Natural rectangular gritstone blocks in the woods at Brimham Rocks
Well, I have been taking a quick look at this new article, just published with a good deal of marketing hype and gullible media coverage:
Anthony Clarke, Jim Leary, Chris Kirkland, Proc. R. Soc. A (2026) 482 (2345): 20260504 .
https://doi.org/10.1098/rspa.2026.0504
I will come back to it with a more detailed discussion, but these are my initial thoughts.
1. Stratigraphic Continuity & Sampling Overreach
The Brimham Grit is mapped by BGS across an extensive area to the west and northwest of Boroughbridge, sitting directly in the path of Devensian ice flowing south and east through the Dales margins. Ice flow during earlier glaciations will not have been significantly different.
The paper conflates an extensive sedimentary feature—the Kinderscoutian Brimham Grit—with a prominent modern landmark (Brimham Rocks) .
The authors have failed to run control samples across the full lateral extent of the formation, meaning that they cannot mathematically distinguish the famous crag from either prominent or unspectacular outcrops or strata many miles away which are now buried beneath glacial deposits.
Sampling of the Brimham Grit was restricted to a single location -- a prominent, easily accessible tourist viewpoint, substituting modern human landscape perceptions and preferences for a rigorous sampling programme.
2. Glacial Dynamics Blind Spot.
2. Glacial Dynamics Blind Spot.
The authors appear to be completely naive about the processes of glacial entrainment. Their simplistic ice-flow objections assume glaciers must have plucked stones from the modern topographic
high points such as Brimham Rocks.
The Brimham Grit is mapped by BGS across an extensive area to the west and northwest of Boroughbridge, sitting directly in the path of Devensian ice flowing south and east through the Dales margins. Ice flow during earlier glaciations will not have been significantly different.
The Vale of York is a thoroughly documented glacial depositional zone; the paper fails to demonstrate that streaming ice cannot have entrained the Devil's Arrows and other prominen gritstone blocks and dropped them nearby as convenient erratics.
3. Visual and Statistical Disconnect Histogram Mismatch:
3. Visual and Statistical Disconnect Histogram Mismatch:
In spite of the claims in the paper, the raw, unmanipulated zircon age histograms presented look visibly distinct to the naked eye, indicating different physical proportions of mineral grains.
Further, there is statistical masking; the multi-dimensional scaling (MDS) models are highly susceptible to being flooded with irrelevant regional "noise" data (e.g., distant Scottish or Southern English formations), which artificially dilutes local variance to force a tight, artificial cluster match.
Finally, the paper relies on the technique of "telling rather than showing," claiming there are no better matches in the region without actually showing us the evidence accumulated over the years by Andrew Morton and other heavy mineral specialists.
All in all, this is extremely poor science from a team which is getting an unfortunate reputation for making spectacular claims on the basis of very limited fieldwork and totally inadequate sampling protocols. This is the third highly controversial paper from the Australian "Curtin University school" of geo-archaeology—led by Dr Anthony Clarke and Professor Chris Kirkland. Their high-profile papers, including the Stonehenge Altar Stone Scottish origin study (Nature, 2024), the Salisbury Plain stream sediment study (Communications Earth & Environment, 2026), and now the Devil's Arrows paper (Proceedings of the Royal Society A, 2026), tend to dazzle the media, and parts of the academic community, because of their high-tech nature.
Clarke and Kirkland have access to some of the world's most advanced LA-ICP-MS (Laser Ablation Inductively Coupled Plasma Mass Spectrometry) equipment at Curtin University in Perth, Western Australia. When a paper is packed with complex U-Pb isotopic data, core geochemistry, and mineral-scale physics, it creates an intimidating "black box." Archaeology peer-reviewers often lack the highly specialized geochronological background to dispute the numbers, assuming that spectacular machine precision equals geological accuracy. Instead of publishing in strict, traditional field-geology journals (where regional specialists would immediately question stratigraphic continuity or lateral lithological variations), they target high-impact, multi-disciplinary, or rapid-communication journals (such as Nature, and Royal Society Proceedings). These platforms prioritize groundbreaking, paradigm-shifting narratives and spectacular "discoveries"over cautious, regional field mapping. And they don't come cheap............
So, to conclude:
So, to conclude:
Clarke et al have shown quite effectively that the stones referred to as a group called the Devil's Arrows have probably come from the Kinderscoutian gritstone in the Millstone Grit group. They have NOT shown that the tall standing stones came from the same precise location -- namely Brimham Rocks.
They have NOT shown that the standing stones were transported by human beings.
They have NOT shown that glacial transport was impossible.
They have NOT ruled out multiple other locations to the west and north-west of Boroughbridge from which the stones might originally have been transported by ice.
Coincidentally I recently had written:
ReplyDeleteA recent paper on residual zircon and apatite grains in 4 samples of river sediments from around Salisbury Plain (Clarke and Kirkland 2026) finds mineral age spectra consistent with the Laurentian basement of northern Britain... and that paucity of more southerly-derived material (despite one of Ordovician age of ~464+/-16 Ma consistent with Pembrokeshire bluestone provenance*) indicates that ice transport was not involved. The arguments invoke substantial landscape modification by mass wasting, ignored in other claims, are tortuous, subjective, and closed to ice, but, in any case, the analysed mineral samples do not derive from where ice could have dumped bluestones to be collected, farther west.
Prompted by Brian’s remarks I then recently added, in relation to the asterisk above:
It is worth considering what the authors actually said in reference to this one Ordovician signature; it underscores the loaded and prejudicial nature of this poor science and misleading writing. “The extreme rarity of this signature underscores the negligible contribution of southwest Welsh, or specifically Preseli, crystalline rock input to the detrital cargo of Salisbury Plain. If ice of sufficient thickness and extent had transported tens of large, multi-tonne bluestone erratics from west Wales to Salisbury Plain, it would be expected to leave a pronounced Darriwilian (Ordovician) zircon signature in the fine detrital fraction; its near absence instead indicates that large-scale glacial transport did not occur.” There are several subjective-cum-illogical remarks in this. The “extreme rarity” is unproven with the sampling done; “specifically Preseli” is unjustified; on the nature and extent of the ice … “If ice…” is a ‘straw man’ of overstatement and expectation. “… expected to leave a pronounced… zircon signature” is an unwarranted supposition, especially given the sampling undertaken. And “near absence” … “indicates large-scale glacial transport did not occur” is nonsense. Are we to suppose the Ordovician zircon reflects small-scale glacial transport, or that it fell from a human conveyor?
I agree with Brian. (Peter Kokelaar)
I asked an AI to put Peter's comment into plain English. I hope this is a fair reading.
ReplyDeleteFirst, the samples are in the wrong place. Whatever ice reached Wessex would have dropped its load on the western side, toward the Somerset lowlands. Sand from rivers on the Plain can't test that.
Second, the inference chain skips a step. Sediment in a river today has been through hundreds of thousands of years of weathering, slope wash and reworking. The paper hand-waves that with "mass wasting" and then treats the modern sand as a faithful record of what ice delivered. Peter calls that tortuous and subjective, and closed to ice from the outset.
Third, the quoted paragraph is loaded. "Extreme rarity" from four samples is not established. "Specifically Preseli" is smuggled in; an Ordovician grain says Ordovician, not Preseli. "If ice of sufficient thickness and extent" is a straw man, an ice sheet built to be knocked down. "Would be expected to leave a pronounced signature" is asserted, not demonstrated. And "near absence indicates transport did not occur" turns weak sampling into a negative proof.
His last line is the sharp one. They did find an Ordovician grain. So what are we meant to make of it? A small glacier? A Neolithic porter with a leaky sack? The joke isn't offering those as the options. It's pointing out that the authors never showed how many such grains ice would have left where they happened to sample, so one grain, or none, can't carry the verdict they hang on it.
Why it belongs under the Arrows post: same team, same shape. A geochemical match that only reaches formation level, dressed as a pinpoint; ice ruled out by expectation rather than by evidence; and the conclusion about human transport written into the framing before the data arrives. Peter is saying the Devil's Arrows paper isn't a one-off, it's a house style, and Brian's "smoke and mirrors" is the right description of it.
Anyone who wants the full argument should read Peter's Stonehenge page at https://kokelaargower.com/stonehenge/, where this comment comes from. It's the clearest account I've read of why a geologist who has actually mapped Anglian erratics on Gower comes down on the side of ice: the bluestone assemblage as a mix that an ice margin would leave, the nunatak model for why spotted dolerite is missing from the Gower trail, Boles Barrow as the boulder in the room, and a western Scottish source for the Altar Stone carried by the same Irish Sea Ice Stream. Illustrated, referenced, and honest about what is and isn't known.
Chef's kiss (if I were a chef)