Erratic scatter, Yosemite

 
Erratics resting on glacially polished and striated granitic bedrock along Murphy Creek, north of Tenaya Lake in Yosemite National Park, USA...........

I have been throwing out old geology and geomorphology text books, and in the process found this photo. It reminds us that if the Stonehenge bluestones were indeed scattered across the landscape of the downs, you do not necessarily expect to find large terminal moraines or indeed coherent glacial deposits in the immediate vicinity.........

Time to sharpen the Razor

 

There are lots of razors about, and sadly, instead of being sharpened and used in normal life, they are for the most part ignored, especially in the field of something called "archaeological science." 

I made the above list some time ago, and  did a post on something I referred to as "John's Razor", for want of a better term.  It is enunciated thus:

Any claim made in a press release or in the media may be ignored unless the original research upon which it is based is freely (ie without limitation) accessible to all who may wish to  scrutinize it knowledgeably.

https://brian-mountainman.blogspot.com/2023/03/johns-razor.html

This Razor is normally shut away in the bathroom cabinet, but right now we have need of it, since during the past week the media outlets have been flooded with wildy enthusiastic nonsense about sarsens and bluestones in general and the Altar Stone in partcular demonstrating that the Neolithic people who built Stonehenge were involved in a great political unification project.  Apparently tribes from all four quarters of the land brought tribute stones to Stonehenge from a multitude of different locations, as a sign of their loyalty and obediance.............  

MPP has of course been playing with this idea for some time, but -- wait for it -- this flood of press coverage is based upon nothing more substantial than a press release connected to a hyperlink that does not work.  

There is NO journal article or published research that we can scrutinize.  This is an appalling state of affairs, which should have caused journalists across the world to ask some serious questions about the reliability of the material which they so readily published and celebrated.  Shame on all of them.  And shame on all of the authors of the said article which some of us have seen in rough draft form but which has still not been published in either a digital or printed form, more than a week after the press embargo ended............

According to John's Razor, we have every right to ignore everything contained in the press release and in the flood of media articles and to question the integrity and the expertise of all those involved in the fiasco.  For all we know, the article has been rejected by the editor of "Archaeology International" on the basis of serious criticisms from the peer reviewers.  Or maybe it has not even been submitted for consideration?

What a shambles.  

What a delicious irony............

The bluestones -- geologically selected, or geologically diverse?

Anybody who reads my blog -- or who just dips in now and then to find out what's occurin' -- will know that for the last 15 years I have been making the point that the Stonehenge bluestones have come from multiple sources.  When one counts the bluestone debris in the "debitage" it seems that there are around 46 known rock types involved.  Clearly there is discussion about what constitutes a rock "type" and where the boundary lies between one "type" and another, given that geologists can be classified either as lumpers or splitters.  Anyhow, you get the message -- there are lots of different bluestone lithologies and hence lots of different provenances.

"Oh no," said geologists Ixer and Bevins many moons ago.  "There are very few bluestone types, specially selected and quarried from specific sacred locations which we have identified."  And so we had Craig Rhosyfelin flagged up as the "Pompeii of Neolithic Quarries" and references to bluestone monolith extraction "on an industrial scale" from the tor of Carn Goedog.

This was of course the Orthodoxy to which all true believers were expected to submit, as part of the belief system preached by the Prophet Michael. He even referred to the ".......extraordinary appearance of the quarries". At both Craig Rhos-y-felin and Carn Goedog, he said, "the outcrops are striking and impressive, with their naturally upright pillars making these places anomalous and remarkable when encountered."  That is simply wishful thinking.  I know both sites rather well, and they are not characterised by "upright pillars".  And they are no more striking than scores of other rocky outcrops in the Preseli district.

Then it all started to crumble away,  with a recognition that there were no identified uses of Rhosyfelin foliated rhyolite monoliths in Pembrokeshire or anywhere else, and the realisation that the spotted dolerite monoliths at Stonehenge were quite diverse, and had actually come from many different places.  So in the view of the independent observer the quarries became redundant, as did the Waun Mawn "lost bluestone circle" promoted so heavily and cynically by Prof MPP on the telly and in print.

https://www.researchgate.net/publication/379121966_The_Stonehenge_bluestones_did_not_come_from_Waun_Mawn_in_West_Wales

But now, in the latest blockbuster article which purports to transform our understanding of Stonehenge, we find that MPP and his merry gang, on the basis of no new evidence, claim that the Stonehenge monoliths have come from multiple sources all over the place.  They call it "composite monumentality".  Stones were carried as tributes or symbols of unification from points all over the British Isles to Stonehenge, which is seen as the great cultural, religious and political focal point of England, Wales and Scotland.

https://brian-mountainman.blogspot.com/2024/12/the-stonehenge-narrative-becomes-even.html

So now they just love the idea of the bluestones coming from multiple provenances and being made of many different rock types.  The more the merrier, seems to be the mantra, since a Stonehenge monument attracting bluestones from 46 (or whatever) different West Wales locations must have been a much more powerful place than a little monument somewhere else attracting stones from just a few places in the neighbourhood.

There is a delicious irony in all of this.  First, according to Bevins and Ixer, the bluestones were not geologically diverse.  And now they are.  You couldn't make it up............

Here come the heavies.........

They really don't like it when people disagree with them, do they?  The Bluestone Gang is on the warpath:

Coming soon:  Bevins, R.E., Pearce, N.J.G., Ixer, R.A., Scourse, J., Daw, T., Parker Pearson, M., Pitts, M., Field, D., Pirrie, D. and Power, M.R. In press. Further discourse on the enigmatic ‘Newall boulder’ excavated at Stonehenge in 1926: correcting the record. Journal of Quaternary Science.

A gang of ten.  Some of them are probably very upset about my review of their 2024 paper, and about my article published in June 2024 in E&G Quaternary Science Journal.  That article was published after extensive expert review and editorial involvement; whatever Bevins et al might think, it was deemed by the editorial team in Germany to be well worthy of publication.  If it has opened up a serious debate, all well and good. 

 So we look forward with interest to reading the latest attempt at "correcting the record".  This involves not just the geologists Ixer, Bevins and Pearce.  Almost all the members  of the Stonehenge establishment are apparently joining forces in an attempt to discredit my article on the Newall Boulder.  They must be seriously worried.  And so they should be.  The narrative on which they have based their academic reputations is under attack, and there is widepstread scepticism out there in the forum of public opinion, as indicated in the public response to the YouTube videos published by Coral and Jacky Henderson in the last fee months..  

Anyway, we shall see what these fellows have to say. Then I assume I will have to correct the corrected record.  Somebody has to do it.  

This is an interesting development, given that for the best part of a decade Bevins, Ixer and Pearce have steadfastly refused to acknowledge that any of their evidence has been questioned in the scientific literature, or that any of their conclusions have been disputed.  Their refusal to cite key publications by Elis-Gruffydd, Downes and me may be seen as a crude sort of  "academic cancel culture" the likes of which I have never seen before, at least  in my own field of geomorphology.  Should I feel flattered that they have now, at long last, acknowledged my existence?

This of course comes hard on the heels of an arrogant and patronising article by Pearce, Bevins, Ixer and Scourse published in Quaternary Newsletter 163 (2024), which seeks to discredit other geologists and to question my knowledge of Quaternary events in Western Britain.  I'm not taking any lessons from them, and will deal with their insulting assault in print, in the coming months.

https://brian-mountainman.blogspot.com/2024/11/a-very-silly-rant-from-pet-rock-boys.html

Never a dull moment.  Long live academic discourse.......

Mike Pitts and the "lost" megaliths that might not be lost at all.......

Some of the parchmarks in the turf at Stonehyenge.  Some of these may mark to positions of stones in the past, but then again, maybe not.........

This is a popular article written by Mike Pitts and published on the BBC  "Future" web site

https://www.bbc.com/future/article/20241220-the-archaeological-mystery-of-stonehenges-long-lost-megaliths

This is how BBC Future advertises itself:

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

We believe in truth, facts, and science. We take the time to think. And we don't accept — we ask why.

In a complex, fast-paced world of soundbites, knee-jerk opinions and information overload, BBC Future provides something different: a home for slowing down, delving deep and shifting perspectives.

We look for answers to the issues facing the world in science. You’ll find stories here on almost every topic that matters. Psychology. Food. Climate change. Health. Social trends. Technology.

What links them all is our approach. Through evidence-based analysis, original thinking, and powerful storytelling, we shine a light on the hidden ways that the world is changing – and provide solutions for how to navigate it. Energised by the everyday, we think no topic is too small to be fascinating. Inspired by obstacles, we believe no subject is too overwhelming to tackle.

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

Well well. Truth, facts and science. Evidence-based analysis, original thinking and so forth. Grand aspirations and claims. So does the Pitts article measure up? Not from where I'm standing. It is packed full of statements and claims that should have been checked and rejected by the BBC Future editorial team.

Bluestonehenge is mentioned but not named, and it is proposed that the pits there once held bluestones that were transported to Stonehenge. That is of course not universally accepted.

The claim that hardly a stone was left undamaged by stone collectors with hammers is somewhat over the top.  The laser survey of 2012 did reveal a great deal of surface damage, but it has been widely accepted since the days of Richard Atkinson that all but one of the bluestones in the bluestone circle are still in their "natural" state, and that the shaping and surface marking by humans is typical of the monoliths in the bluestone horseshoe.

The so-called parch marks in dry weather do NOT necessarily coincide with the positions of Stonehenge monoliths that have since been "lost".  On the contrary, most may simply mark the positions of pits that were dug for monoliths that never actually arrived -- or were never found by the builders who scoured the couhntryside round about.  These pits, like many others on the site, may simply provide evidence of one of many attempts at rearranging a limited number of stones.  Other pits mat be extraction pits from which smaller sarsens and bluestones were extracted from the places in which they were discovered.  Pitts avoids any mention of this possibility, although in the past he has acknowledged that Stonehenge may have been built  in a place where there was a convenient scatter of naturally occuirring monoliths.  On the site today there are only 40 sarsens and 43 bluestones; if there ever was an "immaculate Stonehenge" that means that 50% of the monoliths involved have disappeared.  To accept that is to be involved in a very considerable act of faith.

https://brian-mountainman.blogspot.com/2020/08/unfinished-late-neolithic-monuments.html

With reference to the Boles Barrow spotted dolerite block, Pitts mentions the idea that it might have been glacially transported, but cites only Williams-Thorpe and Thorpe 1992.  That is a very dated reference, and there have been many others making the argument since 1992.  Pitts says "geology has never backed" the glacial transport case -- that is far from the truth.  "Archaeologists now agree" that the stone was taken from Stonehenge?  Really?  Pitts should have had the good grace to admit that he is referring to some geologists and some archaeologists.

Finally Pitts accepts, on the basis of the article by Clarke et al (2024) that the Altar Stone has been "shown" to have come from the far NE of Scotland.  He says:  "The most-travelled megalith at Stonehenge had finally been tracked to its source"........  In fact there are considerable doubts about the origins and provenancing of the samples purported to have come from the Altar Stone, no matter what the media coverage might have claimed.

https://brian-mountainman.blogspot.com/2024/08/the-altar-stone-much-ado-about-nothing.html

Pitts really should be more careful, and so should the BBC.

Christmas Greetings 2024

 

On the road with the Pied Piper, as he leads the media on a merry dance.........

Not for the first time, I have received a foul and abusive message from somebody who should know better,   cursing me for daring to criticise  -- in my post of the other day -- a scientific paper that has not yet been published.....

I kid you not.

https://brian-mountainman.blogspot.com/

So the paper that has been garnering headlines all over the world has not actually seen the light of day.  That confirms what I suspected, having spent some hours looking for it all over the place.  The link given in some of the press reports does not work.  

The UCL press release, subject to a strict press embargo until 20 December, went out to a huge mailing list, with an expectation of vast media coverage, without anybody being able to check on the quality of the paper that was being so heavily promoted.  Some of the key media people were sent pre-publication copies of the paper, and I obtained one of these.  My post was based on my reading of that draft.  I acted quite responsibly and in good faith, read the article carefully, and did not break the embargo.

But this is quite extraordinary.  Just think about it. A group of quite senior academics has set up and orchestrated a huge marketing and media campaign, designed to grab the attention of gullible science and archaeology reporters all over the world -- but in circumstances where nobody could actually get a sight of the actual published article.  That is unbelievably arrogant.

The article of course contains nothing new.  It is essentially an opinion piece, packed from beginning to end with speculations and assumptions.  In the absence of any other evidence about what has gone on here,  we can only assume that the authors (Parker Pearson, Bevins, Ixer, Bradley, Pearce and Richards) simply wanted to get maximum media coverage while the going was good, before anybody had a chance to subject their article to proper scientific scrutiny.  

The Stonehenge narrative becomes even more bizarre...............

Here we go again! 

https://news.sky.com/story/stonehenges-purpose-may-have-been-to-unify-ancient-britain-after-scientists-make-discovery-about-stones-origins-13276723#:~:text=Professor%20Mike%20Parker%20Pearson%2C%20lead,a%20religious%20purpose%20%2D%20as%20a

I knew this was coming.  It's published in "Archaeology International" -- which is now housed in UCL, which just happens to be the institution in which our old friend MPP works.  What a coincidence!!

(Correction 23 Dec -- it is apparently NOT published.....)

A draft of the article has been circulating behind the scenes, and I picked up an unsolicited copy from a contact.  I have looked at it briefly, and I am appalled...........  how is it that stuff like this gets into print?  I will consider the article in more detail when I have seen it in its final published form, but below I make a few comments on the short section about bluestone origins.

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

Stonehenge and its Altar Stone: the significance of distant stone sources

Mike Parker Pearson, Richard Bevins, Richard Bradley, Rob Ixer, Nick Pearce and Colin Richards

Abstract

Geological research reveals that Stonehenge’s stones come from sources beyond Salisbury Plain, as recently demonstrated by the Altar Stone’s origins in northern Scotland over 700km away. Even Stonehenge’s huge sarsen stones come from 24km to the north, whilst the bluestones can be sourced to the region of the Preseli Hills some 225km away in west Wales. The six-tonne Altar Stone is of Old Red Sandstone from the Orcadian Basin, an area that extends from the Northern Isles of Orkney and Shetland to Inverness and eastwards to Banff, Turriff and Rhynie. Its geochemical composition does not match that of rocks in the Northern Isles so it can be identified as coming from the Scottish mainland. Its position at Stonehenge as a recumbent stone within the southwest arc of the monument, at the foot of the two tallest uprights of the Great Trilithon, recalls the plans of recumbent stone circles of northeast Scotland. Unusually strong similarities in house floor layouts between Late Neolithic houses in Orkney and the Durrington Walls settlement near Stonehenge also provide evidence of close connections between Salisbury Plain and northern Scotland. Such connections may be best explained through Stonehenge’s construction as a monument of island-wide unification, embodied in part through the distant and diverse origins of its stones.

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

Extracts

The bluestones have been geologically identified as coming from the area of the Preseli Hills ever since Herbert Thomas (1923) identified the most numerous of the Stonehenge bluestones as spotted dolerites that could be matched with outcrops in those hills. Although occasional attempts have been made to explain the bluestones’ incorporation in Stonehenge as due to transport by glaciers in a previous Ice Age (Judd 1902; Kellaway 1971; John 2024), there is no evidence that glaciers extended more closely than within 100km of Salisbury Plain (Clark et al. 2022), discussed in some detail in Ixer et al. (in press). Claims that one or more bluestone fragments from Stonehenge and its environs show evidence of having been transported by glaciers similarly do not stand scrutiny (Bevins et al. 2023a; in press).

"........in a previous Ice Age"??  I assume that what they mean is "during a previous episode of Quaternary glaciation".

"....... there is no evidence that glaciers extended more closely than within 100km of Salisbury Plain..."  Since when did Clark et al make that claim?  There is perfectly good evidence, adequately discussed in the literature, of glacial deposits at Court Hill (c 70 km from Stonehenge), Kenn  (c 74 km), Bathampton Down (c 40 km), and Greylake (c 70 km), all of which indicate the presence of glacier ice pushing into Somerset from the Bristol Channel.   And what's this nonsense about Bevins et al and Ixer et al in press?  You cannot cite as evidence material which might or might not get through peer review and which might or might not ever be published.  If and when these papers see the light of day, we shall see whether they withstand scrutiny.

Four types of bluestone have been matched geologically with outcrops in Preseli. The source for most Stonehenge’s spotted dolerites (classed as Group 1) has been identified as Carn Goedog (Bevins et al. 2014). Two sources for unspotted dolerites (Stones 45 and 62; Group 2) are Cerrigmarchogion and Garn Ddu Fach, to the west and east of Carn Goedog (Bevins et al. 2014; 2021; Pearce et al. 2022). Remaining spotted dolerites (Group 3) are thought to derive from an area to the east of Carn Goedog but are not matched to a specific outcrop (Bevins et al. 2014). Of the three types of rhyolite at Stonehenge, Group C is matched to a specific location within the outcrop of Craig Rhos-y-felin, 3km to the north of the Preseli ridge (Ixer and Bevins 2011). Finally, Stonehenge’s two Lower Palaeozoic sandstone monoliths are similar lithologically and in terms of age to strata exposed to the north and east of the Preseli Hills (Ixer et al. 2017). 

Let's be straight about this. Not one of the Stonehenge bluestones has been provenanced accurately to a single precise location.  The geological matches are approximate at best, and there can be no certainty about the locations mentioned above because the geologists do not have anything like a comprehensive cover of sampling points across the various igneous outcrops.  They have "possible locations", but that is the best that can be said. And they really have no idea whatsoever where the Lower Palaeozoic sandstone monoliths might have come from, in spite of claims made by Ixer et al in 2017.

The reality is that the Stonehenge bluestones, and the fragments in the debitage, are geologically diverse.  They have come from multiple locations  -- a point frequently denied by Ixer and Bevins, who have sought consistently over the years to demonstrate that the bluestones have come from a very few carefully selected places where they claim to have found quarries.

https://brian-mountainman.blogspot.com/2021/08/the-absurdity-of-quarrying-hypothesis.html

https://brian-mountainman.blogspot.com/2021/06/more-on-stonehenge-dolerites-multiple.html

Excavations at the bluestone sources of Carn Goedog and Craig Rhos-y-felin have uncovered evidence of megalith quarrying dating to the centuries before and around 3000 BC, consistent with the date of Stonehenge’s first stage. At Craig Rhos-y-felin, that precise part of the outcrop with a match for Rhyolite Group C lies directly adjacent to a niche from which a 2.5m long monolith has been removed (Parker Pearson et al. 2015). Quarrying installations include a drystone-revetted, artificial platform at the foot of the outcrop as well as a hollow way or sunken trackway leading from the foot of the platform (Parker Pearson et al. 2019). Quarrying artefacts include three stone wedges still in situ within joints close to the gap left by a removed monolith (Parker Pearson et al. 2022a). Similar evidence of quarrying was found at Carn Goedog, in the form of stone wedges and other stone tools, an artificial platform, niches left by removed pillars, and wedge-holes cut into the joints between pillars (Parker Pearson et al. 2019).

This paragraph is disingenuous and irresponsible.  The so-called "evidence of quarrying" is hotly disputed in print, and it is truly extraordinary that Parker Pearson and his colleagues cannot bring themselves to admit this.  The Rhosyfelin "evidence" was dismissed in two journaal articles by Dyfed Elis-Gruffydd, John Downes and me in 2015, and in a preprint article about Carn Goedog published on Reserarchgate by me in 2019.  The "extraction point" for a 2.5 m long monolith at Rhosyfelin is pure fantasy, and no monoliths made of foliated rhyolite are known from Stonehenge.  The "quarrying installations" are figments of a fertile imagination, and the idea of wedges and "wedge holes" has been dismissed as laughable by Tim Darvill and specialists in rock mechanics.

As for the rest of the article, it reaches new heights of absurdity -- of which more anon.

-----------

The items they refuse to cite:


Brian John, Dyfed Elis-Gruffydd and John Downes. 2015. OBSERVATIONS ON THE SUPPOSED “NEOLITHIC BLUESTONE QUARRY” AT CRAIG RHOSYFELIN, PEMBROKESHIRE". Archaeology in Wales 54, pp 139-148. (Publication 14th December 2015)
https://www.researchgate.net/publication/286775899_
https://www.researchgate.net/publication/286927485_Photo_Gallery

Brian John, Dyfed Elis-Gruffydd and John Downes (2015a). "Quaternary Events at Craig Rhosyfelin, Pembrokeshire." Quaternary Newsletter, October 2015 (No 137), pp 16-32.
https://www.researchgate.net/publication/283643851_QUATERNARY_EVENTS_AT_CRAIG_RHOSYFELIN_PEMBROKESHIRE

and this paper published online:

Brian John (2019) Carn Goedog and the question of the "bluestone megalith quarry"
Researchgate: working paper
April 2019, 25 pp.

DOI: 10.13140/RG.2.2.12677.81121
https://www.researchgate.net/publication/332739336_Carn_Goedog_and_the_question_of_the_bluestone_megalith_quarry
Carn Goedog paper.pdf

------------------------------------

Here is the latest UCL press release:

https://www.ucl.ac.uk/news/2024/dec/stonehenge-may-have-been-built-unify-people-ancient-britain

This is of course the basis of nearly all the press coverage.

Daw's Delusional Denials: the latest episode

The Ramson Cliff epidiorite glacial erratic, at c 80 m above sea level

Yesterday I took a look at our old friend Tim Daw's blog site.  It's worth looking at now and then, since it does occasionally contain items of interest.  Anyway, I was greatly entertained by his latest full-frontal attack on my credibility -- demonstrating yet again his lack of understanding of natural processes and his tendency of shooting from the hip when a little more time might have spent on researching his target.

So what is he on about this time? Well, it's a long piece devoted (as far as I can understand it) to demonstrating that there are no erratics around the Bristol Channel other than those found on the shore platforms between present day high and low tide marks.  He is apparently obsessed with a statement I made about many erratics being found around the Bristol Channel coasts above 100m.  I stand by that, and am more than a little irritated by Tim's selective use of citations and his ignorance of the literature.  My information comes from abundant sources, most of which are cited on my blog and in my published articles.

Some of the erratics are glacial, and some are not.  I have already drawn attention in my blog to the Shebbear and Berry House erratics, which appear to be sarsens.  Ice may or may not have been involved in their emplacement, but they are clearly not in their "original" positions.

https://brian-mountainman.blogspot.com/2024/11/more-on-shebbear-erratic-boulder.html

https://brian-mountainman.blogspot.com/2024/11/the-berry-house-boulder-north-of.html

I accept that the Harmer map of erratics does not show erratics in the Ilfracombe area.  Apologies for that.  My version of the map was clearly a copy of a copy, and what I thought was a dot indicating a recorded erratic was in fact a tight contour line just below the letter "e" in "Ilfracombe".  It's interesting that Harmer did not show any of the erratics in the Saunton - Croyde area either -- even though they had been recorded well before 1928 by other geologists. For example:

Pengelly, J. 1892. The granite boulder on the shore of Barnstaple Bay, North Devon. Transactions of the Devonshire Association, 6, 211-222.

Tim claims -- quite falsely -- that there are no erratic boulders at Lundy,  Court Hill or Nightingale Valley, and that the erratics at Fremington, Baggy Point and elsewhere can be ignored because they are under the 100m contour.  I just do not understand why he is so obsessed with the 100m contour nonsense, because I did not claim that there are vast numbers of glacial erratics above this level on the coasts of Devon, Cornwall and Somerset. If you want me to be pedantic,  I referred in my 2024 Limeslade Boulder article to "the shores of the Bristol Channel" without specifying which ones I was talking about.

Anyway, I am not going to waste my time on this  -- but I will simply reiterate that according to Prof Nick Stephens there are high level glacial erratics near Ilfracombe, that according to Rolfe et al there are high-level glacial erratics on Lundy Island, and that according to Gilbertson and Hawkins there are drift deposits containing erratics up to 122m OD at Portishead Down and elsewhere.  The same authors refer to "erratic rich drifts" on the high-level plateau surfaces of the Cotswolds above Bath, and on the Mendips, "at and above 200m." (p 186)  Geoffrey Kellaway and others demonstrated the same thing in articles published around 1971-72.

If ice from the west affected these areas on the southern shore of the Severn Estuary up to and above 200m, it is a statement of the obvious that the ice surface up-glacier (ie to the west) must have been even higher.  It should come as no surprise to anybody that in those circumstances, on at least one occasion, glacial erratics both large and small must have been dumped on all of the shores of the Bristol 
Channel. We know about some of them, and others no doubt are still to be found.

I just cannot understand why Tim Daw, and his dear friends Ixer, Bevins, Pearce and Scourse, should have a problem with that..............

Madgett, P.A. and Inglis, A.E. 1987. A re-appraisal of the erratic suite of the Saunton and Croyde Areas, North Devon. Transactions of the Devonshire Association, 119, 135-144.

Three million page views

 

Suddenly, without noticing, we have roared through the 3 million page views barrier.  So many thanks to all those who have supported the blog over the years and who have expressed their appreciation of its contents.  Not all readers agree with what I have to say, but that's OK -- evidence is often difficult to interpret, and opinions often vary.  But I try to keep an open and critical mind,  and continue to welcome comments from both supporters and opponents!

The great majority of views now come from people who habitually uise the blog for reference and research purposes -- but a significant nember each month seem to come from Google and other search engines, meaning that the algorithms they use are now taking the blog seriously on all sorts of issues, showing links that are high up on the page rankings.

Onwards and upwards.....

The use of local stone in prehistoric stone settings

Pentre Ifan, built of slabs of locally collected volcanic ash.  

Photo courtesy Hugh Thomas

Hugh Thomas, over on the Preseli360 Facebook page, has just published an interesting post which I am very happy to acknowledge and reproduce below. 

Nobody knows the stone settings of Preseli better than Hugh, and I agree with  him that there was apparently no interest at all, in the prehistoric poeriod, in collecting stones from far away and transporting them from A to B just so that you could build them into your friendly neighbourhood cromlech.

Stephen Briggs called this opportunistic, utilitarian and pragmatic.  He could not see in this area any evidence of monoliths of certain rock types being valued above any others, or deemed to be sacred or special.  Some monoliths (like dolerite, hard sandstone, volcanic ash or lava) were obviously better for building with than flaky rhyolite, shale or mudstone -- so they tended to be used if they were available.  

But long distance stone moving expeditions?  No thanks.  Our ancestors were too smart for that sort on nonsense..........

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

QUOTE

Just a personal thought that has reoccurred to me a number of times over the years...
There are many spectacular quartz boulders to be found in Preseli, and there is certainly a concentration of them around the Bwlch Ungwr , Carn Breseb and Carn Alw area.

If in ancient times stones were being revered as being special and " being moved about" , then why pick stones that all on appearance alone all looked the same and that only modern geologists can largely REALLY tell apart ? To my artistic eyes the most spectacular stone setting would have been a white quartz stone circle and there were MORE THAN ENOUGH quartz boulders around to create that ...I can not imagine for one moment that our ancestors would not have been fascinated by the white gleaming quartz .

Just imagine a quartz circle gleaming in the sunlight or glowing under a full moon, it would have been stunning .

To me this gives weight to the cold fact that any stone setting found around Preseli is made up of stones that were found in the immediate area for convenience...

I have not yet been shown anything or seen anything in Preseli that tells me otherwise, but if the truth of it IS otherwise I am very open to be shown it, because it would be the truth and not just a romantic belief. But the facts supporting the movement of stones would have to be overwhelming and not just theories being shoehorned into this landscape as has been really all along. ..

Those championing theories of stone movement seem to actually rely on the curiousity of people not looking into things TOO closely from the point of view of practicality , because that is when all the problems begin and an unraveling of the theory means it takes further more colorful claims to hold it together, and begins to become impractical from the point of view of human nature. .

I am happy for anyone to show me otherwise , but as it stands , in 2024, despite all I have been shown or read just demonstrates people were here at that time and not transporting stones over great distances in Preseli , the stones left at Waun Mawn ARE from that area and so on .. Nothing has peaked my curiosity to question further ...Yet ..

I am grateful to those who help to keep a sense of practical balance on all of this ..

The inner reaches of Nordvestfjord

 I found a higher resolution copy of this fantastic image of the inner reches of Nordvestfjord. We are looking down the fjord from above the snout of Daugaard-Jensens Glacier, with ntabular bergs and quite extensive sea ice.  To the left of centre there is a low plateau with a thin ice cap, and higher icefields are shown in the distance to the right of centre.

In the far distance, towards top right, we can see the fjord section where the fjord sides are almost vertical and where the fjord scenery is at its most dramatic.

So why the difference between the relatively gentle ice-scoured and moulded slopes of the upper fjord, and the hugely spectacular fjord landscape in its middle and outer sections, towards Hall Bredning and Scoresby Sund?  Well, we don't really know the full picture, but the simple answer must be that the extent of fjord deepening -- and maybe fjord widening too -- is a function of ice discharge.  As the ice of the Nordvestfjord Glacier moved south-eastwards it was supplemented by the ice flowing in from many tributary glaciers over a distance of c 120 km, leading to a gradual stepped deepening of the fjord floor.  Then, as soon as the glacier emerged from the mountain front into the broad embayment of Hall Bredning, it lost its erosive capacity at the threshold and spilled out sideways via a number of diffluent discharge routes.  Just like Hardangerfjord, Sognefjord and many other big fjords throughout the world.......

https://brian-mountainman.blogspot.com/2013/07/nordvest-fjord-east-greenland.htmlhttps://brian-mountainman.blogspot.com/2013/07/nordvest-fjord-east-greenland.html

https://brian-mountainman.blogspot.com/2021/09/the-nordvestfjord-threshold.html

  

Renland dissected plateau

 

On the southern and eastern ringes of the Renland Ice cap (adjacent to Nordvestfjord in East Greenland) there is a plateau landscape which has been heavily eroded by streaming ice and thus heavily dissected. See also the posts on Grundvikskirken, the most spectacular rock pillar of all...........

This landscape is different from that of the Staunings Alps because of the advanced stage of the highly selective linear erosion, with streaming ice cutting vertically down to create troughs now occupied by water (in the fjords) or rapidly flowing ice (in the dry valleys).

Much work remains to be done on Renland -- but in the meantime we can enjoy the fantastic images being assembled by the climbing groups who are attracted to the area.

This is the Renland ice cap in an oblique aerial photo.  Some of the rocky ridges beyond the edges of the ice cap are heavily dissected into spectacular towers and pinnacles.......

Glaciated landscape types

 

I have been looking at some new images of the Staunings Alkps in East Greenland, in what we might refer to as a classic Alpine landscape.  It's heavily glacierized, with no plateau ice caps or snowfields.  Almost all of the snow and ice is found in hollows or depressions, separated by a multitude of sharp peaks, jagged "sawtooth" ridges and pinnacles.  Slopes are very steep, and frost processes dominate in the destruction of bedrock outcrops.  Avalanches and snow bank collapses are frequent.  

This landscape stratches from hoirozon to horizon, and is revealed in all its glory in footage from a low-altitude (5,000m) overflight in a chartered Airbus aircraft, on its way to the North Pole. 

There are thousands of spectacular peaks here, most of them still unclimbed.  But we can understand why the Staunings Alps are now something of a magnet to climbing expeditions........

One thing that I find particularly intriguing is the transition from "alpine country" to "plateau and fjord country" on the northern, western and southern flanks of the mountains.  Look at this photo:

The contrast is staggering -- within a few miles we pass into an old plateau landscape where most of the snow and ice is found on extensive or broken plateaux.  The plateau segments are separated by deep troughs containing outlet glaciers, and there are many places where ice spills over the plateau edge in spectacular "frozen cascades".  

What is the explanation for the differences between these landscapes?  Watch this space.........

Landscape types to the north of Scoresby Sund.  The red line encloses most of the Alpine terrain.

Satellite image of the Staunings Alps / Werner Mountains area

West Angle then and now

 

I still think West Angle is one of the most important interglacial sites in Wales.  I found the above B/W photo in an old box file, dating from the 1960s.  Now, sixty years later, the brick pit has been filled in and the drift cliff is so degraded that I am not sure we can trust the stratigraphy any longer.  It was difficult enough as it was, before all the recent slumping and vegetation disturbance.........

Ailsa Craig -- where all those erratics came from

 

 

Lovely photo of Ailsa Craig in the winter.  There is more of it under the water, of course -- but it's nice to remind ourselves now and then that this is the source of many thousands of small (and very characteristic) white microgranite erratics found around the shores of the Irish Sea and St Georges Channel.

More doubts about the "cold climate" raised beaches of southern Ireland

The Courtmacsherry raised beach exposure.  Overdependence upon OSL 

dates is not a good idea.

P 175 of O'Cofaigh et al, 2012
Quote:
Undoubtedly there is extensive evidence for the beach along the south coast of Ireland forming in a cold-climate environment (see above), and indeed some of the evidence which underpins this interpretation was first noted by Wright and Muff (1904). This includes the presence of erratics within the raised beach gravels and interbedding of the beach gravels with periglacial slope breccias. Previous investigations of the sand facies that overlie the raised beach at sites such as Howe's Strand and Broadstrand have interpreted it as ‘blown sand’ (e.g. Synge, 1978). This is inconsistent with the sedimentology of these sands which exhibit well defined hummocky and swaley cross-stratification consistent with a shallow marine rather than aeolian setting. Thus the facies sequence of raised beach/HCS sands/SCS sands indicates submergence following beach formation. Periglacial slope deposits and isolated angular clasts of local bedrock within these sands indicate the maintenance of a ‘cold’ depositional environment during this submergence.

Sorry chaps, but I beg to differ.  There is NOT "extensive evidence".......  I have gone through the stratigraphic descrtiptions very carefully, and I see NO evidence that the climate was cold at the time of beach formation.  The raised beach and associated sands do not show any evidence of a prevailing cold climate.  There are no signs of a cold climate shell fauna in the beach gravels and sands, and no trace of a warm climate fauna (as in the Patella Beach) either.  There seem to be no examples of interdigitated glacial materials in the raised beach or in the sands.  There is either a clean break between the beach materials and the overlying slope breccia, or some interdigitations of broken bedrock materials, but no evidence is presented to demonstrate that the breccia accumulated under cold climate conditions. The breccias most likely represent local rockfalls and scree accumulations following  a shift in coastline position.  This could be established with reference to the details of coastal morphology and the positions of the local rock cliff.

There appear to be no glacitectonic structures or erosional contacts in the raised beach materials which might indicate the presence of a local ice front.

The fact that the overlying sands are interpretd as shallow marine beds rather than blown sands has no bearing on the "cold climate issue".  And the presence of occasional angular clasts in these beds simply suggests that there were localised rockfalls nearby, or some incorporation of glaciated clasts from the disaggregation of older (pre-existing) glacial deposits on the adjacent coastline.

The junction between the raised beach and the breccia is essentially no different from that which we observe at Poppit, Ogof Golchfa, Broad Haven South and many other locations on the other side of St Georges Channel, in Pembrokeshire.  It is most realistic simply to interpret this junction as representing the climatic shift from interglacial (Ipswichian) to cold climate (Early Devensian) conditions, as concluded by many researchers over many decades.

So the only evidence (as far as I can see) of the cold climate environment is that of the OSL dates.  That's not a good situation.  What if all of those dates are faulty, as a result of faulty calibration or a systematic under-estimation of the ages presented by the authors of this paper?  We all had to learn some pretty harsh lessons from the chaos of amino acid dating a few decades ago, which was so serious that it brought much of the work of the Geological Conservation Review volumes on Wales and the Soutrh-West of England into question.  We await further views on the reliability -- or otherwise -- of the dates.  In the meantime, a degree of scepticism is in order.

See also:

A Marine Isotope Stage 4 age for Pleistocene raised beach deposits near Fethard, southern Ireland
Colman Gallagher, Matt W. Telfer, Colm Ó Cofaigh
Jnl of Quaternary Science, Volume 30, Issue8
November 2015
Pages 754-763

First published: 06 October 2015
https://doi.org/10.1002/jqs.2808

https://onlinelibrary.wiley.com/doi/10.1002/jqs.2808

Quote from Prof G Duller, Aberystwyth:

Samples from sediments whose grains were exposed to daylight during transport or deposition date the time of transport or deposition.The most suitable sediments are those that were exposed to the most daylight during transportation, including wind-blown sands and silts.The optically stimulated luminescence (OSL) signal from minerals is more rapidly reset by daylight than is the thermoluminescence (TL) signal (Fig 8). OSL measurements have made it feasible to look at fluvial and colluvial sediments as well, but care needs to be taken in these cases to assess whether they were exposed to sufficient daylight at deposition to reset the luminescence signal being measured.

Duller, G. A. T. (2008). Luminescence Dating: Guidelines on using luminescence dating in archaeology. English Heritage.

Age of raised beach deposits of South-Western Britain

Raised beach localities in SW Wales

The recent discussions about the Courtmacsherry and Fethard raised beaches, and the suggestion that they might be of early or Mid Devensian age, should not blind us to the fact that over many years evidence has been assembled to indicate that the bulk of raised beaches around the Celtic Sea and Bristol Channel coasts are are truly interglacial -- and probably largely of Ipswichian age. I assembled some of the evidence in my "Nature" article of 1968:

John, BS.  1968. Age of the raised beach deposits of south-western Britain.  Nature, 218 (5142), pp 665-667.

Here is the link:

 https://www.researchgate.net/publication/232783499_Age_of_Raised_Beach_Deposits_of_Southwestern_Britain

The evidence assembled from West Angle and elsewhere still stands -- and of course the evidence relating to the temperate climate of "Patella Beach" times goes back much further, to Strahan (1908) and others.  

Patella and other shell fragments in the cemented Patella raised beach, Gower.  Photo:  Jessica Winder

That having been said, attempts to date the "Patella Beach" exposures on the Gower coasts have been beset by difficulties, and as reported by Jenkins and others in 1985, amino acid dates for Patella shells suggested that they were over 200,000 years old........... Jenkins et al also reminded us that TN George, whose opinions were somewhat mobile, argued at one time that the presence of Lundy granite erratics in the raised beach indicated that it was formed at a time of cold climate, with glacier ice in the vicinity.  Quote: 

"The first modern work on the Quaternary beaches of Gower was by T. N. George (1932) who argued that this Patella beach was deposited in glacial conditions as evidenced by its erratic pebbles which he believed had been rafted on ice-floes. He argued that it predated both Older and Newer Drift Glaciations of Gower....."

It can also be argued that the close proximity of periglacial (?) head or slope breccia to the cemented raised beach exposures might also point to the presence of permafrost or at least a cold climate at the time of beach formation.  As pointed out by Kokelaar (2021) the Patella Beach exposures frequently contain sharp edged and angular rock fragments derived from the immediate vicinity.  But in my view these are most likely to be cliff face rockfall materials which have not been present in the beach for long enough for clast smoothing or rounding processes to have been effective.  (For comparison, many of the present day beaches of Pembrokeshire incorporate recent rockfall materials.)

A cone or fan of rockfall debris dropped onto the pebble beach at Newport in 2019.  Most of this material has now (2024) been dispersed by wave action and incorporated into the beach.

McCarroll (2015) argued that the amino acid dates that have bedevilled the Patella raised beach debate are mostly incorrect, and that the raised beaches date (with rare exceptions) from the Ipswichian Interglacial.

We must keep an open mind and see where the evidence takes us......

The Whitesands boulder bed

 

Two smoothed and rounded giant erratics resting on the interglacial rock platform at Whitesands South in Pembrokeshire.  Like many other boulders resting on the rock platform at this location, they appear to have been in position, affected by wave washing, prior to the deposition of the materials that lie around and on top of them.  In this respect they bear direct comparison with the famous Saunton pink granite erratic and the giant erratic at Baggy Point, which both appear to have been sealed beneath sandrock and slope breccia before being exposed by coastal processes in the current interglacial.

The most logical explanation of these boulders is that they are "lag" features derived from pre-Ipswichian glacial deposits -- isolated following the removal of finer matrix materials.  Following the Ipswichian interglacial, they were covered by, and incorporated into Early and Mid Devensian slope breccias (sometimes cemented) and sandrock, and then later overridden by the Irish Sea ice which laid down the Irish Sea till and its related ice wastage products.   While these sediments accumulated, the position of the coastline was far away, to the west.

The "free" erratic boulders on the rock platforms around the Bristol Channel coasts could be of many different ages, but I see no evidence which might lead to them being attributed to low sea-level stillstands during MIS 3 or MIS 4.

Devon and Cornwall -- coastal erratics

 

The Giant's Rock at Porethleven. This is of a type of garnetiferous gneiss which is not found anywhere else in the UK .

Twin erratics on the rock platform near Godrevy, near Hayle.  Raised beach, sandrock and slope breccia exposed in the cliff. 

No identifiable erratics here, but this section at Portheras (about 4 km from Lands End in Cornwall) shows a beautiful exposure of the raised beach resting on the rock platform and capped by blocky slope breccia suggestive of a periglacial climate.

Thanks to David Evans and his great website for these images which he has made freely available.

https://southwestcoastphotos.com/index.html

Basalt boulder on the rock platform at Trebetherick (photo courtesy Jenny Bennett).  This rock may have come from far away, or maybe from a local source.  There is a dolerite sill nearby.