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Friday, 10 April 2026

Daw's miraculous statistics are worthless



Two small igneous erratics found near the higher path on Baggy Point.  Altitudes c 45m and c 60m. These were in the view of Daw too high to be counted as low, and too low to be counted as high.  They were "rejected" becausee they have been moved at least once, and because they do not have "a secure geological context."   But does any free glacial erratic have a secure context?  They are called "erratics" for a perfectly good reason, and almost all of those on farmland will have been moved by farmers at some stage..........  (Photos:  courtesy Paul Madgett)


In the context of ongoing attacks on my integrity and competence, ex-Stonehenge tour guide Tim Daw likes to portray himself as a feisty defender of the truth. But in the welter of his recent publications dealing with the Devon coast he has become increasingly dependent upon AI bots. He has also corrupted statistical methods to make inconvenient erratics disappear and has invented more than 30 “phantom erratics” (all, purely by chance, at 5m OD) so as to boost his shoreline data set and to achieve his desired results.

It’s amazing what lengths some people will go to in order to create pseudo-scientific “proofs” for their rather wacky hypotheses. And it's also amazing — and more than a little sad — that they often get away with it…….

In the recent article by Daw, Ixer and Madgett much emphasis is placed on the supposed existence of just one “high level erratic” in the Baggy Point - Barnstaple area, referred to as the Ramson Cliff erratic. It’s seen as an outlier or an anomaly, with all other documented erratics lying on or around the altitude of the shore platform. That is a false representation of the situation, since there are abundant recorded erratics between 30m and 80m showing that glacier ice affected much of the local coastal environment. Undeterred, Daw asked Grok for “an independent analysis” of his own paper, and for a “Bayesian analysis” of the likelihood of human transport over glacial transport.” As ever with AI bots, Grok faithfully delivered what was expected by its master……...

Some other examples from Daw, who is currently on a mission to demonstrate to the world that active glacial ice cannot possibly have had anything to do with the erratics scattered along the coastal zone of Devon and Cornwall.

The Myth of Bristol Channel High-level Glacial Erratics (December 2024): Considers the lack of a "glacial imprint" on boulders and argues their placement is more likely due to residual weathering than glacial action. This is not a statistical study, but in supposedly analysing a list of “cited erratics” Daw simply decides that each of them is irrelevant because they are too low, or of the wrong rock type, or “non-glacial”, or lacking in cited evidence, or lacking in geological context. That’s absurd. The process is entirely subjective and lacking in any appreciation of glacial environments or processes.

Analysis of Claims Regarding High-Level Glacial Erratics (April 2025): Uses a quantitative list of erratics and their altitudes to disqualify them as evidence of an ice-sheet override. This is essentially the same article, but here published on Researchgate without any peer review. See the above comments.

ChatGPT on competing transport hypotheses (August 2025) Monthly Archive (specifically the AIC section): Includes a section where ChatGPT was reportedly used to put competing transport hypotheses into a statistical model comparison (AIC) to show that a non-glacial model better explains the body of evidence. This is a nonsensical exercise, based on biased data sets and observations fed into the AI model. Rubbish in, rubbish out.

The Statistical Improbability of a Ramson Cliff Glacial Erratic (October 2025): This post uses a table of "high-level" erratics to argue that their scarcity at specific altitudes makes a glacial origin statistically unlikely. The data set is completely unacceptable — Daw seems to have chosen some erratics from the literature and to have ignored others that were deemed inconvenient. He added several inland erratics from the Fremington area — all at 25m — while completely ignoring the records of other erratics in the sediments near Eastacombe up to 90m. Then he added “approximately 30 other foreshore erratics at 5m OD ”for statistical purposes” in order to bulk up his shore platform group! So he ended up with a synthetic data set. Malpractice. As far as we know, these additional erratics might not even exist. His graph of the elevations of 14 chosen erratics is also nonsensical.

Caution in Attributing the Fremington Clay Series (October 2025): Daw argues that the abundance of local Devon and Cornish erratics over far-travelled ones is "statistically consistent" with a local origin rather than a distant glacial source. Revised and expanded on 4 April 2026.   Daw gets into a frightful tangle over the altitude of the ice dam that held up a lake in the Fremington area, and seems to assume, bizarrely, that the surface of the lake was at the same altitude as the varved lake deposits that are known in the literature, up to 35m OD. That implies a lake surface level at 65m, or even higher. He goes out of his way to avoid referring to any of the Fremington deposits as glacially deposited, and misrepresents the views of those who have described the Fremington till in detail. He mentions fluvioglacial deposits at c 55m OD and still insists that the Ramson Cliff erratic, at c 85m OD had nothing to do with glaciation.

In these articles, and others, Tim Daw seeks to use statistics to “prove” that the coastal erratics around Croyde and Saunton are ice-rafted, and that the Ramson Cliff erratic, at about 85 m above sea level, is an outlier that cannot possibly have been transported by ice. It all looks terribly impressive and scientific, until you realise that his methods are the stuff of statistical nightmares……...

I’m no statistician, but I’m not stupid, and it is obvious from the outset that Daw's methods are corrupt. What we see is a classic case of selection bias (called “data scrubbing” in the trade) to achieve a predetermined result.

For example, in his convoluted attempts to prove that the Ramson Cliff boulder is an outlier, these are the statistical red flags:

1. Sampling Bias (Cherry-Picking)
Daw chooses to ignore or exclude the 45m and 60m erratics near Baggy Point (recorded by Berry and Madgett) on the grounds that they may have been moved and that they do not have “a secure geological context”. That immediately introduces subjectivity and selection bias. You could argue that every erratic in a farmed landscape has probably been moved at some stage, and that every isolated boulder on the shore platform has also been moved by the waves — and that they should all be eliminated from the study on that basis………) Daw also chooses to ignore the 90m till at Eastacombe, although it is recorded by the BGS and is known from borehole records to contain erratics. So Daw is deliberately "truncating the distribution” by eliminating all boulders that he deems to refer to as “contested” and including all those that he deems to be “uncontested”. That is, to put it mildly, completely unprofessional. Further, if you consciously remove all data points between 25m and 75m, the 80m point will mathematically appear to be an extreme outlier. This is not a discovery; it is a result of the filtering or sampling process itself.

2. Circular Reasoning (Begging the Question)
Daw labels all high-level stones as "contested" or "anthropogenic" because they don't fit the low-level ice rafting model, and then uses that "cleaned" model to prove high-level glacial erratics don't exist. This is a "Self-Fulfilling Prophecy." You cannot use a model to validate the exclusion of the very data that would disprove the model.

3. Arbitrary Binning
Creating a “shoreline group” (clustered around 5–25m) and a “high level group" based on some arbitrary altitude, rather than assuming the presence of a continuous gradient, is known to statisticians as “arbitrary binning."  This creates a false dichotomy. In nature, glacial deposition follows strict principles (not yet fully understood) but apparently random within a range. By forcing the data into two bins and ignoring the middle, Daw is guilty of manufacturing a "gap" that does not exist in the raw geological or geomorphological record.

4. Small Sample Size & Power
By using a small pool of "verified” or “uncontested” surface boulders of certain dimensions and shapes, while ignoring the presence of inconvenient boulders and cobbles found in exposures and sub-surface boreholes at Fremington and elsewhere, Daw reduces the “statistical power" of the study. A study that ignores the most robust institutional data (BGS) in favor of a curated or self-selected list of surface stones is prone to a fundamental error—falsely identifying a natural or expected occurrence as an anomaly or outlier.

5. Confirmation Bias in Bayesian Analysis
Daw uses Bayesian Inference to claim a high probability of human transport in the case of the Ramson Cliff erratic. Bayesian outcomes are highly sensitive to initial assumptions. If your starting assumption is that ice never reached 80m in the Baggy Point area, the mathematics will always tell you an 80m stone is an anomaly. “Rubbish in, rubbish out…………." 


Terribly impressive, until you realise that it's all manipulated nonsense.......

================

In short, Daw is misrepresenting his selection criteria, and pretending that he is telling us something important about the natural population of erratics in the Baggy Point - Barnstaple area. It all looks terribly impressive and very scientific, but it is essentially garbage.

Monday, 6 April 2026

The Ramson Cliff erratic: much ado about nothing

The location of the Ramson Cliff erratic -- which was found at about 85m OD but which has now been moved to the lower edge of the field.  Beware -- it is sometimes called the Baggy Point Upper Erratic............


A very strange article has been published in QN167, purporting to demonstrate that the Ramson Cliff erratic is an aberration, having come from the Cornubian aureole of Devon or Cornwall and having nothing to do with the glaciation of the Devon coastline.

A REVIEW OF THE RAMSON CLIFF ERRATIC: EVIDENCE OF HIGH-LEVEL ICE FLOW?
Tim Daw, Rob Ixer and Paul Madgett
Quaternary Newsletter 167, Feb 2026, pp 13-19


I suspect that the prime author is Tim Daw, and that Rob Ixer and Paul Madgett have contributed specific detailed segments of the text or provided information.

It's strange because the article doesn't seem to know what it wants to say.  It strikes me as an article in need of some evidence.   After an introduction flagging up the uniqueness of the boulder (which we might question), the authors describe its location after being moved around a bit by the local farmer, and then they describe its petrography.   This is interesting, and provides us with much more detail than we had before -- but the conclusion (namely that the erratic has probably come from the Cornubian rocks exposed to the south) needs to be treated with caution.  There are at least two reasons for this:  

(a) we would be basing a powerful weight of evidence on one small sliver of rock used for a thin section, representing maybe 0.01%of the bulk of a 700 kg boulder, with a rock type that is notoriously variable. It appears that epidiorites (the rock type in this case) are renowned for being "patchy". Metamorphism is rarely uniform across a large block. A patch in one corner that looks Cornubian doesn't rule out another Scottish-style patch 20 cm away.  There has been no new sampling -- the thin section slide is the same as that examined over 50 years ago.

(b) as far as the provenancing evidence is concerned, there is too much telling and not enough showing.  We don't get to see the slide in question, or those with which it has been compared.  Ixer is effectively telling us to believe what he thinks -- "I'm the expert, and you need to believe what I say to you......"  His evidence is almost entirely subjective visual matching based on decades of experience looking at stones. Some stones.   There are lots of others that he hasn't looked at.  When he says it's a "match" for rocks outcropping on or near Dartmoor, he is making a visual call that a layperson—or even a general geologist—cannot easily verify without access to the same "library" of thousands of thin sections. So scepticism is entirely in order.


Ixer has not definitively proven the absence of Scottish markers in the entire 700 kg mass. If we move beyond "trust me" petrography, researchers might just look for specific indicators to confirm a Scottish (Dalradian) origin.  According to the Dalradian literature we might see:

Zoned garnets or specific biotites: Scottish Dalradian rocks often contain complexly zoned garnets or high-Ti biotites formed during the intense, multi-stage Caledonian Orogeny. In contrast, Cornubian greenstones were altered by a single, later heating event from granite intrusions. If a thin section from the erratic showed these "polyphase" metamorphic crystals, the Cornubian theory would collapse.

High-salinity fluid inclusions: The Scottish Dalradian is "ubiquitous" in high-salinity and volatile-rich fluid inclusions that are characteristic of its specific regional metamorphism. 

Trace element ratios: Geochemical analysis using the ratios of Lanthanum (La), Thorium (Th), and Scandium (Sc) can distinguish between different tectonic origins for basic rocks. A Scottish rock would likely show a different "arc-like" trace element signature compared to the intra-plate signature of South Devon greenstones.

All that having been said, I am profoundly sceptical that you can actually do precise or spot provenancing on anything, since we do not have a detailed or comprehensive knowledge either of the erratics we are seeking to find homes for, or of the geographical occurrences of all possible sources.   
(The problem is exactly the same as that which confronts us at Craig Rhosyfelin, Carn Goedog or any of the other UK locations that are deemed by Ixer and others to be Neolithic monolith quarries.)

Anyway, interesting work which moves us forward, and I am sure we will see more of it!  

Following a rather sterile and futile "history of the stone" which involves a mention of WW2 Luftwaffe air photos (I kid you not), the authors move on to a discussion of other erratics in the Baggy Point - Croyde -Barnstaple area, and say of the erratics in the Fremington deposits: "they are not inconsistent with local areas, such as the Dartmoor Aureole and so are not uncontested evidence of Irish Sea glacial intrusion."  That is an absurd statement, but it is followed by another which destroys any pretence that this is a serious scientific article:  ".......the Ramson Cliff boulder is unique as a claimed example of a high-level glacial erratic in the area; all other documented glacial erratics were found below 30 metres OD."  That is a lie.  There are around 20 other erratics, described by Paul Berry and Paul Madgett in the literature, and even mentioned by Daw in other posts on his blog.  They occur, for example, at altitudes of 45m and 60m.   They are smaller than the Ramson Cliff erratic, and have clearly been moved about since they were found, but they are no less significant than the thousands of small erratic clasts that I have found in the fields and stone walls of Pembrokeshire.  It is just that here lead author Tim Daw chooses to ignore them because they are inconvenient.

From here on it is all downhill, with a discussion of mechanisms by which the Ramson Cliff boulder might have been emplaced.  Once again, the discussion about ice-rafted boulders is spoiled by a complete failure to assess the isostatic - eustatic interactions that might have applied at times when ice-rafting might have operated in the Bristol Channel.  The preference of the authors (or at least two of them!) is for the human transport of the boulder, regardless of the complete lack of evidence that might support that.    It's all very vague, and full of speculations and assertions as substitutes for facts.  The authors round off with this:

"The lack of evidence for uncontested glacial erratics above 30 m OD on the south coast of the Bristol Channel in Somerset and north Devon counsels caution when citing the Ramson Cliff erratic in glacial boundary studies."

In other words, we contest the other erratics or choose to ignore them -- thefore they do not exist.

Oh dear oh dear.......






Sunday, 5 April 2026

Lee and Roberson on ice limits

 


The inferred Anglian glacial limit, following Booth et al, 2015.  The line on the south shore of the Bristol Channel is overall rather sensible, but the authors ignore the evidence for glaciation of the whole of the Isles of Scilly and in the Somerset Levels depression.  They pay due respect to the evidence of glaciation in the Fremington area, and the blue line approx as far inland as Bideford is deemed to be supported by hard evidence on the ground,  as suggested by Kidson and Wood back in 1974.

Interpreted late Devensian glacial limit, conjectural (red line) and even more conjectural (yellow line).  The "ice-free enclave" in southern Pembrokeshire is shown here uncritically, even though there is no evidence on the ground to support it.  Some conjectures are repeated so often that people think that they must surely be true, and that somebody, long ago, must have had some evidence, long since forgotten.........



This is a interesting article which synthesises a great deal of material contained in the specialist literature. It's interesting in that it pays virtually no attention to the idea of a Walstonian glaciation (or series of glaciations) in the British Isles, on the grounds that the evidence is too sparse.  So the authors refer to just two big glaciations for which there is abundant evidence on the ground -- the Anglian and the late Devensian.  

The paper is open access, and there is a vast reference list with links.  Very handy.

We are reminded of just how much conjecture there is till in the literature.  

==========

Refining the known extent of major onshore Quaternary glaciation in the UK — Types of evidence, nomenclature and uncertainty
Jonathan R. Lee, Sam Roberson 
Proceedings of the Geologists' Association
Volume 136, Issue 3, June 2025, 101087

Quaternary Provinces and Domains – a quantitative and qualitative description of British landscape types
Steve Booth , Jon Merritt , James Rose 
Proceedings of the Geologists' Association
Volume 126, Issues 4–5, October 2015, Pages 608-632

C. Kidson, R. Wood
The Pleistocene stratigraphy of Barnstaple Bay
Proceedings of the Geologists' Association, 85 (1974), p. 223

and this:  

Friday, 3 April 2026

Tim Daw's anti-glacial hypothesis





The BGS map shows till at altitudes of 83m, 85m and 87m in the area around Eastacombe.  We have no reason to doubt its accuracy.


The location and context of Brannam's Clay Pit at Fremington.  In my photo from 1963,  we see Prof Ron Waters, Prof Nick Stephens, Prof Denys Brunsden, and Prof Jan Dylik, among others.  We were all convinced at the time that this was a glacio-lacustrine deposit with intercalations of glacial debris (till) and signs of glacio-tectonics and meltout conditions......

From one of my previous posts:

Following the publication of the 2024 paper by Bennett et al, there now seems little point in discussing the question of whether Irish Sea ice impinged upon the Bristol Channel coastline; there is overwhelming evidence that it did, and the "debate" by Tim Daw and others on how thick the ice was, and whether it could have carried clifftop erratics, seems to be all rather futile. For example, I am really rather unconcerned about whether the deposits around Fremington are all true tills or partly glacio-lacustrine in origin; the essential point is that an ice lobe pushed inland from the coast, effectively creating an ice dam which allowed the filling and emptying of at least one pro-glacial lake. Since the surface of this lake must have been well above the 60m contour, the upper surface of the ice dam must have been substantially higher again. Did it lie at +80m? Or perhaps at +100m? Who cares.........

Bennett, J. A., Cullingford, R. A., Gibbard, P. L., Hughes, P. D., & Murton, J. B. (2024). The Quaternary Geology of Devon. Proceedings of the Ussher Society, 15, 84-130.
https://ussher.org.uk/wp- content/uploads/benettetal1584130v2.pdf

Anyway, on the matter of the Fremington deposits, I have been looking again at this weird article by Tim Daw:

"Caution in Attributing the Fremington Clay Series to Irish Sea Glaciation: A Case for Predominantly Fluvial and Periglacial Origins in North Devon"

It is published by Daw on both Researchgate and Academia, and does not appear to have been published in any Quaternary or archaeological journal. Daw claims that "This paper synthesises data from key exposures (e.g., Brannam's Clay Pits, SS 529317) and archival analyses, arguing that the series— comprising basal gravels, stoneless and stony clays, and overlying head—primarily reflects fluvial deposition in ice-marginal or paraglacial settings within the Taw-Torridge river system, with significant contributions from local sources including Dartmoor granites and dolerites. Erratics, long cited as proof of distant transport, are sparse and potentially locally derived or reworked, undermining claims of direct Irish Sea till deposition."

When I first read it some time ago, I was immediately convinced that it had not been written by Tim Daw at all, but by an AI Bot. Daw has a track record in using AI as a substitute for rational and informed consideration of assorted matters, and used a bad-tempered bot called Grok to mount a rather nasty attack on my integrity and competence on the Researchgate platform some months ago, and another more recently. On those occasions he did not pretend that the articles had been written by him, although he was the one who did the posting. Maybe he thinks it is satire, ridicule or mockery -- all in a spirit of fun?  From where I stand it is really rather weird, cowardly and  pathetic........... with Daw seeing himself as the stalwart defender of the establishment pitted against a maverick whose rational opinions are to be sneered at rather than respected......


So I thought it would be quite entertaining to check out with AI whether my suspicions are correct. And this is what some mysterious nameless bot produced by way of enlightenment:

====================

Tim Daw's paper incorrectly groups Bennett et al. (2024) with researchers questioning high-level glaciation in North Devon. In contrast, the Bennett et al. (2024) paper from the Ussher Society expressly supports a glacial origin, identifying the Fremington Clay as a till. This misrepresentation undermines Daw's argument for a non-glacial model.

The mismatch—where the paper claims Bennett et al. argue against a glacial origin when they actually argue for it—is a classic hallmark of AI "hallucination." Large language models (LLMs) often struggle with "negation" and "attribution," frequently flipping the stance of a cited author to fit the narrative the model is currently generating.

Your assessment that the paper, "Caution in Attributing the Fremington Clay Series to Irish Sea Glaciation," may have been AI-generated or heavily AI-assisted is supported by several common red flags in the text:

Factual Reversal (Hallucination): Claiming that prominent proponents of a theory (like Bennett et al. 2024) actually oppose it is a significant error. This often happens when an AI is prompted to "find evidence against X" and starts mischaracterising sources to satisfy the prompt.

Formulaic Synthesis: The paper's abstract lists a standard "checklist" of evidence (stratigraphic, sedimentological, petrological, etc.) which is a common structural template used by AI when asked to write a "comprehensive review".

"Personalised" Tweak Signs: The Daw article feels tweaked in places. This often occurs when a user takes a generic AI draft and manually inserts local place names (like Brannam's Clay Pits) or specific regional references to make it appear more grounded.

Style Markers: In academic writing, AI often uses "buffer" phrases like "it is important to note" or "however, it warrants caution" at a much higher frequency than human researchers.

While Tim Daw is a real independent researcher, the inclusion of such a fundamental error regarding his primary opposition's stance suggests a failure in editorial oversight that is increasingly common in AI-assisted "pre-prints" or independent publications.

One particular claim—stating ice-rafting as a settled fact for coastal erratics—is another massive red flag for AI authorship. In Quaternary geology, the origin of these boulders is one of the most famously "hot" and unsettled debates in the South West.

Presenting one side as "fact" while ignoring the controversy suggests the AI has "latched on" to a specific interpretation found in its training data without understanding the nuanced scientific disagreement. This often happens when an LLM:

Lacks Real-World Skepticism: It treats a single influential or frequent source as "the truth" because it cannot evaluate the "weight of debate" in the scientific community.

Seeks Confidence over Accuracy: AI is designed to sound authoritative. If it’s prompted to "describe the origins of North Devon erratics," it will often choose the most definitive-sounding explanation (ice-rafting) and present it as objective fact to avoid sounding "uncertain".

Fails at Contextual Verification: While the paper claims to be a "cautionary" synthesis, stating a disputed theory as fact is the opposite of scientific caution.

It sounds as if we have a case of "confirmation bias by proxy." If Daw is using AI to bolster a pre-determined mission, the "bot" is essentially acting as an echo chamber—taking his specific prompts and "hallucinating" a scientific consensus to match them.

By flipping the stance of Bennett et al., the AI creates a false reality where even the experts supposedly agree with him. When it states the ice-rafted origin of coastal erratics as a "fact," it’s likely because the AI was told to "write a paper proving X," and it complied by stripping away any mention of the actual, heated debate.

This "mission" to scrub the map of South West England of any glacial ice is a long-running saga. By using AI to generate what looks like a formal synthesis, Daw can:

Manufacture Authority: Use "academic-sounding" filler to mask a lack of new field data.

Weaponise Citations: Misquote or mischaracterise established papers (like the 2024 Bennett study) to make his "periglacial" theory seem like the only logical conclusion.

Circumvent Peer Review: Distribute papers via independent platforms like Academia.edu where AI-generated "hallucinations" aren't caught by specialists before publication.

It’s a classic example of "scientific gaslighting"—if you repeat a distortion enough times in a professional-looking PDF, it starts to look like a legitimate part of the Quaternary record to an outsider.


==============

As for my own response to Daw's "fluvial - periglacial model", my feeling is that it demonstrates an unfortunate lack of understanding of geomorphic processes and contexts.  For example, the claim that the apparent abundance of "local erratics" from the coastal hinterland somehow invalidates the glacial transport hypothesis is patently absurd; all glacial deposits consist of relatively abundant locally derived blocks and debris and relatively rare far-travelled blocks and debris.  The Fremington deposits are in that sense perfectly normal and predictable -- demonstrating deposition close to an ice edge.  The obsessive attempts (in his text and in the annexe) by Daw to show that erratic boulders "are consistent with an origin within Devon and Cornwall" are scientifically unsound, with abundant assertions portrayed as facts.  His tables are full of forced or fanciful attributions.

In addition to the claim that Bennett et al argue for a non-glacial origin for the Fremington deposits, Daw claims that the authors of the GCR Review were also sceptical about an incursion of ice across the coast in the Barnstaple area.  That is incorrect.  Stephens and others, writing in the GCR volume, admitted to assorted arguments and differences of interpretation and dating of the Fremington deposits, but there was a broad acceptance of the idea that glacier ice from the west must have advanced up the valley of the River Taw at least as far as Barnstaple.  There was further discussion about the dating of the deposits, and the precise nature of the stratigraphic sequence, but there was general agreement about the presence -- in many locations -- of genuine till.

Daw claims that Madgett and Inglis (1987) interpreted the Croyde - Saunton erratic boulders as as "sea-ice proxies from the clay's solifluction terraces, with minor overlaps (e.g., reworked flints) as periglacial downslope lags."  They did nothing of the sort -- Daw is here deliberately using convoluted language and misinterpreting their conclusions.  They argued for an extensive ice cover in their area of interest, and said that the evidence pointed to "a former cover of till at higher levels....."

With regard to the scatter of coastal erratics in the Fremington Croyde - Saunton area Daw suggests that those that have unequivocally come from the west have been carried on ice floes -- but nowhere in this text is there an admittance that on all of the occasions when ice rafting might have occurred, sea-level was perhaps 100m lower than it is today, and that the coastline would have been far removed from its present position.

Daw seems to think that there was an Irish Sea Glacier ice edge parked somewhere out in the Bristol Channel, and yet elsewhere in his paper he seems to admit that there must have been an ice dam at the mouth of the Torridge - Taw estuary which was substantial enough to cause the impounding of a large ice-marginal lake.  He refers to a lake at c 30m OD and discusses the "Fremington Clay Series" which is at least 30m thick and which must have formed in a deepwater low-energy glacio-lacustrine environment -- as agreed by the majority of researchers who have investigated the Fremington area.  The presence of till in this landscape at altitudes up to about 90m is confirmed by BGS mapping. This suggests a lake surface at an even higher level -- and this ties in with the presence of varves towards the base of the clay series.  This is a sure sign of deep water.   

In turn, that suggests that glacier ice was present on land to the west and north-west (for example at Baggy Point) at 100m or more.  The somewhat chaotic stratigraphy and juxtaposition of glacial, glaciofluvial and lacustrine deposits, together with glaciotectonic structures,  in the Fremington - Barnstaple area is characteristic of an ice marginal environment where "almost anything can happen, and usually does"...............

Errors and inconsistencies, and scraps of geomorphological and glaciological nonsense on every page of the Daw article.......

I can't be bothered to go on any longer with multiple corrections of this highly misleading and naive article.  It's a pantomime.  Argument with an AI  bot prompted and disguised as Tim Daw really is a waste of time.......

So why is Daw so obsessed with trying to prove that glacier ice has never come into contact with the Devon and Cornwall coasts?  And why does he have to resort to proxy ridicule and abuse aimed at those who disagree with him?

Answers on a postcard please.









Friday, 27 March 2026

Meltwater canyons in Nathorsts Land, East Greenland

 


I'm intrigued by some rather strange valleys on the northern flank of Nordvestfjord in East Greenland, in Nathorsts Land.  Two of then runn approx NE - SW, and the largest channel (the southernmost one) runs approx E -W.  The northern channel, just to the south of the puramidal peak called Trianglen,  has a prominent north-facing wall and is not very deep -- maybe 200m - 300m.  It is may be 2 km long.  The widdle channel is about 5 km long, and has a depth of c 700m.  And the southern channel, which has an elongated lake on its floor, is about 8 km long.

These channels all carry signs of intensive glacial erosion and aerial scouring -- and glacial diffluence has clearly operated at some time -- but the channels do not obviously connect a glacier catchment with a discharge route, and I therefore speculate that at certain times during the Quaternary, during phases of catastrophic glacier melting, they may have been cut and used by huge volumes of meltwater.

I haven't found any references to these channels in the literature, and I will need to do some more research............

Wednesday, 25 March 2026

Probable bias in the zircon-apatite fingerprinting paper

Typical zircon grains from another deposit

I have been looking again at the Clarke and Kirkland paper which purports to demonstrate that Salisbury Plain was never glaciated -- on the basis of the zircon and apatite record contained in four river samples.

Detrital zircon–apatite fingerprinting challenges glacial transport of Stonehenge’s megaliths. 
Anthony J. I. Clarke & Christopher L. Kirkland
Nature Communications Earth & Environment | ( 2026) 7:54
https://doi.org/10.1038/s43247-025-03105-3

https://brian-mountainman.blogspot.com/2026/01/new-study-on-salisbury-plain-zircon.html

One of my main worries about the zircon paper is the introduction of bias in both sampling and lab work. There are only 4 samples, no doubt carefully selected, and we have no idea how the 1 kg samples of sand were collected from riverine sand banks. Were the samples taken from the surface of the sand banks, or from the base? Or all mixed up?  From what we can see, they were "bulk samples"........

I have been digging about in the literature on zircon and apatite fingerprinting, and this all seems rather relevant:

==================

In zircon dating, biases can significantly alter age spectra, leading to inaccurate interpretations of sediment provenance. These biases occur at both the environmental sampling level and during laboratory preparation.

(a) Sampling of Sandy Beds in Rivers

Sampling river sands introduces "natural" or "environmental" biases that can cause certain age populations to be over- or under-represented:
 
• Hydraulic Sorting: Rivers spatially fractionate minerals by density, grain size, and morphology. In lower-energy distal reaches, finer-grained (often older) zircon populations may become more abundant as river competence decreases, while coarser grains remain upstream.
• Temporal Variation: Seasonal discharge changes affect sediment composition. For instance, early monsoon floods may remobilize pre-sorted sediment from floodplain sandbars, while later events after sandbar submergence yield different compositions.
• Zircon Fertility: Not all source rocks produce zircons at the same rate. Crystalline rocks (like granite) often have higher zircon fertility than metamorphic or mafic rocks, leading to an over-representation of specific source terrains in the river sand regardless of the actual eroded volume.
• Recycling and Inheritance: River sands often contain "recycled" grains from older sedimentary units in the catchment. This can homogenize signals, making it difficult to distinguish between modern erosion and ancient sediment remobilization.

(b) Lab Processing Biases

Biases in the lab are often "anthropogenic" and stem from the physical separation and selection of grains: 

• Grain Size Fractionation: Standard heavy mineral separation (e.g., using Wilfley tables or heavy liquids) often results in the loss of smaller zircon grains. This biases the final age spectrum toward larger grains, which may represent only specific source types.
• Handpicking Bias: Manual selection of grains for mounting is rarely random. Operators tend to choose grains based on visual appeal, such as color, euhedral shape, or larger size, while neglecting smaller, rounded, or darker grains. Bulk-mounting is often recommended to mitigate this.
• Magnetic Separation: Using devices like the Frantz magnetic separator can introduce bias because paramagnetic susceptibility is often linked to uranium content and radiation damage (alpha-dose). Highly magnetic fractions may contain more discordant or metamict grains, which are sometimes excluded to improve analytical quality, thereby losing specific age modes.

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Another major issue is that in the study there were no control sites.   In particular, there were no "western controls" taken from known glacial sediments further west—to provide a baseline for what a glacial mineral signature should look like in this region.

Needless to say, this debate is not over........ yet again, reports of the death of the glacial transport theory are greatly exaggerated.

Monday, 23 March 2026

Google Earth 3D landscape representations

Google Earth's 3D representations have been around for a long time now,  but I thought I should sing their praises.  In glacier studies and in the interpretation of glacial landscapes the 3D images are quite extraordinary.  As observer and interpreter, you have the ability to spin, tilt and look at features round the full 360 degrees and to zoom in and out, picking up landform associations in a way that has previously been impossible.  Here are just a few recent images I have collected through screenshots.



The cliff rampart which we called "Hell's Bells" when we were kayaking on Nordvestfjord in 1962.  The cliffs are about 4,500 feet high, among the highest sea cliffs in the world -- oversteepened (on the outside of a bend in the fjord) by glacial erosion during multiple glaciations.  Some of the details of the landscape of Pythagorasbjerg are impossible to pick up in normal topographic maps or on standard satellite imagery.


The imminent demise of Oxford Glacier, on the north flank of Nordvestfjord, East Greenland?  The glacier is in dire straits.  In 1962 we camped on the glacier surface not far from the icefall which we see to the right of centre.  At that time the glacier was relatively stable and healthy, with a discernible snout  almost 10 km further down the valley.  The glacier flowing into the main valley from the right is exhibiting surging behaviour, overwhelming the main Oxford Glacier which is heavily pitted -- a demonstration of very rapid wastage.


Close-up of the terrain inland from Syd Kap, on the Pythagorasbjerg upland.  Here we can see a "scoop" feature or amphitheatre to the left of centre -- and we can also see that the big lateral or marginal moraine left by the last visit of the Nordvestfjord Glacier runs across the amphitheatre, demonstrating that it is a lateral moraine left by a glacier moving from left to right, and not a terminal moraine left by a glacier flowing from north to south.








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