THE BOOK
Some of the ideas discussed in this blog are published in my book called "The Bluestone Enigma" -- available by post and through good bookshops everywhere. Bad bookshops might not have it....
To order, click
HERE

Thursday, 28 August 2014

Stonehenge Empire


I flagged up this multinational co-production about a year ago, and it looks as if it is now made, and is probably in the final stages of editing.  There will be two 60-minute parts -- probably on BBC2 this autumn.  Not yet in the schedules, as far as I can see.......

Interestingly, this doesn't seem to involve National Geographic -- but Smithsonian is in there, and I think I am right in saying that in the past the Smithsonian has generally sponsored the work by the Darvill / Wainwright tribe rather than the MPP tribe.  So it will be interesting to see which "international team of experts" has been involved in putting this latest extravaganza together.

I see no sign of a new Nat Geog Channel documentary on Stonehenge -- and the last one, a few years back, which based the whole programme on MPP's theories, was heavily panned on the basis that there was virtually no evidence in there, but a great deal of fantasy.  Maybe Nat Geog Channel has had its fingers burned, and is waiting for something more reliable before starting advance publicity for a new documentary?

If there is any gossip from the big wide world about all of this, let us know.....

Wednesday, 27 August 2014

How much do the Rhosyfelin partners know?


Here is a screenshot from the University College London web site, relating to the "Stones of Stonehenge" project. It is otherwise called the "Preseli Stones of Stonehenge" project, and currently has funding from: National Geographic Society, Royal Archaeological Institute, and Society of Antiquaries.  It has grown from the Stonehenge Riverside Project, which is now finished, having had a budget of c £500,000.  The budget of the present project is unknown, although somebody must know........ and we do not know how much public money is involved, apart from the fact that many of the "project partners" are paid for their time from the public purse and probably contribute equipment and laboratory / technical assistance via assorted university departments.  You and I, through our taxes, are the ones who pay for all that.  The three major cash funders are educational / charitable institutions which do not advertise the sizes of their grants disbursed to project leaders like Prof MPP.

In the light of the ongoing mystery regarding the research results from three seasons of digging at Craig Rhosyfelin, and the lack of any public statements relating to the radiocarbon dating results of many samples submitted, one wonders how much the project partners know.  In the old days, when I used to be involved in joint projects, we who were partners circulated our results between ourselves, and had an ongoing process of data reporting and information exchange.  Nowadays that process is easy, thanks to things like Dropbox and Cyberduck.

Mike prides himself on the manner in which he consults and bounces ideas around amongst his colleagues.  That's one of the things that comes out clearly from his latest book.  So I have to assume that all of those on the list above are in possession of the radiocarbon dating results from Rhosyfelin, or have at least had a resume or report from MPP............ so why has NOBODY said ANYTHING?




















Monday, 25 August 2014

Regenerated glaciers

 
    
Regenerated glaciers are unusual in that they are able to survive in anomalously low altitude situations because they are physically separated from their ice and snow sources.  The glacier in the top photo -- an unnamed glacier in the Franz Josef Fjord complex of East Greenland -- exists right down at sea level.  The lower photo shows the Supphelle Glacier in Fjaerland, Sogn, Norway.  The lower part of this glacier is only 60m above sea-level, which makes it the "lowest glacier in southern Norway."  In both cases the glaciers are sustained by broken glacier ice which tumbles down a cliff face before becoming compressed and reconstituted down below.  These glaciers are difficult to research, given the constant torrent of ice fragments coming down from above.......  hard hats are not of much use in places such as these, since some of the ice blocks are enormous.....

In the Greenland glacier there is a huge mass of dead ice covered with moraine down at the base of the fjordside.  There is much rockfall debris as well, and it may be that this feature is partly a rock glacier and partly a normal glacier made of ice.

The ice in the lower part of Supphellebreen is much cleaner.  But it is on its way out -- it's melting very fast, both because of warmer conditions down on the valley floor and also because the supply from the icefall above is gradually being cut off.

Friday, 22 August 2014

Mike Pitts has got it wrong



Not for the first time, I'm currently a bit fed up with the constant barrage of unreliable information appearing in the media about Stonehenge and the bluestones.  People who should know better are just plain CARELESS -- not good enough.  So I am in letter writing mode.  Following the publication  of Mike Pitts's piece in the BBC Focus magazine in July, I wrote this to the Editor of the journal.  Sadly, they only publish letters up to a maximum of 120 words, which is not exactly sufficient for the development of an argument or the presentation of evidence.  So I have rejigged mine in a much shorter version, and I hope that will now appear.

This is what might have been published if the journal had had more space available!

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

Letters for Publication,
Focus magazine ‘Reply’,
Immediate Media,
9th floor, Tower House,
Fairfax Street,
BRISTOL, BS1 3BN

17th August 2014

Dear Editor,

Bluestones:  the glacial transport theory is still alive and well

It was good to see an article on Stonehenge and the bluestones in the July 2014 issue of the magazine.  The author, Mike Pitts, has got some things right and some things wrong, and since this is a magazine which encourages respect for science and technology, I hope you will allow me to make certain corrections. 

Pitts says that the thesis of glacial transport of the bluestones is  " .......an old idea, dismissed by mainstream science but still championed by a few." Forgive me for saying so, but that is complacent, condescending nonsense.  The glacial transport hypothesis has NOT been dismissed by "mainstream science" -- whatever that is.  A few geologists and geomorphologists  (for example Scourse, Green and Bowen) have expressed their doubts about the glacial hypothesis in print, and others (for example Williams-Thorpe, Kellaway, Jackson, and yours truly) have written in support of it.  The debate goes on.

Pitts says that the idea of glacial transport is now discredited because the new geological work on the provenances of some of the bluestones shows that they have come from the northern slopes of the Preseli Hills in Pembrokeshire, and not from the southern slopes.  He suggests that if ice had entrained and transported the stones, they should have come from the south-facing or down-glacier slopes, given that the Irish Sea Glacier overrode Pembrokeshire from the NW and flowed onwards to the S and SE.  I am not sure where Pitts got this idea from, but it demonstrates an unfortunate misunderstanding of the complexities of glaciological theory. 

Let's try to explain.  When glacier ice flows across a landscape and inundates everything, there is indeed a tendency for plucking or "quarrying" to occur on the down-glacier flanks of obstacles, which explains the difference between the smoothed and striated up-glacier flanks of roches moutonnees (which are often gently-sloping) and the broken or fractured down-glacier flanks which are often transformed into steep cliffs because of the process of block removal.  This is explained in glaciology by reference to bed pressure and the flow law, with basal melting occurring up-glacier where rock surfaces are under compression, and freezing and thawing -- and the "dragging" away of blocks -- occurring down-glacier where rock surfaces are subject to pressure release and tension. It is probably that theory to which Pitts is referring when he speculates about the origins of bluestones and their mode of transport.

Then things get more complex.  In certain situations (for example where there is a major ridge or mountain range aligned transverse to the direction of ice flow) other processes come into play. In the lee of the obstacle there may be a vast expanse of "dead" or stagnant ice which may have very little effect upon the landscape and which might be overridden by more active glacier ice flowing up over the mountain ridge and then away in whichever direction the ice stream dictates.  So in the Preseli Hills case, the most active ice, capable of erosion and the entrainment of blocks of bedrock, may have had no contact with the tors and other landforms of the southern slopes.  On the northern slopes, in contrast, if the ice was cold and subject to large horizontal compression strain rates, shearing or thrusting (analogous to faulting in solid rock) could well have occurred, and there would be a mechanism also for the partial destruction of tors and the entrainment of large slabs of bedrock.  We see evidence for this type of thrusting -- and the incorporation of vast quantities of bedrock debris -- close to the snouts of certain present-day glaciers, especially in association with the formation of push moraines.  We also see signs of it well inland from the edges of the Greenland ice sheet.

Then things begin to get even more interesting.  Recent modelling work on the British and Irish Ice Sheet by glaciologist Alun Hubbard and various colleagues has shown that it exhibited a sort of "pulsing" behaviour, with alternating surges and ice surface collapses especially in the ice sheet's western sector.   James Scourse and colleagues have shown that one such surge carried glacier ice as far south as the Scilly Isles only about 20,000 years ago.  One of the features associated with surges is thrusting, as fast-moving ice encounters older and more sluggish ice that happens to block its path.  It remains to be seen what relevance this observation has for the entrainment of erratics on Preseli. 

Let's put this on the record:  the preferred locations for the deep glacial quarrying and entrainment of bedrock slabs, monoliths and other debris when the Preseli Hills were deeply inundated by ice would have been the NORTH SLOPES, and not the south-facing ones. 

Sincerely,

Dr Brian John

Methane vents in Siberia



This is a photo of one of the vents in Siberia -- approx 30m across, and probably 50 - 70m deep. It's rather spectacular -- and in my view not a pingo. I'll coin the term "methane vent" for it -- I don't think anybody has given these things a name before now.

This is an interesting article from Nature -- another consequence of global warming as permafrost melts in some areas where it has until now been rock solid, with annual melting of just a thin "active layer."  There is pretty catastrophiv lelting as well in parts of Arctic North America.

http://www.nature.com/news/mysterious-siberian-crater-attributed-to-methane-1.15649#/ref-link-1

Nature | News

Mysterious Siberian crater attributed to methane

Build-up and release of gas from thawing permafrost most probable explanation, says Russian team.
Katia Moskvitch
31 July 2014

A mystery crater spotted in the frozen Yamal peninsula in Siberia earlier this month was probably caused by methane released as permafrost thawed, researchers in Russia say.
Air near the bottom of the crater contained unusually high concentrations of methane — up to 9.6% — in tests conducted at the site on 16 July, says Andrei Plekhanov, an archaeologist at the Scientific Centre of Arctic Studies in Salekhard, Russia. Plekhanov, who led an expedition to the crater, says that air normally contains just 0.000179% methane.
Since the hole was spotted in mid-July by a helicopter pilot, conjecture has abounded about how the 30-metre-wide crater was formed — a gas or missile explosion, a meteorite impact and alien involvement have all been suggested.
But Plekhanov and his team believe that it is linked to the abnormally hot Yamal summers of 2012 and 2013, which were warmer than usual by an average of about 5°C. As temperatures rose, the researchers suggest, permafrost thawed and collapsed, releasing methane that had been trapped in the icy ground.
Other researchers argue that long-term global warming might be to blame — and that a slow and steady thaw in the region could have been enough to free a burst of methane and create such a big crater. Over the past 20 years, permafrost at a depth of 20 metres has warmed by about 2°C, driven by rising air temperatures1, notes Hans-Wolfgang Hubberten, a geochemist at the Alfred Wegener Institute in Potsdam, Germany.
Hubberten speculates that a thick layer of ice on top of the soil at the Yamal crater site trapped methane released by thawing permafrost. “Gas pressure increased until it was high enough to push away the overlying layers in a powerful injection, forming the crater,” he says. Hubberten says that he has never before seen a crater similar to the Yamal crater in the Arctic.
Larry Hinzman, a permafrost hydrologist at the University of Alaska in Fairbanks and director of the International Arctic Research Center, says that such craters could become more common in permafrost areas as the region heats up.
In Siberian permafrost, large deposits of methane gas are trapped in ice, forming what is called a gas hydrate. Methane remains stable and frozen at certain temperatures, but as the permafrost warms, and its internal strength decreases, it may be less able to withhold the build-up of sub-surface gases, he says, leading to a release.
But such gas hydrates normally occur at depths of at least 100 metres, says Carolyn Ruppel, a geophysicist in charge of the gas hydrates project at the US Geological Survey in Woods Hole, Massachusetts. The depth of the Siberian crater is not known. When Plekhanov and his team tried to measure its depth with a video camera tied to a 50-metre rope, the camera did not reach the bottom. But the video footage suggests that the depth to a pool of water at the bottom of the crater is around 70 metres, Plekhanov says. The water could add considerably to that dry depth, he adds.
To confirm what caused the crater, Plekhanov says that another visit is needed to check the methane concentration in air trapped in its walls. That will be difficult, however: “Its rims are slowly melting and falling into the crater,” Plekhanov says. “You can hear the ground falling, you can hear the water running, it’s rather spooky.”
Since the crater was reported, local reindeer herders have noted a similar but smaller hole nearby. Although the hole is yet to be confirmed, scientists worry that the release of trapped methane could threaten local industry and communities. “If [a release] happens at the Bovanenkovskoye gas field that is only 30 km away, it could lead to an accident, and the same if it happens in a village,” says Plekhanov.
To avoid such an event, the Russian team has now suggested drilling holes into the permafrost to release the pressure artificially. But Hinzman says that it would be extremely difficult to do so, if not impossible, as one would have to know exactly where the build-up was in the first place.

Naturedoi:10.1038/nature.2014.15649

References
Romanovsky, V. E., Smith, S. L. & Christiansen, H. H. Permafrost Periglac. 21, 106–116 (2010).

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

 We keep on discovering new things on Planet Earth.  The methane vents also occur on a much smaller scale in Alaska, where they are seen in winter lake ice .   The bubbling up of methane from rotting vegetation on the lake floor -- or from melting permafrost -- is sufficient to keep the lake ice from melting.   Here the features are generally less than a metre across, and of course they are ephemeral -- when the lake ice melts, they disappear.  The dominant form is the circle, as you might expect.  Here are two pics found on the web:








Thursday, 21 August 2014

Review of Mike Parker Pearson's 2012 book


 One of the pages from the book.  A little less certainty and a little more circumspection might have been appropriate......

This review, having been in the Cambridge system for the best part of a year, is now on the web site of The Antiquaries Journal:

Stonehenge. Exploring the Greatest Stone Age Mystery. By Mike Parker Pearson. pp 406, Simon & Schuster, London, 2012.
ISBN 9780857207302. £25 (hbk).

Brian John

The Antiquaries Journal, FirstView Articles
http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9243563&fulltextType=BR&fileId=S0003581514000043


This is a real curate's egg of a book. It isn't just about Stonehenge, but about the Stonehenge Riverside Project which has been investigating the landscape around the monument for almost a decade. So there is a great deal about Durrington Walls, the River Avon, the Cursus and “Bluestonehenge.” I'm not sure where the "target readership" of the book is -- it is too chatty, amiable and rambling in style to be an academic tome, and too detailed and specialised to be aimed at a general readership. The presentation is not very wonderful either -- I can't think of any other recent Stonehenge book that is less attractive to look at or use, printed as it is on a bulky cream paper which renders all illustrations flat and dull. There are abundant maps, photos and diagrams, but they are unnumbered and some are not even referred to in the text, causing one to wonder whether they were added as afterthoughts.

The text is at times clear and informative, at other times quite muddled, hopping about in time and space, and taking what another reader has referred to as “bizarre side roads” such as the Druids, earthworms, the politics of research funding, and the reburial of prehistoric human remains. The book could have done with much tighter editing.

As for the contents, I have to admit to major concerns. Parker Pearson appears to have little respect for academic rigour, and a much greater liking for the process of telling a good tale. The book’s narrative is full of first-name bonhomie, giving the impression that conclusions on important matters are simply arrived at via jolly chats between good mates over a pint or two in the nearest available hostelry. In chapter after chapter, I could just not work out where evidence ended and speculation began -- and over and again I had to conclude that hypotheses were being used as substitutes for facts, and that many matters simply assumed to be correct had never been through a proper peer-review process. When a senior academic publishes a book of this type, one has a right to expect accurate and impartial presentation of field evidence to be followed by the outlining of working theories, with hypothesis testing next and tentative but still testable conclusions to round things off. It appears that Parker Pearson does not do scientific method........

The “sinking stomach” feeling comes in this book even before the Introduction is over and done with, in definitive statements about the quarrying, shaping and transporting of Preseli bluestones. There is no reference to alternative explanations; speculations are stated as facts. So the book goes on, with many interesting pieces of evidence and insights spoiled -- for this reader at least -- by unsupported assumptions just as things are getting interesting. For example, the section on “Bluestonehenge” (Chapter 15) asserts that there were 25 pits that contained bluestones, which were later transferred to Stonehenge. But as I see it, and as other commentators have also pointed out, there is no evidence for 25 pits and no hard evidence that any of them actually held bluestones. In Chapter 16 the author asserts with great conviction that Stonehenge is where it is because of the discovery by its Neolithic builders that there were “periglacial stripes” which were aligned precisely with the midsummer solstice sunrise and the midwinter sunset. These features happen to have been revealed in a dig within the Avenue; but the author does not even try to convince us that they are unique, let alone significant. The need for a good story has simply trumped academic rigour. In Chapter 17 (on the origins of the bluestones) Parker Pearson’s enthusiasm for a good story once again runs away with him, and in attempting to discredit the “glacial transport theory” he misrepresents the arguments of proponents and even uses a map of the wrong glaciation to reinforce his scepticism.

Nowhere in the book does Parker Pearson question the thesis that there were about 82 bluestones imported from West Wales, or that the sarsens were transported from the Marlborough Downs area, or that the stone monument was actually completed. That’s a pity, since other authors are nowadays - quite rightly - testing these assumptions.

When he comes to his section on the “bluestone quarries” at Carn Goedog and Rhosyfelin the author really gets enthusiastic. At the latter site “.... we realized that we had not just a prehistoric quarry but a perfectly preserved one -- the Pompeii of prehistoric stone quarries.” Dramatic statements like that should be made sparingly by academics; and I have seen no evidence of any quarrying activity at Rhosyfelin, where the rockfall material examined thus far seems to me to be entirely natural. I am not aware of any peer review of Parker Pearson’s ideas about “the Rhosyfelin megalith quarry” prior to their publication in this book. And I am not aware that any geomorphologist has ever been involved in any discussions over site interpretation. That is regrettable, to say the least. Then he gets even more enthusiastic, fantasising about whole communities moving stone circles from Wales to Stonehenge as part of some grand political unification project. Again, who cares about evidence when you have such grand and all-encompassing ideas to play with?

There are too many other highly dubious statements to recount in the space of a brief review. Suffice to say that this book is a profound disappointment, since Parker Pearson is a good communicator who spoils everything with his tendency to make sweeping assertions about certainties that do not exist. To quote the author himself (p 308): “We cling onto what we think are certainties and it can be difficult to recognize when a mistake has been made earlier, back down the line, because it has taken on the status of incontrovertible fact.” Quite so.

Brian John

Past Lecturer in Geography, Durham University

Wednesday, 20 August 2014

Another evening of jolly tales from the Stone Age.....


Here we go again -- the latest blockbuster from MPP will be on 17th Sept 2014 (presumably at the end of the 2014 dig?) at Castell Henllys, which is the site of the National Park's Iron Age Village.  (Not far from Castell Mawr, as it happens.)   I think we know what he'll be saying....

See what I mean about the National Park now being completely absorbed into the process of myth propagation for commercial purposes?  Note that the entry fee this time is £3.50.....  and Rhosyfelin is, as we assumed, being promoted as a key archaeological site of local and even global significance.  Hmmm.....

I somehow doubt that I'll be getting a response from Phil Bennett to that letter I wrote!