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!!

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.

Ancient cataclysmic floods -- erratics from Lake Missoula drainage events

 

A nice little gallery of erratic pics from YouTube videos on the topic of the Missoula floods.  More info here:

https://www.nps.gov/iafl/index.htm

https://volcanoes.usgs.gov/observatories/cvo/Historical/LewisClark/Maps/map_missoula_floods.shtml

https://en.wikipedia.org/wiki/Missoula_floods

The floods (maybe as many as 100 flood "events" during the Quaternary) were all cataclysmic in the best sense of the word, but naturally we know most about the latest series of meltwater outbursts at thge end of the last (Wisconsin) glacial episode.    Many of the giant erratics are well over 100 km from their source areas.  Many were incorporated in glacier ice and swept away in icebergs following the collapse of each successive ice dam -- these have many of the diagnostic characteristics of typical glacial erratics.  They are often sub-rounded or sub-angular.  But others are angular or sharp-edged, suggesting they they were literally ripped away from the bedrock by the force of the water, armed as it was with abundant fragments of glacier ice.

More on the West Kennet granidiorite mystery

Some of the coherent cobbles found at West Kennet.  They are interpreted as "corestones" or solid rock remnants which have survived while the outer parts of a boulder (or several) are weathered away.

Cunyan Crags -- a possible source area

Here is a new article on the mystery of the strange rotten granidiorite bits and pieces found at West Kennet. The article is not out yet in printed form -- it is dated as 2025.  It's a detailed paper, and although the authors (as ever) tend towards an explanation of the boulder as "yet another possible example of Late Neolithic long distance prehistoric transport" they admit to being puzzled.  Are they correct in indicating that the 77 bits have possibly all come from one boulder derived from the Cunyan Crags area of Cheviot, in Northumberland?  Time will tell.........

Of course, boulders such as this one could have been picked up by overriding ice and carried southwards -- rather like the Whin Sill erratics described by Olwen Williams-Thorpe and others many years ago. But why on earth would anybody want to collect the boulder (if it was just one) from a till exposure or from a glaciated ground surface and cart it off to West Kennet?

https://brian-mountainman.blogspot.com/2021/11/breaking-news-another-igneous-erratic.html

https://brian-mountainman.blogspot.com/2012/01/whin-sill-erratic-cluster-in-stevenage.html

https://brian-mountainman.blogspot.com/2012/04/chunk-of-whin-sill-in-london.html

"Geochemical provenancing of igneous glacial erratics from Southern Britain, and implications for prehistoric stone implement distributions" by Olwen Williams-Thorpe, Don Aldiss, Ian J. Rigby, Richard S. Thorpe, 22 FEB 1999, Geoarchaeology, Volume 14, Issue 3, pages 209–246, March 1999

http://onlinelibrary.wiley.com/doi/10.1002/%28SICI%291520-6548%28199903%2914:3%3C209::AID-GEA1%3E3.0.CO;2-7/abstract

Put this down as one of the mysterious boulders of Southern England and the Channel coasts..........

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

Rob Ixer, Richard Bevins, Nick Pearce, Duncan Pirrie, Josh Pollard, Alex Finlay, Matthew Power and Ian Patience. 2025 "Exotic granodiorite lithics from Structure 5 at West Kennet, Avebury World Heritage Site, Wiltshire, UK." Wiltshire Archaeological & Natural History Magazine, vol. 118 (2025), pp. 1–18




ABSTRACT


Seventy-seven pieces of very weathered pyroxene-bearing granodiorite corestone excavated from trenches 2, 3 and 9 within Structure 5 of West Kennet in 2019 and 2021 and varying from small pebbles to >500grms cobbles, have a total weight of 22kg. Detailed petrographical and geochemical analyses of typical samples show them to share an unusual (for Britain) and distinctive mineralogy and petrography and also suggest they are all from a single outcrop/subcrop. The essentially unaltered pyroxene-bearing granodiorite carries ‘large’ skeletal zircon crystals, which are a determinative characteristic. Petrological comparisons with similar British granodiorites show that its origin is to be found within the large, 60km and lithologically highly diverse Cheviot Igneous Complex of Northumberland, more than 450km from West Kennet. Three Cheviot samples were selected for comparative analysis, one chosen for its petrographic similarity to the corestones, as suggested by previous workers, a second, close to the first and also to significant Neolithic activity at Threestoneburn Stone Circle, and finally a third based on petrography and notable topography, namely Cunyan Crags.  Only the last sample shares a sufficient number of similarities that there warrants further investigation in that area. The corestones are highly exotic with regard to their find spot and although it is difficult to conceive of any practical use for them, West Kennet provides yet another possible example of Late Neolithic long distance prehistoric transport, a distance of between 450km if taken from outcrop and 150km if collected from secondary glacial drift sources, although North Sea coastal glacial tills as a source for the stones appears unlikely and from East Anglia very unlikely. The original Cheviot Hill location remains unidentified but is being actively sought.

The Courtmacsherry "glacial" raised beach

  I have been looking again at the evidence for the Courtmacsherry raised beach, and am still very puzzled.  The dating of it is hugely dependent upon the reliability of OSL dating, and I'm a bit worried about some of the other grounds cited for it being formed at a time of high RSL in MIS 3 or 4.  I have nagging doubts, and remain to be convinced that it is not Ipswichian in age, like most of the other raised beaches in the SW of the British Isles.

I have been reading the excellent article by Colm O'Cofaigh et al (2012), and have concerns about the following:

Extracts from p 175

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.

We suggest that high
relative sea level and the submergence indicated by the facies
sequence of raised beach deposits overlain by shallow marine sands
are related to glacioisostatic depression during ice sheet build-up on
land combined with still high eustatic sea level prior to the LGM. The
interpretation of high RSL during ice sheet build-up is consistent with
observations of erratics in the beach gravels (proposed byWright and
Muff to record deposition from floating ice) and the presence of
periglacial slope breccias interbedded with the beach and overlying
shallow marine sands.

Colm Ó Cofaigh, Matt W. Telfer, Richard M. Bailey, David J.A. Evans, 2012
Late Pleistocene chronostratigraphy and ice sheet limits, southern Ireland
Quaternary Science Reviews 44 (2012) 160-179.

First, the evidence of erratics within the raised beach gravels is NOT a ground for claiming that the beach is a cold-climate feature. Second, how do the authors know that the slope breccia is a genuine cold-climate deposit rather than one associated with rockfalls such as one sees all the time on a temperate coastline subject to wave attack?  Third, the transition from shoreline deposits to shallow-water marine deposits suggests a transgression or rising sea level, but that does not of itself prove glacio-isostasy or the advance of a glacier from the north or from anywhere else.  Raised beaches may be formed at a time of falling sea-level, or rising sea level, or indeed oscillations over a few metres over thousands of years.

The raised beach deposits are apparently devoid of organic materials -- which is a pity!  A shell fauna such as that seen in the Gower raised beaches would be rather valuable in sorting this matter out........

I'm struck by the similarity between the southern Irish sites and West Angle, at the mouth of Milford Haven.  Here there are interglacial sands, silts and clays which have been overridden and partly destroyed by advancing ice which left behind a characteristic Irish Sea till.  I have dealt with West Angle in many posts on this blog (use the search box), and I do not see any features there that might support the idea of an Early or Mid Devensian glaciation or a high RSL on the Pembrokeshire coast coinciding with a global sea-level at about - 80m. This of course implies isostatic depression of the coastline by around 80m, which in turn implies an ice load imposed by a glacier c 300 - 400m thick.  That's a big ask for the Early or Mid Devensian........

The surveyed exposure at West Angle, showing a sequence of supposed interglacial marine and estuarine deposits overlain by till.

Quaternary events on the North Devon coast

Prof Nick Stephens's map of ket Quaternary features in the South West.  Many of the features on this map are now known to be incorrect, but note Lake Maw -- centred on the Somerset Levels, withy an overflow to the south

Been looking again at this major contribution:

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

https://ussher.org.uk/wp- content/uploads/benettetal1584130v2.pdf

I think we are getting pretty close to a consensus here:

Quote:

Glaciation appears to have modified the landscape south of the Bristol Channel relatively little, although this is not surprising given that the ice from both the Irish Sea and South Wales did not penetrate far beyond the present north Devon and Somerset coast. Presumably the relatively easily deformed marine deposits flooring the Bristol Channel allowed the ice to flow along or across the valley until reaching the resistant rocks on today’s northern coast of Devon. Here, river valleys parallel to the coast and also truncated may in fact be ice- marginal landforms (Rolfe, 2015; Gibbard, et al. 2017). The BRITICE project (Clark et al., 2020) takes a broad view of the glacial limits in Britain but suggests that the pace of ice retreat from the Celtic Sea may have varied according to bed topography. In addition, Scourse et al. (2021) propose short- lived events of ice advance down the Celtic Sea that may have affected the north Devon coast and the further possibility that the ice margin had advanced as far as the shelf break at 25.5 ka.

Lake Maw is still a puzzle!  In my correspondence with Philip H and Philip G we have pondered on Lake Maw.  Use the search box to look at earlier posts.  If ice really did cross the Bristol Channel and hit up against the clifflines of N Devon and N Cornwall, in the Late Wolstonian or Late Devensian (and maybe at other times too!) then an ice barrier must have blocked the Bristol Channel and impounded a considerable meltwater lake in the Severn Estuary  -- referred to by the older workers (including Frank Mitchell and Nick Stephens) as Lake Maw.  But in that case, where are the lacustrine clays that might be expected in this lake?  

A similar lake -- Glacial Lake Teifi -- filled a broad depression in the Teifi Valley when Irish Sea ice moved in from Cardigan Bay from the W and NW.  No shorelines have been identified (which means that its surface level was anything but stable) but there are abundant laminated lake clays in many locations, as described by Fletcher and Siddle (1998) and Etienne et al (2006). At the time of its greatest extent it was more than 10 km wide and 40 km long.

doi:10.1016/j.quascirev.2005.03.019

The interesting thing about this lake is that it formed during the ADVANCE of the ice from the Cardigan bay, rather than during its dissolution.  It appears that the ice advanced over the lake deposits, creating complex structures and depositing Irish Sea till and glaciofluvial sediments as it did so,

The full sequence of events is not yet elucidated......