The presence of Asbestos Containing Material (ACM) on the byways at Stonehenge is giving rise to lots of comments and confusion and Wiltshire Council has not been helpful in engaging with the community to explain the situation.
My summary of the situation:
1) There was a problem in 2017 with the grassing over of the A344 where asbestos contaminated poor quality top soil was brought in, and then removed which caused a delay. This was a completely separate and unconnected incident to the current Byway 12 Drove problem. https://www.sarsen.org/2017/06/wiltshire-council-recommend-letting.html for details.
2) The drove passes over the site of the former Stonehenge aerodrome and debris from its demolition is widespread either side of the drove and even south of the A303. A BBC report on the aerodrome: https://www.facebook.com/share/v/19pkgeCqtR/
A film of the demolition https://cutt.ly/JrK4KWq7
I documented in the problem in 2016: https://www.sarsen.org/2016/06/stonehenge-solstice-asbestos-warning.html
3) Even without sight of these the required desk-based initial assessment should have classified the former aerodrome site as a brownfield site with a high risk of asbestos contamination, from the records of its construction, when asbestos containing sheeting was commonly used for roofing and walls, and its demolition. Wiltshire Council or its contractors should have started with a Phase 1 contaminated land assessment, involving a desk study of historical records, maps, and site walkovers to pinpoint potential asbestos sources from past demolitions. If risks are indicated, this progresses to asbestos-specific surveys: a UKAS-accredited professional survey for locating visible ACMs, and a more intrusive refurbishment and demolition (R&D) survey to uncover hidden materials through sampling and analysis.
These surveys are underpinned by key UK regulations to safeguard health, safety, and the environment. The Control of Asbestos Regulations 2012 (CAR 2012) mandates a "duty to manage" asbestos risks, requiring assessments and potential HSE notifications for licensable work. The Construction (Design and Management) Regulations 2015 (CDM 2015) oblige clients to provide pre-construction information on hazards, integrating asbestos surveys into project planning. Additionally, the Environmental Protection Act 1990 (Part 2A) serves as a framework for contaminated land remediation.
On the 21st August 2025 I walked the Drove and small ACM fragments were easily spotted, photos below.
On the 27th August 2025 Wiltshire Council in an FOI response stated: Unfortunately, we encountered an issue where some imported materials did not meet our specifications and had to be removed, causing further delays. More recently, a report identified the presence of asbestos sheeting on the byway. This discovery necessitated an extension of the TTRO into September to ensure safe removal and compliance with environmental regulations. It is believed that the asbestos originated from remnants of former airfield hangars previously located on the site.
Until the hazard is dealt with no maintenance work can be carried on that section, whether the rest of the right of way network can be reopened as work appears to be close to being finished is another question.
Our baffled blogger friend is confused by the science of the analysis of the now famous cow tooth, unfortunately he then uses that inability to comprehend to spread misinformation. Here is my very quick, simplified analysis which might help correct the record.
The key is this figure;
Figure 6 from the paper "Sequential multi-isotope sampling through a Bos taurus tooth from Stonehenge: Investigating cattle mobility in the Neolithic" by Evans et al. (2025), published in the Journal of Archaeological Science https://doi.org/10.1016/j.jas.2025.106269 . It illustrates lead (Pb) isotope data in μ (^{238}U/^{204}Pb) versus T (model age in Ma) space for sequential enamel samples from a Neolithic cow's third molar (M3), dated to approximately 3350–2920 BCE, excavated from Stonehenge's ditch.
This diagram is constructed from raw Pb isotope ratios (^{206}Pb/^{204}Pb, ^{207}Pb/^{204}Pb, ^{208}Pb/^{204}Pb) measured via MC-ICP-MS on the nine slices, converted to μ and T using the Albarède et al. (2012) method, and plotted against 1SD ore reference fields (excluding 10% outliers for robustness). Complementary Sr isotopes show a unidirectional decrease from 0.7144 (winter, radiogenic, consistent with western Britain/old rocks) to 0.7110 (summer, less radiogenic, Chalk-like), while Pb concentrations fluctuate with peaks and troughs, decoupling from Sr.
The trajectory indicates complex Neolithic cattle husbandry, potentially tied to Welsh-Stonehenge connections (e.g., bluestone transport via livestock haulage). The Pb shift from English-like (higher-μ, younger-T) to Welsh-like (lower-μ, older-T) signatures is not solely attributed to geographic mobility but to a mix of dietary Pb (geogenic from local environments) and skeletal remobilisation. During stress, stored skeletal Pb—from early life exposure to Welsh-like sources—can enter the bloodstream and incorporate into forming enamel, decoupling Pb from Sr (which remains dietary). This echoes prior UK isoscape work, supporting Welsh origins or exposure for the cow's early life. Other factors may include foddering across landscapes or seasonal changes. The paper concludes this provides the first isotopic evidence of Neolithic cattle mobility linked to Wales, enhancing theories of long-distance networks, though physiological drivers must be considered.
Model ages T for Pb isotopes estimate the time (in Ma) since Pb was last separated from its uranium (U) and thorium (Th) parent elements in source rocks, based on measured isotope ratios. It's a numerical solution to a system of equations assuming single-stage evolution from primordial Pb:
A fascinating new excavation and paper on Le Plasker, recently published in Antiquity, sheds fresh light on the origins of the Carnac megalithic complex. This discovery marks an important addition to Europe’s most celebrated Neolithic landscape, revealing not only a newly identified section of alignments and a pre-megalithic tomb, but also crucial insights into how stone was chosen, sourced, and arranged. The research highlights the sophisticated choices of Neolithic builders, who manipulated their environment with symbolic intent rather than relying solely on the nearest available materials. Excavations show that construction here involved deliberate quarrying, long-distance transport, and symbolic manipulation of the landscape. Across the wider Carnac complex, the integration of tombs, alignments, and imported materials reflects sustained communal effort and cultural intent rather than opportunism.
Before megalithic construction, the site was used in the Late Mesolithic (c. 5700–5100 cal BC). Excavations uncovered a hut-like structure with a ditch and three small monoliths, one potentially anthropomorphic. This early use, still visible centuries later, likely influenced the choice of the site for later monuments.
Chronology: 4790–4640 cal BC.
Source: Locally quarried granite.
Details: A circular mound (3.3 m diameter, 0.15 m high) covered a dry-stone cist. The cist (0.7 × 0.9 m) likely held a single tightly flexed burial, though no remains survived.
Associated Features: Six oval pavements nearby; two contemporary cooking pits.
Significance: Among the earliest monumental tombs in Brittany, marking a transition from pit burials to megalithic architecture.
Arrangement: 46 monoliths within 20 m south of the mound, aligned along an east–west axis through the cist.
Characteristics: Natural surfaces placed upwards; largely unworked, with only minor modifications for handling.
Source: Granite quarried >2 km away, not from the immediate plateau.
Significance: Likely intended to recreate a rocky landscape absent at the site, embedding symbolic meaning in material choice.
Chronology: 4670–4250 cal BC.
Evidence: Foundation pits (1.8 m wide), filled with 60+ wedging stones (>100 kg), suggest uprights over 3 m tall.
Features: At least three north–south alignments, constructed in multiple phases. Some pits were paired with cooking pits, possibly used in feasting or as light sources for stones.
Significance: Demonstrates phased construction over three centuries, with repeated communal mobilisation and symbolic integration of hearths and stones.
Form: 1.4–1.5 m wide pits filled with charred granite blocks, often aligned with stone rows.
Function: Likely for communal cooking, but may also have illuminated or ritually emphasised standing stones.
Chronology: Contemporaneous with alignments; final hearths date 4250–4050 cal BC.
Significance: Suggests ritual or feasting contexts integral to monument use.
Finds at Carnac Region: Alpine jadeite axes (~800–1000 km) and Iberian variscite beads (~500–1000 km).
At Le Plasker: Few artefacts were recovered, mainly lithics and ceramics, including Late Castellic motifs.
Significance: Carnac as a whole had Europe’s highest density of such imports, situating Le Plasker within long-distance exchange networks.
The Carnac complex, spanning over 10 km, integrates tombs, tumuli, alignments, and colossal stones such as the 20 m Grand Menhir Brisé at Locmariaquer (transported 7–10 km). At Le Ménec and Kerlescan, thousands of uprights were aligned over several kilometres. Le Plasker contributes a missing segment of this vast architectural project, strategically placed on a ridge visible from the sea.
The evidence from Le Plasker undermines the view of opportunistic stone use. From a Mesolithic hut to a pre-megalithic tomb, to centuries of alignments and cooking pits, the site reflects deliberate reuse, symbolic landscape creation, and communal effort. Builders selectively quarried stone from kilometres away and integrated imported prestige materials into a monumental setting. Like Stonehenge in Britain, Carnac exemplifies how Neolithic societies reshaped their landscapes with symbolic and social intent, not simply pragmatic use of local stone.
Reference:
Blanchard, A. et al. (2025) ‘Le Plasker in Plouharnel (fifth millennium cal BC): a newly discovered section of the megalithic complex of Carnac’, Antiquity, 99(406), pp. 915–934. https://doi.org/10.15184/aqy.2025.10123.
An excellent example of editors helping the scientific discourse and discovery progress. Originally the commentary was going to be published in the journal as a comment but as it grew to encompass new findings it was more appropriate to publish it elsewhere.
Richard E. Bevins, Nick J.G. Pearce, Rob A. Ixer, James Scourse, Tim Daw, Mike Parker Pearson, Mike Pitts, David Field, Duncan Pirrie, Ian Saunders, Matthew Power, The enigmatic ‘Newall boulder’ excavated at Stonehenge in 1924: New data and correcting the record, Journal of Archaeological Science: Reports, Volume 66, 2025, 105303, ISSN 2352-409X, https://doi.org/10.1016/j.jasrep.2025.105303. (https://www.sciencedirect.com/science/article/pii/S2352409X25003360)
This will only fuel Brian's erratic thoughts on the value of editors, peer review and self published papers:
One minute he’s brandishing peer review as a shield against pseudoscience; the next, he’s dodging it for the "democratic" joys of ResearchGate, all while lobbing grenades at journals that snub him. It’s a gloriously irregular ride, swinging from high-minded ideals to self-justifying rants, with a constant undercurrent of frustration at the archaeological establishment. Let’s map this journey chronologically, with full quotes in italics and titles as clickable URLs, raising an eyebrow or two along the way. Spoiler: consistency isn’t his forte, but the passion? Pure gold.
We start on Tuesday,
26 April 2011, with John sounding like a guardian of scientific purity in On
Pseudoscience: “The following are some of the indicators of the possible
presence of pseudoscience. • Evasion of peer review before publicizing results
(called 'science by press conference').[41] Some proponents of theories that
contradict accepted scientific theories avoid subjecting their ideas to peer
review, sometimes on the grounds that peer review is biased towards established
paradigms, and sometimes on the grounds that assertions cannot be evaluated
adequately using standard scientific methods. By remaining insulated from the
peer review process, these proponents forgo the opportunity of corrective
feedback from informed colleagues.” Peer review is sacred here – no
shortcuts, no press conferences. Noble stuff! But brace yourself; irony’s
coming.
Jump to Saturday,
19 December 2015, in The Rhosyfelin Affair: after the famine, the feast,
and cracks appear: “because of the way in which the papers have been written
but because the journal editors (Chris Scarre and Mike Pitts) have apparently
gone along with this comprehensive sidestepping of scientific norms.”
Editors are now accomplices in shoddy science. Amusingly, this primes his own
leap away from those norms.
By Monday,
12 September 2016, in New online paper: Rhosyfelin is NOT a quarry,
John’s gone full rebel: “what to do with the paper as submitted and
rejected? There would be no point in sending it to another journal, since it
was written FOR the journal Antiquity and would make little sense anywhere
else. For better or for worse, I have now published it online as a 'working
paper.' This means it becomes available for people too see and to comment on,
and I can alter it if anybody points out mistakes or pieces of unfortunate
phraseology. Does it have any 'status' or 'academic value'? I leave that for
others to judge, but I quite like the 'democratic publishing' process that is
now possible, thanks to the web and online publishing platforms like
ResearchGate. In the process of making revisions I have taken on board all of
the comments from the Antiquity editor and my own referees and those chosen by
him -- and I thank all of them for their help in improving the manuscript. It
is now as reliable, I think, as anything you are likely to read in a learned
journal anywhere.” Oh, the irony! That 2011 warning about dodging peer
review? Forgotten. He’s now bypassing journals, calling it “democratic.”
Sceptical me wonders: empowerment or just a rejected author’s cope?
The love for open platforms surges in Monday,
2 November 2020, Waun Mawn and Proto-Stonehenge -- all fantasy, no facts:
“Democratic peer review, beyond the reach of manipulative and biased
editors, is something that I find quite refreshing on the Researchgate
platform........” Editors are “manipulative” now, and ResearchGate’s
crowd-sourced scrutiny is his new muse. Quite the pivot from peer review as
anti-pseudoscience hero.
Yet in Saturday,
20 February 2021, Do you believe in scrutiny?, he nods to Carl
Sagan: “One of my heroes, Carl Sagan, wrote a great deal about science and
scientific scrutiny, and argued that without careful peer-review and
assessment, science is effectively dead. Peer review is not a guarantee of
quality. I like publishing on Researchgate and Academia, as long as there is no
pretence involved.” Peer review’s vital, but flawed – and he’s still got
one foot in ResearchGate’s camp. I
By Saturday,
17 July 2021, Archaeology and interpretative inflation — who’s to blame?,
he’s spreading the blame: “The authors of journal articles MUST take full
responsibility for how they are represented in the media — they after all are
the ones who write the abstracts, and who sign off the press releases. So get
real, editors — rubbish in rubbish out. Archaeologists are not as innocent as
you make out. It’s about time that academic archaeologistrs — and their
geologist colleagues — started to take their academic duties and
responsibilities seriously by presenting hard evidence (and admitting to
controversy where it exists) instead of peddling myths.” Editors and
authors are both culprits now. Scepticism spikes: if everyone’s messing up, why
not fix it?
In Wednesday,
26 October 2022, Through the two million barrier, John levels the
playing field: “I insist that blogs such as mine are no more disreputable
than certain academic journals and web sites, given what we know about the
corruption that is associated with the peer review process. Some journals
maintain high standards, and operate a very good peer review process -- but
some peer reviewed articles are so appalling that they do nothing for the
reputations of published authors and bring the journals themselves into
disrepute.” Blogs as journal peers? A bold claim, but it feels like a
defensive jab.
He doubles down in Thursday,
1 December 2022, How to sell a hoax: “it has occurred to me that
what you really need, as an ambitious hoaxer, is an academic context in which
critical scrutiny is suspended and material gets published because of the
reputations of the authors rather than on the basis of scientific or academic
worth. The Stonehenge bluestone myth or hoax has been perpetrated not just with
the connivance of the Editor of 'Antiquity' journal (see below) but with the
active support of scores of other editors and peer reviewers as well. ..the
peer reviewers and editors have been negligent in allowing these bits of
over-interpretation and 'myth promotion'..” Peer review enabling hoaxes?
Spicy, especially from our former pseudoscience foe.
Tuesday,
9 May 2023, The ResearchGate phenomenon, sees him preaching: “ResearchGate
does not charge fees for putting content on the site and does not require peer
review. As readers will know, I am a great fan of ResearchGate, and I have
uploaded many (but not all) of my papers onto the site over the years. The big
advantages of ResearchGate, from an author's point of view, are: 3. The ability
to publish 'pre-publication' articles or 'working papers' for scrutiny and
comment by peers. Such articles may then be corrected or modified on the basis
of feedback and comments, and submitted later to journals. This makes the peer
review process quite democratic -- unlike the peer review process undertaken by
journal editors, which is secretive and often biased, and which can be
unreliable. As we know, many articles are published that should never have seen
the light of day, and some that are quite worthy are rejected on the basis of
biased and ill-informed reviews by anonymous peer reviewers. the peer review
process is collapsing, as journal editors find it increasingly difficult to find
qualified reviewers for submitted articles. So the idea that journal articles
are somehow more reliable and respectable than Researchgate working papers (for
example) no longer holds.” ResearchGate’s no-fee, no-peer-review model is
his utopia. But wasn’t dodging peer review a pseudoscience red flag? The
selective memory is chuckle-worthy.
In Sunday,
19 March 2023, The bluestone papers -- some available, some inaccessible
and invisible, he tackles critics: “As faithful readers of this blog
will know, over the years we have published scores of comments from a
mysterious geologist (let's call him Dr X) on the matter of peer-reviewed
publications. He has often suggested, under one pseudonym or another, that the
only 'publications' that have any value are those that appear in peer-reviewed
specialist journals. Because of that, he suggests, my publications that appear
online on the Researchgate and Academia web sites are not worthy of serious
academic attention. In effect, he tells me, nobody is going to take me
seriously until my evidence and interpretations appear in proper archaeological
journals, so I should 'put up or shut up'............. Now of course I fully
acknowledge that Dr X has a point. Learned journals are reputed to be the 'gold
standard' routes for the dissemination of scientific (and humanities) research,
since peer review and editorial scrutiny supposedly guarantee quality, shutting
off rubbish that might otherwise appear in the public domain and cause mayhem.
That's the theory, anyway. In reality, nonsense articles do appear with
frightening regularity in learned journals, since the researchers who submit
articles are nowadays allowed to recommend -- or even choose -- their own
referees, and since editors who want things published will always find a way,
regardless of the quality of the material being considered. This is why
fraudulent articles have to be retracted with alarming regularity. But things
are not that simple. As we have seen, 'Antiquity' journal, which年生
itself as one of the top-ranked journals, deserves praise for making its
articles genuinely open access -- but not from the date of publication. So
those who want to read them as soon as they are published are frustrated. Their
editorial standards are appalling too, and they have been responsible for
publishing the three papers from MPP and his associates which have done most to
disseminate the new mythology of the bluestones. As for myself, I fully accept
that I could and should have published more in learned journals. I have offered
to submit one or two things to archaeology journals over the years, but you
will not be surprised to learn that editors (with rare exceptions) will not
touch anything from me with a bargepole. They won't even look at a manuscript.
I wonder why? So by default I have taken to using Academia and Researchgate as
my publishing platform. I like the latter best, because it is so efficient and
simple to use.” He concedes journals’ “gold standard” status but cries foul
over rejections. Sceptical note: if editors won’t bite, is ResearchGate really
a choice or a fallback?
Monday,
1 January 2024, Thought for the New Year: The Death of Science,
brings apocalyptic vibes: “Every year we seem to see standards slipping
further, with papers published (with massive accompanying PR) which should
never have seen the light of day. I wonder, on such occasions, what sort of
peer review process operates, and what motivates editors to accept and publish
material which is so blatantly defective.” Slipping standards – a classic
gripe, but from a self-publisher, it’s peak pot-kettle humour.
In Tuesday,
20 August 2024, The Nature article: where was the publishing threshold?,
he zooms in: “The reviewers are clearly influenced by the assurance that the
long-distance transport of bluestones over sea or land was exceptional but not
impossible, since it is already known (so say the authors) that they moved 80
bluestones over 225 kms from Preseli to Stonehenge. If the referees had been
properly informed that the human transport of the bluestones was and is hotly
disputed, they would have been much more sceptical about the 750km journey
proposed for the Altar Stone. The publication threshold would have been a great
deal higher. Almost certainly the authors would not have been allowed to get
away with 4 surrogate samples rather than actual ones. And the referees would
have looked for much stronger evidence to support the proposition that the
Altar Stone could not possibly have come from any of the alternative ORS
terranes examined by the authors. All very dodgy indeed..........” Dodgy
referees, lax thresholds – his distrust is in overdrive.
Finally, in Sunday,
11 May 2025, The increasingly bizarre defence of Bluestone Orthodoxy,
and Sunday,
10 August 2025, My Response to Daw's Desperate Diatribe, he turns on
anonymous reviews and even ResearchGate: “Anonymous peer reviews in
circumstances such as these are of course completely worthless, and I refuse to
engage with this one. If a reviewer does not wish to publish his / her name
alongside disparaging and insulting comments, why should anybody take them
seriously? What on earth is this article doing on the Researchgate web site? I
am contacting the moderators to check out what their policy on AI might be, and
to ask for the removal of something that makes no pretence at all to represent
original scientific thought or process.” And: “He even asked
Researchgate to change the typeface at the head of the article, to make it look
as if it was extracted from an academic journal. Cheap stunt. I'm amazed that
Researchgate accepted it, given that it contains no scientific content
whatsoever.” His beloved platform betrays him with “cheap stunts” and AI
nonsense. The irony’s rich – the democratiser doubting the democracy! And, of course, there were no such cheap stunts, as he knows, the site doesn't set the typeface, or judge the content.
John’s arc is a riot: from peer review purist to its
fiercest critic, championing self-publishing until it disappoints. It’s
passionate, contradictory, and delightfully erratic. One can’t help but grin:
if only he’d submit a journal article about it!
I was lucky enough to be able to watch the filming of the concert that Spinal Tap and friends put on last night at Stonehenge. The rocks formed the backdrop to the stage and gave an opportunity for some photos.
"Our research highlights the strong parallels between the intense concentrations of activity associated with feasting event(s) at various henges and enclosures in southern Britain around 2500 BC, including Durrington Walls, Mount Pleasant and West Kennet palisaded enclosures, and at Newgrange. While there are clear similarities and differences in the character of the monuments at these places, contemporaneous largescale seasonal gatherings at midwinter for monument building and feasting occurred at each. At Newgrange and Durrington Walls, at least, we can now say that the feasting was focused on pigs that had been specially fattened on mast in advance. In combination, this suggests that these places may have been strongly interconnected through highly fluid and intersecting webs of contact at this time, thereby resulting in shared practices and worldviews."
Guiry E., Beglane F., Carlin N., Orton D., Teeter M., Szpak P.(2025). Pigs, pannage, and the solstice: isotopic insights from prehistoric feasting at Newgrange. Proceedings of the Prehistoric Society, 1–21, https://doi.org/10.1017/ppr.2025.10063
A fascinating study which will lead to reinterpretation of much Neolithic feasting data. The isotopic evidence from fattening on mast is important.
On a quick read through I am a little concerned that it seems that the peak of pig slaughtering was more likely to be November rather than at the Solstice for their conclusions. This is based on May farrowing which is at the end of the seasonality of Wild Boar and pigs raised naturally.
AI was challenged to propose a novel addition to the debate on how Neolithic megaliths were moved. The result is the Neolithic Trackway Mats Theory, a practical and original idea drawing from modern engineering and known Neolithic technology. (If this has been proposed before apologies for failing to identify a source.)
The core idea involves using Neolithic ground mats—constructed from bundled or woven branches, reeds, or similar biodegradable materials—to create temporary trackways across difficult or soft terrain. These mats would be laid ahead of the megalith to provide a firm base, reducing resistance when moving massive stones. They could be moved and reused, similar to modern site trackways used for heavy vehicles on soft ground. This method would be particularly effective for crossing bogs, marshes, or waterlogged soils, common in many British Neolithic landscapes.
Portable ground protection mats are widely used today. Heavy machinery, cranes, and even tanks move across soft or fragile ground by placing mats under their tracks or wheels. These mats distribute weight, prevent sinking, and can be repositioned as needed. The concept translates easily to Neolithic conditions, given the resources and technology available at the time. For example, see modern archaeology compounds.
Neolithic communities had the skills to construct trackway mats from reeds, branches, bracken, hides or woven timber. Unlike the permanent brushwood foundations of the Sweet Track near Glastonbury, this theory proposes temporary, moveable mats. Preconstructed mats could be placed to form a temporary trackway, lifted, and moved forward as stone transport progressed. These mats would prevent rollers or sledges from sinking into the soil, reduce friction, and support immense weights on weak surfaces, particularly in soft valley floors, ancient bogs, or glacial till.
Trackway mats would make it easier for people—and possibly draught animals—to move heavy stones across rough or soft terrain. By spreading the load over a wider surface area, mats prevent sinking into mud or ruts, which would otherwise cause delays. The textured surfaces of the mats also improve traction, reducing slipping risks while pulling or pushing. Mats effectively transform uneven or boggy terrain into a temporary roadway, enabling more efficient transport with less effort.
The trackway mats theory complements existing timber rail systems proposed for Neolithic stone transport. Mats could be placed beneath and around timber rails to stabilise them and ensure they remain level on uneven or soft ground. This creates a consistent surface, reducing the likelihood of rails shifting or sinking. Mats also simplify the process of laying rails, preventing them from sinking during placement, and facilitate sledge movement by minimising friction. Workers could alternate between extending mats and rails, enabling rapid progress across varied terrain.
The Neolithic trackway mats theory offers a practical, resource-conscious solution to the challenge of moving megaliths across Britain's varied landscapes. Drawing on modern engineering and archaeological precedent, the simplicity and adaptability of mats could have made them indispensable in Neolithic construction.
Several studies have explored timber slipways (or rails) for megalith transport. Below is a summary of key findings:
The Ramson Cliff Boulder
Colin A. Whiteman, Periglacial landforms and landscape development in southern England,
Proceedings of the Geologists' Association, Volume 136, Issues 1–2, 2025, 101059, ISSN 0016-7878,
https://doi.org/10.1016/j.pgeola.2024.04.006.
(https://www.sciencedirect.com/science/article/pii/S0016787824000178)
Abstract: The south-central and south-east England Geological Conservation Review region is unique in Britain in lying completely outside the margins of Quaternary ice sheets. In view of this, the area has been described as a ‘relict periglacial landscape’. This implies that the region has evolved its current form substantially under the influence of seasonal and/or perennial frost. In fact, modern research has demonstrated that permafrost, either continuous or discontinuous, likely existed across probably the whole of the region at different times during the Quaternary...
"There have been a few speculative claims of glaciation occurring within this GCR region (e.g., Martin, 1920; Kellaway et al., 1975), but they have received negligible, if any, support. Far-travelled erratics are conspicuously absent from the region, except on the West Sussex coastal plain around Selsey, and these have been attributed to ice rafting on the basis of striations scored across underlying Cenozoic clays. If there ever were local glaciers within south-central and southeast England, it is unlikely that they would have deposited easily-recognisable erratics. Furthermore, no convincing glacial landforms have been described, and computer modelling (Hubbard et al., 2009; Clark et al., 2018) appears to support the absence of glaciation from this region. Thus it can safely be assumed that, uniquely in Britain, the Quaternary GCR area covering south-central and south-eastern England remained beyond the outermost margins of all Quaternary ice sheets."
Human Transport Theory — Neolithic builders quarried and deliberately hauled the stones from Preseli to Stonehenge.
Glacial Transport Theory — Glaciers during a past ice age moved the stones part or all of the way, leaving them for humans to collect.
The debate is often framed qualitatively, but here ChatGPT put the competing hypotheses into a statistical model comparison using the Akaike Information Criterion (AIC). This approach allows us to quantify which theory better explains the total body of evidence — and to measure the strength of that preference.
ChatGPT chose and researched the criteria without my input,to avoid any accusations I have biased the test. For instance I would have included the recent Bevins et al Newall Boulder paper which it doesn't appear to do so. The prompt used was: "Using Akaike Information Criterion (AIC) evaluate the Human vs the Glacial Transport Theories for the bluestones at Stonehenge" and then a further prompt to "dig deep and run a realistic calculation". The text and analysis is by ChatGPT.
AIC evaluates models by balancing:
Goodness of fit (how well the model explains the data)
Parsimony (penalising models with more free parameters)
For a model :
Where:
= number of estimated parameters
= maximum likelihood of the model given the data
Lower AIC indicates the better balance of fit and simplicity. A ΔAIC greater than 6 is typically considered strong evidence for the lower-AIC model.
ChatGPT treated each transport theory as a predictive model:
Human Transport predicts:
Specific source outcrops match the bluestones.
Evidence of quarrying at Preseli.
No glacial erratic trail into Salisbury Plain.
Dates of extraction and placement coincide with human activity.
Glacial Transport predicts:
Erratics from Preseli present in southern England.
Geological signs of glaciation in Wessex.
Stones represent a random glacial mix.
No need for extensive Neolithic transport infrastructure.
ChatGPT compiled 10 published, peer-reviewed observations from the last two decades. Examples:
Geochemical fingerprinting of rhyolitic debitage at Stonehenge ties it to Craig Rhos-y-felin, and dolerite matches Carn Goedog — two very specific Preseli sources.
Quarry-like features with Neolithic radiocarbon dates have been reported (though contested).
Surveys of ~50,000 Avon terrace pebbles found no extra-basinal erratics.
The last British–Irish Ice Sheet never reached Salisbury Plain; no local glacial deposits are known.
The “Newall boulder” from 1924 excavations matches Preseli lithology and is argued not to be a glacial erratic.
Strontium isotopes of cremated remains at Stonehenge reveal individuals from the Preseli region.
Counter-evidence: some geologists interpret at least one Stonehenge boulder as glacial, and others argue quarry “features” may be natural.
For each observation, ChatGPT estimated the likelihood that such evidence would be seen if the model were true. For example:
| Observation | P(Human) | P(Glacial) |
|---|---|---|
| No erratic trail to Stonehenge | 0.85 | 0.05 |
| Quarry-like features at Preseli | 0.80 | 0.30 |
| One boulder possibly glacial | 0.35 | 0.65 |
Multiplying the probabilities across all ten observations gives the model likelihood. With (no parameters estimated from the data), AIC reduces to .
| ID | Observation | P(Human) | P(Glacial) | ln P(Human) | ln P(Glacial) |
|---|---|---|---|---|---|
| E1 | Rhyolitic debitage at Stonehenge matches Craig Rhos-y-felin (specific Preseli outcrop). | 0.9 | 0.3 | -0.10536 | -1.20397 |
| E2 | Spotted dolerite matches Carn Goedog; quarry-like features & dates ~3350–3000 BC reported. | 0.8 | 0.3 | -0.22314 | -1.20397 |
| E3 | Avon terrace survey (~50k pebbles) found no extra-basinal erratics near Stonehenge. | 0.85 | 0.05 | -0.16252 | -2.99573 |
| E4 | No glacial deposits on Salisbury Plain; Devensian limit far away; Anglian evidence absent locally. | 0.8 | 0.2 | -0.22314 | -1.60944 |
| E5 | The 'Newall boulder' from the 1924 excavation geochemically tied to Craig Rhos-y-felin; argued non-erratic. | 0.75 | 0.25 | -0.28768 | -1.38629 |
| E6 | Strontium isotopes of cremations show some individuals from West Wales (Preseli region). | 0.6 | 0.4 | -0.51083 | -0.91629 |
| E7 | Preseli lithologies concentrated at Stonehenge; no 'erratic train' between Preseli and Wessex. | 0.85 | 0.1 | -0.16252 | -2.30259 |
| E8 | Bluestones include multiple distinct Preseli lithologies traceable to specific sources (non-random mix). | 0.8 | 0.4 | -0.22314 | -0.91629 |
| E9 | Peer-reviewed critique argues quarry 'features' may be natural (reduces strength of quarry claim). | 0.4 | 0.6 | -0.91629 | -0.51083 |
| E10 | Peer-reviewed paper promotes glacial-transport reading of at least one Stonehenge boulder. | 0.35 | 0.65 | -1.04982 | -0.43078 |
| Model | ln L | AIC | ΔAIC | Akaike Weight |
|---|---|---|---|---|
| Human Transport | −3.86 | 7.73 | 0.00 | 0.9999 |
| Glacial Transport | −13.48 | 26.95 | 19.22 | 0.0001 |
Interpretation:
ΔAIC ≈ 19 is far beyond the usual “strong evidence” threshold. The Human Transport model overwhelmingly outperforms the Glacial Transport model given the current dataset. The Akaike weight (~99.99%) can be read as the probability that the Human model would be selected as the better among these two, if the analysis were repeated with similar data.
ChatGPT ran a conservative sensitivity test, reducing the likelihoods for Human-leaning evidence and increasing those for Glacial-leaning evidence. Even then:
Human: AIC = 11.17, weight = 0.983
Glacial: AIC = 19.25, weight = 0.017
The ranking stayed the same, and the Human model retained decisive support.
The statistical edge comes from multiple, converging lines of evidence:
Tight geological matches to specific Preseli outcrops.
Lack of supporting glacial deposits or erratic trails in the region.
Archaeological connections between Preseli and Salisbury Plain during the relevant time frame.
While some uncertainties remain — especially regarding the nature of “quarry” features — the overall pattern fits human agency much more closely than glacial happenstance.
Applying AIC reframes the bluestone transport debate from a narrative clash to a quantitative test. On the present evidence, the Human Transport theory is not just slightly better — it is orders of magnitude more likely than the Glacial Transport theory to explain the Stonehenge bluestones.
(Grok produced similar numbers when asked the same question and was given the same freedom to research and score)
Rerunning the test with the fully referenced evidence table from https://www.sarsen.org/2025/08/evidence-for-glacial-transport-theory.html gave this:
Results:
| Model | ln L | AIC (k=0) | ΔAIC | Akaike weight |
|---|---|---|---|---|
| Human transport | −1.625 | 3.25 | 0.00 | ~1.0000 |
| Glacial transport | −18.971 | 37.94 | 34.69 | ~0.00000003 |
Interpretation:
With ΔAIC ≈ 34.7, the Human Transport theory is overwhelmingly preferred over the Glacial Transport theory on this dataset — the Akaike weight is essentially 100% in favour of human transport.
