Some of the ideas discussed in this blog are published in my new book called "The Stonehenge Bluestones" -- available by post and through good bookshops everywhere. Bad bookshops might not have it....
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Wednesday, 20 September 2023

Bullet-shaped erratics


A roughly bullet-shaped erratic boulder on Alexander Island, Antarctica.  Photo by Andy Emery, published on the web site

The Newall Boulder, now in Salisbury Museum. (Acknowledgement:  BGS photo.)

This is quite fun -- a large erratic boulder in Antarctica with a shape that is very similar indeed to that of the famous "Newall erratic" much discussed on this blog and elsewhere.  There is a large specialist literature on the mechanisms that come into play in the shaping of subglacial and englacial erratics. I have done many posts on this.  Te see them, use the search box.

 I don't want to pretend that most glacial erratics are shaped like rough bullets, because erratics come in all shapes and sizes. Lithology initially (following entrainment) plays a large part in determining their shapes, as does distance of travel.  But what the literature suggests is that erratics slowly evolve towards an "ideal" shape in which we can recognize a blunt bullet-shaped and heavily abraded snub nose or upglacier end, a broader rough (and less heavily abraded) down-glacier end, and longer faceted flanks affected by streaming ice.  Here there may be striations or even pressure fractures on the flanks, although the number of facets may vary according to the rock's history,  texture and internal weaknesses.

See also:

Thursday, 14 September 2023

The conundrum of the coastal erratics

The Ramson Cliff erratic, deposited 80m above sea level by floating ice? I think not........ (Photo courtesy Paul Madgett)

My recent spat with Tim Daw about the possible ice rafting of the large erratics found on parts of the coasts of SW England was quite fun, arising from the fact that he tends to accept some of the things said about ice rafting by other geomorphologists, whereas I do not.  It's actually quite easy to find references to ice rafting in the specialist literature, including the GCR volume on South West England in 1998 and a more recent paper by Phil Gibbard and others in 2017.  Tim cites them both on his blog, and seems to think that I am blissfully unaware of their contents.  Let that pass with a reminder that I have cited both of these sources on innumerable occasions on this blog, sometimes agreeing with the authors on assorted matters, and sometimes not. 

So Tim can be forgiven for thinking that many geomorphologists who have studied the coasts of Devon and Cornwall think that the big boulders at Porthleven, Croyde, Saunton and elsewhere have been "rafted" by floating ice from the north and west.  That may have been true 25 years ago, but now that we understand isostatic and eustatic interactions much better than we did, any current author who proposes an ice rafting mechanism must be challenged.  I cannot see any possible combination of environmental circumstances that would permit the long-distance ice rafting transport of large erratics onto the coasts of the Bristol Channel and the English Channel near or above present sea level. At the beginning and end of each glacial episode, when ice rafting might have occurred, the coastlines of the day were scores if not hundreds of kilometres away from their current positions. We must remember that the epidiorite erratic on Ramson Cliff (near Baggy Point) is 80m above sea level, and we must assume that the "apparent concentration" of big erratics between the present-day high and low tide marks arises simply because that is where large stones are washed clean by wave action and are exposed to view.  It is entirely logical to assume that there are many more such erratics, some above (buried in sediments) and others in deep water below the current intertidal zone.

So this isn't really an argument between archaeologists and geomorphologists.  I think that some geomorphologists in the past have been rather careless in stating that the big erratic boulders of the South-West are possibly or probably ice-rafted, and have failed to take account of isostatic and eustatic oscillations and their timing with regard to climate change.

Clean sea ice off the coast of Antarctica.  Debris tends to be carried in floating remnants of glaciers -- in icebergs and bergy bits.  Other mechanisms for the incorporation of  erratic boulders and other debris are considered in "Coastal Geomorphology of High Latitudes", a monograph written by David Sugden and me, published by Edward Arnold.


New insights into the Quaternary evolution of the Bristol Channel, UK
ISSN 0267-8179.
DOI: 10.1002/jqs.2951

See these posts:

Tuesday, 12 September 2023

The mythologising of Stonehenge

Visit Britain refers to Stonehenge as "one of the most prehistoric monuments in the world."   
OMG -- whatever next......?

As mentioned before on this blog, not everybody loves Stonehenge or approves of the manner in which it has been hijacked for political and quasi-religious purposes.  There has been a lot of criticism of the manner in which Stonehenge is promoted as a "British icon" at the expense of other equally, if not more, impressive monuments including Callanish, Skara Brae, Avebury and Silbury Hill. 

In the vanguard of the attacks on Stonehenge as "the first great focal point in British history" are the Scottish archaeologists Gordon Barclay and Kenny Brophy.  We have discussed their work previously on this blog:

....... and have noted the furious and even vicious response from those whose work they directly and indirectly criticised.
Last year they wrote this article:  

Stop Projecting Nationalism Onto Stonehenge
Two archaeologists respond to the portraits of Queen Elizabeth II beamed onto Stonehenge—the latest attempt to appropriate the monument for nationalist messages.
20 JUN 2022

The article was essentially a response to the rather tasteless and degrading projection of eight images of the late Queen onto the sarsens of Stonehenge.

They said:  "As archaeologists interested in the way contemporary society manipulates the past, we keep an eye open for all sorts of Stonehenge-related nonsense and consider ourselves quite unshockable. But English Heritage’s decision surprised even us in its blindness to nationalist appropriation of the past, as well as its all-round tackiness."   In reality, Stonehenge never was a real English symbol, let alone a British one.   Barclay and Brophy also said that the mythos of an ancient pan-British identity (with Stonehenge at its centre, acting as its symbol for branding or marketing purposes) fails to take into account the variability of life in late Neolithic Britain, evident in the diverse regional styles of monuments, buildings, funerary practices, and aspects of the economy.

Now, in a new article, Kenny Brophy launches another attack, following a visit to Stonehenge which left him singularly unimpressed.

It's essentially a blog post, and an opinion piece.

AUGUST 29, 2023
Little Britain

He has a go at the right-wing press and its obsession withy Brexit and Britishness:  "Stonehenge also has a disturbing history as an icon for English and British nationalists, and has increasingly become a political plaything for right-leaning newspapers in recent years, a symbol of Brexit Britain. The exploitation of archaeological research results in the media and amongst alt-right groups is troubling and should worry us all. Feeding the news cycle, and indulging some aspects of Stonehenge celebrity, have very real risks."

"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. I almost feel sorry for the ageless trilithons, with nothing by concrete to support them, a monument that is so important to some people that it was not allowed to fall into ruination for fear of losing its power-giving qualities."

I AGREE WHOLEHEARTEDLY WITH THE THRUST OF THE ARTICLE.  And it's such a pity that other mainstream archaeologists have been so reluctant to accept that the Stonehenge obsession is immensely damaging to British archaeology as a whole -- not just through the appropriation of funds that could be better spent elsewhere, but through the damage done to the scientific process as groups of senior academics distort and even invent evidence in order to reinforce one ruling Stonehenge hypothesis after another.  

Tuesday, 5 September 2023

MPP's new dig near Crosswell

Chris Johnson and the little Crosswell standing stone / scratching post at SN122363, back in 2016.  It's made of foliated rhyolite similar to that exposed at Rhosyfelin

On 10- Sept MPP and his team will be back in Pembs, digging on four ditched circles, traces of which were seen in 2016-17.  It will be interesting to see what turns up.......

Cambrian Arch Soc:

Professor Mike Parker Pearson was awarded £2000 towards costs of excavations in 2023 at Ffynnongroes, Crosswell, Pembrokeshire on four ditched circles, which may be Middle Neolithic ‘formative henges’ rather than ploughed out Bronze Age tumuli.

The team members mooched about in that area south of the main road some years ago.  I suspect they are  now going to dig on some features picked up near Pensarn with earlier instrumental surveys…..  They have referred in the past to a "bluestone ring" in the Pensarn area, but did not prove its existence.  No doubt they will still be searching for a stone ring (or several) made of Rhosyfelin rhyolite, which can be interpreted as the initial parking place for at least some of the Stonehenge bluestones.

Some years ago I reported:
In the western Pensarn pit there are apparently traces of a Neolithic embanked enclosure of some sort -- a very subtle feature, since the sediments are very thin here and no sign of it could be seen on the ground surface.  It was picked up in 2016 by geophysical work including LIDAR.  Apparently there are some "very unusual features" showing up, which are not commonly seen in the British Neolithic.  It may be a henge of some sort.  Organic materials have been recovered, and these will go off for C14 dating.

 Here is the advert for volunteers:



You may be aware that Mike Parker Pearson and his team will be excavating at Crosswell, Pembrokeshire between September 10 and 29 and would like to provide an opportunity for volunteers to come and get involved in the excavation. If you would like to take part, please provide the details below:


  • Name 
  • Contact e-mail 
  • Contact telephone number
  • Emergency contact name and number
  • Any medical issues that the team should be aware of
  • Dates available between 10 and 29 September.

Thursday, 31 August 2023

The inexorable perpetration of unreliable research

Here we go again --  deja vu for the umpteenth time.  Yet another article extolling the virtues of Waun Mawn as the place where Proto-Stonehenge was located.  The usual simplistic version of the narrative, designed here for tourists and interested lay people........ and to hell with the truth.

This is, of course, more for entertainment than education, but nonetheless it teaches us what happens when researchers irresponsibly publish research which is half-baked or simply downright defective, promoting a narrative designed to be appealing and exciting, involving huge assumptions and speculations that have little or no relation with the real world.  Of course many of the points made in this careless Travel Newsletter were dismissed by people like myself from day one, before being dismissed belatedly by MPP's team members themselves.  They have been forced to accept (from their own work)  that the famous pentagonal stone socket had nothing to do with any Stonehenge monolith, that the stones at Waun Mawn had nothing to do with any stone quarries, and that there is nothing in the evidence suite that connects Stonehenge and Waun Mawn.  There never was a complete -- or even partial -- stone circle here.  And there are no demonstrable astronomical alignments that make any sense.

The author of this piece was clearly aware that Tim Darvill had questioned the reliability of the Waun Mawn narrative last year -- but nonetheless the temptation to spread a thrilling narrative was too much for the writer and the editor.  So they went ahead and published it, with a nonsense headline designed for maximum impact.

Yet again, the members of the public are misled by a false narrative flagged up as "scientific research".  It's all rather sad......


Interested In Stonehenge? See Where It Once Stood In Wales Before It Was Taken To England.
Aaron Spray
The Travel -- Newsletter
29 August 2023

Wednesday, 16 August 2023

The Newall Boulder: the human transport hypothesis is as dodgy as ever

The bullet-shaped Newall Boulder now held in Salisbury Museum.  The faces have varying degrees of "freshness".  At the top of this photo we can see the damage done by geological sampling.

I should, of course, have been asked to review this paper prior to publication, but nowadays researchers effectively get to choose their own reviewers and to ban those who are deemed likely to be unfriendly........  Anyway, here is the peer review I would have written, if I had been asked.

Declaration of interest:  I have personally examined the "Newall Boulder" in Salisbury Museum, and have already expressed reservations about a previous report co-authored by Ixer, Bevins and Pearce (see note at the end of this review). 

Peer review

Richard Bevins, Rob Ixer, Nick Pearce, James Scourse, Tim Daw. 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 2023: 1-15

This paper seeks to demonstrate that a small sub-angular boulder found in a Stonehenge excavation was knocked off the tip of a rhyolite monolith that no longer exists, having earlier been excavated from a known site in West Wales prior to human transport to Stonehenge for use in a bluestone setting.  The claim that natural processes were not at any stage involved in the entrainment, transport and emplacement of the boulder is an extraordinary one, which can only be supported by extraordinary and powerful evidence.  Has that irresistible evidence now been provided?  In the view of this reviewer, the answer is "No".

At the beginning of the paper the authors suggest that there are eleven known "bluestone lithologies" which must have been associated with specific numbered orthostats.  The labelling of these lithological groups is confusing, to put it mildly, and the authors fail to acknowledge that each group probably  involves stones from several different provenances.  Further, during the excavations at Stonehenge at least 46 "exotic" rock types have been turned up in excavations, many of them having no links at all with any of the known "bluestone orthostats".  To ignore them is to defy logic. Angular fragments, abraded pebbles and cobbles found in the sediments, which may be crucial for the interpretation of what happened at Stonehenge, are simply dismissed by the authors. This fact alone undermines many of the claims made here about the human transport of the bluestones.  If the bluestones were selected for their "special" qualities or indeed quarried from sacred sites, do the authors really believe that monoliths and smaller stones were extracted deliberately from 46 different places?

In their literature review relating the the glacial transport / human transport controversy, the authors should have made reference to the modern work relating to very extensive glaciation by the Irish Sea Glacier, and the modelling work suggesting that the glacial transport of the Stonehenge bluestones was "not impossible" (Hubbard et al, 2009).

In their examination of the 18 "Newall stones" from the Hawley excavations at Stonehenge, the authors make somewhat heavy weather of the suggestions that some, at least, might have come from North Wales.  My understanding is that the suggestions of North Wales / Lake District origins for the small boulder referred to as RSN18, by Harrison and other BGS geologists, were very tentative.  But they were all quite convinced that the boulder (referred to as a strongly welded acid vitric tuff or ignimbrite) was different, geologically, from any of the known rhyolites (at that time) from Mynydd Preseli.  I agree with that. The Newall Boulder rock is darker in colour, rougher and more "flinty" than the rhyolite of Rhosyfelin. 

The authors' investigations of the petrography of the thin sections from the Newall Boulder are interesting but inconclusive.  The authors claim that "petrographically the RS18 fragment matches rhyolitic tuff from Craig Rhos-y-felin", in turn claimed as the "dominant source of the Stonehenge rhyolitic debitage" and as the site of a Neolithic bluestone quarry.  This is not supported by the evidence presented.  The photomicrographs comparing the texture and lithology of RS18 and Craig Rhos-y-felin rhyolite show similarities, but not perfect matches, and there remains a strong possibility that RS18 has come from elsewhere on an extensive rhyolite outcrop, or even from another outcrop entirely unrelated to Craig Rhos-y-felin. Attempts by the authors to demonstrate that the foliations in the Newall boulder and on the rock face at Rhos-y-felin indicate that the one was derived from the other are unconvincing, since we are not told how many other outcrops of foliated rhyolite there may be in West Wales. The whitish weathering crust, also cited as an indicator of a Rhos-y-felin origin, is also unconvincing, since whitish weathering crusts are present on many other West Wales rhyolite outcrops.

The reported pXRF work on the Newall boulder, also reported in section 2 of the paper, is similarly inconclusive. The bivariate plots shown in Figure 6 were -- as is normal in papers of this type -- created specifically in order to demonstrate affinities,  but this does not mean that the demonstrated relationships are unique or significant.  The overlaps between the fields for the Newall samples and the Rhos-y-felin samples may be no more marked, for example, that the relationships between the Newall samples and the plots for Carn Alw,  Ty Canol Wood, or Maiden Castle, which the authors may have, but have chosen not to show us.

Slickenside features on one face of the boulder, which must coincide with a fault plane.  

On page 9 the authors accuse Kellaway of mistakenly interpreting slickenside lineations as glacial striations.  Kellaway was a good geologist, and I do not believe he could have made such a stupid mistake.  The striations which he interpreted as having a glacial origin are much more subtle and discontinuous, and can be seen only during a minute examination of the boulder surface. This matter is discussed again on page 10, where there is a serious misrepresentation of the characteristics of glacial striae.  Striae are NOT typically continuous over a large proportion of a facet surface.  The clast shown in Figure 9 may be an ideal text-book illustration, but the great majority of striated clasts which I have encountered during a lifetime of working with glacial sediments are not like this at all; many of them show just one or two surface scratches, which may or may not be sub-parallel or cross-cutting.  The Newall Boulder, which I have examined, has a few very subtle scratches that may be striae, and they are quite distinct from the slickenside features shown in Figure 10.

It is disingenuous of the authors to pretend that because slickenside features are present on the Newall Boulder and at Craig Rhos-y-felin, this demonstrates a source for the boulder.  Slickenside features including slickencrysts are common across West Wales, in all faulted lithologies and of all ages.

On page 12 the authors refer to the "consistency of lithologies" in the Newall bluestone assemblage as an indication of "human selection of the material" rather than "a random process of entrainment in glacial till".   The entrainment of debris in glacial deposits is not a random process.  The authors do not explain why or how human beings should have selected around 46 different lithologies (mostly from the west)  for incorporation into Stonehenge sediments.  Were they disinterested in lithologies from the north, east and south?   They claim that "several of the bluestone lithologies have been sourced to specific outcrops in North Pembrokeshire, namely Craig Rhos-y-felin, Carn Goedog, Cerrigmarchogion and Carn Ddu Fach."  That is a misleading statement; these sources have been suggested, but never adequately proved, and indeed in the papers referenced the authors themselves accept that there are NO definitive sources that are beyond dispute.  The fact that many of the bluestones come from a limited geographical area is NOT suggestive of the human selection of the bluestones; on the contrary, since so many different rock types are represented in the Stonehenge assemblage of bluestone clasts, the supposition must be that glacial transport was responsible for stone transport on a substantial scale.  It is vanishingly unlikely that small fragments and cobbles in the debitage (many of them quite unrelated to bluestone orthostats) were selected and then carried to Stonehenge by human beings.

The authors argue on p 11 that the "snub nose" shape of the Newall Boulder is typical of outcrops at Craig Rhos-y-felin.  I know the site, and I do not accept that. They also suggest that the boulder is probably the broken tip of a destroyed orthostat (maybe stone 32d) at Stonehenge.  On the contrary, the boulder's "bullet shape" is suggestive of glacial transport, with abraded edges and discernible facets.   They also suggest that the "fresh" surface of the boulder shows where it was broken from the complete orthostat.  However, the fresh surface of the boulder is of very limited extent, and does not coincide with a sizeable cross-cutting fracture scar.  Examination of the boulder shows that Kellaway was most likely correct in assuming that part of the exposure of dark blue "fresh rock" was the result of limited damage (probably man-made) inflicted on a boulder only slightly larger and heavier than the one we see today.  Also, it borders on the absurd to suggest that a flimsy and fractured rhyolite orthostat with dimensions no greater than 2m x 40 cm x 30 cm would have been quarried from Rhosyfelin, transported to Stonehenge, and incorporated into a bluestone setting without falling apart in the process.  Indeed, the unsuitability of Rhosyfelin rhyolite for use as standing stones has now been accepted by Bevins, Ixer and other authors who some years ago flagged up the site as "the Pompeii of Neolithic quarries."  The evidence against quarrying at this site was presented in detail in two peer-reviewed papers by John, Elis-Gruffydd and Downes which have been completely ignored by the authors of the present paper.

Finally, on the matter of glaciation and glacial erratic transport, the authors summarise the evidence relating to erratic trains and glacier extent in the Bristol Channel arena which has been presented by selected researchers.  They ignore the work of other researchers, and in doing so they fail to address the glaciological conundrum of how the ice of the Irish Sea Ice Stream can have reached the shelf edge in the Celtic Sea without also overwhelming the inner reaches of the Bristol Channel and the Somerset Lowlands.  They also fail to mention the modelling work which has shown that glacier extent at the time of the Greatest British Glaciation might well have involved an ice edge on or near Salisbury Plain.  They fail to mention the presence of very old glacial sediments in the Somerset Levels, near Bath and on the coasts of Devon and Cornwall, and the presence of high-level erratics on the coasts of the South-west of England which cannot be explained other than by an extensive glaciation. They claim (falsely) that there are no "bluestone erratics" in the vicinity of Stonehenge, while ignoring the fact that most of the Stonehenge bluestones are not beautiful pillars as portrayed in the textbooks but classic glacial erratics (boulders and slabs) with distinguishable facets, abraded edges and thick weathering crusts.  The evidence of Stonehenge glaciation is staring the authors in the face, without apparently being noticed.

The authors claim that Clark et al (2022) and Gibbard et al (2022) summarise the most recent evidence of Devensian and earlier ice limits in Britain, and that there have been no significant changes in proposed ice edge positions.  But those two authors would be the first to admit that there are large inconsistencies in parts of the evidence base, and some of the "accepted" ice limits in parts of the Bristol Channel /Celtic Sea arena do not actually make much sense.......... 
It is clear that we are still some way from the telling of the full story.

An attempt by Gibbard and Clark to represent the ice edges for three glacial episodes.  In places these lines are matched by good "ground truthing", and in places they are highly speculative.  The Wolstonian ice edge shown for mid-Wales makes no sense at all....... 

However strong the evidence of glaciation and glacial transport may or may not be, it is far stronger than the evidence for human bluestone transport.  No evidence for human bluestone haulage from West Wales to Stonehenge has ever been found by the present authors or by anybody else, and the authors should have the good grace to admit this.  Indeed, there is no good evidence for substantial stone haulage with respect to any of the great megalithic monuments of the British Isles.

The contention that the Newall Boulder is not a glacially transported clast is unsupported by the evidence presented in this paper, as is the contention that it is a knock-off from a mysterious unknown Rhosyfelin rhyolite orthostat.  

Without considerable revision, this paper is not of sufficient quality for  publication in a serious scientific journal.


Declaration of interest: the following items are relevant:

Monday, 14 August 2023 -- a repository for all the best fairy tales

Erratic resting on a bergy bit in a vast glacier meltwater lagoon in Iceland.  Nothing to do with the sea or the coast, but deemed by TD to have something to do with coastal boulder emplacement........

I don't usually waste valuable space on this blog to considering the contents of other blogs --  but our friend Tim Daw, over on, has just demonstrated that when it comes to matters glacial he really is out with the fairies.

In a post entitled "erratic castaway" he argues 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."  He has done a nice little image search on Google and has come up with a couple of pictures of glacial erratic boulders resting on bits of floating glacier ice -- and he assumes that these photos prove his hypothesis. 

Oh dear -- how best to put this in the kindest possible way?  Tim has clearly never heard of eustatic and isostatic sea-level effects, and is clearly blissfully unaware that at a time when ice rafting of the type he now demonstrates was occurring around the British Isles, relative sea level was more than 100m lower than it is today, and the coastline of the Bristol Channel coasts was more than 100 km to the west.  The whole of the Celtic Sea arena was dry land.  During the Quaternary interglacials, when sea-level was more or less where it is today, with the coast in more or less its present position, there is no way that the ice rafting of large erratic boulders can have occurred in southern Britain.

This blog has a very good search facility, and there are abundant articles on glacial isostasy and palaeo-coastal positions.  I recommend to Tim that he does a little research.......

Tim should stick to what he knows.  As I have said before to those who purport to be bluestone experts, with friends like him, who needs enemies?