Correcting the Lithological Identification of Buried Bluestone Stumps 32d and 32e at Stonehenge

Bevins et al (2025) is mainly noted for its forensic examination of the Newall Boulder and its confirmation that Glacial Transport played no part in transporting the bluestones to Stonehenge. However there is another research item within it which may be overlooked.  

Excavation of cutting C45 in the east sector of the site. Professor Atkinson (kneeling by Bluestone stumps 32d and 32e) examines a find

Acknowledgement and Citation

This standalone research extraction is derived directly from the following source, which provides the primary data, analysis, and evidence discussed herein:

Bevins, R.E., Pearce, N.J.G., Ixer, R.A., Scourse, J., Daw, T., Parker Pearson, M., Pitts, M., Field, D., Pirrie, D., Saunders, I., Power, M., 2025. The enigmatic ‘Newall boulder’ excavated at Stonehenge in 1924: New data and correcting the record. Journal of Archaeological Science: Reports 66, 105303. https://doi.org/10.1016/j.jasrep.2025.105303.(https://www.sciencedirect.com/science/article/pii/S2352409X25003360)

All interpretations, evidence, and conclusions presented below are based on this paper, with specific references to its sections, figures, and supporting data. This updated version integrates historical context from prior publications by Bevins and Ixer (and co-authors), tracing the evolution of identifications for Stones 32d and 32e. These earlier works progressively linked rhyolitic debitage to potential parent monoliths, shifting focus from 32e (suggested in 2011) to 32d (confirmed in 2015 onward), culminating in the 2025 correction.

Introduction

The Stonehenge monument includes several buried stumps of bluestones, which are smaller megaliths distinct from the larger sarsen stones. Among these, the stumps designated as Stones 32c, 32d, and 32e—located in the bluestone circle between upright bluestones 32 and 33—have been subject to historical misidentification (Bevins et al., 2025, Section 4). Originally excavated by Richard John Copland Atkinson in 1954, these stumps were described in Atkinson's publications (1956, 1979) as follows:

• Stone 32c: altered volcanic ash,
• Stone 32d: spotted dolerite,
• Stone 32e: rhyolite.

This identification has been perpetuated in subsequent literature, including plans by Thorpe et al. (1991), Williams-Thorpe and Thorpe (1992), and Cleal et al. (1995), leading to ongoing confusion (Bevins et al., 2025, Section 4). Recent re-examination of photographic evidence from Atkinson's 1954 excavation, combined with petrographic analysis, indicates that the identifications of Stones 32d and 32e were reversed. This correction aligns with the petrographical characteristics of known bluestone lithologies and supports provenancing efforts linking certain bluestones to sources in north Pembrokeshire, Wales (Bevins et al., 2025, Sections 3 and 4).

Historical Identifications in Bevins and Ixer Publications

Research by Bevins and Ixer on Stonehenge bluestones has evolved over time, initially focusing on debitage (stone fragments) and later linking these to buried stumps. Early work introduced the 'rhyolite with fabric' lithology (now Rhyolite Group C) from Craig Rhos-y-felin (formerly Pont Saeson), but did not address specific stumps (Ixer and Bevins, 2010; Bevins et al., 2012). By 2011, they tentatively suggested Stone 32e as a potential parent monolith for rhyolitic debitage, noting: "There is one buried stump at Stonehenge (stone 32e) that they say could well be from Pont Saeson (to be confirmed)" (Ixer and Bevins, 2011, as summarized in secondary sources like Pitts, 2011). This was based on petrographic matches but remained provisional.

In 2015, as co-authors with Parker Pearson et al., Bevins and Ixer shifted focus to Stone 32d, identifying it macroscopically as foliated rhyolite despite Atkinson's dolerite classification: "On the basis of macroscopic appearance, Bevins and Ixer identify SH32d... as a ‘spotted dolerite’ bluestone, even though its appearance is most unlike spotted dolerite. Its dimensions... correspond closely with those of a recess at Craig Rhos-y-felin" (Parker Pearson et al., 2015). This marked the first explicit re-identification of 32d as rhyolite, with no further emphasis on 32e in this context.

Subsequent references in later works (e.g., Bevins et al., 2023a; Parker Pearson et al., 2022a) reinforce this, but the 2025 paper provides the definitive correction using archival photos.

Evidence for Re-identification

Atkinson's excavation (Section C45) exposed the three buried stumps immediately north of Stone 33. A previously unpublished photograph from Historic England's archives (image P50774), taken during the 1954 excavation, provides visual evidence of their morphologies (Bevins et al., 2025, Figure 5a). Analysis of this photograph reveals distinct features:

• Stone 32c (northernmost stump): This appears as a darker, rounded, domed stump with a parallel fabric or parting, indicating weathering. It matches Atkinson's description of altered volcanic ash (tuff). Petrographic examination confirms it as Andesite Group A (Ixer et al., 2022, 2023; Bevins et al., 2025, Section 4). Thin sections from a sample collected by Henry Cunnington in 1881 (Salisbury Museum accession 1983.20.46) corroborate this, showing a chlorite-rich volcanic tuff (Bevins et al., 2025, Section 4).
• Stone 32d (central stump): This stump exhibits a strong foliation, breaking into planar sheets on a centimetre scale, forming steps and small ledges. Visible light/dark banding parallels the foliation (Bevins et al., 2025, Figure 5b). These characteristics are inconsistent with spotted dolerite (a massive, non-foliated igneous rock) but identical to foliated rhyolite from Craig Rhos-y-felin in north Pembrokeshire (Rhyolite Group C; Bevins et al., 2025, Section 4). For comparison, in-situ exposures at Craig Rhos-y-felin show similar centimetre-scale foliation and fracturing (Pitts, 2022; Bevins et al., 2025, Figure 5c).
• Stone 32e (southernmost stump, closest to Stone 33): This is a massive, blocky stump with flattish facets, lacking foliation. It aligns with spotted dolerite, not rhyolite as Atkinson described. Its resistance to weathering (evident in the domed but robust shape) further supports a dolerite classification, possibly spotted (Bevins et al., 2025, Section 4).

The misidentification likely stems from an error in Atkinson's recording or transcription, as the rock types are visually and texturally distinct (Bevins et al., 2025, Section 4). Cleal et al. (1995) compounded the issue by labelling both 32d and 32e as "spotted dolerite" in cross-sections, while marking 32c as uncertain. Other publications, such as Chippindale (1987) and Johnson (2008), often refer to these stumps generically as "bluestones" without specifying lithologies, perpetuating ambiguity (Bevins et al., 2025, Section 4).

Current online resources, such as the Stones of Stonehenge website (accessed 2025), reflect the corrected identifications:

• Stone 32c: Volcanic Group A (now Andesite Group A),
• Stone 32d: Rhyolite Group A-C (now Rhyolite Group C),
• Stone 32e: Dolerite (possibly spotted).

This aligns with broader provenancing studies, where Rhyolite Group C debitage at Stonehenge matches Craig Rhos-y-felin petrographically and geochemically (Bevins et al., 2011, 2012, 2023a; Bevins et al., 2025, Sections 3 and 4).

Implications

Correcting the identifications of Stones 32d and 32e has significant implications for understanding Stonehenge's construction and the sourcing of its bluestones (Bevins et al., 2025, Sections 4 and 10). Stone 32d, as foliated rhyolite, likely represents the parent monolith for debitage fragments, including the Newall boulder (excavated nearby in 1924 by Lt-Col Hawley; Bevins et al., 2025, Sections 2 and 4). This supports human transport from Welsh sources rather than glacial deposition, as the limited lithological variety at Stonehenge suggests selective quarrying from discrete locations like Craig Rhos-y-felin (Bevins et al., 2025, Sections 7 and 10).

The reversal also resolves discrepancies in earlier literature challenging links between Stonehenge rhyolites and Welsh outcrops (e.g., John, 2024a; Bevins et al., 2025, Section 4). Future studies should prioritise direct sampling of these stumps where feasible, though non-invasive methods (e.g., portable XRF) could confirm the re-identification without disturbance (Bevins et al., 2025, Section 3.2).

Conclusions

Re-examination of Atkinson's 1954 excavation photograph and petrographic comparisons demonstrates that Stone 32d is foliated rhyolite (Rhyolite Group C) and Stone 32e is spotted dolerite, reversing their original identifications. Stone 32c remains correctly identified as altered volcanic ash (Andesite Group A) (Bevins et al., 2025, Section 4). This correction refines the bluestone assemblage inventory and strengthens provenancing ties to north Pembrokeshire, emphasising the need for critical review of historical records in archaeological geology (Bevins et al., 2025, Section 10).

References

• Bevins, R.E., Pearce, N.J.G., Ixer, R.A., Scourse, J., Daw, T., Parker Pearson, M., Pitts, M., Field, D., Pirrie, D., Saunders, I., Power, M., 2025. The enigmatic ‘Newall boulder’ excavated at Stonehenge in 1924: New data and correcting the record. Journal of Archaeological Science: Reports 66, 105303. https://doi.org/10.1016/j.jasrep.2025.105303.
• Atkinson, R.J.C., 1956. Stonehenge. Hamish Hamilton, London.
• Atkinson, R.J.C., 1979. Stonehenge. Penguin Books, Harmondsworth.
• Bevins, R.E., Pearce, N.J.G., Ixer, R.A., 2011. Stonehenge rhyolitic bluestone sources and the application of zircon chemistry as a new tool for provenancing rhyolitic lithics. Journal of Archaeological Science 38, 605-622.
• Bevins, R.E., Ixer, R.A., Webb, P.C., Watson, J.S., 2012. Provenancing the rhyolitic and dacitic components of the Stonehenge landscape bluestone lithology: new petrographical and geochemical evidence. Journal of Archaeological Science 39(4), 1005-1019.
• Bevins, R.E., Ixer, R.A., Pearce, N.J.G., Scourse, J., Daw, T., 2023a. Lithological description and provenancing of a collection of bluestones from excavations at Stonehenge by William Hawley in 1924 with implications for the human versus ice transport debate of the monument's bluestone megaliths. Geoarchaeology 38, 771-785.
• Chippindale, C., 1987. Stonehenge Complete. Thames and Hudson, London.
• Cleal, R., Walker, K.E., Montague, R., 1995. Stonehenge in its landscape: twentieth-century excavations. Archaeological Report, 10. English Heritage, London.
• Ixer, R.A., Bevins, R.E., 2010. The petrography, affinity and provenance of lithics from the Cursus Field, Stonehenge. Wiltshire Archaeological & Natural History Magazine 103, 1-15.
• Ixer, R.A., Bevins, R.E., 2011. Craig Rhos-y-felin, Pont Saeson is the dominant source of the Stonehenge rhyolitic debitage. Archaeology in Wales 50, 21-31.
• Ixer, R.A., Bevins, R.E., Pearce, N.J.G., Dawson, D., 2022. Victorian gifts: New insights into the Stonehenge Bluestones. Current Archaeology 391, 48-52.
• Ixer, R.A., Bevins, R.E., Pirrie, D., Power, M., 2023. Treasures in the Attic. Testing Cunnington's assertion that Stone 32c is the 'type' sample for Andesite Group A. Wiltshire Archaeological & Natural History Magazine 116, 1-15.
• John, B.S., 2024a. A bluestone boulder at Stonehenge: implications for the glacial transport theory. E&G Quaternary Science Journal 73, 117-134.
• Johnson, A., 2008. Diagram of Stonehenge. Available at: https://commons.wikimedia.org/wiki/File:Stone_Plan.jpg.
• Parker Pearson, M., Bevins, R.E., Ixer, R.A., Pollard, J., Richards, C., Welham, K., Chan, B., Edinborough, K., Hamilton, D., Macphail, R., Schlee, D., Simmons, E., Smith, M., 2015. Craig Rhos-y-felin: a Welsh bluestone megalith quarry for Stonehenge. Antiquity 89(348), 1331-1352.
• Parker Pearson, M., Bevins, R.E., Pearce, N.J.G., Ixer, R.A., Pollard, J., Richards, C., Welham, K., 2022a. Reconstructing extraction techniques at Stonehenge’s bluestone megalith quarries in the Preseli hills of west Wales. Journal of Archaeological Science: Reports 46, 103697.
• Pitts, M., 2011. Bluestones on News at Ten. Mike Pitts Digging Deeper blog. https://mikepitts.wordpress.com/2011/12/20/bluestones-on-news-at-ten/.
• Pitts, M., 2022. How to build Stonehenge. Thames & Hudson.
• Thorpe, R.S., Williams-Thorpe, O., Jenkins, D.G., Watson, J., Ixer, R., Thomas, R., 1991. The geological sources and transport of the bluestones of Stonehenge, Wiltshire, UK. Proceedings of the Prehistoric Society 57, 103-157.
• Williams-Thorpe, O., Thorpe, R.S., 1992. Geochemistry, sources and transport of the Stonehenge Bluestones. Proceedings of the British Academy 77, 131-161.
• Stones of Stonehenge website: http://www.stonesofstonehenge.org.uk/2020/07/below-ground-stumps.html (accessed 2025).

 

• stumps.html (accessed 2025).

Pobl nid rhewlifau a gludodd gerrig gleision o Gymru i Gôr y Cewri – ymchwil newydd

Cafodd cerrig gleision byd-enwog Côr y Cewri eu cludo o Sir Benfro i Wastadfaes Caersallog gan bobl ac nid rhewlifoedd fel yr honnwyd yn flaenorol, yn ôl ymchwil wyddonol newydd.

Mae tîm o arbenigwyr dan arweiniad Prifysgol Aberystwyth - ac mewn cydweithrediad â gwyddonwyr yng Ngholeg Prifysgol Llundain (UCL), Prifysgol De Cymru a Phrifysgol Caerwysg - wedi ail-ymweld â’r dadleuon ynghylch a gafodd y cerrig mawrion eu symud dros 200km o orllewin Cymru i Swydd Wilton gan rew neu bobl.

Fel rhan o’u hastudiaeth, buon nhw’n canolbwyntio ar ‘glogfaen Newall’, a gloddiwyd yn Stonehenge ym 1924 ac a fu’n ganolog i’r drafodaeth yn y degawdau diwethaf.

Mae rhai astudiaethau wedi disgrifio clogfaen Newall fel maen dyfod rhewlifol, gan gefnogi'r ddamcaniaeth mai rhew oedd yn gyfrifol am gludo'r creigiau a ddefnyddiwyd i godi’r cylch cerrig enwog ar Wastadfaes Caersallog.

Serch hynny mae aelodau o’r tîm dan arweiniad Aberystwyth wedi cynnal archwiliad manwl o glogfaen Newall – gan ddefnyddio technegau dadansoddi pelydr-X, geocemegol a microsgopig yn ogystal â dadansoddi gweadedd arwynebedd – ac mae’n nhw’n dweud ‘nid oes tystiolaeth i gefnogi’r dehongliad ei fod yn faen dyfod rhewlifol’.

Daw’r astudiaeth i'r casgliad hefyd bod clogfaen Newall yn ddarn o rhyolit oedd yn weddill o’r broses cynhyrchu offer cerrig. Fe ddaeth yn wreiddiol o Graig Rhos-y-Felin yng ngogledd Sir Benfro ac fe’i cludwyd i Gôr y Cewri gan bobl Neolithig. Hon o bosib oedd rhan uchaf Carreg 32d sydd bellach wedi torri â’i darn gwaelod wedi’i gladdu tan ddaear.

Cyhoeddir eu canfyddiadau ynn nghyfnodolyn y Journal of Archaeological Science: Reports, ac fe’u disgrifir fel y crynodeb mwyaf cyflawn hyd yma o'r data gwyddonol cyhoeddedig sy’n ymwneud â chlogfaen Newall.

Dywedodd prif awdur y papur, yr Athro Richard Bevins o Adran Daearyddiaeth a Gwyddorau Daear Prifysgol Aberystwyth:

“Rydyn ni wedi cynnal archwiliadau manwl o glogfaen Newall Côr y Cewri a’i gymharu â channoedd o samplau o graig o Sir Benfro. Mae ein canfyddiadau’n cynnig tystiolaeth ddigamsyniol bod y clogfaen wedi’i wahanu oddi wrth biler o rhyolit a ddeilliodd o Graig Rhos-y-Felin, gyda samplau o’r naill le a’r llall yn dangos nodweddion petrolegol a mwynegol union yr un fath nas canfuwyd yn unman arall yn Sir Benfro er gwaethaf chwilio helaeth.

“Mewn cydweithrediad â chydweithwyr archeolegol, daethon ni o hyd hefyd i dystiolaeth gref o weithgaredd chwarela helaeth yng Nghraig Rhos-y-Felin yn y cyfnod Neolithig, sy’n ategu ymhellach ein dadl mai pobl a gludodd y cerrig o Sir Benfro i Swydd Wilton. Byddai hynny wedi bod yn gamp anhygoel ond, fel y dengys Côr y Cewri ei hun, byddai wedi bod yn bosibl ac mae digon o dystiolaeth y byddai technoleg cludo ar gyfer symud cerrig trwm wedi bod ar gael i bobl Neolithig ar y pryd.

“Yn ogystal, ni ddaethpwyd o hyd i’r garreg las yn unman arall ar Wastadfaes Caersallog ac eithrio yng nghyffiniau agos Côr y Cewri ei hun. Pe baen nhw wedi’u symud yno gan rewlifoedd, byddai dosbarthiad llawer mwy gwasgaredig o gerrig tebyg ar draws y rhanbarth.”

I gloi, dywed awduron yr astudiaeth “rydyn ni’n ategu ein dehongliad blaenorol nad yw clogfaen Newall yn faen dyfod rhewlifol, nad oes tystiolaeth o rewlifiant ar Wastadfaes Caersallog, a bod y cerrig gleision wedi’u cludo i Gôr y Cewri gan bobl ac nid gan rew.”

Mae’r rhestr lawn o awduron fu’n rhan o’r astudiaeth yn cynnwys Richard E. Bevins, Nick J.G. Pearce ac Ian Saunders (Prifysgol Aberystwyth); Rob A. Ixer a Mike Parker Pearson (Coleg Prifysgol Llundain); James Scourse (Prifysgol Caerwysg); Tim Daw, Mike Pitts a David Field (ymchwilwyr annibynnol); Duncan Pirrie (Prifysgol De Cymru) a Matthew Power (Vidence inc.).

Roedd yr Athro Bevins a’r Athro Nick Pearce o Brifysgol Aberystwyth hefyd yn rhan o astudiaeth bwysig a gyhoeddwyd yn 2024 yn dangos mai tywodfaen o ogledd-ddwyrain yr Alban oedd y Maen Allor yng nghanol Côr y Cewri ac nid oedd un o’r cerrig gleision o Fynydd Preseli yn Sir Benfro fel y credwyd cyn hynny.

Mae’r Athro Bevins yn ddiolchgar i Ymddiriedolaeth Leverhulme am ddyfarniad Cymrodoriaeth Emeritws.

Dolenni:

Journal of Archaeological Science: Adroddiadau - https://doi.org/10.1016/j.jasrep.2025.105303

Humans not glaciers moved bluestones from Wales to Stonehenge – new research

The renowned bluestone boulders of Stonehenge were transported from Pembrokeshire to Salisbury Plain by humans and not glaciers as previously claimed, according to new scientific research.

A team of experts led by Aberystwyth University - in collaboration with scientists from University College London, the University of South Wales and the University of Exeter - has revisited arguments around whether the large stones were moved more than 200km from west Wales to Wiltshire by ice or people.

They focused their study on a distinctive piece of rock known as the ‘Newall boulder’, which was excavated at Stonehenge in 1924 and which has been central to the debate in recent decades.

Some studies have described the Newall boulder as a glacial erratic, supporting the theory that ice was responsible for transporting the rocks that built the famous stone circle on Salisbury Plain.

However members of the Aberystwyth-led team have carried out a detailed examination of the boulder - using X-ray, goechemical and microscopic analysis as well as surface textural analysis - and say ‘there is no evidence to support the interpretation that it is a glacial erratic'.

The study also concludes that the Newall boulder is a piece of rhyolite debitage originally sourced from Craig Rhos-y-Felin in north Pembrokeshire and transported to Stonehenge by Neolithic people, possibly being the broken top of Stone 32d, now a buried stump.

Their findings, published in the Journal of Archaeological Science: Reports, are described as the most complete summary to date of the published scientific data relating to the Newall Boulder.

Lead author Professor Richard Bevins from the Department of Geography and Earth Sciences at Aberystwyth University said:

“We have carried out detailed examinations of Stonehenge’s Newall boulder and compared it with hundreds of rock samples from Pembrokeshire. Our findings provide convincing evidence that the boulder was detached from a pillar of rhyolite which originated from Craig Rhos-y-Felin, with both samples showing identical petrological and mineralogical features not found elsewhere in Pembrokeshire despite extensive examination”.

“In collaboration with archaeological colleagues we also found strong evidence of extensive Neolithic stone extraction at Craig Rhos-y-Felin, which further supports our argument in favour of human transport of the rocks from Pembrokeshire to Wiltshire. It would have been an incredible feat but, as Stonehenge itself shows, it would have been possible and there is plenty of evidence of haulage technology for moving heavy boulders that would have been available to Neolithic people at that time”.

“Additionally, bluestone has not been found anywhere else on Salisbury Plain with the exception of the immediate environs of Stonehenge itself. Had they been moved there by glaciers, there would be a much more dispersed distribution of similar stones across the region”.
In conclusion, the study authors say “we reiterate our previous interpretation that the Newall boulder is not a glacial erratic, that there is no evidence of glaciation on the Salisbury Plain, and that the bluestones were transported to Stonehenge by humans and not by ice.”
The full list of authors involved in the study includes: Richard E. Bevins, Nick J.G. Pearce and Ian Saunders (Aberystwyth University); Rob A. Ixer and Mike Parker Pearson (University College London); James Scourse (University of Exeter); Tim Daw, Mike Pitts and David Field (independent researchers); Duncan Pirrie (University of South Wales) and Matthew Power (Vidence inc.).
Professor Bevins and Professor Nick Pearce from Aberystwyth University were also involved in a major study published in 2024 which showed the Altar Stone at the heart of Stonehenge was a sandstone transported from north-east Scotland and was not one of the bluestones from Mynydd Preseli in Pembrokeshire as previously thought.

Professor Bevins is grateful to the Leverhulme Trust for an award of an Emeritus Fellowship.

Links

Journal of Archaeological Science: Reports: doi.org/10.1016/j.jasrep.2025.105303

Correcting the Record on the Ramson Cliff Erratic

The latest Quaternary Geology of Devon report has this to say about the Ramson Cliff erratic on Baggy Point:

"In north Devon, however, in addition to the blocks in the till,an isolated block of epidiorite was found at about 80 m OD on Baggy Point promontory [SS 4356 4070] by Madgett andMadgett (1974) which can only have been emplaced by an icesheet. Whilst this implies ice-sheet transport,..."

Bennett, J.A., Cullingford, R.A., Gibbard, P.L., Hughes, P.D. and Murton, J.B. 2024. The Quaternary Geologyof Devon. Proceedings of the Ussher Society, 15, 84-130.

Quandoque bonus dormitat Homerus - they are wrong, in error, and it is with understanding, not condemnation that I need to correct them.

Their error is not without consequences as it provides succor to the Glacial Transport Theory of Stonehenge as it desperately seeks a drop of evidence in its fact free desert death.

Even before its recent repositioning on the cliff edge the boulder wasn't in a secure context, the first hearsay reports of it - https://brian-mountainman.blogspot.com/2015/01/the-erratics-at-baggy-point-croyde-and.html - have it as a standing stone. An artefact of human movement. And how and when it arrived in that position is a mystery as there are no records of such a standing stone or boulder in the records. 

To say it, "can only have been emplaced by an icesheet," is naïve and credulous, with the lack of any other such erratics at such a height the prior assumption must be that is is very, very unlikely. 

A crack team of investigators have investigated the historical sources, and it is the sources that tell the real story,  https://www.sarsen.org/2025/07/the-mystery-of-ramson-cliff-boulder.html

The Mystery of the Ramson Cliff Boulder

Chapter One: A Curious Find on Baggy Point

It was a splendid summer holiday and the Famous Five—Julian, Dick, George, Anne, and Timmy the dog—were staying in the charming village of Croyde, on the rugged North Devon coast. The Bristol Channel sparkled under the sun, and the cliffs of Baggy Point beckoned for adventure. One morning, as they rambled along the crest above Ramson Cliff, Timmy bounded ahead, sniffing furiously at a large, angular boulder on the coast path.

The "high level" epidiorite erratic on Ramson Cliff (photo: Paul Madgett)

 

“Gosh, what’s this?” exclaimed George, running her hand over the rough epidiorite surface. “It’s not like the smooth stones on the beach below!”

Julian, ever the leader, examined it closely. “It’s jolly odd for such a big rock to be up here, all alone. It’s the only one high above sea level on this coast, I’d wager!”

Anne, peering over his shoulder, wondered if the boulder once stood upright, as if placed deliberately. “I think it has been recently moved here. It looks like it was once upright, like a beacon or a rubbing stone. Maybe it was an ancient standing stone. I must find out all about it.”

Dick, always ready for a mystery, grinned. “I bet it’s a clue to something! Let’s call it the Ramson Cliff Boulder. Perhaps it’s a forgotten treasure marker!”

Julian stood up deep in thought. “In my detective books it is always important that the evidence is not moved before it is examined. I’m reading a jolly good story now where a handkerchief was taken to the police station and it couldn’t be used as evidence to show that the missing lady had been on the bus because it wasn’t recorded in its original position. I bet it’s the same for this stone.”

Timmy barked in agreement, and the Five decided to investigate.

Chapter Two: Clues from the Past

The Five headed to the village library, where they met Mrs. Madgett, a kind geologist who, with her husband Paul, had recorded the boulder in 1969 for the Quaternary Newsletter (Vol. 14, November 1974).

She explained that there was an old man in Wales who was convinced that this boulder showed that there was a glacier in the last ice age and if it reached up over the cliff to drop the rock it then went onto to Stonehenge and dropped more rocks there.

“Gosh,” said Anne, “if he thinks this one rock proves all that, it is really important we get to the bottom of this mystery.”

 Mrs Madgett pulled out an old piece of paper which was the report of the discovery:

 

“It was hidden from the coast path and by a stone wall to the south,” Mrs. Madgett explained. “But in the early 1970s, Farmer Tregellis ploughed the field, dislodged it, and dragged it to the edge by the Coast Path. Now it’s half-hidden by gorse bushes!”  The boulder had “always been there,” (*) and he hadn’t moved it before because it felt like part of the land.

But the Five were puzzled. Why had there been this boulder, unlike any other, in the middle of an eight-acre arable field called Ramson, where stones had been cleared to build walls?

George used her Ordnance Survey map to work out where it was spotted in the field, she was a whizz with maps. To help the others she then marked it on an aerial photo.

 Julian frowned. “If it was moved, how do we know where it really came from? Could it be a prehistoric standing stone, like the one near Putsborough?”

Mrs. Madgett nodded. “That’s one idea. The Putsborough stone is local sandstone, but this boulder’s rough and angular, not wave-worn like the erratics at Saunton Down End or under Saunton Cliffs. Perhaps it was raised upright long ago,  dragged up from the shore, and the rough bits ae where it got damaged when it was moved.”

Dick’s eyes lit up. “What if it’s a beacon marker? I found an old map in Early Devon Maps (Ravenhill & Rowe, 2000, pp. 52–53) that marks ‘Cride Beacon’ right near this spot!”

Anne shivered with excitement. “A beacon for pirates or smugglers, maybe?”

George, practical as ever, wasn’t convinced. “Let’s check proper records. If it’s important, it should be on Ordnance Survey maps or old photos! It should show up if it was in the middle of the field all those years ago.”

Chapter Three: The Missing Map Marks

The Five pored over Ordnance Survey maps (National Library of Scotland) but found no trace of the boulder. They examined a 1940s aerial photo (Historic England) and another from the North Devon AONB NMP Project (Knight et al., English Heritage Project 6083).  Nothing!

Julian found a really old map in a dusty drawer. “Look, even the 1839 Georgeham Tithe Map  doesn’t show a boulder.”

“That’s dashed queer,” said Julian. “A boulder this big should’ve been noticed!”

Dick scratched his head. “Unless it was moved there later. Maybe it’s a boundary stone, like the one in Mearlands field nearby!

The Five checked the Devon and Dartmoor Historic Environment Record (Heritage Gateway), which listed a boundary stone (HER number MDV61368) in Mearlands, a field named from the Anglo-Saxon gemoere (boundary). The tithe map showed strips marked by “mearstones.” Could their boulder have been dragged from Croyde Bay, as suggested by Stephens et al. (1998) in The Quaternary History of North Devon and West Somerset (JNCC), It is possible, however, that this boulder was dragged up from Croyde Bay to act as a boundary marker”?

Chapter Four: A Wartime Twist

The Five’s investigation took a thrilling turn when they met old Mr. Penrose, who remembered Baggy Point during World War II. “The American Army took over in 1943,” he said, sipping his tea. “They turned it into an Assault Training Centre for D-Day, bulldozing hedges and walls for company-sized exercises with live ammunition!” (The American).

George’s eyes widened. “Gosh, they might’ve moved the boulder or disturbed the field!”

Anne nodded. “Maybe that explains why it’s not in old records. If it was moved during the war or later, it’s not in its natural spot!”

Julian summed up wisely, “We must remember that sometimes, things moved by hands or history can fool even the keenest detectives. It’s why original position and context matter so very much.”

Timmy woofed, as if agreeing. The Five realised the boulder’s history was muddled by human activity—farming, boundaries, and wartime changes.

Chapter Five: Solving the Mystery

Back at Ramson Cliff, the Five sat by the boulder, now near the Coast Path, and pieced together their clues. Julian summed up: “It’s not on maps or photos, so it wasn’t always here. The field was cleared for farming, and there’s a boundary stone nearby. The war disturbed the area, and the boulder was moved in the 1970s. It’s not a glacial erratic with a clear geological story.”

Dick added, “It might’ve been a standing stone or beacon marker, but we can’t prove it. It’s more like an artefact of human meddling! That’s the answer.”

George patted Timmy. “Well, we’ve solved it, even if it’s not pirate treasure. It’s a jolly good mystery!”

Anne smiled. “Let’s have a picnic to celebrate—ginger beer and all!”

As the sun set over Baggy Point, the Five enjoyed their picnic, content that the Ramson Cliff Boulder, though not a glacial clue, was a splendid adventure.

 

The latest on Stonehenge Sarsen Sources - July 2025

In 2020, a landmark geochemical study by Nash et al. proposed that most Stonehenge’s sarsen stones, came from West Woods, about 25 km to the north in the Marlborough Downs. Using portable X-ray fluorescence (pXRF) and Bayesian PCA of trace elements such as zirconium and niobium, they tied 50 of the 52 stones to a geochemical signature matching this source. Among the most carefully matched was Stone #58, part of a central trilithon, sampled in 1958 via the now-famous “Phillips Core.”

The latest of a series of papers in the journal Archaeometry, debating the interpretation of geochemical data and its implications for the monument has just been published. This exchange highlights the nuances of scientific provenancing: data can be reanalysed differently, leading to conflicting conclusions. To clarify the sequence of claims and counterclaims chronologically, based on the provided documents and the broader context.

The Original Claim: Nash et al. (2020)

• In a landmark study, David Nash and colleagues used portable X-ray fluorescence (pXRF) to analyse 52 sarsen stones at Stonehenge, taking multiple readings per stone. For Stone #58 they also analysed the sample of it, the pXRF matched the stone to 49 other stones so they could use the sample as being representative of them.
• They also sampled sarsen outcrops from 20 potential source areas across southern England.
• Using Bayesian principal component analysis (BPCA) on immobile trace elements (e.g., normalised to zirconium to account for silica dilution during rock formation), they concluded that 50 of the 52 stones share a common chemistry, likely originating from a single source: West Woods.  A variant of PCA that incorporates prior information, BPCA is beneficial in geological provenancing because it handles missing data and reduces dimensionality while preserving meaningful geochemical trends.
• Two outlier stones had different signatures, suggesting multiple sources overall.
• This implied organised transport from a concentrated area rather than scattered local boulders.

The Challenge: Hancock et al. (2024)

• R.G.V. Hancock and team reinterpreted the same dataset from Nash et al. (2020), focusing narrowly on Stone #58.
• They used absolute elemental concentrations (not normalised) and selected different discriminating elements (e.g., Ga, Fe₂O₃, Hf).
• Their analysis suggested the data do not definitively match Stone #58 to West Woods. Instead, they argued: “as a minimum, the Wiltshire sites of Clatford Bottom and Piggledene with West Woods a distant third, appear as potential sources of stone #58. None of these locations, however, has elemental concentrations from one up to three samples that would geochemically merge with those of the Phillips core samples.”
• They criticised Nash's choice of elements (e.g., Hf's correlation with Zr making it less useful) and highlighted issues like detection limits and data quality variability in the original dataset.
• Key point: They aimed to "replicate" Nash's findings but ended up questioning the certainty, emphasising that sarsen geochemistry can vary even within a single outcrop due to formation processes.

The Comment: Nash and Ciborowski (2025)

• Nash and T.J.R. Ciborowski respond directly to Hancock et al. (2024). They identify three main "problems" with Hancock's approach:
1. Use of absolute concentrations: Sarsens form through silica cementation, which dilutes trace elements. Nash argues for normalising data (e.g., to Zr, an immobile element) to correct for this; Hancock's raw data ignores dilution effects, potentially leading to misleading comparisons.
2. Selection of discriminating elements: Hancock used elements like Fe and Ga, which can be mobile during weathering or silicification, making them unreliable for sourcing. Nash prefers immobile ones (e.g., Zr, Nb, Th) that better reflect the parent sediment's signature.
3. Single-sample comparisons: Hancock compared single samples from outcrops to the Phillips' Core, ignoring intra-site variability. Nash used multi-sample ranges and statistical envelopes to account for heterogeneity in silcretes.
• They defend West Woods as the probable source, noting that Hancock's reanalysis overlooks petrological (rock structure) evidence and wider silcrete literature. They include figures showing how dilution affects concentrations and petrographic images of zircon grains.

The Response: Hancock et al. (2025)

• In the “Archaeometry - 2025 - Hancock - On Sourcing Stonehenge Sarsen Stone #58...", Hancock and colleagues counter Nash's criticisms.
• On absolute concentrations: They argue silica dilution has minimal practical impact in this dataset, as most samples are 97–100% SiO₂. They point to examples where lower-SiO₂ samples (silicified sandstones) show extreme variations unrelated to dilution.
• On element selection: Minor differences exist (e.g., Nash used Rb, Th, U; Hancock used Ga, Fe₂O₃), but Hancock claims these don't explain the divergent conclusions. They question Nash's use of Hf (due to its correlation with Zr) and Fe₂O₃ (not significantly different across high-SiO₂ samples).
• On single samples: Hancock clarifies they didn't rely on single samples for their own analysis but used Nash's provided data. They note anomalies in some Nash samples (e.g., from Monkton Down and Totterdown Wood) that don't fit neatly.
• They reiterate that the source of Stone #58 remains uncertain and call for re-examination of Nash's claims. They also touch on potential glacial transport of sarsens, adding another layer to the debate.

Further Support from Recent Studies: Harding et al. (2025)

A recent paper by Harding et al. (published online January 2025 in Proceedings of the Prehistoric Society) applies the same pXRF geochemical techniques to two outlier sarsens in the Stonehenge landscape: the Cuckoo Stone and Tor Stone, located on opposite banks of the River Avon.

Key findings:

• Both stones exhibit geochemical signatures statistically indistinguishable from the majority of Stonehenge sarsens, pointing to West Woods as their likely origin.
• They were probably transported and erected in the early Late Neolithic (early 3rd millennium BCE), contemporary with Stonehenge Phase 1 and about 400-500 years before the main sarsen structures.
• Visibility analysis shows the stones were intervisible and positioned to form a "planned portal" across the River Avon, integrating into the broader Neolithic landscape.

This study, co-authored by Nash and Ciborowski, reinforces the West Woods sourcing hypothesis and extends the timeline of sarsen movement into the Stonehenge area. It also counters ideas of local sarsen abundance by arguing geological conditions on Salisbury Plain were unsuitable for forming large boulders like those at West Woods.

• Unresolved Issues: Methodological debates persist, but glacial claims are a red herring. Future work might use advanced zircon dating or quarry surveys to confirm West Woods.
• Implications for Stonehenge: Human transport from West Woods implies Neolithic ingenuity. Dismissing glaciation strengthens this narrative, avoiding unproven shortcuts.

 

What to Make of It All?

This back-and-forth is classic academic discourse: science thrives on scrutiny, and geochemical sourcing is inherently tricky for materials like sarsen, which form in variable groundwater environments. Here's a hopefully balanced take:

• Strengths of Nash's Position: Their original study is comprehensive, using non-destructive methods on the actual monument and statistical rigour to handle variability. Normalising for dilution is standard in geochemistry, and West Woods fits archaeologically (it's a dense sarsen field, suitable for quarrying multiple stones).
• Strengths of Hancock's Position: Reanalysing existing data is valid and cost-effective. They highlight real issues like data quality (e.g., detection limits) and question over-reliance on certain elements. If dilution effects are overstated, absolute concentrations might suffice for this specific dataset.
• Points of Agreement: Both sides acknowledge sarsen heterogeneity and the limitations of single-sample data. They agree the dataset is valuable but interpret its nuances differently.
• Unresolved Issues: The debate centres on methodology rather than new evidence. Stone #58 might be from West Woods, but Hancock's work introduces doubt. Were all sarsens from one source? Future work could involve more sampling, advanced techniques (e.g., laser ablation ICP-MS for precise zircon analysis), or integrating geophysical surveys of potential quarries.
• Implications for Stonehenge: If West Woods is confirmed, it suggests sophisticated Neolithic logistics over 25 km. If not, it opens doors to multi-source models, perhaps involving local boulders. This doesn't upend Stonehenge's story but refines it, science is iterative.

The geochemical back-and-forth remains a healthy academic exercise, with Nash's normalised, multi-sample approach appearing more robust for silcretes, while Hancock highlights valid data limitations. West Woods still leads as the probable source for most sarsens, supported by archaeological fit (dense boulder fields for quarrying).

However, Hancock's invocation of glacial transport based on John (2009), positing that ice sheets might have naturally deposited sarsens near Stonehenge, reducing the need for human effort, warrants particular scepticism. This idea, echoed in fringe theories for Stonehenge's bluestones (smaller Welsh stones), lacks empirical support and contradicts established geology. During the Last Glacial Maximum (LGM, ~27–19 ka ago), the British-Irish Ice Sheet (BIIS) covered Scotland, Ireland, most of Wales, and northern England, but stopped well north of Wiltshire's Marlborough Downs and Salisbury Plain. Southern England was periglacial, cold tundra with permafrost, but ice-free, as glaciers flowed from highlands without extending south. No glacial erratics (transported boulders) of any kind, let alone sarsens, have been found on Salisbury Plain.

Recent studies (2024–2025) further debunk glacial theories for Stonehenge stones. A July 2025 analysis of the "Newall boulder" (a bluestone fragment) found "no evidence to support an interpretation that it is a glacial erratic. Nash's dismissal, that glacial ideas have "no basis in fact”, is thus justified; invoking them risks pseudoscience, as sarsens form from local Palaeogene sands, not distant bedrock.

• Unresolved Issues: Methodological debates persist, but glacial claims are a red herring. Future work might use advanced zircon dating or quarry surveys to confirm West Woods.
• Implications for Stonehenge: Human transport from West Woods implies Neolithic ingenuity. Dismissing glaciation strengthens this narrative, avoiding unproven shortcuts.

In summary, the debate refines provenancing without resolution yet, but glacial transport is soundly refuted.

References: 

Ciborowski, T. J. R., D. J. Nash, T. Darvill, et al. 2024. “Local and Exotic Sources of Sarsen Debitage at Stonehenge Revealed by Geochemical Provenancing.” Journal of Archaeological Science: Reports 53: 104406. https://doi.org/10.1016/j.jasrep.2024.104406.

Hancock, R. G. V., M. P. Gorton, W. C. Mahaney, S. Aufreiter, and K. Michelaki. 2024. “Stonehenge Revisited: A Geochemical Approach to Interpreting the Geographical Source of Sarcen Stone #58.” Archaeometry 67, no. 1: 1–19. https://doi.org/10.1111/arcm.12999.

Hancock, R. G. V., M. P. Gorton, W. C. Mahaney, S. Aufreiter, and K. Michelaki. 2025. “ On Sourcing Stonehenge Sarsen Stone #58: A Response to Nash and Ciborowski's Comments.” Archaeometry 1–3. https://doi.org/10.1111/arcm.70028.

Harding, P. et al. (2024) ‘Earliest Movement of Sarsen Into the Stonehenge Landscape: New Insights from Geochemical and Visibility Analysis of the Cuckoo Stone and Tor Stone’, Proceedings of the Prehistoric Society, 90, pp. 229–251. doi:10.1017/ppr.2024.13.

John, B. S., & Jackson, L. Jr. (2009). Stonehenge's Mysterious Stones. Earth, 54(1), 36–42 https://www.researchgate.net/publication/270162075_Stonehenge's_mysterious_stones

Nash, D. J., and T. J. R. Ciborowski. 2025. “Comment on: Stonehenge Revisited: A Geochemical Approach to Interpreting the Geographical Source of Sarsen Stone #58.” Archaeometry 1–14. https://onlinelibrary.wiley.com/doi/10.1111/arcm.13105.

Nash, D. J., T. J. R. Ciborowski, J. S. Ullyott, et al. 2020. “Origins of the Sarsen Megaliths at Stonehenge.” Science Advances 6, no. 31: 1–8. https://doi.org/10.1126/sciadv.abc0133.

Correcting the Record - A rebel without a cause.

Dear old Dr John rants: "Twitter (now X) which I can't get at since Mr Musk has decided that I am not a bona fide follower or disciple. Something about the new paper "refuting any glacial transport"..........."

What a rebel, sticking it to the man, standing up against Musk. We are all with you bro on the picket line.

Except he hasn't been banned - https://x.com/Bluestone4 - The account exists and appears active, with no visible indication of a ban or suspension—no "Account suspended" message or blank profile. I expect he has just forgotten his password. 

The Newall Boulder Excavation Report

With the publication of the definitive report on what is known as the "Newall Boulder" - Bevins et al (2025) - and the subsequent publicity as the Glacial Transport theory is given its coup de grâce, I thought it worthwhile revisiting an earlier post of mine from 2022. https://www.sarsen.org/2022/06/an-erratic-source.html

This identified the excavation report, and what appears to be a photo of it in situ. 

In Hawley's 6th Report Jan 1926 Vol V1 No.1 The Antiquaries Journal which is of his 1924 excavations he describes finding a foreign stone and also a photo of the excavation.

I think the stone pictured in the middle of the very left hand side of the excavations around stone 8, judging by the scale, is about the right depth and size to be the foreign stone he mentions. This provides the original context for the stone.  (Click to embiggen)

Kellaway's description seems to match it very well:

Reference: Bevins, R.E. et al (2025) (The enigmatic ‘Newall boulder’ excavated at Stonehenge in 1924: new data and correcting the record
(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)
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)

Revealing Lichen Covered Rock Carvings At Stonehenge

Another paper on the fascinating and innovative discovery methods of identifying rock art at Stonehenge that is hidden under the lichen has been released;

Gavin Leong , Matthew Brolly , David J. Nash , Novel lichen simulation and laser scan modelling to reveal lichen-covered carvings at Stonehenge, Results in Engineering (2025), doi: https://doi.org/10.1016/j.rineng.2025.106377 

This follows the pre-print released earlier this year:

Leong, Gavin and Brolly, Matthew and Anderson-Whymark, Hugo and Nash, David and Bedford, Jon, Novel Approaches for Enhanced Visualisation and Recognition of Rock Carvings at Stonehenge. Available at SSRN: https://ssrn.com/abstract=5126093 or http://dx.doi.org/10.2139/ssrn.5126093

and Gavin Leong's thesis:

Leong, G. (2024) Revealing lichen-covered rock art at Stonehenge: where terahertz imaging and photogrammetry meet machine learning, lichen simulation, and image analysis algorithms. PhD thesis, University of Brighton. Available at: https://research.brighton.ac.uk/files/49055416/PhD_Thesis_Gavin_Leong.pdf

Gavin Leong's PhD thesis, titled "Revealing Lichen-Covered Rock Art at Stonehenge: Where Terahertz Imaging and Photogrammetry Meet Machine Learning, Lichen Simulation, and Image Enhancement" and submitted in May 2024, serves as the foundational bedrock for the subsequent research outputs, including the February 2025 preprint on enhanced visualisation and recognition of exposed rock carvings and the July 2025 journal pre-proof on lichen simulation for detecting obscured carvings, both of which he led as the primary author. Drawing from extensive fieldwork at Stonehenge and innovative interdisciplinary approaches, Leong's thesis meticulously developed key methodologies such as the difference of Gaussians (DoG) and pseudo-depth mapping (PDM) techniques for visualising faint carvings on non-lichenised surfaces, achieving the discovery of new axe-head motifs on Stone 53, while pioneering the application of MeshNet—a 3D shape classification neural network—for semi-automated carving recognition with 90.7% accuracy on photogrammetry-derived meshes; these elements directly underpin the visualisation-focused preprint, providing the baseline tools and empirical discoveries that were refined and cited therein. Furthermore, the thesis introduced the groundbreaking Ramalina siliquosa diffusion-limited aggregation (RDLA) simulation, informed by laser-scanned lichen thickness data from Stone 30, to digitally replicate lichen occlusion on carving meshes, enabling denoising strategies that reduced visual noise by 70.7% and facilitating MeshNet retraining for 73.3% accuracy on simulated lichen-covered surfaces—innovations that form the core of the later journal article, extending the thesis's non-invasive ethos to address the 23% lichen-covered areas at Stonehenge without physical removal. Leong's comprehensive exploration of terahertz time-domain spectroscopy (THz-TDS) in laboratory and fieldwork settings, including partial least squares regression for substrate recovery beneath lichen layers up to 35 mm thick and at water contents below 18%, not only validated subsurface imaging as a complementary tool but also highlighted ethical conservation challenges, laying the groundwork for broader applications in global rock art sites and related fields like forest canopy modelling. Through rigorous experimentation, detailed appendices on code implementations, and a synthesis of machine learning with heritage science, Leong's doctoral work not only anticipated the challenges of lichen obscuration but also provided the theoretical, methodological, and empirical foundations that enabled the two papers to advance the field, deserving full credit for his pioneering contributions that bridge archaeology, remote sensing, and computational simulation in a manner that promises lasting impact on cultural heritage preservation.

The February 2025 preprint, titled "Novel approaches for enhanced visualisation and recognition of rock carvings at Stonehenge," introduced innovative visualisation techniques such as difference of Gaussians (DoG) and pseudo-depth mapping (PDM) to enhance the detection of faded carvings on exposed surfaces, leading to the discovery of four new carvings, ten potential carving areas, and nine alternative interpretations on Stone 53, while also demonstrating the efficacy of the MeshNet neural network for semi-automated carving recognition with 90.7% accuracy on non-lichen-covered meshes derived from photogrammetric data; it further suggested future extensions to lichen-obscured regions.

The later paper from July 2025, titled "Novel lichen simulation and laser scan modelling to reveal lichen-covered carvings at Stonehenge," explicitly builds upon the foundational preprint from February 2025 by addressing a key limitation identified in the earlier work—namely, the inability to analyse approximately 23% of Stonehenge's stone surfaces due to coverage by the fruticose lichen Ramalina siliquosa, which potentially obscures additional Early Bronze Age axe-head and dagger carvings. In contrast, the later paper extends this by developing a novel species-specific lichen simulation called Ramalina siliquosa diffusion-limited aggregation (RDLA), which modifies base diffusion-limited aggregation (DLA) with cone-based attachment (CBA) modes, logistic functions for branching behaviour, and efficiency improvements informed by new laser scan data from Stone 30 to capture real-world lichen thickness distributions (up to 37.5 mm, far exceeding typical carving depths of less than 1 mm). This simulation is applied to the photogrammetry-derived carving meshes from the earlier study (referred to as seed meshes), creating a database of digitally lichen-covered surfaces; subsequent denoising techniques, including cloth simulation sheathing and distance mapping, reduce lichen-induced visual noise by 70.7% as quantified by probability of superiority metrics, enabling clearer visualisation of underlying carvings via depth maps without physical lichen removal. A standout new result is the retraining and testing of MeshNet on these simulated lichen-obscured meshes, achieving 73.3% accuracy in distinguishing carvings from non-carvings (with high recall at 86.0% but lower precision at 68.5%), demonstrating that laser scanning combined with denoising and MeshNet remains viable for non-invasive detection even under shrubby lichen cover, albeit with reduced performance compared to the 90.7% baseline on clean data from the preprint. Additionally, the paper provides empirical data on lichen thicknesses from multiple species at Stonehenge, highlighting R. siliquosa's unique obscuring potential, and discusses broader applications, such as adapting RDLA for other fruticose lichens, subsurface imaging alternatives like XRF or terahertz, and extensions to global rock art sites or even unrelated fields like forest canopy modelling and virtual environment ageing effects, thereby advancing ethical conservation practices and opening avenues for further discoveries at Stonehenge and beyond.

Correcting the Record on the Ice Rafted Erratics of the Bristol Channel.

Ice Rafting Reconsidered — The Case for Floating Boulders in the Bristol Channel

In a recent blog post, Brian John reiterates his long-held skepticism toward the idea that the giant boulders scattered along the southern coastlines of the Bristol Channel were transported by floating ice. He argues that such a mechanism is “implausible” given glacial sea-level depression, and suggests that invoking isostatic rebound as a counterpoint is "special pleading."

However, three new peer-reviewed studies published in 2024 present compelling evidence that fundamentally contradicts this view and establish a well-supported case for ice-rafted boulder emplacement during the Middle to Late Pleistocene.

🧊 Gibson & Gibbard (2024): Stratigraphic Evidence for Ice-Rafted Boulders

This comprehensive review of Wolstonian Stage glaciation shows that large erratic boulders, including far-travelled lithologies from Scotland and northern England, are found resting on wave-cut rock platforms around the Bristol Channel and south coast. Crucially, these boulders are:

• Stratigraphically overlain by raised Ipswichian beach deposits, dated to 130–90 ka, showing they pre-date the last interglacial highstand.
• Interpreted as being ice-rafted, not dropped by grounded glacier ice — based on their scattered, isolated distribution and lack of associated till.

This directly challenges the notion that ice rafting is geologically implausible at these elevations.

🌊 Scourse (2024): Glacio-Isostatic Adjustment Enabled High Sea Levels

In a recent review of British–Irish Ice Sheet (BIIS) dynamics from MIS 5d to 2, Scourse provides strong evidence for:

• High relative sea levels during MIS 4 and MIS 3, caused by glacial isostatic loading as the BIIS expanded.
• Coincident ice margins calving into marine waters, which allowed icebergs and sea ice to transport and deposit debris onto present-day coastal sites.

This directly refutes Brian John’s claim that isostatic rebound cannot explain the present elevations of erratics — and shows that conditions were suitable for ice rafting in the Bristol Channel.

🪨 Bennett et al. (2024): New Mapping of Devon and Cornwall Boulders

Using LIDAR and field survey, Bennett and colleagues have documented discrete concentrations of far-travelled giant erratics along the coasts of south Devon and Cornwall. Their findings show:

• These boulders sit in intertidal and raised marine settings, not within glacial tills.
• Their distribution and lithologies are consistent with ice-rafting melt-out — not glacial pushing or dumping.

This further weakens the grounded glacier-only hypothesis and supports episodic marine deposition.

🧠 Common Sense Revisited

Brian John invokes the boulder-strewn Baltic coastlines as an example of wave-modified glacial sediments rather than ice-rafted material. But this comparison overlooks key differences:

• The Baltic has no tides and experienced greater isostatic uplift than southern Britain.
• Its glacial history and hydrodynamics differ greatly from the open Atlantic-fed Bristol Channel.

Context matters. The conditions in SW Britain during MIS 6 to 3 allowed for calving margins and floating ice — and the evidence now supports this interpretation.

✅ Conclusion: Floating Ice Delivered Boulders to the Bristol Channel

The 2024 studies converge on a new, evidence-based understanding:

• The southern coasts of Britain experienced periods of high relative sea level and iceberg activity during the Late Middle and Early Late Pleistocene.
• This created conditions suitable for the deposition of ice-rafted erratics.
• The hypothesis is no longer speculative — it's now robustly grounded in stratigraphy, dating, and geomorphology.

It’s time to update the narrative. Rather than dismiss the ice-rafting model, the latest science shows that it played a real role in shaping these iconic coastal landscapes.

---

References:

• Gibson, S. M. & Gibbard, P. L. 2024 (October): Late Middle Pleistocene Wolstonian Stage (MIS 6) glaciation in lowland Britain and its North Sea regional equivalents – a review. Boreas, Vol. 53, pp. 543–561. https://doi.org/10.1111/bor.12674. ISSN 0300-9483
Scourse, J.D. (2024), The timing and magnitude of the British–Irish Ice Sheet between Marine Isotope Stages 5d and 2: implications for glacio-isostatic adjustment, high relative sea levels and ‘giant erratic’ emplacement. J. Quaternary Sci., 39: 505-514. https://doi.org/10.1002/jqs.3611
• Bennett, M. R. et al. (2024). Evidence for Middle Pleistocene ice-rafted debris in south-west England: A GIS and field-based reassessment. https://ussher.org.uk/wp-content/uploads/benettetal1584130v2.pdf.

Still no evidence for an ice flow over the Somerset levels.

Correcting the record with regards to an embarrassing flight of fancy that there is evidence in the latest research for a glacial ice flow towards Stonehenge. 

“The paper by Ely et al. (2024) provides no basis for asserting that ice flowed over the Somerset Levels, as this region is not mentioned in connection with any ice advance. The simulation extending furthest south into the Celtic Sea, covering parts of Cornwall and Devon, is explicitly noted as lacking empirical support (Page 23). "In the simulation which reaches the furthest south in the Celtic Sea, an ice extent for which there is currently no evidence occurs over south‐west England (Cornwall and Devon), with ice advanced over the present‐day coastline." The claim of ice flowing over the Somerset Levels would thus be an overreach beyond the paper’s findings. In the broader Celtic Sea and Irish Sea regions, ice flow is generally inferred to be southwards or south-westwards, particularly associated with the Irish Sea Ice Stream, with no evidence presented for a south-easterly flow in the Bristol Channel. Figure 21, which addresses ice extent and fast-flowing regions, does not depict specific flow directions in the Bristol Channel but highlights model-data mismatches in the Celtic Sea.”

Ely, J.C., Clark, C.D., Bradley, S.L., Gregoire, L., Gandy, N., Gasson, E., Veness, R.L.J. and Archer, R. (2024), Behavioural tendencies of the last British–Irish Ice Sheet revealed by data–model comparison. J. Quaternary Sci, 39: 839-871. https://doi.org/10.1002/jqs.3628

Figure 21. The location and persistence of fast flow. Fast flow was defined as regions of ice flowing above 100m a−1. Values reflect the number of NROY simulations (likelihood) that produce ice stream flow for over 100 years (persistence), once the differing durations of ice cover each NROY produces are accounted for. (a) Overall persistence of ice stream conditions map. (b) and (c) show the locations of trimlines (Clark et al., 2018) in relation to ice streams. Note how many are co‐located with regions of low ice stream persistence and likelihood. Overall, this map could be viewed as a proxy for glaciation‐scaled erosivity and compared with the distribution and type of landforms such as tors, roches moutonnées, U‐shaped valleys, bedforms, etc. Modern‐day coastline is shown for orientation. [Color figure can be viewed at wileyonlinelibrary.com]

The Demise of the Glacial Transport Theory for Stonehenge’s Megaliths

 

The Demise of the Glacial Transport Theory for Stonehenge’s Megaliths

Author: Tim Daw

July 2025

Correspondence: tim.daw@gmail.com

Keywords: Stonehenge, bluestones, sarsens, glacial transport, human transport, Neolithic, Craig Rhos-y-Felin, West Woods

Licence: CC BY 4.0

DOI: 10.13140/RG.2.2.17981.37604

 

Abstract

The glacial transport theory for Stonehenge’s bluestones and sarsens, which posits that glaciers conveyed these megaliths to Salisbury Plain, has been a longstanding and contentious hypothesis. Dr. Brian John has been its principal advocate for bluestones, with Hancock et al. (2025) tentatively extending the idea to sarsens. This paper synthesizes recent research by Bevins et al. (2025) and Nash and Ciborowski (2025), among others, to critically evaluate the theory’s validity. Petrographic and geochemical analyses demonstrate that the Newall boulder—a key piece of evidence for glacial transport—is a human-transported rhyolite fragment from Craig Rhos-y-Felin, not a glacial erratic. Likewise, robust geochemical sourcing of the sarsens to West Woods, coupled with the absence of glacial deposits on Salisbury Plain, refutes glacial movement. Archaeological evidence, including Neolithic quarrying sites and parallels in long-distance megalith transport, further substantiates human agency. The glacial transport theory is thus rendered untenable, leaving its remaining proponents the choice to seek improbable new evidence or to contribute to the refinement of human transport models, in alignment with the current scientific consensus.

Introduction

“In science, it often happens that scientists say, ‘You know, that’s a really good argument; my position is mistaken,’ and then they actually change their minds and you never hear that old view from them again. They really do it. It doesn’t happen as often as it should, because scientists are human and change is sometimes painful.” -  Carl Sagan

At the outset of Dr. John’s academic career, the theory of continental drift was resisted by a minority of fixist adherents—a position he likely regarded as reactionary and unscientific (Oreskes, 1999). Today, Dr. John occupies a similar position as the principal proponent of the glacial transport theory for Stonehenge’s bluestones, arguing that glaciers conveyed these stones from West Wales to Salisbury Plain. A comparable hypothesis has been tentatively proposed for the sarsen stones (Hancock et al., 2025). However, recent studies—most notably Bevins et al. (2025) on the Newall boulder and Nash and Ciborowski (2025) on sarsen provenance—have systematically dismantled these claims. This paper synthesizes these findings and broader evidence to demonstrate that the glacial transport theory for Stonehenge’s megaliths is no longer viable in mainstream scholarship, with human agency now firmly established as the mechanism of transport.

Refutation of Glacial Transport for Bluestones

Bevins et al. (2025) conducted a comprehensive re-examination of the Newall boulder, a rhyolite fragment excavated at Stonehenge in 1924 and long cited by Dr. John (2024a) as key evidence for glacial transport. Through petrographic analysis, SEM-EDS, and portable XRF, the boulder was conclusively identified as originating from Craig Rhos-y-Felin in north Pembrokeshire, likely as debitage from the buried stump of Stone 32d. Its foliated texture, presence of stilpnomelane crystals, and geochemical profile—particularly Zr/Th ratios—correspond to Craig Rhos-y-Felin rhyolite, not to other regional sources. Claims of glacial features, such as bullet-shaped morphology or surface scratches, are dismissed as products of natural weathering, with no diagnostic glacial striations present.

Extensive surveys have failed to identify glacial deposits or erratics on Salisbury Plain. Furthermore, the restricted lithological diversity of the bluestone assemblage (12–15 rock types, as opposed to the 46 claimed by John) supports the hypothesis of deliberate human selection from specific Welsh sites. This is corroborated by evidence of Neolithic quarrying at Craig Rhos-y-Felin and Carn Goedog, with radiocarbon dates placing activity between 3400–2900 BCE (Bevins et al., 2025; Parker Pearson et al., 2022a).

While localized ice movement near Mynydd Preseli may have transported some bluestones short distances, the absence of spotted dolerite erratics beyond 18 km renders this geologically insignificant compared to the evidence for Neolithic human transport. The Altar Stone’s origin in the Orcadian Basin (~750 km away), which glaciers could not have transported due to flow directions (Clarke et al., 2024), further undermines the glacial hypothesis. Collectively, these findings leave Dr. John’s position without empirical support, as his primary evidence—the Newall boulder—is conclusively non-glacial.

Refutation of Glacial Transport for Sarsens

Hancock et al. (2024) posited that Stonehenge’s sarsen stones, particularly Stone 58, may have been glacially transported, citing the potential for ice coverage of the Marlborough Downs during the Last Glacial Maximum (LGM). Nash and Ciborowski (2025) refute this, noting that the BRITICE-CHRONO Project (Clark et al., 2022) places the southern limit of the ice sheet far north of Salisbury Plain and the Marlborough Downs. No glacial deposits or erratics have been found in the region.

Geochemical analysis, including portable XRF and Bayesian principal component analysis, confirms that 50 of 52 sarsens share a common chemistry, pointing to West Woods (~24 km away) as the source, not Clatford Bottom or Piggledene as previously proposed (Nash et al., 2020; Nash and Ciborowski, 2025). Methodological flaws in Hancock et al.’s analysis, such as misinterpretation of Zr normalization, further weaken the glacial transport argument. The established human transport of sarsens—some weighing up to 40 tonnes—parallels the evidence for bluestones and underscores Neolithic capabilities for long-distance megalithic haulage.

The Consensus: Human Agency

The preponderance of evidence supports human transport for both bluestones and sarsens. Archaeological investigations at Craig Rhos-y-Felin and Carn Goedog have uncovered stone tools, wedges, trackways, and radiocarbon dates that align with Stonehenge’s construction (~3000 BCE), confirming Neolithic quarrying activity (Parker Pearson et al., 2019, 2022a). The sourcing of the Altar Stone to northeast Scotland and the sarsens to West Woods demonstrates long-distance transport, consistent with other Neolithic sites such as Newgrange and West Kennet, where stones were moved distances ranging from 5 to 80 km (Cooney, 1999; Piggott, 1962).

The absence of glacial features on Salisbury Plain, combined with the precise sourcing and restricted lithologies of the bluestones, renders glacial transport implausible. The theory’s reliance on speculative claims—such as boulder morphology or hypothetical ice coverage—has been systematically debunked by recent research.

Dr John’s Path Forward

As the sole remaining advocate of the glacial transport theory, Dr. John faces a pivotal choice: persist with a refuted hypothesis or join the ranks of scholars who have embraced new evidence and revised their positions. He may continue searching for erratics or glacial deposits closer to Salisbury Plain, though extensive surveys suggest this is unlikely to yield results. Alternatively, he could contribute his expertise to refining models of Neolithic human transport or exploring cultural connections, as evidenced by sites like Waun Mawn and Crosswell (Parker Pearson et al., 2021). His legacy may thus be shaped either by intransigence or by a willingness to prioritize evidence over prior allegiance.

Conclusion

The glacial transport theory for Stonehenge’s bluestones and sarsens is no longer tenable. It is not pining for the fjords; it has passed on. Recent studies by Bevins et al. (2025) and Nash and Ciborowski (2025) demonstrate, through geochemical, petrographic, and archaeological evidence, that these stones were not glacially transported. The absence of glacial deposits, restricted lithological diversity, and confirmed quarrying sites leave no empirical foundation for the theory. While proponents of glacial transport have stimulated valuable debate and research, the overwhelming weight of evidence supports Neolithic human agency, situating Stonehenge within broader patterns of prehistoric monument construction.

 

References

•              Bevins, R.E. et al (2025) (The enigmatic ‘Newall boulder’ excavated at Stonehenge in 1924: new data and correcting the record

(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)

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)

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•              Clarke, A.J.I., Kirkland, C.L., Bevins, R.E. et al. (2024) A Scottish provenance for the Altar Stone of Stonehenge. Nature 632, 570–575. https://doi.org/10.1038/s41586-024-07652-1

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•              Cooney, G., (1999). Landscapes of Neolithic Ireland. London: Routledge.

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•              Hancock, R. G. V., Gorton, M. P., Mahaney, W. C., Aufreiter, S., & Michelaki, K. (2025). Stonehenge revisited: A geochemical approach to interpreting the geographical source of sarsen stone #58. Archaeometry, 67(1), 1–19. https://doi.org/10.1111/arcm.12999

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•              John, B.S. (2024a). A bluestone boulder at Stonehenge: implications for the glacial transport theory. E&G Quaternary Science Journal. 73. 117-134. 10.5194/egqsj-73-117-2024.

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•              John, B.S. (2024b). An igneous erratic at Limeslade, Gower and the glaciation of the Bristol Channel. Quaternary Newsletter, 162, pp.4–14.

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•              Nash,D J. et al.(2020) Origins of the sarsen megaliths at Stonehenge. Sci.Adv.6, eabc0133. https://doi.org/10.1126/sciadv.abc0133

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•              Nash, D.J. & Ciborowski, T.J.R. (2025). Comment on: ‘Stonehenge revisited: a geochemical approach to interpreting the geographical source of sarsen stone #58’. Archaeometry, pp. 1–14.  https://doi.org/10.1111/arcm.13105

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•              Oreskes, N., (1999). The Rejection of Continental Drift: Theory and Method in American Earth Science. Oxford: Oxford University Press.

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•              Parker Pearson, M. et al. (2019) ‘Megalith quarries for Stonehenge’s bluestones’, Antiquity, 93(367), pp. 45–62. https://doi.org/10.15184/aqy.2018.111

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•              Parker Pearson, M. et al. (2020) Stonehenge for the Ancestors. Part 1: Landscape and Monuments. Leiden: Sidestone. https://www.sidestone.com/books/stonehenge-for-the-ancestors-part-1

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•              Parker Pearson, M. et al. (2021) ‘The original Stonehenge? A dismantled stone circle in the Preseli Hills of west Wales’, Antiquity, 95(379), pp. 85–103. https://doi.org/10.15184/aqy.2020.239

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•              Parker Pearson, M. et al., 2022a. Reconstructing extraction techniques at Stonehenge’s bluestone megalith quarries in the Preseli hills of west Wales. Journal of Archaeological Science: Reports, 46, p. 103697. https://doi.org/10.1016/j.jasrep.2022.103697

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•              Piggott, S., 1962. The West Kennet Long Barrow: Excavations, 1955–56. London: HMSO.