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Thursday, 28 February 2019

Another whale in another forest


Interesting media coverage today for a rotting carcass of a humpback whale which has been found on the Atlantic shore near the mouth of the Amazon River.  Apparently it lies about 15m inland from the shoreline, and the speculation is that the animal was very dead when it arrived, and that it was washed inland during an unusually high tide, with considerable waves washing into the forest.  

Bloggers will recall this post:


in which I speculated about the origins of a blue whale found in among the debris of the submerged forest on the Pembrokeshire coast.

At a time of rising sea-level, around 7,000 years ago, there must have been many examples of dead marine mammals being washed onto the shore and tangled up among the broken tree stumps and fallen branches resulting from the overwhelming and destruction of the forest.


Wednesday, 27 February 2019

Yet another quarry hunters' hypothesis bites the dust

Broken blocks and slabs of spotted dolerite on the southern flank of the Carn Goedog tor.  Sharp-edged fractures predominate, as you would expect in an area much affected by frost-shattering.  The shapes of these stones are quite different from the shapes of the five "Carn Goedog bluestones" at Stonehenge.


The five named spotted dolerite bluestones at Stonehenge did NOT come from a bluestone quarry.

Here is another post on the little matter of the Carn Goedog "bluestone megalith quarry" which is greatly loved by Parker Pearson, Rob Ixer, Richard Bevins and a whole host of others.

First: the latest article, which has reverberated round the world in a welter of gushing praise:

Megalith quarries for Stonehenge's bluestones
Mike Parker Pearson, Josh Pollard, Colin Richards, Kate Welham, Chris Casswell, Charles French, Duncan Schlee, Dave Shaw, Ellen Simmons, Adam Stanford, Richard Bevins and Rob Ixer.
Antiquity, Volume 93, Issue 367
February 2019 , pp. 45-62

https://www.cambridge.org/core/journals/antiquity/article/megalith-quarries-for-stonehenges-bluestones/AAF715CC586231FFFCC18ACB871C9F5E

https://www.cambridge.org/core/journals/antiquity/article/megalith-quarries-for-stonehenges-bluestones/AAF715CC586231FFFCC18ACB871C9F5E/core-reader

Do these people ever do any joined-up thinking? I have been undertaking some more fieldwork at Carn Goedog, followed by some simple desk research.

I asked myself a simple question: Could the Stonehenge spotted dolerite bluestones named in the article have been quarried at Carn Goedog during the Neolithic?

Quote: At least five bluestone pillars (Stones 33, 37, 49, 65 & 67) were taken from Carn Goedog, and probably many more (Bevins et al. 2013). The multiple and large recesses in the rock face are further evidence that pillar removal was extensive at this outcrop, even though quarrying in the early modern period has obscured evidence of pillar removal in the western part of the outcrop.

So let's check out those five "pillars" (only one is a pillar, and three might be called slabs, but let that pass for a moment) on Simon Banton's splendid web site.

http://www.stonesofstonehenge.org.uk/search/label/Stone%20067


33 -- well worn short and stumpy pillar. Rectangular section. Standing. Signs of some shaping? Spotted dolerite with whitish spots. A axis 1.68m above ground. Weight 0.51 tonnes above ground.


37 -- smallish well-rounded boulder, slightly slab-shaped and set on end. Standing. One of the strangest shapes of all the stones. Spotted dolerite with moderate spots. A axis 1.27m. Weight above ground 0.81 tonnes.


49 -- small irregular slab with quite sharp edges. Standing. Upright. Broken angled fracture at one end. Also a facet / missing chunk off one edge. Spotted dolerite with pinkish spots. A axis 1.90m, B 1.60m. C 1.80m. D1.63m.


65 — irregular elongated boulder with well-rounded edges. Recumbent. Some signs of facets? Typical glacial erratic. Axis A 0.28m. B 0.15m. Very small indeed.


67 — slightly tapering elongated pillar. Recumbent. Well rounded edges — signs of facets on the broadest end. The other end is embedded in the ground.) Axis A 0.41m. Weight 1.59 tonnes?

Now these five bluestones "taken from Carn Goedog" may indeed be made of the right sort of spotted dolerite and they might indeed have come from the Carn Goedog dolerite sill, but just look at their shapes and dimensions.  Apart from number 33, as fine a mottley collection of battered slabs and boulders as you are ever likely to see. There is no way that these were extracted fresh (with the use of wedges and levers) from a Neolithic quarry at Carn Goedog -- they are so heavily weathered and abraded, with (for the most part) rounded or well-rounded edges and corners, and even with facets quite clearly seen in the photos, that they have to be glacial erratics. They have been lying around for very much more than 5,000 years.  Forget about weights and dimensions for the moment (these are unreliable anyway) -- but there is nothing about them that suggests quarrying.  If one examines the detached blocks in the "quarry" area examined by the Parker Pearson team at Carn Goedog, there are sharp corners and relatively unabraded surfaces -- quite unlike stones 33, 37, 49, 65 and 67 at Stonehenge.

Why was this fundamental problem not pointed out to Parker Pearson by the two geologists involved in this work?  Or maybe it was, and they all thought they could get away with yet another con trick.......


I rest my case.  Another nail in the quarry hunters' coffin.


Geology references:

"Geochemistry, Sources and Transport of the Stonehenge Bluestones", O. Williams-Thorpe & R. S. Thorpe (Proceedings of the British Academy, 77, pp 133-161, 1991)

BEVINS, R.E., R.A. IXER & N.G. PEARCE. 2013. Carn Goedog is the likely major source of Stonehenge doleritic bluestones: evidence based on compatible element geochemistry and principal components analysis. Journal of Archaeological Science 42: 179–93.

Glacial features on Carn Goedog

Photo taken from Carn Alw, looking towards the hillside tor of Carn Goedog -- in the middle distance.

I spent a whole afternoon up at Carn Goedog yesterday, enjoying perfect summer weather -- in February.   That's not the way it should be, but it was truly wonderful up there.

I'm working on a new paper about Carn Goedog,  which will not please the megalithic quarrymen, but somebody has to do it........

More in due course on the geology and the archaeology (well, there isn't really any archaeology to talk of at Carn Goedog, but you know what I mean.)  But I made some careful observations on the geomorphology of the tor.

The spotted dolerite outcrops and associated "rock litter" at Carn Goedog are spread across a vast area -- around 60,000 sq m.  The tor is undoubtedly very old, and it has been denuded my many different processes over a vast amount of time -- we are talking of many millions of years.   The most obvious processes that have affected the tor during the last million years are frost-shattering and downslope slumping and collapse -- these processes are still operating, and because there are so many balanced and rocking stones on the north face of the tor one has to move about rather cautiously......  some of them might be referred to as "perched blocks".  But the most recent intensive phase of periglacial activity must have been during the 70,000 years or so of the Devensian cold phase.  (That's a long time, when set aside the mere 20,000 years or so since the cold phase ended.......)  During that time, I should not be surprised if the whole of the Carn Goedog area was buried or "blotted out" by vast snowbanks, maybe for many centuries at a time.  The shady north-facing slopes of mountain ridges  are perfect places for snow accumulation and survival.

What interests me increasingly is this question: to what extent was the tor affected by glacier ice during the Anglian, Devensian and maybe other glaciations as well?


Classic ice-moulded or scoured rock surface on the north flank of Carn Alw.  The ice action reponsible was almost certainly late Devensian.  If the moulding had been  from an earlier glacial episode, this face would by now have been covered with scree.


There are six or seven different locations on the north face of the Carn Goedog tor where we can see ice-moulded bedrock slabs.  These are always north-facing, indicating ice assault from the north.  That figures, since all of the other evidence from North Pembrokeshire points to ice movement involving the Irish Sea Glacier, from the N or NW.  I have shown some images of these undulating moulded and smoothed surfaces here:

https://brian-mountainman.blogspot.com/2015/05/ice-moulded-surfaces-carn-goedog.html



Above:  two locations where undulating ice-moulded slabs can still be seen on the northern flank of the Carn Goedog tor.


The highest of the slabs is very close to the summit of the tor, at about 950 ft (290 m), and this suggests that the whole of the tor was overtopped by ice at some stage.  That of course must have happened during the Anglian glaciation, when the ice may well have been 1,000m thick when it crossed Preseli and flowed off south-eastwards and eastwards towards the Bristol Channel and the Somerset coast.  That's when any erratics from this area must have been entrained and transported. So are the highest slabs on the tor around 250,000 years old?  We need some detailed weathering studies and cosmogenic dating to sort that out.......

But something more fascinating is that the bulk of the visible ice-moulded slabs on the north face of the tor are at or below an altitude of 800 ft (243 m).  It's quite possible that there are others above that altitude that have been buried or obliterated by rock collapse from the myriad of rocky ridges and "mini-summits" on the flank of the tor.  More detailed research may well be rewarding in this respect. But below this approx altitude of 250m it's possible that glacier ice impinging on the face of the tor has removed some boulder debris that might have masked old ice-moulded surfaces and even freshened up the surfaces themselves.

So can Devensian surfaces be differentiated from Anglian surfaces?  Again, cosmogenic dating may be required to sort it all out........

This is not the first time I have speculated about a change in the landscape and the nature of the deposits coinciding with the 250m contour.  I have suggested many times that the ice of the Devensian Irish Sea Glacier pressed against the Mynydd Preseli north face, and here are two  of my maps:



Two suggested ice limits for the Devensian Irish Sea Glacier.  The lower map -- which I now think is most likely to be reliable -- shows the Carnedd Meibion Owen ridge (and its tors) affected by Devensian ice -- but with no ice topping the main upland ridge.

It then starts to gert a bit messy when we bring the Preseli Ice Cap into the frame -- as suggested in earlier posts such as this one:


As Chris will remember from our rambling up on Banc Llwydlos back in 2016, there are apparently glacial deposits at around 340m -- but which ice body are they related to, and how do they relate to the marginal meltwater channel traces that we see right across the north Preseli landscape?  Work in progress...........


Computer generated modelling of the possible extent of an ephemeral Preseli Ice Cap during the Devensian.  (Thanks to Henry Patton and others.)

But the evidence is accumulating:

1.  The Tafarn y Bwlch moraine -- altitude between 250m and 280m.


2.  The morainic accumulation in the col to the west of Carn Goedog -- altitude  broadly similar.

3.  The ice smoothing on the northern face  of Carn Alw and on many other bedrock exposures at and below a similar altitude.

4.  Area of undulating terrain which looks like a moraine -- not far from Hafod Tydfil.  Similar altitude.

5.   Hummocky area between Carn Alw and Carn Goedog, crossed by  deep gullies and by the old drover's route.   Abundant boulders littering the surface.  Altitude c 250m.  Photo below.


My current thesis is therefore that  Carn Goedog and the rest of the north flank of Preseli has been affected at least twice by the Irish Sea Glacier.  During the first episode, around 250,000 years ago, ice flowed across the whole landscape, and even the Preseli summits were deeply submerged.  At that time, there was at least one episode of strong erosion, with the ice creating moulded surfaces on the north face of the tor and also entraining many loose slabs, boulders and elongated "pillars."   Much more recently, around 20,000 years ago, in Late Devensian times, there was a short-lived ice incursion again by the Irish Sea Glacier, during which the ice edge lay at an altitude of approx 250m on the north face of the upland ridge.  There may have been an interaction with a small ice cap centred on Preseli, but the details of this still need to be worked out.









Monday, 25 February 2019

The strange methods of the megalithic quarry-hunters


MPP and colleagues in the early stages of the Rhosyfelin dig. (Pic: Green Man Tours)
The big stone on which MPP is standing was announced (somewhat prematurely) to the world as an abandoned orthostat originally intended for transport to Stonehenge, from "the Pompeii of prehistoric stone quarries........"  By 2012 the myth machine was hard at work.



Satellite image of the hillside to the east of Carn Goedog tor.  This route, crossing the lowest col on the Preseli Ridge, has been used for millennia by travellers -- so nobody should be at all surprised if multiple traces of occupation are found.

I have dealt with this before, on a number of occasions, but once again it has come to the top of the pile of issues, in the light of the latest (2019) Antiquity article by Prof MPP and his merry gang.  The bizarre methods of the megalithic quarry-hunters might -- in another context -- cause amusement rather than concern, but we have seen in recent days how a piece of fundamentally flawed research can be "sold" to the media through a high-pressure PR campaign backed up by very carefully placed and orchestrated social media comments -- for example on Facebook and Twitter.  The media, as we have all noticed in many contexts, no longer has any concern for the truth, and lacks any instinct for checking the reliability of what they publish.  They seem to accept without question that if something comes with the name of a professor (or two, or three) attached, it is probably reliable........  Lack of scrutiny and time pressures mean that press releases are immediately regurgitated and even elaborated upon -- encouraging readers to accept as "the truth" things that have already been falsified in other media coverage weeks or months earlier!  Strange old world.........

There are three reasons why the strange "research" of the megalithic quarry-hunters should be dismissed out of hand by the science community:

1.  It is assumptive research, based entirely upon the assumption that its findings were predestined to be found correct.  On other words, the researchers have arrived on-site (at both Rhosyfelin and Carn Goedog) with a ruling hypothesis in their minds, and they have orchestrated all of their findings simply in order to "prove" it.  They have even retreated into a state of denial about the fact that the research is hotly disputed.

2.   Without apparently realising it, the researchers have attached "artificial significance" to the two sites investigated, simply because these are the sites they happen to have worked on. By the same token they have attached artificial significance to many of the features observed, assuming them to be "unique" or "significant" and apparently not asking themselves whether they are commonplace natural features not at all affected by the hand of man.

3.  They have not examined any control sites.  So again, the things that are labelled as engineering features cannot ever be demonstrated as being unique or significant, since it is never demonstrated that these features do NOT occur in other contexts.

These are three fundamental flaws in the work, which Dyfed, John and I have flagged up in our two peer-reviewed papers and which I have explored in my book.  But apparently the archaeological community is completely unconcerned.  The popular and "learned" papers by MPP and his colleagues continue to be accepted for publication, I suppose because they are deemed by editors and referees to be original and exciting -- I have seen no mention anywhere in the archaeology literature of any concerns about the methodology employed in the field.

Let's just look at these matters in a bit more detail.


Heavily abraded (and probably very old) fracture scars at the so-called "monolith extraction point" at Rhosyfelin.  No evidence has been cited by MPP and his team to demonstrate that a "bluestone monolith" was taken from here.

1.  Assumptive research.

From the very beginning, the research involving bluestone megalith sources and quarrying has been underpinned by an interconnected set of assumptions.  It was accepted (for reasons that are shrouded in mystery) that the glacial transport of bluestones from west Wales towards Salisbury Plain was an impossibility.  Therefore the stones must have been carried by human agency.  Therefore they must have been "special" of even magical.  Therefore the places that they came from must have been revered. And if they were revered, it must be possible to find them.  They must also have valued these places so highly that the stones must have been quarried, rather than just picked up, because quarrying would have been deemed an act of reverence -- with the sheer effort involved deemed to be a pleasure and a sacred duty.  The act of carrying of the stones would also have been invested with huge sacred significance -- enhancing the status of all those involved.  So it goes on -- and before we know where we are, there is a vast edifice of assumptions, speculations and fantasies piled up sky-high, blotting out the sun.
https://brian-mountainman.blogspot.com/2018/07/assumptive-research.html   
https://brian-mountainman.blogspot.com/2018/08/more-from-megalithic-quarrymen.html

One of the most deeply flawed of the assumptions made by the archaeologists is that some of the Stonehenge bluestones have been "spot provenanced" to "within a few square metres" at both Rhosyfelin and Carn Goedog.  Nothing could be further from the truth.  The geologists (Ixer and Bevins) must know that they have NO precise matches between samples from these two sites and the megaliths found at Stonehenge.  All they have is an approximate match between some fragments of "debitage" found at Stonehenge and some samples taken from the Rhosyfelin rock outcrops.  The foliated rhyolites with Jovian fabric found at Rhosyfelin also outcrop at multiple other locations that have not been sampled.  The geologists know this, but they too have been swept along on a wave of euphoria into "over-selling" their own work.  That will come back to haunt them.  By the same token, they have indications that maybe five of the spotted dolerite monoliths at Stonehenge might have come from the Carn Goedog area.  They cannot say that they have come from the tor -- and they have to accept that the dolerite sill which has a number of identified characteristics outcrops across a wide swathe of countryside between Cerrig Marchogion and Carn Alw -- a distance of more than 3 km.

http://brian-mountainman.blogspot.co.uk/2015/09/rhosyfelin-some-geological-questions.html
https://brian-mountainman.blogspot.com/2019/01/the-rhosyfelin-monolith-extraction.html

In other words, the assumption that certain bluestone monoliths MUST have come from Rhosyfelin and Carn Goedog is not supported by the published geological research, and it is fatally flawed.

Another extremely worrying feature of the research at both sites is the tunnel vision of the archaeologists in using radiocarbon dates (of which there are many) to confirm the quarrying hypothesis.  As many have pointed out, the sheer range of dates from organic materials is such that all that can be said is that there has been intermittent use of these sites from the Mesolithic to the Middle Ages.  It has not been demonstrated that this "long occupation" scenario has anything to do with quarrying, and neither is there any clustering of dates in the "right places" and "at the right time" for any confirmation of Neolithic or Bronze Age quarrying activity.  In fact, so haphazard are the dates that Prof Danny McCarrol and myself have both come to the view that the dates falsify the quarrying
hypothesis: "Those dates have now been published in the journal Antiquity and in fact they lend absolutely no support whatsoever to the quarrying hypothesis; a fair appraisal would be that they actually falsify it conclusively. Unfortunately that is not the interpretation of the authors of what is, sadly, one of the worst papers I have ever read."

https://brian-mountainman.blogspot.com/2018/05/did-antiquity-authors-conclusively.html

2.  Artificial significance.

When Dyfed Elis-Gruffydd, John Downes and I started to look at Craig Rhosyfelin during the extended dig by MPP and his colleagues, we immediately realised that they were looking at multiple natural features and interpreting them as "engineering features" indicative of  quarrying activity -- because that is what they wanted to find.  In our QN paper we described the stratigraphy and Quaternary features of Rhosyfelin, as exposed in the dig, and concluded that this is an interesting site displaying perfectly normal and predictable traces of glacial, periglacial and glacio-fluvial processes.  In our "Archaeology in Wales" paper we enumerated the features attributed to quarrying, including things referred to as an extraction recess, a loading platform, a quarrying face, a quarried monolith, a revetment, a transporting trackway, hammer stones, and elongated "railway tracks" -- just to mention a few.  We examined all of them, and found no traces of human agency.  (That having been said, we were happy to accept the traces of occupation -- including a hearth and a camping site -- as perfectly valid.)  In our paper, we accused the archaeologists of over-enthusiasm in the allocation of "engineering labels" without convincing evidence -- but we also accused them of selective citation of evidence and also of the selective removal of inconvenient rock fragments and sediments in order to enhance the "quarrying"hypothesis.  We referred to the creation of archaeological artifices at Rhosyfelin, and we stand by that accusation.  We will go further, and say that exactly the same thing has happened at Carn Goedog, as illustrated in the paper just published.  For example, in recent press coverage the Carn Goedof "loading platform" is given great prominence and illustrations of it are endlessly reproduced.  But when you look at these illustrations you will see not the slightest trace of anything that looks like a platform......... some people, I fear, seem to inhabit a fantasy world........

https://brian-mountainman.blogspot.com/2017/09/the-artificial-significance-of.html
https://brian-mountainman.blogspot.com/2015/12/bluestone-quarry-archaeologists-are.html
https://www.researchgate.net/publication/286775899_OBSERVATIONS_ON_THE_SUPPOSED_NEOLITHIC_BLUESTONE_QUARRY_AT_CRAIG_RHOSYFELIN_PEMBROKESHIRE

Rhyolite crags in the Brynberian Valley.  There has been no "control dig" in the vicinity of this crag -- and the archaeologists cannot claim "uniqueness" for anything at Rhosyfelin.

3.  Control sites.

In some ways, the failure of the archaeologists to examine control sites is the most serious condemnation and invalidation of their research methods.  They have not conducted any control digs in the Afon Brynberian Valley beneath any of the other crags (of which there are several) in order to demonstrate that Craig Rhosyfelin is unique in any way.  They have not conducted any digs adjacent to any of the other spotted dolerite tors on Preseli (of which there are many) in order to demonstrate that the platform, "monolith extraction locations", soil layers, stone arrangements and other so-called "quarrying features" are in any way unique.  I have examined many of these tors over many years, and as far as I am concerned there is NOTHING unique at Carn Goedog which points to it being either a sacred location or a site for monolith quarrying.  There is nothing significant, either, in the presence of organic materials beneath, adjacent and on top of some of the stones uncovered during the dig.  This is after all a perfect temporary camp site which must have been used by local people over many thousands of years.  It lies very close to the lowest col or crossing point on the Preseli upland ridge, and in the eighteenth and nineteenth centuries it lay on one of the most important drovers routes in West Wales.  It is virtually inevitable that there will be more traces of human occupation here than on any other of the Preseli tors up on the top of the ridge -- and this has nothing whatsoever to do with quarrying. The authors of the latest "Antiquity"paper seem to be blissfully unaware of any of this.

https://brian-mountainman.blogspot.com/2016/11/brynberian-gorge-paradise-for-neolithic.html
https://brian-mountainman.blogspot.com/2018/08/more-from-megalithic-quarrymen-2.html

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

This is all profoundly depressing -- since I cannot for the life of me work out why the points made above have not been made by other archaeologists.  The conclusion must be that they are no more aware of scientific methodology than the authors who have written these weird papers on Rhosyfelin and Carn Goedog.









Sunday, 24 February 2019

Last interglacial sea-levels


Raised beach of cobbles on St Agnes, Isles of Scilly.  This one is not far above HWM.  How old is it, and to what extent has it been modified post-deposition?


A commonly reproduced sea-level curve for the "stage 5" interglacial and the glacial episodes before and after it.  The new research suggests that following the "highstand" at the beginning of the interglacial, sea-level stabilised for maybe 10,000 years or more after that at a slightly lower level -- without violent oscillations.


Some important new material relating to the fixing of sea-levels during the last interglacial -- assumed to be the period during which most of the raised beach deposits (of which we speak quite often on this blog) were formed.  Essentially, this new research suggests that sea-level might have been 6m above present MSL in the early part of the interglacial (coinciding with major ice-sheet melting); that it then stabilised at around +2m for the rest of the interglacial; and that it then started to fall to its lowest level of -126m at the peak of the last glacial episode.

Of course, this does not necessarily give us a foolproof relative sea-level curve for West Wales and the Celtic Sea arena, since isostatic factors always come into play.  Even the weight of water flooding into the Celtic Sea will have had the effect of depressing the crust, leading to a greater than expected relative sea-level rise.  And delayed isostatic responses related to the addition and removal of ice loads will have complicated things further.  But gradually things become clearer.........

What we do NOT have here is information about earlier interglacial sea-levels -- ie those that might have influenced the cutting of the rock platforms which are almost certainly composite in age.

but I'm flagging this up again because of the current interest in raised beaches and their ages.

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

The main points of the new research:

The last glacial interval (which we refer to as Devensian, Weichselian or Wisconsin) was about 20,000 years ago, and sea level was about 126 meters (413 feet) below modern sea level at that time.

Turning to the Last Interglacial (Ipswichian):

"Globally, the climate was warmer by 1 to 2 °C during the part of the Last Interglacial Period referred to as Marine Isotope Stage 5e (MIS-5e) between 127,000 and 116,000 years ago," said Victor Polyak the first author and co-principal investigator and senior research scientist in the UNM Department of Earth and Planetary Sciences. "While this is a well-studied period, we still do not know the exact behavior of sea level during MIS-5e. What we know for certain is that sea level was higher when climate was 1 to 2 °C warmer 120,000 years ago.

"This is the most accurate, best resolved sea level record for MIS-5e of the last interglacial period," said Polyak. "It provides exceptionally accurate timing of the sea level history during the above mentioned period and shows that it rose to 6 meters above present sea level ~127,000 years ago, it would have gradually fell to 2 meters by 122,000 years ago, and would have stayed at that elevation for the remainder of the sea level highstand to 116,000 years ago," says Onac.

Article:
Victor J. Polyak, Bogdan P. Onac, Joan J. Fornós, Carling Hay, Yemane Asmerom, Jeffrey A. Dorale, Joaquín Ginés, Paola Tuccimei, Angel Ginés. A highly resolved record of relative sea level in the western Mediterranean Sea during the last interglacial period. Nature Geoscience, 11, 2018 (10 Sept); pp 860-864.



Abstract

The magnitude and trajectory of sea-level change during marine isotope stage (MIS) 5e of the last interglacial period is uncertain. In general, sea level may have been 6–9 m above present sea level, with one or more oscillations of up to several metres superimposed. Here we present a well-dated relative sea-level record from the island of Mallorca in the western Mediterranean Sea for MIS-5e, based on the occurrence of phreatic overgrowths on speleothems forming near sea level. We find that relative sea-level in this region was within a range of 2.15 ± 0.75 m above present levels between 126,600 ± 400 and 116,000 ± 800 years ago, although centennial-scale excursions cannot be excluded due to some gaps in the speleothem record. We corrected our relative sea-level record for glacio-isostatic adjustment using nine different glacial isostatic models. Together, these models suggest that ice-equivalent sea-level in Mallorca peaked at the start of MIS-5e then gradually decreased and stabilized by 122,000 years ago, until the highstand termination 116,000 years ago. Our sea-level record does not support the hypothesis of rapid sea-level fluctuations within MIS-5e. Instead, we suggest that melting of the polar ice sheets occurred early in the interglacial period, followed by gradual ice-sheet growth.

Saturday, 23 February 2019

Twitter Revamp



If there are any Twittering people out there, herewith a notification that I have revamped my Twitter Bluestones page and reactivated it following some confusion over user names etc.   This is where you can find it:

https://twitter.com/Bluestone4/with_replies

As you might expect, I am using it to go after those charlatans who keep on regurgitating all that nonsense about Stonehenge bluestone quarries and who do not even have the guts to accept and place it on record that there is a dispute going on in regard to the nature of their "evidence."

Thursday, 21 February 2019

Carting the stone


This is a delightful painting which somebody put on Twitter.  Forget who the artist was -- but apparently it dates from 1894, and shows a large slab of quarried stone being carried to somewhere where it will be used.  

Splendid horses and harnesses, splendid cart with extremely sturdy wheels, and an excellent roadway.     Nice gentle terrain too.  Around 5,000 years earlier, things might have been a tad more difficult......

Wednesday, 20 February 2019

The "megalith quarries" -- how fake news proliferates


This is just a snapshot of what comes up on doing a Google news search for "megalith quarries".  I haven't tried to reckon how many web sites, newspapers and magazines have picked up on the press release pushed out by Antiquity, UCL and maybe other institutions as well.  But there may well be hundreds of them worldwide, just three days after the article was "published online" (although it has been in circulation since last August).

It's actually quite frightening how gullible these media outlets are.  Many of them have simply regurgitated the press release as they received it.  Others do a bit of tweaking.  Others employ a house journalist or a guest writer to re-hash the contents.  Others seize the opportunity to do a piece of "extended coverage" which incorporates lots of bits and pieces (including maps and photos) from past articles about Stonehenge.   Nobody -- NOBODY -- does any scrutiny, and I would not mind betting that none of these pieces is actually based upon a careful reading of the article itself.

The assumption is that if the article is written by a senior professor and his colleagues, it must be reliable. Furthermore, if it is published by a "reputable" journal like "Antiquity" it must be even more reliable...........  but what the media outlets and the journalists clearly do not realise is that THERE HAS BEEN NO CAREFUL SCRUTINY of the manuscript either by the Editor or the referees who might have looked at it.  (We know that there has been no scrutiny, because if there had been, the authors would have been forced to acknowledge that their evidence is disputed -- and they would have been forced to deal with the criticisms levelled at the "quarrying evidence" by Dyfed, John and myself and by others.)

So this appalling article, full of unsupported assertions and flights of fancy, is accepted as "the unchallenged truth" by the mainstream media, without any questioning at all.  And MPP and his mates, guilty as charged with scientific malpractice, are allowed, yet again, to get away with foisting fake news on the gullible public.  Who needs Merlin, aliens and spacecraft when you can have magic stones from Wales and wild tribes from the west bearing gifts?

It would all be hilarious if it were not so serious.........

Somebody asked me not so long ago why I don't defer to these senior academics and offer them more respect.  I told them that I only offer respect to those who earn it by accepting, in print, that their ideas are disputed, and by addressing the evidence and the interpretations of those who challenge their assumptions.  It's called academic debate.

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

PS.  A lot of people are reading this article right now --  total reads over a thousand now.  Strange that MPP and his friends still fail to have noticed it.....

https://www.researchgate.net/publication/286775899_OBSERVATIONS_ON_THE_SUPPOSED_NEOLITHIC_BLUESTONE_QUARRY_AT_CRAIG_RHOSYFELIN_PEMBROKESHIRE








Tuesday, 19 February 2019

Yet more on the "quarries"-- scientific malpractice unrestrained



Here we go again......... more media coverage arising from the same old non-story.  The gullibility of the media knows no bounds. This "new" article was published on 18th February, and of course the "exciting" new idea of the A40 bluestone transport route is heavily featured in The Guardian and elsewhere. Free public access to the paper is here:

https://www.cambridge.org/core/journals/antiquity/article/megalith-quarries-for-stonehenges-bluestones/AAF715CC586231FFFCC18ACB871C9F5E/core-reader

The most despicable thing about this paper -- and here I blame both the authors and the editor of "Antiquity"  -- is that there is no mention of the dispute about the origins of the "quarries" and no citation of the two "inconvenient" peer-reviewed papers by Dyfed Elis-Gruffydd, John Downes any myself that were published in 2015.  The authors know all about them.  They have never questioned the reliability of either our observations or our conclusions -- and yet they have wilfully ignored the research, in order to bolster the false premise that the quarrying ideas are unchallenged.  That is scientific malpractice, pure and simple -- and it is hardly credible that the community of academic archaeologists allows these people to get away with it.  Do they really think that their reputations are enhanced by such behaviour?   What do their own departmental colleagues and their students think?  What does English Heritage think?  What do the research funding bodies think?  I wonder.........  

This paper has been floating around for some time, and I have dealt with it in detail already:

https://brian-mountainman.blogspot.com/2018/08/more-from-megalithic-quarrymen-3.html
https://brian-mountainman.blogspot.com/2018/08/more-from-megalithic-quarrymen-2.html

As I said back in August:

So does this new paper move things forward, and give us the solid material we have been waiting for? Sadly, no. This is another flimsy piece of assumptive research, in which the central hypothesis (namely that there are Neolithic bluestone quarries in Pembs, used for the extraction of Stonehenge megaliths) is never questioned. It is simply taken as read by the authors (all 11 of them) that there are Neolithic quarries at Rhosyfelin and Carn Goedog, and that there is no need to convince their readers of the correctness of their assumptions. This demonstrates extraordinary arrogance on the part of the authors, and it also demonstrates an almost complete lack of editorial scrutiny on the part of a serious academic journal. What does this tell us about the state of British archaeology? That's a question for another day.......

Please, dear God, when is this nonsense going to come to an end?

I also said this, and assume that somewhere there must be an archaeologist who took note of it:

This paper is so seriously defective, in almost every respect, that I find it bizarre that it ever found its way into an academic journal published by Cambridge University Press. It is not a research paper; it is piece of unabashed marketing. I have asked this before, and I ask it again -- where is the scrutiny from within the archaeological establishment? How is it that so many serious and senior archaeologists -- and two senior geologists -- have allowed their names to be attached to it as co-authors?

And the most serious issue of all. If I, as a local person with a detailed knowledge of this site and with an academic background, had not been around at this moment in history, and had not been able or willing to look at the excavation site and to scrutinise the research output from the MPP team, everything in this article would have been accepted as THE TRUTH. Just think about it..........

And think about this. If this is the level of non-scrutiny applied to Rhosyfelin and Carn Goedog, how many other British archaeological sites are there which have been wildly misinterpreted and which have had nonsensical narratives attached to them?

Rhetorical questions, I know. But sometimes they are needed. Actually, rhetorical questions don't need answers. Maybe these questions do.

There are plenty of sensible archaeologists around. But when are they going to speak up? Quite seriously, if they do not, archaeology will become a standing joke.


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

Megalith quarries for Stonehenge's bluestones
Mike Parker Pearson , Josh Pollard , Colin Richards , Kate Welham , Chris Casswell, Charles French, Duncan Schlee, Dave Shaw, Ellen Simmons, Adam Stanford, Richard Bevins  and Rob Ixer
Antiquity, Volume 93, Issue 367
February 2019 , pp. 45-62

ABSTRACT
Geologists and archaeologists have long known that the bluestones of Stonehenge came from the Preseli Hills of west Wales, 230km away, but only recently have some of their exact geological sources been identified. Two of these quarries—Carn Goedog and Craig Rhos-y-felin—have now been excavated to reveal evidence of megalith quarrying around 3000 BC—the same period as the first stage of the construction of Stonehenge. The authors present evidence for the extraction of the stone pillars and consider how they were transported, including the possibility that they were erected in a temporary monument close to the quarries, before completing their journey to Stonehenge.

There is a reference to the "Millennium Stone" fiasco, no doubt designed to discredit the "sea transport" hypothesis and bolster the A40 hypothesis:

https://www.telegraph.co.uk/news/uknews/1343999/Stonehenge-dream-is-sunk-by-the-Millennium-jinx.html

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

These are the two 2015 articles -- both carefully edited, peer-reviewed and revised in line with referees' comments -- which Parker Pearson and his colleagues apparently cannot bring themselves to read, let alone cite or discuss in print.

https://www.academia.edu/19788792/Quaternary_Events_at_Craig_Rhosyfelin_Pembrokeshire
Brian John, Dyfed Elis-Gruffydd and John Downes (2015a) "Quaternary Events at Craig Rhosyfelin, Pembrokeshire." Quaternary Newsletter, October 2015 (No 137), pp 16-32.

Brian John, Dyfed Elis-Gruffydd and John Downes (2015b)  "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_

Sunday, 17 February 2019

The Devil's Stone at Shebbear


I just came across this wonderful photo by James Ravilious of the turning of the Devil's Stone at Shebbear in Devon. A little reminder that there are erratic boulders in the strangest of places.......

Flights of fantasy re the Stonehenge stones


Katy Whitaker:
WHAT IF NONE OF THE BUILDING STONES AT STONEHENGE CAME FROM WILTSHIRE? 
OXFORD JOURNAL OF ARCHAEOLOGY 2019

Many thanks to Katy Whitaker for sending me, on request, her paper recently published in the Oxford Journal of Archaeology.  She knows I'm going to criticise it rather energetically -- so all credit to her!

Anyway, as I expected, it's a rather strange piece of work, and it's difficult to know whether it is
serious in its intent, and whether Katy actually believes what is now in print. It was intended to challenge accepted theory, and in her Acknowledgements she describes how the gauntlet was thrown down:

In 2016, the conveners of the third Neolithic and Early Bronze Age Research Students’ Symposium threw down a gauntlet. The provocation, ‘Anarchy in the UK?’, challenged speakers to construct alternative pasts diverging from, disrupting, or inverting, linear narratives of social evolution in the period c.4000 cal BC–c.1500 cal BC. This paper resulted from that challenge. This work was supported by the Arts and Humanities Research Council (grant number AH\L503939\1) through the South, West, and Wales Doctoral Training Partnership.

All that having been said, this is now a paper in a learned journal, and it should have been  subject to proper review.  Frankly, I'm amazed that it has found its way into print, and that the Editor and referees have not insisted on much tighter writing and much more careful consideration of a wide range of points.  Throughout the text there are unsupported assertions and an apparent lack of appreciation of what exists in the literature.  Perhaps I should not be too surprised -- I have complained before that for some journals the practice of peer review seems to have been abandoned.

I'll refer to the paper in more detail in another post, but  on an initial reading I'm struck by the following:

1.  In following up her argument that the Stonehenge stones -- of all sorts -- were "chosen" or "selected" because of their special properties (colour, size, shape, texture) or because they were from special localities, Katy seems to lump all bluestones together as "igneous", and does not  adequately consider the wide variety of rock types (including soft and flaky "rubbish stones") that come under the "bluestone" label.

2.  She does not consider why the "special" bluestones brought to Stonehenge are not supplemented by other "special" stones from  all other compass directions -- for example Old Red Sandstone megaliths from the Brecon Beacons or igneous monoliths from the Welsh Borders, or granite monoliths from Cornwall, or sandstone blocks from the east.

3.  She completely ignores (I think we can probably say "wilfully ignores") the work of Kellaway, Williams-Thorpe,  and others of us who have argued that the glacial transport of monoliths and smaller rock fragments eastwards from Pembrokeshire by the Irish Glacier is not just possible but probable. There is not a single citation of any work that happens to be "inconvenient" to the central hypothesis; that is extraordinary, and I am amazed that the Editor and the referees of this paper allowed the author to get away with it.  Quote: Possible glacial explanations for the presence of bluestone in Wiltshire have been firmly contradicted on a number of grounds (Darrah 1993; Green 1973, 1997; Pitts 2000; Bevins et al. 2016).  This is the full extent of the discussion of the possible role of glacier ice......

4.  The author ignores, as far as I can see, the increasingly commonplace view (expressed by David Field and others) that the collection of stones of all types was a rather utilitarian matter with no great mystical or spiritual component attached.  In other words, the builders of Stonehenge used whatever stones they could gather, from close at hand wherever possible.

5.  The author does not mention the other view, which is gaining currency,  that the builders of Stonehenge ran out of stones (or energy, or motivation) and that the monument was never finished.

6.  In arguing that the re-use of some stones at Stonehenge indicates that such stones were specially revered (having come from older sacred monuments) the author fails to consider the much stronger likelihood that stones were re-used simply because there was a stone shortage.

7.  Interestingly, Katy gives quite detailed consideration to the packing stones, mauls and hammer stones found at Stonehenge, and suggests that these too were carefully selected because they held "significance".   There is some very useful material here, to which I shall return. But again she fails to consider what natural processes might have  led to the introduction of these materials into the neighbourhood.

8.  The author accepts without question that the "identification" of a bluestone quarry at Rhosyfelin by MPP et al is correct -- without any recognition that the quarrying hypothesis is hotly disputed in the peer-reviewed literature.



The final sentence of the paper summarises the central hypothesis:
If none of Stonehenge’s building stones came from Wiltshire, but were contributed over time in a series of collaborative undertakings by varied groups of people from far and wide, then the monument might typify social differentiation as the outcome of, rather than the precursor to, prehistoric monument building.

This is of course extremely fanciful -- and maybe a little tongue-in-cheek -- but the paper gives us an insight into the fantasy world inhabited by many modern academic archaeologists who apparently have no appreciation whatsoever of natural processes, and who apparently have no wish to find out more.  There seem to be rather a lot of people out there who have no particular wish to disturb, let alone abandon, what the infamous Dr Kurding called "the ignorance of a lifetime".





Saturday, 16 February 2019

Drangajökull and Kaldalon, NW Iceland


Ever since Dave Sugden and I worked in the valley of Kaldalon in NW Iceland in 1960, I have been fascinated by Drangajökull, the ice cap that dominates the plateau to the NE of the valley.  For very many years the ice cap has been shrinking, and is destined to go the way of Glamajokull, which used to exist on another segment of high plateau on the western side of Isafjardardjup.

In recent years there has been more work on the ice cap, and I culled a few images from the new papers.  The ongoing shrinkage is inexorable, and all down to climate change -- and the glacier snouts (three of them) are just the most obvious places to look at what is happening.  Up on the plateau, the ice edge is retreating year on year, and the above map shows how the old "subglacial surface" is gradually being exposed.


A recent satellite image of the ice cap, with the Kaldalon trough visible top right.  To the left of centre are the small outlet lobes and glaciers of the Reykjafjördur - Leirufjördur area.


The nunataks on the skyline are on the NE side of the ice divide.  This photo was taken in the Reykjafjördur valley.


Another reconstruction of the ice cap as it appears today.


It's interesting that a small and vulnerable ice cap like this one has outlet glaciers that are liable to surging behaviour.  The 1750 position of the ice front in Kaldalon appears to have been located not far from the massive terminal moraine that almost blocks the valley. That big moraine has now been dated to the Younger Dryas.  The 1750 position was possibly the outermost glacier position of the "Little Ice Age".  Fragments of a smaller moraine (which we mapped in 1960 and which is referred to as Moraine 1 by Brynjolfsson et al, 2015) may have been constructed during the stillstand following a powerful surge, during which the ice flowed across fertile land that had been previously farmed.   At any rate, since 1760 the glacier has retreated several kilometres as far as the trough head, which is nowadays partially exposed, with the overall retreat disturbed by several recorded short-lived advances which must be interpreted as surges.   This has coincided with a halving of the extent of Drangajöll, down to 262 sq km.





Glacier snout positions in the Kaldalon trough, as reconstructed by Brynjolfssson et al, 2015.  The snout position coincides with a substantial "valley-side esker" and a ridge of lateral moraine;  inside the snout position is an extensive area which we referred to in 1960 as "The Trout Pools" -- essentially a wide expanse of pitted outwash, representing the meltout of detached ice masses during a period of rapid ice edge retreat.




The most substantial surge occurred in 1994-99, when the snout advanced by 1 km -- with a similar surge recorded in the Leirufjördur valley.  That's an advance of 200m per year.


The surging behaviour of these glaciers ins intriguing, given the overall poor state of health of the ice cap itself.

Below are some Kaldalon images culled from the web, with thanks to the photographers.  A magical place -- and it was even more magical in 1960, before the building of the road and the bridge.












A bit of fun from 1983........




Geomorphologists are (in public, anyway) quite a serious lot, and it's not often that they let their hair down and poke fun at each other -- so it was an opportunity not to be missed when the then Editor of GEOPHEMERA (the Newsletter of the British Geomorphological Research Group) agreed to publish this in 1983, in Vol 29 (July 1983, pp 28-31).  In the piece, I take affectionate digs at a great many of the famous geomorphologists of the day, and most of them (not all!) were quite amused when they read it.  Geomorphologists will get most of the jokes, and it will all be nonsense to everybody else........

Click to enlarge.


Raised beach cobbles contained in till

The till exposure at Popplestones on the Isle of Bryher.  Well-rounded raised beach cobbles are incorporated in the till.

Clifftop till near Flimston in Pembrokeshire.  Here the till incorporates vast numbers of white quartz pebbles which are well rounded.  They come in this case from ancient unconsolidated Oligocene clays and pebble beds that were once widespread on the Flimston coastal platform.

One of the interesting features of the glacial sequence in the Isles of Scilly is the occurrence of raised beach cobbles in Devensian till.  This feature is especially notable on the island of St Agnes (which of course lies to the south of the Devensian ice limit according to other authors), where the till is thin and patchy and confined to the west coast.  The till at Popplestones on Bryher also contains many rounded and striated cobbles that must have been incorporated into till by ice that rode over pre-existing raised beaches or storm beaches.

Is this so unusual as to cause a problem?  Well, if you look into the older literature on the Quaternary deposits of Devon, Cornwall and the Scilly Islands there is much discussion about "redeposited till" and "till in a secondary position"  -- and one gets a feeling that researchers have in some cases been reluctant to  accept that ice picks up, rather indiscriminately, loose materials from any deposits that it happens to pass over.  So till containing rounded pebbles is sometimes interpreted as very ancient, disaggregated and then reconstituted downslope after incorporating raised beach pebbles as a consequence of periglacial downslope movement under gravity.  That line of reasoning can become very convoluted and very arid -- ignoring the fact that the simplest explanations for things are often the correct ones.

If you find a till containing raised beach cobbles the simplest explanation is that the raised beach was there first (somewhere upglacier) and that the till came later.  In the case of the Isles of Scilly, the reasonable interpretation is that the raised beach is Ipswchian and that the till is Devensian.

https://www.researchgate.net/publication/328413421_Evidence_for_extensive_ice_cover_on_the_Isles_of_Scilly/figures?lo=1

In 1965 - 66 David Sugden and I were initially quite mystified by the occurrence of striated and rounded raised beach cobbles in till at multiple locations in the South Shetland Islands. We found fresh marine cobbles in till in 19 different locations, on six different islands in an area where there was still much lying snow across the landscape;  so there must be many more undiscovered locations also.   The till exposures were found at many different altitudes, up to an altitude of 275m.  One of the interesting things about the pebbles and cobbles contained within the till was that a large proportion were "fresh" and unaffected by frost shattering -- unlike many of the pebbles in the higher raised beaches on the ice-free peninsulas.

Detail of residual raised beach materials found in an area of fresh till.  The survival of these cobbles and pebbles suggests that the affected raised beach was not exposed to intense periglacial weathering (or frost shattering) conditions for very long before being overriden by glacier ice. Barton Peninsula, King George Island, at 150m above sea level.

On Barton Peninsula we observed this patch of more or less undisturbed raised beach at an altitude of c 150m, surrounded by fresh till and frost-shattered slope breccia.

In our interpretations of the cobbles in the till we had no problems at all with our basic interpretations of processes and relative ages -- but we were initially quite concerned about finding raised beach traces at 275m (902 ft) -- far higher than any other raised beaches ever found in Antarctica.  At last our conclusion was that the extraordinary high altitude had something to do with the isostatic forebulge effect, with the sites around the South Shetlands lifted by a considerable amount as the ice mass over the Antarctic Peninsula and West Antarctica  expanded and depressed the crust further south.




The lesson from all of this?  If you find raised beach cobbles contained within a till, the standard rules of stratigraphy apply.   If the till looks fresh and undisturbed, it is probably in its original condition and position. The raised beach that provided the cobbles to the overriding ice must be older, and must lie either in the immediate vicinity or an unknown distance up-glacier. That should not be a problem for anybody.