Monday, 25 September 2023

The Altar Stone in close up

Full size photo -

Thought experiment: What if the Altar Stone is a later, say, Roman addition to the monument? Is there anything that proves it isn't? If it was what would we expect it to be like? How could we tell? Where might they have brought it from?

Saturday, 23 September 2023

The Altar Stone - Not welsh, so where is it from?

An important paper on the Stonehenge Altar Stone has just been released:

It probably didn't come from South Wales and surrounding areas.

Its petrographic fingerprint which includes a diagnostic high Barium (Ba) content mostly doesn't match the Old Red Sandstones (ORS) of the area, and the ORS rocks there that also have a high Ba don't match other characteristics. 

The hunt for the source is on.  Suitable areas that also have neolithic sites are the top suspects.

AlexD, CC BY-SA 3.0, via Wikimedia Commons - Old Red Sandstone is coloured Brown 

The paper: (behind a paywall but ask the authors for a copy if you know them)

The Stonehenge Altar Stone was probably not sourced from the Old Red Sandstone of the Anglo-Welsh Basin: Time to broaden our geographic and stratigraphic horizons?


Stone 80, the recumbent Altar Stone, is the largest of the Stonehenge foreign “bluestones”, mainly igneous rocks forming the inner Stonehenge circle. The Altar Stone’s anomalous lithology, a sandstone of continental origin, led to the previous suggestion of a provenance from the Old Red Sandstone (ORS) of west Wales, close to where the majority of the bluestones have been sourced (viz. the Mynydd Preseli area in west Wales) some 225 km west of Stonehenge. Building upon earlier investigations we have examined new samples from the Old Red Sandstone (ORS) within the Anglo-Welsh Basin (covering south Wales, the Welsh Borderland, the West Midlands and Somerset) using traditional optical petrography but additionally portable XRF, automated SEM-EDS and Raman Spectroscopic techniques. One of the key characteristics of the Altar Stone is its unusually high Ba content (all except one of 106 analyses have Ba > 1025 ppm), reflecting high modal baryte. Of the 58 ORS samples analysed to date from the Anglo-Welsh Basin, only four show analyses where Ba exceeds 1000 ppm, similar to the lower range of the Altar Stone composition. However, because of their contrasting mineralogies, combined with data collected from new automated SEM-EDS and Raman Spectroscopic analyses these four samples must be discounted as being from the source of the Altar Stone. It now seems ever more likely that the Altar Stone was not derived from the ORS of the Anglo-Welsh Basin, and therefore it is time to broaden our horizons, both geographically and stratigraphically into northern Britain and also to consider continental sandstones of a younger age. There is no doubt that considering the Altar Stone as a ‘bluestone’ has influenced thinking regarding the long-held view to a source in Wales. We therefore propose that the Altar Stone should be ‘de-classified’ as a bluestone, breaking a link to the essentially Mynydd Preseli-derived bluestones.

Richard E. Bevins, Nick J.G. Pearce, Rob A. Ixer, Duncan Pirrie, Sergio Andò, Stephen Hillier, Peter Turner, Matthew Power,

Journal of Archaeological Science: Reports, Volume 51, 2023, 104215,ISSN 2352-409X,


Friday, 22 September 2023

Ground Penetrating Bayonet

Before modern gizmos were invented the usual way to locate buried stones was to prod the ground with a bayonet, Alexander Thom amongst others was a keen proponent of the method into the 1960s.

So it is fascinating to spot a bayonet in among the tools of Atkinson's 1958 excavations at Stonehenge.

 It appears to be an Enfield Socket Bayonet fitted with a handle - or something similar.

I note English Heritage sell replica bayonets - - "This type of bayonet was manufactured in England from 1853 to around 1870 and saw service until about 1875. It was designed to fit the Enfield 1853 Pattern Musket (also known as the P53 Enfield). It saw service in the Crimean War, American Civil War, New Zealand Land Wars and the Indian Mutiny. It is a typically British design in that it has a blade “shoulder” and is shallow fullered."

Though I doubt they would approve of their use at Stonehenge now.


Excavations between fallen Trilithon upright stone 55 which broke into two pieces. 1958. 

Thursday, 21 September 2023

The underside of stone 55B - 1958

The underside of stone 55B as it is lifted from its fallen position. An unreported stone lift.

Wednesday, 20 September 2023

1958 Excavation Of Altar Stone, Stone 80 Photographer: Atkinson, R J

Craig Rhos-y-felin Bullet Stones

The rhyolite boulder collected by R. S. Newall in 1924 from an excavation at Stonehenge which has been discussed before at length - - has an appealing "bullet" shape.

The pillars at Craig Rhos-y-felin, where the boulder has been petrographically matched to, tend to have these rounded tips and the excavations there revealed many such bullet shaped tips that have broken off. These boulders still at the quarry obviously haven't been transported anywhere and so the bullet shape of the boulder "is a tale... signifying nothing.” 

Photo by Adam Stanford - annotated by me

Photo by Mike Parker-Pearson with "Newall's Boulder" floated in by me. 

Photos of quarry from, and more information available at :

Craig Rhos-y-felin: a Welsh bluestone megalith quarry for Stonehenge 

Published online by Cambridge University Press: 07 December 2015 

Mike Parker Pearson , Richard Bevins , Rob Ixer , Joshua Pollard , Colin Richards , Kate Welham , Ben Chan , Kevan Edinborough , Derek Hamilton , Richard Macphail , Duncan Schlee , Jean-Luc Schwenninger , Ellen Simmons and Martin Smith

Craig Rhos-y-felin 2014 - 2023

Click  any photo to embiggen A few photos from my periodic visits - the vegetation recovery from 2014, the excavation years to 2023 is great to see.  The bottom photo looking down on it is from 2016 - Please feel free to copy and use the photos if they are useful

Thursday, 7 September 2023

Strange lines in the landscape

Two parallel soil marks behind what was the car park, not seen them before.  

I can't see any evidence on the 1943 photo;

UPDATE - a slightly different shot to the first one shows dust (I think)billowing up from the end of the further line. I think they may be marks left by a cultivator. But no sign of a tractor.

Tuesday, 29 August 2023

The Little Britain Stonehenge

Kenny Brophy - "...recently visited Stonehenge, curious to see how this icon of Britishness is presented to visitors and tourists. ...It is very clear that the Stonehenge experience – the real Stonehenge – is a long way removed from the idealised Stonehenge we keep getting told about. If this monument is a jewel in the crown, it’s a fake.

The reality is sadly many miles removed from the glossy airport adverts – make no mistake, visiting Stonehenge in the summer these days is a tawdry, tacky experience...

...The very existence of Stonehenge is political, created in many phases of activity that were designed to empower and boost certain individuals and interest groups. Medieval stories about the stones were political too, origin myths to support claims of power and the status quo. These stones have been and continue to be used to peddle myths about the past while conserving power and control today – academic power, political power, power over access, an essential celebrity and politician photo opportunity, a place that one has to be associated with...

Thanks Kenny, it's a great gift to be able to see, what we might think of as ours, as other see it. It should free us from many blunders and foolish notions. If only the fanciful wrappings and devotions might be stripped from it and reveal the real Stonehenge. 

One of the many reasons I preferred the old visitor centre was its honesty of purpose and architecture.   

Thursday, 24 August 2023

An Erratic Train of Thought

As we continue to wait for the analysis of the Mumbles erratic, which was claimed to be the "smoking gun" of the Stonehenge Bluestone Glacial Transport idea, it is worth reconsidering the pantheon of coastal erratics in the southwest of Britain. Conventional glacial theory says they shouldn't be there, but they are, so the theory needs refining. That they were entombed or carried on icebergs seems to be the most probable answer.

Quaternary of South-West England edited by S. Campbell, C.O. Hunt, James D. Scourse, D.H. Keen, N. Stephens

The good Dr John, however, seeks inadvertently to confuse:  "Whatever its erratic history may be, the boulder demonstrates that the Irish Sea Glacier impinged upon the Gower coast, carrying erratics from the west and displacing local Welsh ice on at least one occasion."

The source of the erratic is important, if it was entrained in a glacier and dropped by the glacier then the source and destination must be connected by a plausible path. But if it sailed free in or on an iceberg then the source could be unconnected, and its position doesn't demonstrate the extent of the glacier at all.

Wednesday, 16 August 2023

The Ice Rafted Giant's Rock at Porthleven, Cornwall (probably).

Photo thanks to Rob Ixer

"...many authors have favoured ice-rafting as the most likely mechanism for emplacement of the Giant's Rock and similar large erratics in the South-West. Indeed, Tricart (1956) also favoured this mechanism to explain the presence of large erratics on the French Channel coast. However, if floating ice carried the erratics to the south coast, then problems arise regarding contemporary Pleistocene sea levels. Mitchell (1972) sidestepped the problem of low sea levels during glacial stages by arguing that these erratics were rafted into position at the beginning of the Saalian Stage when the level of the sea might still have been relatively high after the preceding, warm, Hoxnian Stage. Similarly, Stephens (1966b) argued that the large erratics could have been emplaced by pack-ice and icebergs during the waning of an early pre-Saalian (Anglian?) glacial period when world sea level would have been high enough to allow the erratics to be `floated' into position (Fairbridge, 1961). As an alternative hypothesis, Stephens suggested that towards the end of the Saalian ice-sheet glaciation, isostatic depression of the land had allowed the sea to move icebergs against these coasts despite a generally low eustatic sea level. Such a mechanism is similar to recently proposed models of Late Devensian glaciomarine sedimentation in the Irish Sea Basin (e.g. Eyles and McCabe, 1989, 1991). Bowen (1994b) recently suggested that the Giant's Rock could have originated in Greenland and then been transported to the South-West on ice-floes from a disintegrating, Early Pleistocene, Laurentide ice sheet. In support of the ice-rafting hypothesis, the most convincing evidence is that the erratics are very largely confined to a narrow coastal zone, invariably below 9 m OD, and within the reach of storm waves today..."


"The Giant's Rock is the most impressive and intriguing of the large erratics found around the south and west coasts of Britain. Despite having attracted scientific interest for nearly a century, its exact origin and mode of emplacement are still unknown and it remains the subject of much controversy. Although some workers have maintained that the 50-ton erratic was emplaced directly by glacier ice, most believe that it was delivered to its present location on floating ice..."

Tuesday, 15 August 2023

Debating Visual Truth at Stonehenge in the Seventeenth Century

Inigo Jones, perspective of Stonehenge, from Stone-heng Restored (London: Printed by James Flesher for Daniel Pakeman, 1655), plate 42


Over the course of the seventeenth century, two representations of Stonehenge—one published in William Camden’s Britannia (1600) and the other in Inigo Jones’s Stone-heng Restored (1655)—were invoked repeatedly in an intensifying debate over the monument’s origins. This debate engaged both the virtuosi community of the Royal Society and members of the closely related, fledgling world of English architectural discourse, and the two representations became the common ground for both conversation and contestation. This paper traces the entangled afterlives of these two images, and argues that their reproduction and reinterpretation by members of natural history, antiquarian, and architectural communities created both discord and new, collective knowledge. Drawing on recent work exploring how images produced for divergent purposes and audiences were integrated into natural philosophical study, I explore how, through their reproduction, alteration, and recontextualization, these images functioned as tools of both division and mediation, and created space for debate and new investigation.

Kaemmer, H. (2023). Description or Design: Debating Visual Truth at Stonehenge in the Seventeenth Century. Nuncius, 38(2), 278-310.

William Rogers, perspective of Stonehenge from William Camden’s Britannia (London: Printed for George Bishop, 1600), 252

Inigo Jones, inscribed plan of Stonehenge, from Stone-heng Restored (London: Printed by James Flesher for Daniel Pakeman, 1655), plate 38 Citation: Nuncius 38, 2 (2023) ; 
10.1163/18253911-bja10064  Courtesy of the Getty Research Institute

Monday, 14 August 2023

Erratic Castaway

Just a reminder that any Glacial erratic found on the edge of a body of water is probably a boulder that hitched a ride on an iceberg rather than evidence of actual glaciers. 

"An iceberg carries a rock though Jökulsárlón, Iceland's glacial lagoon."

Norway, Svalbard, Spitsbergen. Nordvest-Spitsbergen National Park, Liefdefjorden, Monacobreen aka Monaco Glacier. Large boulder floating on iceberg in front of glacier.

It seems that the erratic found on the Mumbles seashore -  - is just another fascinating example of this phenomenon, having probably enjoyed a cruise around St David's Head rather than the proof of anything else, despite the lurid headlines and press release:

Stonehenge mystery solved: 'Smoking gun' discovery provides 'missing piece' of puzzle

Across the water in North Devon there are about twenty examples of these probable dropstones, Baggy Point is one explains more.

A fuller explanation of them, and the debate about how they arrived is at:

And at

Thursday, 10 August 2023

Current terminology of the Stonehenge bluestones lithologies.

From: Bevins, R., Ixer, R., Pearce, N., Scourse, J., & Daw, T. (2023). 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, 1–15.  

Sunday, 6 August 2023

Moving Poetry from Google's Bard


From a distant land carried
By the hands of ancient people
Stones still stand tall


Bluestones from afar,
Carried by ancient hands,
Standing strong today.


Old men recount a fantastic tale,
That the ancient 'henge stones are glacial.
But their theory lacks,
Any supporting facts,
So the myth is complete cock and bull.


I met a traveller from an antique land,
Who said, "Dost thou know
The bluestones are the work of a human hand ?
And do they not still stand, and still they show
That their sculptor well those passions read
Which yet survive, stamped on these lifeless things?"
For the hand that mocked them and the heart that fed:
The false words that icy fingers brought them here
The King of Kings, pure proven truth, has clearly said
To tell the charlatans to look and despair.
Of their theory nought remains. Round the decay
Of that colossal Wreck, boundless and bare
The lone and level grasses stretch far away.”

(Image from Microsoft Bing Image Creator)

Wednesday, 26 July 2023

Moving and raising megaliths in France


 A collection of informative videos put online by the “CPIE Val de Vilaine – Association Nature et Mégalithes”

Tuesday, 25 July 2023

La construction du dolmen de Menga, Mantequera, Málaga

Dolmen de Menga (Official Site)

The Dolmen of Menga (Spanish: Dolmen de Menga) is a megalithic burial mound called a tumulus, a long barrow form of dolmen, dating from 3750–3650 BCE approximately. It is near Antequera, Málaga, Spain. It is one of the largest known ancient megalithic structures in Europe. It is 27.5 metres (90 ft) long, 6 metres (20 ft) wide and 3.5 metres (11 ft) high, and was built with thirty-two megaliths, the largest weighing about 180 tonnes (200 tons). Wikipedia -
Text used under the Creative Commons Attribution-ShareAlike License 4.0

Human Transport of Megaliths - Experimental Evidence

The Bougon burial mounds are a group of five burial mounds constituting a Neolithic necropolis located in the commune of Bougon in the Deux-Sèvres department. The first monuments were built in the 5th millennium BC but the site was used until the middle of the 3rd millennium BC. A museum of prehistory, housing rich archaeological collections from excavations in the region, was built by the Departmental Council of Deux-Sèvres inside the archaeological park encompassing the site.

The archaeological park which integrates the necropolis also contains several educational spaces intended to evoke the construction of megaliths , through the experiments carried out between 1979 and 1998 in Exoudun-Bougon, and the large Neolithic collective habitat of the Fief Baudouin discovered in Airvault .

- The text and photos are translated from the French version of Wikipedia entry for the site and used under under CC BY-SA 4.0 - 

1979 experiments

These experiments were directed by Jean-Pierre Mohen. For details see Jean-Pierre Mohen and Chris Scarre (with the participation of F. Bouin, E. Cariou, P. Chambon), The tumulus of Bougon (Deux-Sèvres): Megalithic complex from the 5th to the 3rd millennium , Paris, Errance 2002 (ISBN 2-87772-240-6 and 978-2-87772-240-7 ) 

The first experiment concerned the extraction of a large megalithic slab of 3 m by 2.50m from a rocky outcrop located on the Chaumes plateau in Exoudun . The block was surrounded on three sides by large cracks. The fourth side was hollowed out by three people with chalk hammers . Wider notches were dug with these same hammers and antler picks, in the faults to drive wooden wedges into them. The wooden corners were wetted to make them swell in volume and the slab came off after an hour of work. It was then lifted with wooden levers to be able to slide wooden rolls of about 10 cm in diameter intended to move it .

The second experiment aimed to test a transport system for a monumental slab of the type found in tumulus F2. Faced with the impossibility of having a natural slab of this type, a concrete copy of the slab of tumulus F2 was made (identical weight and volume - a single slab 6 m long by 3.50 m wide and 1.30 m high whose weight is estimated at 32 tons). A removable transport path was built with unbarked wooden rollers 40 cm in diameter. The ropes were made from viburnum and ivy fibers by a craftsman according to a tradition still in force on local farms at the beginning of the 20th century . The block, covered with a braided rope net, rested on the wooden rollers arranged perpendicular to the two rails of the raceway. On July 28, 1979, 230 people pulling on ropes and 20 others pushing the block managed to move it 40 m away. Raising the block to 0.50m in height with three levers was then successfully tested.

Experimental archaeology: equipment used 

Liberliger, CC BY-SA 4.0, via Wikimedia Commons - Click to enlarge

1997 experiment

In 1997, F. Collin and B. Poisonnier experimented on site with a new “proto-wheel” type traction system with the 32-tonne test block. In this system, the principle of the removable path is retained but each roller is transformed into a hub after having fitted four recesses at each end. These recesses are intended to receive levers arranged radially to drive the movement of the roller. The experiment made it possible to move the block with only about thirty people while saving most of the ropes and the pullers. However, no mechanism of this kind is attested in the Neolithic period.

1998 experiment

In 1998, B. Poisonnier and R. Joussaume experimented with the construction of a trilith at a height of 1.50 m using levers and wooden wedges.

By Jochen Jahnke, CC BY-SA 3.0,

Bullets and Scratches

Oh, dear. It seems our erratic Doctor is confused. He wonders why I mention the "bullet" shape of Newall's boulder and the supposed glacial striations or striae. I will admit I may well have missed or forgotten much of his blog, so many disquisitions, so little time.

But I didn't think I had misremembered, the bullet shape is declared to be diagnostic and the scratches to be glacial striae only a year ago.

25 July 2023  

2 July 2022

Click scans to embiggen


Sunday, 23 July 2023

Dr. Whitaker's Sarsen Thesis

Sarsen stone in southern Britain: an archaeological and ethno-historical approach to an ancient industry

Katy A. Whitaker September 2022


This thesis is an inter-disciplinary study of human engagement with the silcrete called sarsen stone, found dispersed across parts of south-central and south-eastern England and used prolifically since prehistory...

Nearly 800 pages of Sarsen goodness - It is a big download but worth it.

Erratic Opinions

It might be thought unkind to remind people of the erroneous opinions that have been published on Newall's Boulder now the full scientific analysis is available and any suggestion it is a glacial erratic dismissed. But I think a sample of them should be archived. We should see them as the grit in the oyster, worthless irritants except when they help pearls to be produced.

 Click scans to enlarge. All from 

Saturday, 22 July 2023

The Erratic that came in from the cold

Newall's Boulder - Salisbury Museum

To cut a long story to its appropriate length: 

"A rhyolite boulder collected by R. S. Newall in 1924 from an excavation at Stonehenge has been pivotal to arguments concerning glacial versus human transport of the bluestones to Stonehenge. Initial studies suggested that the boulder came from north Wales, and hence was a probable glacial erratic. New petrographic and geochemical analyses however support it being from Craig Rhos‐y‐Felin in west Wales, the source of much debitage recovered from Stonehenge. Examination of the form and surface features of the boulder provides no evidence for it being erratic. Instead, it is considered to be one more piece of debitage probably derived from a broken‐up monolith."

The full paper is available here:

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: DOI:10.1002/gea.21971

Richard Bevins Rob Ixer Nick Pearce James Scourse Tim Daw

Hawley's excavation of 1924 possibly with "Newall's Boulder" highlighted.
Click photos to embiggen 

The more excitable section of the Glacial Transport true believers thought it showed signs of glacial striations where it had been dragged under the ice from Wales but the marks are just a slickensided surface. The paper: "We note that identical slickensides characterise the bedrock outcrop at Craig Rhos‐y‐Felin where we can see clear evidence of lateral movement between adjacent blocks in the outcrop".

The bullet like shape was even cited as evidence of it being ice transported but luckily Dr Brian John provides a photograph showing an identical boulder still happily lying at the Craig.

To illustrate the point further I have superimposed the "Newall Boulder" from Salisbury Museum on to Dr John's photo:

And for completeness here it is floating in what may have been its original position, the tip of one of the pillars at Craig Rhos‐y‐Felin, showing how its shape is characteristic of the rocks in situ.

It seems unlikely that a broken bit of stone was transported to Stonehenge, though less likely things have happened, so the question is when did the pillar break. I tend to think it was probably when the pillar was being re-erected and it was an accident. Or it might have been deliberate.

It could well have been part of Stone 32d which now only survives as a buried stump.

Do read the complete paper, but the simple message is: the boulder and the samples taken from it show no signs of being glacially transported, it is simply "one more piece of debitage probably derived from a broken‐up monolith".

Thursday, 20 July 2023

The Sarsen Stone Route to Stonehenge

I originally published my ideas of the route the sarsen stones were taken along to Stonehenge in Nov 2011
Since then the source of the stones has been mainly refined to the West Wood area and so I have just refined the route. 

It is available at the this link: 
I also took the opportunity to calculate the slope up on Salisbury Plain, it is 50m rise over 1km, a 1:20 slope.

I would emphasis that I think this line just defines a corridor, I am sure that on the ground sensible deviations to either side would be obvious.

 Click to embiggen

Tuesday, 4 July 2023

Massive Granite Pre-historic Heads

The Olmec colossal heads are some of the most impressive and enigmatic sculptures of the ancient world.

Cabeza Colosal nº1 del Museo Xalapa.jpg

CC BY-SA 3.0, Link

They were erected between 1200 and 400 BC, during the Preclassic period of Mesoamerican chronology. The earliest heads are believed to have been carved at the site of San Lorenzo, which was the first major Olmec city. The heads were then transported to other Olmec sites, such as La Venta and Tres Zapotes. 

They are carved from single boulders of basalt, which can weigh up to 40 tons, and were transported over long distances, sometimes as far as 150 kilometers (93 miles). 

 The exact method of transportation is unknown, but it is likely that the Olmecs used a combination of methods, including: 
  • Water transport:The Olmecs lived in a region with many rivers and streams, so it is likely that they used boats and rafts to transport the heads over water. 
  • Log rollers: When traveling over land, the Olmecs may have used log rollers to help move the heads. This would have required a large number of people to push and pull the heads, but it would have been the most efficient way to move such heavy objects. 
  • Causeways and ramps:The Olmecs also built causeways and ramps to help facilitate the movement of the heads over land. These structures would have made it easier to move the heads over uneven terrain and to lift them up and over obstacles.

The Olmecs were a highly skilled and organized people, and they must have used a great deal of ingenuity and manpower to transport the colossal heads to their sites. The fact that they were able to do so is a testament to their engineering and organizational skills. 

 Here are some additional details about the transportation of the Olmec colossal heads:
  • The heads were carved from basalt, which is a very hard and dense rock. This made them difficult to carve, but it also made them very durable. 
  •  The heads were all carved in a similar style, with large, almond-shaped eyes, prominent noses, and thin lips. This suggests that they were all created by the same group of people.
  • The heads were often placed in groups of two or three, and they were sometimes arranged in lines. This suggests that they may have had some symbolic meaning, such as representing the Olmec rulers or their ancestors.
  • The heads were found at several Olmec sites, including San Lorenzo, La Venta, and Tres Zapotes. This suggests that the Olmecs had a widespread and complex culture. 

 The Olmec colossal heads are a fascinating and mysterious part of the ancient world. Their transportation and placement are still a matter of debate, but they are a testament to the ingenuity and engineering skills of the Olmec people.

Saturday, 3 June 2023

Preseli Stone Wedges

During a wander round the wonderful Preseli area we came across several examples of stone wedges in clefts of rocks. 

 And even a wedge and apparent hammer stone just waiting to be posed in a convenient crack (no damage to any stone was done, and the tools returned to where they were found)

So are these wedges natural happenstances or old tools, and if so how old?

Mike Parker Pearson's latest book Stonehenge, a Brief History gives some details of the ones he has examined.

Click to embiggen