Some of the ideas discussed in this blog are published in my new book called "The Stonehenge Bluestones" -- available by post and through good bookshops everywhere. Bad bookshops might not have it....
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Tuesday, 17 July 2018

The shallowing of the Baltic

Isostatic uplift following a glacial episode is difficult to comprehend — but in the Baltic region the changes brought about can easily be appreciated during a single lifetime.  In the Stockholm Archipelago the rate of uplift has fallen off, but the land is still rising from the sea at a rate of about 5 mm per year.  That’s 5 cm per decade, and 25 cms over 50 years.  When I first built this magnificent jetty the water was quite deep enough to moor our rowing boat alongside under all conditions, given the rises and falls of water level in line with pressure changes and changes of wind direction.  Now, however, the water is too shallow to moor the rowing boat alongside, and algal blooms have made the water quality very poor as well.  This in turn leads to increased rates of sediment accumulation, and already the sound between the mainland and our little island just offshore is occasionally devoid of any water at all, particularly during the winter.

The only consolation is that as isostatic uplift continues, the size of our little piece of real estate gets bigger every year!

Monday, 16 July 2018

The “false stone” near Everleigh

Thanks to Phil Morgan for this bit of interesting information.  He has been looking at a book by John Ogilby who was appointed "His Majesty's Cosmographer and Geographic Printer” in 1674.   In 1675 he published maps of England, and one of these maps ( p 85 of the book) shows the route from Salisbury to Camden.  The route is read from the bottom to the top of the first (left-hand) strip, and then continues to the bottom and then to the top of the second strip and so on. To the north of the village of Everley (now spelt Everleigh) (SU 2069 5434) Ogilby shows 'false ftone' with a small standing stone symbol (circled red on map), alongside the old road.

On the current OS map the location is recorded as 'Falstone Pond', possibly a corruption of False Stone Pond. Phil wonders, quite reasonably, about the origin of the stone in the middle of a chalk downland landscape.  If the stone was called the False Stone in antiquity would that, perhaps, indicate that it is foreign to the locality and was either deposited there by glacial action, or dumped there by disgruntled neolithic stone shifters? 

Does anybody know anything about this old stone?

The moraine at the Ness of Brodgar

Quote: “This is the temple complex of the Ness of Brodgar, and its size, complexity and sophistication have left archaeologists desperately struggling to find superlatives to describe the wonders they found there. “We have discovered a Neolithic temple complex that is without parallel in western Europe. Yet for decades we thought it was just a hill made of glacial moraine,” says discoverer Nick Card of the Orkney Research Centre for Archaeology. “In fact the place is entirely manmade, although it covers more than six acres of land.”

There is renewed interest in the Ness of Brodgar, on which extensive excavations have been going on for some years.  We have covered this site before — use the search facility and look for “Orkney” and “Ness of Brodgar”.  

Our friend Nick Card is fond of saying things such as those quoted above — and while he acknowledges the fact that this is glaciated terrain (across which the Devensian ice flowed from south-east towards north-west) it is patently absurd to suggest that the whole of the Ness is man-made.  This is a moraine ridge with a Neolithic complex of buildings built on top of it.  It’s wonderful enough as it is, without the need for all this hyperbole.........

Saturday, 14 July 2018

Why do people believe what they are told by senior academics?

This is a rather interesting article from the BBC web site, addressing the question of why people in general do not choose to stand up to authority.  Why do they do what they are told to do, even when their actions may cause harm and even though they may be morally questionable?  In parallel we have the questions of belief — why do people tend to believe what they are told by authority figures such as politicians, civil service people, policemen or, dare we say it, senior academics?  Of course, the authority figures love it when people defer to them and accept what they say, or do what they are told to do — it butters up their egos and increases their sense of self-esteem.  But most people follow instructions anyway — for very complex reasons.  One of those reasons is sheer laziness — people cannot be bothered, in this complex world, to work things out for themselves, so they defer instead to “experts” or authority figures who can — and willingly do — take on the job of doing the thinking on their behalf.

I find this rather interesting because of the response I have come across occasionally at my talks when I apply close scrutiny to the “findings” and assumptions of the quarrymen.  It’s not unusual for people (and, of course, the media) to accept what they are told by MPP and his merry gang because they are senior academics who are asssumed to know exactly what they are talking about and who should, in the nature of things, be deferred to or respected.  In contrast, I can safely be dismissed as a
nutter because I am NOT a senior academic.  Once or twice, I have even had members of an audience expressing outrage:  “It’s disgraceful that you should question the motives and the quality of research of these senior archaeologists!  After all, archaeology is their field, and they are trained to know exactly what they are looking at.  And they would never knowingly put into print anything that might be questionable!”  In this way I am made to feel like a party pooper, spoiling all the fun — and as the BBC article points out, it is easy to impose a sense of guilt on anybody who does NOT defer to authority and who, because of his or her independent or defiant attitude, makes life difficult for those who would set the agenda and tell the rest of us what to think and how to behave.

Interesting stuff.  So should I go with the crowd, and accept everything I see in print?  I think not, even if it means upsetting those who tend to defer to authority.  I was taught to think for myself, to apply scientific method, to apply scrutiny (and a degree of healthy scepticism) to the research work of others, and to follow academic convention in presenting and analysing evidence.

In this era of false news and alternative truths, these old standards (that were drummed into me in
Oxford and which I tried to drum into my own students in Durham) are more important than ever.  So, ladies and gentlemen, feel free to stand in front of the tanks, go nose to nose with those who are bigger and stronger than you are, and think for yourself if you wish to maintain any sort of dignity.

A very closely related issue is that of the “naked emperor syndrome” — where, according to the old story, everybody bowed and scraped, and pretended that the Emperor was fully clothed, until somebody brave enough or innocent enough said: “Look, the Emperor has no clothes!”    We are not talking about the personalities of particular individuals here, but about human nature......

Wednesday, 11 July 2018

The dressing of the bluestones

I have been pondering on the dressing of the bluestones.  As we all know, of the 43 bluestones at Stonehenge, those in the bluestone circle are undressed, and are best described as an assortment of boulders which appear to be in their natural state — greatly abraded and deeply weathered, and of many different lithologies.  These characteristics are conveniently ignored by the quarrymen who, by all accounts, want them all to have been quarried from Carn Goedog, Rhosyfelin and presumably from another twenty or so quarries as yet undiscovered.

Turning to the bluestones in the bluestone horseshoe (or oval), we see stones that are more obviously shaped.  Six of them are pillar-shaped, and their shapes are of course used by those who oppose the glacial transport thesis and who argue for human transport.  “It is quite impossible,” they say, “for stones with these shapes to have been carried for 200 km or more by glacier ice.”  There is weight to this argument, for although there are plenty of elongated glacial erratics known from around the world, glacial transport processes, whether in the ice, on the ice or beneath the ice, would tend to break up stones whose length is up to five times their width or depth.  So the natural conclusion might be, if you are a believer in the “glacial erratic” hypothesis, that the shaping of the stones was done at the Stonehenge end rather than in the stone source area.  There has of course been much debate about this; some have argued that it would make no sense for “undressed pillars” to be transported by Neolithic argonauts all the way from Preseli to Stonehenge, if the fellows involved knew that much of the weight of the stones would be got rid of on arrival.  No, goes the argument — the stones must have been shaped in the quarries where they came from, and then carried in their dressed state. Economy of effort an all that......

So we come to the Stonehenge Layer and the debitage which — to their great credit — Rob Ixer and Richard Bevins have concentrated upon in many of their papers.  Look up “debitage” on this blog and you will find many entries and much discussion.  Ixer and Bevins have concentrated in recent years on the “non-spotted-dolerite” material, because it is inherently more interesting although it is less abundant.  Because much of the debitage studied (all from the 50% or so of the stone setting area that has been investigated) does not apparently come from known standing stones, the thinking goes that it must have come from “unknown standing stones” which have been destroyed.  This conveniently slots into the argument that there were once 80 or more bluestones on the site and that almost half of them have been taken away or systematically destroyed over a long period of time.  We know from written records that Stonehenge has indeed been used as a quarry in historical time, and there is also some evidence, as Olwen Williams-Thorpe and her colleagues have pointed out, of certain stones being used for the manufacture of axes and other tools.

Now take a look at this very influential article from Aubrey Burl.......

What if the bulk of the debitage and the Stonehenge Layer has not come from stone setting destruction at all, but from the much earlier period of stone setting CONSTRUCTION?  I know no no evidence that might contradict this thesis.  As I have argued in my book, the most parsimonious explanation of the bluestones and the related debitage at Stonehenge is that the monument was built more or less where the stones were found; that a recumbent Altar Stone might have determined the location; that much of the debitage (and maybe some of the packing stones and hammer stones) came from the breaking up of “inconvenient” smaller glacial erratics; that there never were many more than 43 bluestone monoliths on the site; and that the known shaped dolerite monoliths in the bluestone horseshoe were shaped on the site from larger blocks of dolerite that were dumped in the vicinity at the end of the Anglian Glaciation. Again, economy of effort.....

I know that this contradicts the interpretation of Ixer and Bevins, writing in “Chips off the Old Block” and other papers —  but it makes a great deal more sense.

Monday, 9 July 2018

A spot of book bombing.....

Don’t blame me for this — Tony has been up to his mischief again!  Nice pic of Prof Michael Wood at a recent lecture and signing session in Frome, with a copy of a certain well-known book on his desk.  Anyway, I hope he reads it and goes on to buy the new one........

Saturday, 7 July 2018

Assumptive research

This is called (by the archaeologists) a ruined revetment or dry stone wall, used for loading bluestone monoliths onto sledges or rafts before they were shipped off along a “hollow way.”  That is the assumption.  Geomorphologists, on the other hand, see clear evidence of glacial and fluvioglacial processes that have been at work in a chaotic dead-ice environment.  What is the truth?

This is a quote from a recent letter received from Brian Roberts, one of my old colleagues in the Durham University Geography Department.  He says: “Assumptive research’ is more common than one might expect … and embedded assumptions create vast barriers, dams, holding up research … YET flexibility is unwelcome.....”

This is what somebody at the University of Louisville says about assumptions in research: “An assumption is an unexamined belief: what we think without realizing we think it. Our inferences (also called conclusions) are often based on assumptions that we haven't thought about critically. A critical thinker, however, is attentive to these assumptions because they are sometimes incorrect or misguided. Just because we assume something is true doesn't mean it is.”

This is advice to research students:  “Think carefully about your assumptions when finding and analyzing information but also think carefully about the assumptions of others. Whether you're looking at a website or a scholarly article, you should always consider the author's assumptions. Are the author's conclusions based on assumptions that she or he hasn't thought about logically?”

Another quote:

A good hypothesis statement should conjecture the direction of the relationship between two or more variables, be stated clearly and unambiguously in the form of a declarative sentence, and
be testable; that is, it should allow restatement in an operational form that can then be evaluated 
based on data.  Generally, an assumption refers to a belief. An assumption does not require any evidence to support it. It is commonly based on feelings or a hunch. 

Could it be that the profound differences of opinion and “research behaviour” which come out of my spat with the archaeologists over “the bluestone quarries” are explained by the different research cultures that exist in the sciences and the social sciences?  In science there is the presumption that everything is observable and/or testable, and that hypotheses must be used because (although you hope that they are true) they are falsifiable.  Karl Popper has always been the hero for many of us with science backgrounds.  On the other hand, in the social sciences there is the little matter of human behaviour to be taken into account — and human behaviour, as we know, is sometimes logical and sometimes not.  People do the strangest of things for the strangest of reasons.  The being the case,  we can assume quirky or illogical behaviour, and if something is apparently inexplicable we can always try to explain it as having “an unknown ritual purpose.”  This releases the social scientist from the constraints of science, and allows him or her to get away with much more profound or extensive
assumptions than would be permitted in geology or physics or chemistry.

So what we have in the case of Rhosyfelin and Carn Goedog is a “quarrying assumption” rather than a “quarrying hypothesis.”  From the very beginning of the research at both sites, the archaeologists have assumed that they have been looking at Neolithic bluestone quarries because this is what was (in their view) pointed at by the research by geologists Richard Bevins and Rob Ixer.  It was not considered necessary to test a hypothesis — but simply to assemble evidence in order to confirm the correctness of the assumption.  This explains the unscientific methods used by the digging team, making it obvious to all independent observers that they were not interested in testing a working hypothesis, but were intent upon confirming a ruling hypothesis or assumption.

When archaeologists are fixed in this mind-set, they can ignore scientific methods even though they use “scientific” tools in their research. They can claim, as MPP has done, that archaeology is not a science and that it is therefore freed from scientific constraints. So assumptions rule, and evidence and arguments from other disciplines (such as geology, geomorphology or pedology) can be ignored if they are inconvenient.

It is of course deeply worrying when this style of thinking becomes prevalent, and when papers which are deeply flawed scientifically are published in “reputable” journals.  It is even more worrying when people say to me (as they have done) that we should not apply scrutiny to the papers published by archaeologists, because they are always dealing with the erratic obsessions and belief systems of human beings — so if something makes no sense whatsoever, that’s perfectly all right........

Friday, 6 July 2018

The Somerset ice lobe

We have discussed this before, in considerations of the shape of the Anglian ice front and its extent towards the east.  I am a firm believer in topographic control over glacier ice, particularly in areas near the ice edge.  These images help us to understand what might have happened in the Anglian glacial episode — note that Gilbertson and Hawkins thought that the ice might have pushed as far as the Dorset Downs, but that it did not override the Blackdown Hills, the Quantocks or the Mendips.  That means that glacial traces might be found around (beneath?) Bridgwater, Street, Wells, Yeovil and Glastonbury — but probably not Frome, Westbury and Warminster.

But then we have the problem of those enigmatic traces of glaciation in the Bath area — and we know that ice pressed across the coast in the area around Kenn, Clevedon, Portishead etc because glacial and fluvioglacial deposits in that area are well documented.  And if, as we have suggested, the Mendips WERE overridden by ice at some stage, then the lower area to the east (centred on Frome) might well carry some traces of glaciation.  Let’s call this intelligent speculation at the moment — underpinned by SOME quite strong evidence......

We have of course suggested in past posts that Kellaway may well have been right when he suggested TWO ice lobes, one heading for Bath around the northern flank of Mendip, and the other heading for the chalk scarp around Mendip’s southern edge.

Thursday, 5 July 2018

The Easter Island quarries

Recently there has been press coverage of some new work on the Easter Island heads — how they were moved and erected.  But the quarrying evidence is pretty well incontrovertible.  Now THIS is what I call evidence — demonstrated, illustrated, enumerated and cited.  What a contrast with the situations at Rhosyfelin and Carn Goedog....... where we have been TOLD a great deal and SHOWN nothing which can properly be cited as “evidence”.  

The new article, in the Journal of Archaeological Science, deals mainly with the method used for getting the big stone hats onto the heads of some of the statues.  There is a report here:

Wednesday, 4 July 2018

Glaciation of the Bristol-Gloucester region

This is from Wikipedia — I have quoted from this Regional Geology before, but I still get people saying “But there is no evidence of glacier ice ever having extended to the east of the Bristol Channel.” Well there is evidence, and it not disputed. There is a huge amount of research, and there are abundant papers in the peer-reviewed literature.

Glacial deposits, Quaternary, Bristol and Gloucester region
Green, G W. 1992. British regional geology: Bristol and Gloucester region (Third edition). (London: HMSO for the British Geological Survey.)

The glacial deposits of the region are mostly scattered remnants and provide difficult problems of interpretation. The earliest drift deposits are represented by remaniĆ© patches of erratic pebbles of quartz, ‘Bunter’ quartzite and, less abundant, strongly patinated flint lying on the surface of or within fissures in the Cotswold plateau up to a height of 300 m above OD. On the eastern boundary of the present region and in adjacent areas to the east, there are scattered patches of sandy and clayey drift with similar erratics, which are now known collectively as the ‘Northern Drift’. The general opinion is that the deposits are heavily decalcified and probably include both tills and the fluviatile deposits derived from them. They predate organic Cromerian deposits in the Oxford area and thus provide evidence for pre-Cromerian glaciation (see summary in Bowen et al., 1986)[1].

High-level plateau deposits in the Bath-Bristol area comprise poorly sorted, loamy gravels with abundant Cretaceous flints and cherts and have been correlated with the ‘Northern Drift’.

The Anglian glaciation is better represented in the district. In the Vale of Moreton there is a three-fold sequence. At the base lies the Stretton Sand, a fluviatile, cross-bedded quartz sand, which has yielded a temperate fauna including straight-tusked elephant and red deer. This was formerly dated as Hoxnian in age but now must be considered to be older. The Stretton Sand is similar to the supposedly younger Campden Tunnel Drift (see below), and it has been suggested that the temperate fauna in it is derived from an earlier interglacial deposit. The overlying Paxford Gravel, which comprises local Jurassic limestone material, has yielded mammoth remains and has an irregular erosive contact with the Stretton Sand. At the top, up to several metres of ‘Chalky Boulder Clay’ with derived ‘Bunter’ pebbles may be present. Thin red clay is locally present immediately beneath the till, possibly representing a feather-edge remnant of the glacial lake deposits of Lake Harrison.

At the northern end of the Cotswolds, in the gap between Ebrington Hill and Dovers Hill, the Campden Tunnel Drift consists of well-bedded sand and gravel with ‘Bunter’ pebbles and Welsh igneous rocks, and two beds of red clay with boulders, probably a till. The deposits occupy a glacial overflow channel, up to 23 m deep, caused by the ponding of the Avon and Severn valleys by the Welsh glacier farther downstream.

Evidence in Somerset and Avon, combined with that from South Wales, for an Anglian glacier moving up the Bristol Channel has been accumulating in the last decade or so. The construction of the M5 motorway through the Court Hill Col on the Clevedon–Failand ridge led to the discovery in the bottom of the col of a buried channel, 25 m deep and filled with glacial outwash deposits and till. Drilling has since proved similar drift-filled channels in the Swiss and Tickenham valleys crossing the same ridge. South of the ridge, and rising from beneath the Flandrian alluvium of Kenn Moor, marine, brackish and freshwater interglacial sand and silt overlying red stony and gravelly till and
poorly sorted cobbly outwash material were disclosed in drainage trenches and other works. AAR results indicate that whilst the bulk of the interglacial deposits are Ipswichian in age, samples of Corbicula fluminalis from fluvial deposits directly overlying the glacial deposits give a much earlier date and suggest that the latter are Anglian in age (Andrews et al., 1984[2]). Similar local occurrences of possible till have been reported beneath the Burtle Beds of the Somerset levels. In the light of these and other discoveries, the glacial overflow hypothesis of Harmer (1907)[3] for the cutting of the Bristol Avon and Trym gorges has been revived to explain why these rivers cut through hard rock barriers in apparent preference to easier ways through adjacent soft rocks.

Jump up ↑Bowen, D Q, Rose, J, McCabe, A M, and Sutherland, D G. 1986. Correlation of Quaternary Glaciations in England, Ireland, Scotland and Wales. Quaternary Science Reviews, Vol. 5, 299–340.
Jump up ↑ Andrews, J T, Gilbertson, D D, and Hawkins, A B. 1984. The Pleistocene succession of the Severn Estuary: a revised model based upon amino acid racemization studies. Journal of the Geological Society of London, Vol. 141, 967–974.
Jump up ↑ Harmer, F W. 1907. On the origin of certain canon-like valleys associated with lake-like areas of depression. Quarterly Journal of the Geological Society of London, Vol. 63, 470–514.

Sunday, 1 July 2018

Coming soon — new book from the Magalithic Portal

I’m happy to give support to the new book from the Megalithic Portal — edited by Andy Burnham.  More info can be found here:

On the web site there are some sample pages and also info on how to pre-order.  It looks beautifully designed, with great maps, photos and diagrams, so it will probably become an essential item on the bookshelves of all who are interested in old stones....

I’ll give more info closer to the publication date in September.

Saturday, 30 June 2018

Out with the fairies on the Great Stone Road

More press coverage of the latest twist in the bluestone transport narrative.  No matter how deeply
you dig, you will find no new evidence here.  It simply appears that the geologists Ixer and Bevins were determined to say something new, for reasons that are unclear.......... could a new book on the bluestones have had anything to do with it?

In the wonderful map showing the “great stone road” and the other “bluestone route” options, there is not a scrap of evidence in support of any of them, as I have pointed out in my book.  The thesis seems
to be this:  glacial transport was impossible, therefore the stones were manhandled across country or across the sea, therefore there must have been a route, and our route might just be a better one than anybody else’s.........

The route speculators have been playing games ever since HH Thomas started the craze in 1921 — playing on the gullibility of the public and the naivety of the media.  Nothing, apparently, changes....... and those who play the route game are as cynical as ever.

The only thing that is “new” is the map of the Senni Beds reproduced in the Antiquity article.  But there is nothing in that map or in any associated research to point to Hay on Wye as the source area for the Altar Stone or for any other bits of debitage at Stonehenge. Until the geologists have more evidence to give us about the sandstone monoliths and debitage, and about the precise characteristics of the Senni Beds, why don’t they just keep quiet?

Friday, 29 June 2018

Geologists in fantasy land

Thanks to Alex for bringing this to my attention.  Norman Hammond is the reporter responsible for this complete nonsense — but who fed this stuff to him?  Why, none other than our old friends Rob Ixer and Richard Bevins........

It presumably came from a press release associated with the recent paper on HH Thomas and on another recent paper in “Antiquity” which I shall shortly take a look at.  But there was no new evidence in either paper relating to the Altar Stone or to bluestone provenances, so this article is based on no evidence whatsoever.  This is nothing short of wild fantasising, and I cannot for the life of me understand why two respectable geologists have allowed themselves to be dragged into, and cited in, this sort of gutter journalism.


PS.  Mind you, I'm a fine one to talk -- some of the press coverage when my new book was published was quite incredible!  The Daily Mail article was a thing to behold.   Then the coverage in all those newspapers in the Australian outback was especially wonderful.  But I did at least send out to the press a carefully written press release which they then did terrible things to.  In the case of this Times article, I think Norman Hammond is probably reflecting quite closely what he was told.....

Tuesday, 26 June 2018

Posting problems

Excuse me, faithful readers, but I am having problems with Blogger again.  They have still not fixed the problem relating to Email notifications of comments, and there is another problem relating to the composing and editing of posts.  Scrolling is impossible when using an iPad, and I cannot add photos in the same way as I did when using my faithful old MacBook.  So some posts may end up being very messy and devoid of images......

Google and Blogger are looking rather incompetent these days......

Monday, 25 June 2018

Spotted dolerite and retail therapy

Did you know that you can do wonders for your health by buying big lumps of bluestone? Thanks to Chris for this piece of intelligence from the Netherlands:

“I was shopping for some crystals on Saturday and saw the enclosed. Looks like genuine spotted dolerite for 50 Euros per kilo. The owner of the store has published a book in which "Preseli Blauwe steen" is described as being useful for the third eye.
"Helps to let go of emotions. Stimulates you to go and do something. This stone comes from the Stonehenge area. It helps to surface old memories. Balances the bodily energies. Stone that can transport you to the underworld and to the heavens. Used to return a portion of soul that you lost in previous lives."

This certainly looks like genuine bluestone. It’s been broken off a larger block with a heavy hammer, by the look of it.  We know that there are several entrepreneurs who sell bluestone lumps collected in Preseli, bluestone “crystals” and bluestone “jewellery” —You can track them down by doing a simple Google search. Again, the prices are sky high. As we have reported on this blog, the National Park staff are on the record complaining about people who collect up bits of bluestone from the Carn Meini area in particular. But there is no law against people who collect and sell bluestone lumps that have come from private land on the south side of Preseli — and there are of course abundant boulders waiting to be “farmed”....

But the interesting thing about the stone discovered by Chris is that it is claimed to have come “from
the Stonehenge area.” Did somebody really collect it from near Stonehenge? If so, I’m sure EH would be rather interested to know where it came from!

Thursday, 14 June 2018

Historic document from 2000

Ah -- this brings back happy memories! A Western Mail press cutting from April 2000, in the early stages of the Millennium Stone Pull.

This reminds us that when the pullers started with the project, all wore yellow gloves and PULLED on the ropes.  But many found that very hard work, getting rope burns and blisters on their hands -- and so after a while the organisers developed a sort of harness for each puller, with a bar in front of the chest and a connection behind onto the main haulage rope.  So those who were drawing the stone along were facing forward and PUSHING --  and were able to use their body weight much more effectively.  The men with the levers who walked along behind the stone were there to lever the loaded sledge back into position when it slid sideways -- as it did with alarming frequency.

In spite of these innovations, and the use of modern ropes and friction-reducing Netlon to increase sliding efficiency on asphalt roads, the stone pull was still an unmitigated disaster, proving without a doubt to all of those involved that the hypothetical human haulage of 80 bluestones from Presell to Stonehenge was just about as reliable as the "aliens from outer space" hypothesis.

Wednesday, 13 June 2018

Meanwhile, in the Brecon Beacons

Thanks to Phil for 4 images of the cirque called Craig Cerrig-gleisiad (glitter-stones crag) in the Brecon Beacons.The top one looks south into the Taff Valley; the second one looks out of the cirque, over the lip, towards Brecon and Hay on Wye in the distance; the third looks into the cirque, with the headwall in the distance.  The last photo, below, shows the inside of the cirque with Pen y Fan and Corn-du in the distance.

There are some very spectacular glacial features in the Beacons, all well recored and studies over the years. The ice divide in this area seems to have been very mobile -- apparently shifting about in all compass directions during the course of the Devensian.

Monday, 11 June 2018

More from the ice divide

Purely by chance, this was posted on Facebook today by Stephen John (no relation).  Fabulous image -- taken on the remote upland road to the Elan Valley.  Again, this is typical ice divide terrain, maybe covered by relatively stagnant and cold-based ice for most of the Devensian cold episode.  That means maybe 50,000 years of ice cover, with remarkably little landscape modification.

Craig Rhosyfelin -- "the monolith extraction point" -- again

Fracture scar left when a small slab (maybe 5 cms thick and c 20 cms wide) fell away relatively recently.  The scar edges are sharp and fresh.

I applied some close scrutiny to the "monolith extraction point" at Rhosyfelin on my last visit -- referred to by Mike Parker Pearson and colleagues as located in a "recess."  There isn't any recess there, and there is no evidence at all that a single stone might have been taken from the point at which MPP has charmingly posed for a thousand photographs.

As I have pointed out before, the rock face here has several prominent fracture scars which must have been created when small slabs of foliated rhyolite fell away and accumulated at different times at the foot of the crag.   If they were present in 2011, these must all subsequently have been carted away and dumped by the archaeologists, who were interested above all else in the 5 years of digs in looking for monoliths capable of being carted off to Stonehenge or to "proto-Stonehenge".  It's possible, of course, that some of the slabs broke away while the site was affected by glacier ice and torrents of meltwater;  they may have been incorporated into overriding ice, or moved downstream before being dumped.  They must all have been quite small, and easily modified or destroyed.

A very old fracture scar on the same face; note how heavily abraded the outer edge of the scar is.  The slab that dropped away from above it must have parted company wit the rock face many thousands of years ago.

Another clean fracture, also heavily abraded.  A late Devensian feature?

Irregular fracture scars towards the base of the exposure.   Several slabs have fallen away here, one c 6 cms thick and probably another around 4 cms thick.  Again the scars are heavily abraded -- suggesting the action of either ice or meltwater.

The sample that was taken away for cosmogenic exposure dating about 3 years ago must have come from somewhere on this face.  The dating must have been completed long since -- I wonder why the result has never been published?  But then nobody likes to publish inconvenient evidence, do they?

More comments about the book....

Two more comments from senior academics. (By the way, I did not make them up.)   I'm quite encouraged.  Of course, there will be negative and aggressive reviews in assorted journals from people with vested interests and maybe from some who don't wish to take my arguments on board.  Such is life....

"..........your recent book The Stonehenge Bluestones. Excellent! I believe you! I read it from cover to cover.  Your demolition job on the Bluestones did me good. ‘Assumptive research’ is more common than one might expect … and embedded assumptions create vast barriers, dams, holding up research … YET flexibility is unwelcome!"

"Only had a quick browse so far but seems you've done a grand job updating... Excellent stuff." 

Thursday, 7 June 2018

Stonehenge -- rhyolite in a Mesolithic context?

Pit 9580 -- from p 46 of Cleal et al, 1995

On looking through Ros Cleal's mammoth tome the other day, I came across a rather interesting reference to a "rhyolite chip" in what appears to be a Mesolithic context.   This would not, of course, be the first time that a piece of bluestone has been uncovered in a pre-Stonehenge context.......

In Chapter 4 ("Before Stonehenge") Michael Allen makes use of the unpublished notes of Martin Trott, working for Wessex Archaeology at the behest of English Heritage, to study those famous post holes in the old Stonehenge car park.

In Pit 9580 (the easternmost pit, very close to the old Visitor Centre), there was a very varied fill of sediments about 1.3 m thick.  The pit seems to have been re-cut and modified several times, the most prominent modification being a transformation into a wide shallow pit (purpose unknown) just 70 cms deep.   Trott described primary, secondary and tertiary contexts.  The most interesting thing about the recut tertiary fill at the top of the sequence (context 9581) is that it contained a piece of rhyolite weighing 62g, at a depth of 20 cm.  Then we come to some circular reasoning -- Allen says:  "this latter find is of some significance as it indicates that this layer was not earlier than, and was probably contemporary with, the dressing of the bluestones (phase 3)."  That is one explanation -- the other is that the rhyolite chip was there when the pit was in use, or was being filled in, very much earlier than Bluestones Phase 3. This latter explanation is supported by the radiocarbon date of 8400 +/- 100 yrs BP obtained from charcoal in the tertiary fill layer.  The layer is pretty well homogenous, and there is no reason to think that the rhyolite chip was introduced and buried here more than 3,000 years after the Mesolithic pit was finally filled.  If it had been, there should be signs of some break in the stratigraphy.

Then it gets even more confusing, since detailed work on the molluscan fauna and on pollen analyses from the side of the opened pit indicate a "hiatus" between the lower parts of the pit fill and the "tertiary fill" near the surface.  Allen and other researchers suggest that there was indeed a break of as much as 5,000 years between the Mesolithic and Neolithic activity.  In the Mesolithic (Boreal) period there was a wooded landscape, and when the sediments of the tertiary fill were emplaced the landscape was much more open.  But is that assumption of a long hiatus based upon the assumption that rhyolite cannot possibly have been present in the neighbourhood during the Mesolithic?  Could the clearance of land and its transformation from open woodland to a grassland area have taken place rather quickly -- or over a few thousand years -- during the Mesolithic, as a result of burning?  Should we believe the radiocarbon date, or treat it as an aberration?

This is all very intriguing -- does anybody have more information?

Ice shed country -- Cambrian Mountains

Llyn Cwm-byr, near Pumlumon

I keep on discovering fascinating landscapes.  I discovered another one the other day, while travelling home from giving a talk in Bishops Castle, in the Welsh Borders.  We took  detour off the Newtown - Aberystwyth road and took minor roads via Devil's Bridge to Pontrhydfendigaid and Tregaron.  I had been that way before without seeing much, but this time it was a real hot summer's day, with blue sky and fantastic visibility.

This is part of Wales's empty quarter, with a rolling -- almost prairie - like -- landscape of broad river valleys, wide depressions with lakes in them, and hilly areas with gentle slopes.   This is the core of the Cambrian Mountains and the main watershed of Wales, with some streams flowing west and others flowing east -- but no glaciated troughs.  During the big glacial episodes this area has been at the heart of the Welsh ice cap -- so there has been very thick ice sitting on this landscape -- but it has done virtually nothing in terms of landscape modification.   The ice has been effectively stagnant, and probably cold-based,  maybe with occasional aerial scouring but no streaming.  The whole landscape reminded me of parts of the basalt plateaux of NW Iceland, except that here there are the remnants of a very old fluvial landscape which has been largely unmodified for millions of years.

Must try to get back there soon, so that I can take a more careful look.......

The Cambrian Mountains of mid-Wales, between Aberystwyth and Newtown.  The undulating "watershed plateau" is clearly seen in the centre of the map.  The brown-coloured area is the highest part of the plateau, around Pumlumon.

Typical landscape on the plateau

Extract from the BGS glacial map of Wales, showing Devensian ice movements at the centre of the Welsh Ice Cap.  Note the outlet glaciers flowing away from the ice-shed area -- the Rheidol and Ystwyth Glaciers flowing west, and the Wye and Severn Glaciers flowing NE and SE respectively.  

Friday, 1 June 2018

Herbert Thomas scrutinized

A new review of Herbert Thomas and his work has just been published in Antiquity journal. Was he a brilliant geologist, or a bit of a charlatan?  I'll report on the detail in due course, but in the meantime here is the Abstract and the reference list -- the latter makes a good check-list of the papers by Bevins and Ixer.  With a bit of luck, the hyperlinks will work........
(As we all know, I don't agree with the authors that they have definitively identified the locations from which some of the bluestones and the debitage at Stonehenge have come -- the best that can be said is that they have narrowed things down to the most likely neighbourhoods.)


Retracing the footsteps of H.H. Thomas: a review of his Stonehenge bluestone provenancing study
Richard Bevins and Rob Ixer
Antiquity, May 2018.

Published online: 31 May 2018


The long-distance transport of the Stonehenge bluestones from the Mynydd Preseli area of north Pembrokeshire was first proposed by geologist H.H. Thomas in 1923. For over 80 years, his work on the provenancing of the Stonehenge bluestones from locations in Mynydd Preseli in south Wales has been accepted at face value. New analytical techniques, alongside transmitted and reflected light microscopy, have recently prompted renewed scrutiny of Thomas's work. While respectable for its time, the results of these new analyses, combined with a thorough checking of the archived samples consulted by Thomas, reveal that key locations long believed to be sources for the Stonehenge bluestones can be discounted in favour of newly identified locations at Craig-Rhos-y-felin and Carn Goedog.


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Thursday, 31 May 2018

Why the "human agency" thesis cannot be the default preference

A stone with a mind of its own.......

I have many discussions with experts off the record, and in one recent exchange of opinions with a senior geomorphologist we have agreed to differ on what the "default hypothesis" should be, given that there is no "smoking gun" or "killer fact" in the glaciers versus humans debate.  His view is essentially that of Prof James Scourse, who said many years ago that since there is no firm evidence of glaciation on Salisbury Plain we must therefore assume that glacial entrainment and transport of the bluestones was effectively "impossible" -- and that no matter how unlikely it might seem, the human agency thesis has to be the one to go for.  (The reason for that is that we know that Neolithic people were rather clever, and if they were clever enough to know quite a lot, they probably knew how to carry large stones over long distances........)

I disagree fundamentally with that.  Nobody should ever say that the glaciation of Salisbury Plain was impossible, especially since modelling shows that it was indeed possible, and since there are glacial deposits in the SW counties including Somerset.  The Stonehenge bluestones themselves look like a glacial erratic assemblage, and if they look like erratics they may well be erratics!  We must also remind ourselves that there is no physical evidence of any sort which supports the idea of either Neolithic quarrying in Pembrokeshire or long-distance human transport of the bluestones, and which withstands scrutiny.

In those circumstances the balance of probability must lie with the glacial entrainment and glacial transport thesis.  Some evidence trumps no evidence, any time.   In summary:

Ten fundamental problems with the human quarrying & transport thesis

1. There is no sound evidence from anywhere in the British Neolithic / Bronze Age record of large stones being hauled over long distances (more than 5 km or so) for incorporation in a megalithic monument. The builders of Neolithic monuments across the UK simply used whatever large stones were at hand.

2. If ancestor or tribute stones were being transported to Stonehenge, why have all of the known bluestones come from the west, and not from any other points of the compass? Were belief systems and "local politics" quite different to the north, east and south?

3. There is no evidence either from West Wales or from anywhere else of bluestones (or spotted dolerite or Rhosyfelin rhyolite in particular) being used preferentially in megalithic monuments, or revered in any way. The builders always used whatever was available to them in the vicinity, and it can be argued that stone availability was a prime locational determinant for stone settings.

4. If long-distance stone haulage was "the great thing" for the builders of Stonehenge, why is there no evidence of the development of the appropriate haulage technology leading up to the late Neolithic, and a decline afterwards? It is a complete technological aberration.

5. The evidence for Neolithic quarrying activity in key locations is questionable. No physical evidence has ever been found of ropes, rollers, trackways, sledges, abandoned stones, quarrymen's camps, or anything else that might bolster the hypothesis. The so-called “engineering features” are entirely natural.

6. The sheer variety of bluestone types (near 30 when one includes packing stones and debris) argues against selection and human transport. There cannot possibly have been ten or more "bluestone quarries" scattered across West Wales.

7. Bits and pieces of experimental archaeology on stone haulage techniques (normally in "ideal" conditions) have done nothing to show that our ancestors could cope with the sheer physical difficulty of stone haulage across the heavily-wooded Neolithic terrain of West Wales (characterised by bogs, cataracts, steep slopes and very few clearings) or around the rocky coast. The one reasonably "authentic" project (the moving of the "Millennium Stone" in the year 2000) was a shambles and a disaster.

8. Neither has it been shown that the Stonehenge builders had the geographical awareness and navigational ability to undertake long and highly complex journeys with very heavy loads.

9. And if there was a "proto-Stonehenge" somewhere, built of assorted local stones and then dismantled and taken off to Stonehenge, where was it? The mooted "Preselite" axe factory has never been found, and neither has the mythical Stonehenge precursor.

10. Analyses of bluestone monolith stone shapes does not suggest that elongated “pillars” were preferred. Slabs, stumps and boulders of all shapes and sizes are highly suggestive of a glacial erratic assemblage.

Wednesday, 30 May 2018

Bluestones 34 and 35a

Bluestone 35a, exposed in the pit opened by Darvill and Wainwright in 2008.  (Source: Tim Darvill)

I'm happy to draw attention to the 2009 report by Darvill and Wainwright -- dealing with the main findings from the 2008 Stonehenge dig.  Interesting material, written in a lively and accessible style.

Much of the report is about the Stonehenge Layer, but this is what the authors say about the two bluestones which they encountered.

Let us move hastily along to the next period of Stonehenge, where three sockets relate to stones that are still visible above the ground surface. Stone 35a and Stone 34 are both part of the Bluestone Circle that is such a striking part of all the later phases of the monument. Both stones are still above ground. Stone 35a is a massive block, but projects only a few centimetres above ground level (fig 9). Petrologically speaking, this one is very close to the material from Carn Menyn to which Geoff referred earlier. I think that you can see straightaway that this is the natural patina on the rock and it has been smashed up in relatively recent times, sufficient that no new patina has developed on the exposed faces. As we shall see a little later, that is not surprising. But there it is in its place, going down the best part of a metre into the ground.

The next one along is Stone 34. It is a beautiful stone that extends into the ground more than a metre, so that less than one-third of it is sticking up above the ground and the rest is now under the ground. You can also just make out a massive hole next to the stone, which is partly filled with concrete, put there when Atkinson refilled the trench, probably to give it support. It is fairly certain that when Atkinson was digging here Stone 34 was loose and you could move it, and, given the size of the hole, there is no question that material could get into the ground alongside that stone.

Stone 35a is particularly spectacular, showing a very complex history.  It has a flattish base, and sits on the chalk bedrock in quite a stable fashion.  The side facing the camera is clearly a fracture plane which is heavily weathered.   How did the breakage occur, and when did it happen?  We can see several other fractures within the rock, so it is in a dodgy state, and presumably always has been.   The relatively fresh and unweathered upper surfaces show the spotted dolerite in all its glory; these appear to be fresh fractures, and I think Darvill and Wainwright are right in their conclusion that these breakages are relatively recent in the life of the stone -- maybe dating from the "destruction of the bluestone circle."  They say that two - thirds of the bluestone circle has been smashed up, carted away and incorporated into the Stonehenge Layer -- but I think that is an unsupportable statement, since nobody knows how many bluestones were in the circle when it was at its most complete --  and there is no evidence to support the contention that it ever was "complete" as shown in all the Stonehenge publicity material.  I have argued many times that the whole monument was abandoned in an incomplete state, because the builders ran out of stone........

The pic of stone 34 is a nice one too.  This one is apparently complete -- although its base was not fully excavated by Darvill and Wainwright.  As fine a weathered and battered glacial erratic as one is ever likely to see.