stonehenge were “howling barbarians, practically savages,” and acknowledge them as skilled tenacious craftspeople who had no need of a deus ex machina in the shape of glaciers, aliens or Merlin. So until we see a shred of evidence that glaciers brought the bluestones across the water we are entitled to ignore the Glacial transport theory. The question has rightly been put but there are no observations to support the hypothesis of glacial transport nor has the null hypothesis, that they were transported by humans, as many other stones at that period were and as even they were on part of their journey, been put in doubt by any observations.

Conclusion: There is not a shred of hard evidence in support of the idea of long-distance glacial transport of bluestones from Wales to Stonehenge, either by land or sea.


  1. Thanks Pete -- now we are all pontificating. More and more assumptions piling up. We could go on for ever. I have never claimed that there is solid and incontrovertible evidence for glaciation on Salisbury Plain -- although the shapes and characteristics of all those glacial erratics in the outer circle seems pretty good to me.

    Just a few points:
    1. Re "unfound bluestones" -- there may be till somewhere on Salisbury Plain, or it may be so old that it has been destroyed. Again absence of evidence is not evidence of absence. There are certainly smaller bits and pieces of bluestone in the sediments that are too small to have been used as monoliths. Abundant scattered references to finds, as you know. Some serious research needs to be done on the packing stones, for a start.
    2. The weight of bluestone debris? A noble effort, but the Stonehenge Layer is highly variable in thickness and distribution, and the density of stones per cubic metre is also highly variable. If you think that there may be enough in the way of fragments to account for 30 bluestones, remember that Rodney Castleden calculated that there was enough debris to account for 3. Hmmm -- who is closer to the truth, I wonder?
    3. THE monolith? Assumptions again -- and it wasn't me that raised this issue. Just referring to Neil's little list.
    4. Carn Goedog? Come now, Pete. You know I have done a paper on Carn Goedog, which almost everybody has read. In case you missed it:
    421 reads, and counting.
    5. Two different sets? Your humble opinion ....... what would an intermediate stone actually look like?
    7. Glacially entrained Welsh bluestones south of Bristol? In the Somerset glacial deposits there are dolerites, rhyolites, tuffs and limestones -- there has been no definitive geological work,but a number of workers have suggested Pembrokeshire provenances.
    Many other stones have been transported long distances by the builders of megaliths? Really?!!! That's not what Olwen Williams-Thorpe and her colleagues concluded, after the only decent study on the subject.
    No observations support the glacial transport hypothesis? That is just not true - there is abundant evidence to the west of Salisbury Plain- but I would agree with you that there is a big question mark still over the chalk downs.

  2. Sorry Tim -- I put in "Pete". Late at night, and not paying attention..... goodnight!

  3. The questions look oddly familiar, almost as if I could have written them myself ...

    In any case, Dr Johns is a lovely man who's taken the time on several occasions to enlighten me concerning certain aspects of how glaciers work. These things are marvelous engines with more than a few surprises.

    Unfortunately, after exhaustive review, I have come to the conclusion that it is unlikely to a high degree of probability that sheets of ice transported the Bluestones to Stonehenge or its near environs.

    And while I concur that absence of evidence isn't evidence of absence, I must hark to the first question, which throws that quote to the wind. No doubt about it -- glaciers leave enormous trains of evidence behind, and there simply isn't any for a considerable distance to the north, east, or west of the Salisbury Plain.

    So how did the 80+ Bluestones get there?
    Well, there's only one plausible explanation.

    ND Wiseman

  4. When considering that oh-so-long-in-the-tooth hunch of Dr. Brian John's I also think it time to be brutally frank. I'm inclined now to think less and less about glacial transport, and more and more about a rapidly melting ice flow (now scarcely able to carry a seagull, never mind a polar bear...).

    Sorry to mention the seagull. Don't know what came over me...

    Colin Berry

  5. Apols: that should of course have been ice floe... No pun intended, honest...

  6. I do tend to agree that if we want to worry about anything, it is probably the climate crisis we should be concentrating on......

  7. Seriously, I think it's time to consider two factors that might rationalise the deployment of megaliths via human-transport alone, over a vast distance (140 odd miles or so, old currency) but with no pressing time scale (indeed, one in which leisurely progress was considered not just tolerable but desirable).

    I am presently in the process of replacing my Model 1 (chiming bluestones) with Model 2. (I make no apologies, having discarded 9 models before arriving at my final Model 10 - flour-imprinting/radiant heat roasting - for the Turin Shroud).

    I'm more than happy to unveil Model 2 here on Tim's site - even here, buried in Comments, should anyone be seriously interested.

    Here's a handful of clues. Think difficulty but effective mobile air raid shelter for migrant Neolithic pastoralists. Think warm cuddly lambs (and a few less cuddly pigs for good measure), both needing protection from spears and arrows fired by dangerously close hunter-gatherers lurking in nearby woodland. Think Phase 1 lengthwise (not crosspiece) bridging lintels serving a highly practical (defensive!) purpose. Yes, air-raid shelter for both migrants and their accompanying livestock! Go figure!

  8. Here's a link to the notion flagged up in my above comment, hastily put together with the aid of MS Paint.

    The "lintel" (colour-coded blue) might better be described as a (dolmen-like) capstone, albeit serving its own unique purpose for protecting migrants and unfamiliar territory, en route to the safer open expanses of the elevated chalk downland of Salisbury Plain.

  9. Apols for the omitted passage: that should have read:

    The "lintel" (colour-coded blue) might better be described as a (dolmen-like) capstone, albeit serving its own unique purpose for protecting migrants and their livestock, venturing into unfamiliar territory, en route to the safer open pastures of the elevated chalk downland of Salisbury Plain.

  10. Further postscript: have just this minute tacked the following onto the Appendix of the current posting on my sciencebuzz Blogger site:

    Thus far (midday, Sat 21 Dec) - no feedback! (Oh well, that's the so-called INTERnet for you!). What a waste of time and energy (at least where flagging up of new science-based thinking via progressive modelling is concerned - as distinct from endless mulling over of old largely discredited ideas is concerned).

    Colin Berry

  11. Am trying to remain positive, despite the deafening silence.

    Here's my plan, given the festive season. I'll hold off posting formally on Model 2 (initial deployment of bluestones in transit from Wales to Salisbury Plain for use as overnight air raid shelter (protection from enemy spears and arrows).

    I'll post the broad outline first on my sussingstonehenge site The more self-critical science-based evaluation will be on my sciencebuzz site shortly after.

    Expect to see another new input: it's to do with the precise route taken from Pembrokeshire (etc?) to Salisbury Plain. I personally do not buy into sea transport, sharing the views of Mike Parker-Pearson and others. But that still leaves rivers, notably the Severn as major obstacles.

    There's a point just a few miles downstream from Gloucesterwhere where the River Severn is a mere 100 yards or so across, just before widening out into the Severn Estuary. Rafting bluestones across would still be challenging assignment, especially if there were 80 or so to be shifted.
    I suspect cross-river transport at that major point was assisted by a regular-as-clockwork phenomenon that occurs 130 days per year in response to tidal phases of the moon. Yup, it's called the Severn Bore, a mighty wave of heaped-up water which flows not just straight down the middle, but at certain bends in the river from one side to the other. Go figure! I reckon that wave was exploited by Neolithic bluestone transporters, needing to get their air raid shelter components from one side of a major river to the other...

    Colin Berry

  12. Some might say there are "glaciation" phenomena closer to home... Like the Comments facility on this so-called 'WEBsite'...

  13. New (forthcoming) title: Jan 2020:

    A unified hypothesis for (a) Stonehenge (b) the Avebury Stone Circles and Avenues (c) Silbury Hill (d) West Kennet Long Barrow (d) Durrington Walls (e) West Amesbury (f) those enigmatic controversial bluestones from the Welsh mountains (g) trilithons and their unexplained lintels (h) sarsens (i) alternative means of excarnation.

    Instalment 1: science buzz site, Jan 1, 2020

    Instalment 2: WordPress site, Jan 8, 2020

    Instalment 3: WordPress site, Jan 15, 2020

    Instalment 4: science buzz site, Jan 22, 2020

    Instalment 5: WordPress site, Jan 29, 2020

    Roll on Wednesday (New Year's Day) when the conclusions from 7 years of pontification will be summarised (at least to my own satisfaction).

    Comments (including criticism) will be invited on both sites, that being what the internet is about - a forum for quick communication/instant criticism, in contrast to the conventional route via so-called reputable journals relying as they do on anonymous referees and rarely (if ever) a feedback facility.

    Colin Berry (retired PhD scientist)

  14. Voila the title of that New Year posting of mine, as flagged up earlier on Tim's site:

    Here for 2020 is an entirely new and original model for Stonehenge. It proposes, among other things, DUAL REASONS for carting those bluestones all the way from the Welsh mountains to Salisbury Plain.

    Happy New Year to one and all!

    Colin (Berry) aka sciencebod