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

Tuesday, 29 September 2015

Striations at Stonehenge



We have had some recent discussion on this, and Myris has kindly brought to my attention the enclosed -- written by HH Thomas for the BGS Annual Report -- I'd hazard a guess and say the date was around 1920.

The text is almost a hundred years old, and much has moved on since then (including our understanding of glacier behaviour), but what's interesting is a reference to a large flake of bluestone showing "good" glacial striations.  On the whole I would trust HHT on whether the marks were glacial striations or not -- he had after all seen a lot of them in his time in Wales.

Others have also mentioned striae on bluestone monoliths, but they seem to be very indistinct and open to other interpretations too.  Mind you, we should not be surprised.  The mottley collection of stones and stumps of all shapes and sizes is after all best explained as a suite of glacial erratics  -- as we might have mentioned before.....

Four cheers for William Smith


Good for William Smith!  This was William Smith's map that started it all -- with a recognition that rocks were arranged regularly and according to certain rules, that they could be identified by their textures, colours and fossil contents, and that all rocks exposed today represent the conditions that prevailed when they were originally emplaced.  This followed Hutton's revolutionary Principle of Uniformitarianism of 1785.

This map, showing the spatial arrangements of rocks in the UK, underpinned the vast interest in the tracing of glacial erratics in the 1800's -- a process that involved many academic geologists and amateurs as well.  So this is where it all began -- the provenancing work of Rob Ixer and Richard Bevins today is a recent manifestation of this instinct for geological detective work.

This looks like a really interesting exhibition in the National Museum of Wales.....

http://www.museumwales.ac.uk/cardiff/whatson/8508/Reading-the-Rocks-the-Remarkable-Maps-of-William-Smith/

Monday, 28 September 2015

A Long History of Rhosyfelin (4th version)


 

I have revised this document to take account of the latest information.  It's essentially a guide to what happened in the Ice Age, with a simple explanation how the regional chronology is represented at this site.   The more promotion there is for the quarry idea, the less convincing it becomes.  If you go to Craig Rhosyfelin "cold" and with no preconceived notions fixed in your head, and ask yourself what you are looking at, what you find is a rather beautiful craggy rock in a wooded valley, with a long history of landscape evolution and an interesting set of Quaternary sediments.  And signs of occasional settlement by hunters or travellers.  End of story.

A Long History of Rhosyfelin (4th version) 


This is an informal explanation of the history of landscape evolution, and sediment accumulation, at Craig Rhosyfelin in North Pembrokeshire. The site is claimed by archaeologists to be a Neolithic bluestone quarry, but that is not supported by the evidence on the ground.

Saturday, 26 September 2015

Bluestones and the "smoking gun"





About a year ago I published a post on this blog relating to a 2011 paper from the team involved in the Rhosyfelin and Carn Goedog digs.  It represents their thinking at the time the project started.  It's interesting to look at it again, since this article contains their most comprehensive assessment of the glacial transport hypothesis.  It is to the credit of the team members that they did at least consider some of the pros and cons, and give some time and space to looking at the arguments presented by Olwen Williams-Thorpe and her colleagues in 1991.  Here is the piece:

 http://brian-mountainman.blogspot.co.uk/2014/09/the-discrediting-of-glacial-transport.html

It will come as no surprise to anybody that I think the arguments presented against the glacial transport hypothesis are faulty -- as I state in my blog piece.  Also unsurprisingly, the human transport hypothesis is then accepted as fact, with analysis devoted to "how" and "why" the stones were carried / dragged / pushed / sailed / punted all the way from West Wales to Stonehenge.  The essential acceptance of the hypothesis is based upon no facts at all, but on a string of speculations and fantasies.  There is no itemisation of the flaws in the human transport thesis, as there is in the case of the glacial transport thesis.  The authors should have noted the following:

1.  There is no sound evidence from anywhere in the British Neolithic / Bronze Age record of large stones being hauled over long distances for incorporation in a megalithic monument.
2.  The builders of Neolithic monuments across the UK simply used whatever large stones were at hand.
3. If ancestor 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?
4.  There is no evidence either from West Wales or from anywhere else of bluestones (or spotted dolerite in particular) being used preferentially in megalithic monuments, or revered in any way.
5.  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.
6. The evidence for quarrying activity in key locations is questionable, to put it mildly.
7.  The sheer variety of bluestone types  (I still insist the figure is somewhere near 30 when one includes packing stones and debris) argues against selection and human transport.  There cannot possibly have been up to 30 "bluestone quarries" scattered about West Wales.
8.  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.
9.  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.  Aubrey Burl made this point forcefully many years ago, and it remains forceful today.
10.  And if there was a "proto-Stonehenge" somewhere, built of assorted local stones and then dismantled and taken off to Stonehenge, where was it?

In relation to point (8) on the above list, the authors of the article have argued on a number of occasions that the discovery of a genuine bluestone quarry would be the "smoking gun" that would sort the issue out once and for all.  The quarry hunt has become something of an obsession.  Well, that's all very well, except that the evidence for ancient quarrying is incredibly difficult to interpret since we are dealing with the pre-metal tools era and with acidic environments in which bone and other organic materials do not survive for very long.  As we have seen at Rhosyfelin and Carn Goedog, one man's Neolithic quarry is another man's natural rock outcrop.  In my book the supposed trackways, platforms, ramps, pivots, scratches, rails, revetments, pillars and so forth at Rhosyfelin and Carn Goedog are figments of a fertile imagination -- and some of them have even been unconsciously "manufactured" by those involved in the archaeological digs.

Actually there are scores of "smoking guns" that might sort out the bluestone transport arguments.  One would be a discovery of a bluestone monolith on a sledge, buried in the mud of the Severn Estuary.  Another would be a discovery of an unequivocal glacial deposit on Salisbury Plain.  Another would be a collection of erratics scattered about in the Stonehenge landscape, or not far from it.  Another would be a sunken Neolithic boat somewhere in Carmarthen Bay, with a bluestone monolith in it.   Another might be a bluestone monolith abandoned somewhere near Abergavenny, with the remails of a haulage contractor crushed beneath it..........

Dream on, folks -- there must be plenty of other possibilities........

========================
The paper:

"STONEHENGE: CONTROVERSIES OF THE BLUESTONES"JOURNAL OF ANDALUSIAN PREHISTORY
No 1, 01 // 2011, pp 219-252

 
Summary

Whilst the sarsen stones of Stonehenge were brought from a short distance of about 30km away,
the smaller bluestones originate in Wales, over 200km to the west. This remarkable distance for the
movement of megaliths is unparalleled anywhere in the prehistoric world; some geologists have
suggested that the bluestones were carried by glaciers in a previous Ice Age but others point out
that there is no evidence for past glaciations ever having reached Salisbury Plain or even close to it.
This paper proposes that the bluestones were dragged by Neolithic people around 3000 BC, taking
a largely overland route except for a crossing of the River Severn. This contrasts with the conventional thinking that the stones were carried on boats across the sea from Milford Haven in south Wales to southeast England. It presents evidence for new sources of some of the bluestones on the northern flanks of the Preseli hills, as well as rejecting the long-held notion that the sandstone Altar Stone came from the area of Milford Haven. Finally, it proposes that the Preseli bluestones were selected for transport to Stonehenge because they represented the ancestry of one line of Britain’s
earliest farming migrants who arrived in the Preseli region shortly before 4000 BC.


Authors:

Mike Parker Pearson (Department of Archaeology, University of Sheffield). 
[ M.Parker-Pearson@sheffield.ac.uk ]
Joshua Pollard (Department of Archaeology, University of Southampton). 

[ Joshua.Pollard@bris.ac.uk ]
Colin Richards (School of Arts, Histories and Cultures, University of Manchester). 

[ colin.c.richards@manchester.ac.uk ]
Julian Thomas (School of Arts, Histories and Cultures, University of Manchester). 

[ julian.thomas@manchester.ac.uk ]
Kate Welham (School of Conservation Sciences, Bournemouth University).
Richard Bevins (National Museum of Wales, Cardiff).
Robert Ixer (Freelance geological consultant, Sutton Coldfield).
Peter Marshall (Honorary lecturer, University of Sheffield).
Andrew Chamberlain (Department of Archaeology, University of Sheffield).
 

Tuesday, 22 September 2015

The Millennium Stone Fiasco




Just in case there is still somebody out there who thinks that the bluestones at Stonehenge were transported by enthusiastic (or reluctant) human beings all the way from West Wales to Stonehenge, here is the chapter from my book that deals with the great Millennium Stone Fiasco, just to put you right off the idea.......

https://www.scribd.com/doc/231584137/The-Millennium-Stone-Fiasco

Of course, Prof MPP now thinks that all this stuff about sledges and rollers and rafts is nonsense.  The stones were simply carried by groups of volunteers, resting on a sort of lattice work of bamboo (oops -- sorry -- substitute oak or whatever, and forget the weight of the lattice cradle....).  The latest theory is that the stones were carried in relays of about 2 miles at a time, with one carrying team passing the load on to another all the way along the A40 and thence to Bristol and thence to Salisbury Plain.

Sunday, 20 September 2015

Rhosyfelin -- goodbye to the evidence

 Rhosyfelin after restoration, 20th September 2015

Sad to say, I went over with my wife and son to pick blackberries and crab apples in the Brynberian Valley today, and this is the sight that met us when we got to Craig Rhosyfelin.  The whole of the dig has been filled in, and that huge pile of spoil adjacent to the two dig sites has been dumped back into place, making it impossible to make any further examinations of the stratigraphy which was so beautifully exposed.  The whole site has also been re-seeded.

The two pits as they appeared during the 2015 dig -- exposing a fascinating sequence of glacial and post-glacial sediments on the valley floor. Both of the pits seen here are now filled in.

Actually I'm not criticising the dig team for this piece of restoration. All digs come to an end, and all dig sites have to be restored as carefully as possible, to meet the terms of the consents they have received from the planning authorities and the landowners.  So all the evidence has now disappeared, which might of course be very convenient indeed for anybody who does not wish it to be scrutinized by experts who might raise certain uncomfortable issues.......

I just wish that the closure of the pits could have been deferred.  I did ask the National Park if parts of the excavation site could be kept open so that other geomorphologists could take a look over the coming months, but my letter was ignored.  I wonder why?  What's the hurry? 

Anyway, I just hope that the archaeologists have a detailed plan of exactly where the outlines of these pits are located.  Inside those outlines, future work will clearly be a waste of time, since the sedimentary sequence is destroyed, but on the outside it will still be possible for other researchers to open up pits or to put down drill holes which might help geomorphologists to resolve outstanding problems.

Thank goodness that I have a good photographic record.......

This photo, from a couple of weeks ago, shows the extended dig site from 2014 and the new pit to the left.  The whole of this area has now been filled in with spoil, masking all of the sedimentary exposures.




Were Rhosyfelin fragments used as tools?



I was chasing around for information on lithics and stone tools used in the Neolithic, and I came across this piece on Mike Pitts's blog from the year 2011.  Interesting.  He suggests here that rhyolite is rather useful for the making of tools of various kinds -- especially for cutting things -- and that maybe some of the Rhosyfelin rhyolite found in the Stonehenge debitage is associated with tool-making either in conjunction with orthostat destruction or with tool manufacture at Rhosyfelin itself.  This is something I have suggested before, many times, on this blog.  The illustration above comes from his blog, and presumably shows various rhyolite chips and flakes up to 5 cm long.

Pitts on rhyolite chips and flakes...

https://mikepitts.wordpress.com/2011/12/20/bluestones-on-news-at-ten/

"One of the distinctive features of the rhyolitic rocks is that they are flinty – they have a good conchoidal fracture. That makes them relatively easy to break up, if they are standing as monoliths at Stonehenge. But it also makes them pretty good for making tools, or portable artefacts of some kind. There are plenty of flaked bluestone “tools” in museum collections from Stonehenge (some of them from my own dig, as illustrated above, from my PPS report). Which of these are made from debris created when stones were dressed on site? Which are made from broken up megaliths? And which were made in Wales and brought to Stonehenge by people visiting, perhaps on a pilgrimage of some kind? Clearly the distinction has important implications for how we understand Stonehenge.

These are questions that future research can answer, through excavation in Wales and at Stonehenge and study of the debris – that we can do this is a reflection of the quality and utility of the new research. Ixer and Bevins identified five groups of rock amongst the rhyolitic pieces they studied, of which three (by far the bulk of all they saw) they have matched to the Pont Saeson outcrops. There is one buried stump at Stonehenge (stone 32e) that they say could well be from Pont Saeson (to be confirmed), but the four standing rhyolitic stones are different. One of the latter (stone 48) belongs to one of the two very rare classes that Ixer and Bevins identified, which have yet to be matched to a source. One way excavation at Stonehenge would help us, is in allowing modern identification of the stumps and other bits of megaliths at the site.
"

Wiki:  In lithic stone tools, conchoidal fractures form the basis of flint knapping, since the shape of the broken surface is controlled only by the stresses applied, and not by some preferred orientation of the material. This property also makes such fractures useful in engineering, since they provide a permanent record of the stress state at the time of failure. As conchoidal fractures can be produced only by mechanical impact, rather than frost cracking for example, they can be a useful method of differentiating prehistoric stone tools from natural stones. .............  A swelling appears at the point of impact called the bulb of percussion. Shock waves emanating outwards from this point leave their mark on the stone as ripples. Other conchoidal features include small fissures emanating from the bulb of percussion.

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

This is all a nice idea, but it's worth making the point that there are no -- or very few -- conchoidal fractures in the Rhosyfelin foliated rhyolites.   The fractures are not curved and crescentic, but tend towards being straight and flat.  Just take a look at this photo of rather typical splintered or shattered fragments from the rockfall debris on the flank of the crag:


In my discussions with visitors to Rhosyfelin we have had many duscussions about whether fresh flakes and slivers, either picked up or knocked off the edges of exposed rock surfaces, or even knocked off orthostats at Stonehenge, would make desirable and valuable tools for cutting flesh, skinning animals etc.  Some of us think the foliated rhyolite is rather soft to be used for long-lasting tools, and others disagree.  Edges are certainly very sharp indeed.  Maybe such flakes were so abundant that they could be treated as disposable items, rather like plastic knives are used as cheap substitutes for knives made of Sheffield steel?

This is an interesting dilemma, which maybe needs some input from lithics experts.  What do others think?

Friday, 18 September 2015

Inishcrone - Another glacial entrainment mechanism




This is a fascinating photo from the new QRA publication listing "the top 50 Quaternary sites" in the British Isles.  It's from Inishcrone, in County Sligo in Ireland.

Conventionally, the entrainment of rock slabs on the base of a glacier is assumed to involve two basic processes:

first, a compression process on the glacier bed where high stresses are placed on a vulnerable rock surface which is partly under compression and partly under tension.  That leads to the fracturing of the rock.

second, a "freezing-on" process by which blocks are frozen onto the glacier bed and dragged away on the glacier bed or carried upwards along thrust planes.

The point at which the one process gives way to another is the point at which pressure is released on the glacier bed, and where a film of meltwater on the bed gives way to refreezing.  This is the classic explanation of why and how roches moutonnees are formed.  See many entries in this blog on precisely that topic.

In other situations we know that super-erratics can be incorporated into the bed of a glacier by shearing on a huge scale.  For example, slabs of chalk over a kilometre long have been known to be incorporated into glacier beds because of the massive pressure exerted by thick ice and because of the peculiar circumstances associated with the shear stresses on permeable glacier beds.  Complex physics and rock mechanics.......

The Inishcrone example is fascinating, because it shows yet another entrainment process.  Here, it appears that loosely-jointed limestone beds have actually been bull-dozed by the over-riding ice, giving rise to folding or buckling structures and then the complete elimination of the original stratification of the beds as they are literally smashed up.   Much more information here:

Page 48 in  https://www.qra.org.uk/top-50-quaternary-websites/

Carn Goedog -- have the quarry hunters gone completely bonkers?


 Joint-controlled blocks, slabs and columns at Carn Goedog -- similar to the features found on many of the spotted dolerite tors of Preseli.  Some of the blocks have been loosened by overriding ice, and others are subject to frost-action and collapse under the force of gravity.

So now the quarry hunters have given up on Craig Rhosyfelin (having decided that there is nothing much more of interest to discover) and have determined that Carn Goedog is the site of the Holy Grail.  The logic seems to be:

1.  The geologists have said that Carn Goedog is probably the major source of spotted dolerite orthostats at Stonehenge.
2.  Glacial transport or erratics from here to there was impossible.
3.  Therefore there must have been a major Neolithic quarry at Carn Goedog.

All perfectly simple.  Last year two (or was it three?) pits were opened on the upslope flank of the tor, and there was much talk of finding "proto-orthostats", but nothing of any great interest was discovered. There was also much talk of the settlement site on the downslope (northern) side of the tor being a "quarryman's village" in spite of hints from the Dyfed Archaeological Trust that the stone walls there appeared to come from many different occupational phases.  But what the hell?  A good story is what we need, and that is what we will get...... so there is really no alternative to the view that Carn Goedog was a major Neolithic quarry.

At this point, dear reader, please pause a while and take a look at previous posts on Carn Goedog by putting "Carn Goedog" into the search box.  I know the site very well indeed, having been there probably scores of times over many years.  One of my favourite places, examined in detail during my investigations of glacial processes in the Preseli hills.


Carn Goedog seen from the east.  The settlement site is at the foot of the crags, near the right edge of the photo.  The archaeological dig has taken place in the col between the crags and the mountain side, left of centre.  This pic is from 2014.  The toilet tent can be seen in the col, on the skyline.  This is also on the old drover's route. Click to enlarge.

So, back to Prof MPP's lecture of the other evening at Castell Henllys.  He started his section on Carn Goedog with unrestrained excitement, announcing that this was the place where there had been orthostat extraction "on an industrial scale."  He showed slides of some of the crags on the extensive tor, with a variety of elongated slabs and columns, attributable of course to the jointing or fracture patterns which are in some cases almost like the columnar jointing sometimes seen in basalts.  Carn Goedog is not unique in this respect.  We see the same thing in Carn Meini and in many other Preseli tors.  (They are very special craggy outcrops, made of dolerite rather than granite, and they give Preseli its rather special character.)  I have crawled all over these crags for many years, and have never seen anything which can be interpreted as unnatural or man-made, apart from one drill hole in the rock probably made by a geophysicist.  We know that stones have been taken from here by local farmers (and maybe by the chapel-builders of Felindre Farchog) but their "quarrying" has been very opportunistic, and I reckon that pillar-shaped rocks have been taken from here and there on the accessible part of the crag adjacent to the col or old drover's route, and then taken away by horse and cart (or maybe using horse-drawn sledges, which were popular in Preseli in the nineteenth century because wheels were a nuisance in boggy terrain).  Most of those pillars were intended to be used as gate-posts.

Prof MPP likes his "Eureka!" moments, and we got one in this talk too, when he explained that he suddenly realised that from one particular spot (I know it well) there had been a group of pillars from which several had been removed, leaving three behind in a sort of "pillar depot", and ready to go.........  (I love the way in which "the ones that got away" theme returns to all these Neloithic quarry narratives.  We have seen it at Carn Meini with Profs GW and TD, and at Rhosyfelin with the Neolithic "proto-orthostat" which turned out not to be Neolithic at all.....)  The whole idea is of course pure fantasy.  This is a heavily glaciated ancient tor made of densely jointed spotted dolerite,  from which many blocks and pillars have been removed by ice entrainment, and in which there have been massive alterations of crag morphologies by freeze-thaw processes and block settlement under the influence of gravity, over a very long period of time.

Next, we heard about a soil that had been developed in a place from which a pillar had supposedly been removed, and in which a piece of charcoal from c 4,000 BP had been found.  That is probably based on one of the Carn Goedog radiocarbon dates.  That's very interesting, but it tells us precisely nothing about how the supposedly missing pillar had been removed, or when.  MPP tells us it was  taken away in the Neolithic -- and presumably carried off to Stonehenge -- but that is complete speculation.

Next, we heard about the results of the 2015 excavation on the site, extending out from the crags and into the boggy "col" which was used as the old drover's route in the 1700's and early 1800's.  MPP announced that the diggers had discovered a "pavement" of slabs laid flat on the ground, a band of smaller stones that had "clearly" been laid in a ditch of some sort, a "ramp" used for moving stones away from the quarry, and then finally some elongated stones that had been laid on edge, suggesting that they had been used as trestles for some reason as yet unknown.

From where I sat, this was no more convincing than any of the stuff about props, revetments, pivots and railway lines at Rhosyfelin.  The "pavement" seemed to consist of one or two flattish rocks lying flat, which is what flattish rocks generally do. The line of stones in a ditch simply looked like smaller stones deemed to be in a line -- maybe because all the stones on either side had been removed.  The ramp seemed to be an artifice, just like the "quarry face" at Rhosyfelin.  And the extraordinary idea that stones lying on edge had maybe been used as trestles left even the most gullible members of the audience looking a bit gobsmacked......  As ever, the impression comes over that Prof MPP and his colleagues have arrived at a site determined to describe what they expected to see, and not what is actually there.  Anything that might possibly have had some "engineering" function is given a function, no matter how far-fetched that might be.    The engineering glossary gets larger and larger. Amazing -- and very worrying.

The Prof claimed that he could see where the later quarrying of the Carn Goedog crag had been undertaken by local 18th C and 19th C farmers towards the western end, and that the Neolithic quarry could be clearly seen at the eastern end, around the area of the 2015 dig.

He mentioned that various other radiocarbon dates had been obtained on bits of charcoal, one giving a date of 5,200 yrs BP and dating from the Mid-Neolithic.  I got a bit confused by his arguments about dating, but the message seemed to be that the main quarry here was in operation several centuries BEFORE the stones were taken to Stonehenge to be used in the bluestone horseshoe, indicating that the stones were used initially in some Mid-Neolithic (before 5,000 yrs BP) structures in the neighbourhood -- and that probably means in large tombs or long barrows.  So the hunt is now on -- those tombs have to exist somewhere in the area, and they have to be found.  Tally Ho!  Several more years of hunting for the archaeologists.  In their view the quarry problem is sorted, and now the tomb hunt is on.  Indiana Jones to the rescue, as ever.......... and one day the tomb of doom will assuredly be found.

But don't the radiocarbon dates confirm the presence of a Neolithic Quarry?  No, they don't.  We have not thus far been given any stratigraphic or locational contexts for the dates that have been mentioned, and as with all research projects of this type we don't know how many age determinations have been reported and how many have been withheld.  We have to reserve judgment until we see the full published results, but until then the default position has to be this. Some dated bits of charcoal in the soil in a location like this tell us that there were fires at various times, and that bits of wood were burnt, suggesting human presence -- but they do not tell us anything at all about why people were here, whether they had a permanent or ephemeral presence, or whether they were hunters, travellers, traders or quarrymen.

I'm not surprised that an audience of people who do not know the site will tend to accept almost everything at face value, and indeed to get rather excited because a learned professor has chosen to share with them some brand new discoveries that have not yet been divulged even to the scientific community.  But what I am surprised by is the apparent acceptance of MPP's narrative by all the people he is working with.  There are lots of them, all with their special skills.  No doubt most of them are rather intelligent.  Some are even professors. But have they all become infected by a sort of mass hysteria?  Are there no restraining voices?  And don't any of them know anything about Occam's Razor or the scientific method?

PS.  Apologies, dear readers!  It's been pointed out to me that the wording of the final paragraph above was not very clever.  Point accepted.  I referred to "relatively ill-informed" members of the audience without qualifying that to mean "relatively ill-informed about the site in question".  That's what I actually meant.  Of course I also accept that those who take the trouble to attend lectures on local archaeological matters are on the whole wonderfully intelligent, with at least some background knowledge of the Neolithic and the Ice Age!  Anyway, I have now changed the wording appropriately.

Thursday, 17 September 2015

Rhosyfelin -- the new pit


This is the new pit at Rhosyfelin, out on the valley floor.  Having heard that this pit (and the old one, presumably) would be filled in today, I just happened to be passing this morning, and popped in to take some pics before everything disappeared.

This is the "old ground surface" which is being dated as 7,500 years old. It is the upper surface of the clay-rich till and other sediments which underlie the foxy red iron-stained horizon.  We don't know how many stones have been taken away by the archaeologists -- but in the middle of this little lot, Prof MPP claims to be able to see a curving "routeway" along which bluestone orthostats from his beloved quarry were trundled on their way down the valley (northwards) and thence towards Stonehenge.  If you can see a trackway here, you are a better person than I. 

According to the gospel story, this trackway is connected to a "loading platform" and a quayside and revetment, just to the left off the edge of the photo.  This is what the latter features look like in reality:

This is the "revetment" or quayside -- the big boulder at the water's edge was supposedly put into position by the quarrymen, as part of the facility to make loading (onto what?) easier.  The huge boulder lying flat on the surface of the glacial sediments was supposedly a part of the "loading platform" where orthostats were assembled prior to despatch.  No comment.

No doubt it will be rather a relief to the archaeologists that by now this whole scene will have been buried as they put all the spoil back into position, making further scrutiny by sceptics like me quite impossible.....

Wednesday, 16 September 2015

Rhosyfelin -- the glacial transport theory is alive and well


 A Devensian till exposure at Rhosyfelin.  There is the little matter of glaciation to be considered......

Apparently the work at Rhosyfelin is done, and the archaeologists will be filling the dig holes in tomorrow and restoring the site.  That's a pity, since there is still a lot of useful geomorphology that could be done if the sediment exposures had been left accessible.  Ah well, future explorers of the site will have to dig their own holes.

After five years of intense excitement, we come away with NOTHING that compromises the glacial transport hypothesis.  The foliated rhyolite provenancing work is interesting, but is irrelevant as far as the bluestone transport debate is concerned. 

What we now know is that there has been occupation of the site intermittently since the Mesolithic, but none of that occupation can be tied to quarrying activity, and there are no tools, artefacts, antlers, shoulder blades or hammerstones which can be cited as evidence of quarrying or digging activity.  We have already dealt with the fantastical features described by Prof MPP in his lectures, including fulcrums, pivots, props, railway lines, platforms and working floors, packing materials, revetments and quaysides, worked rock faces, ramps and trackways, and scratches created by stones being dragged along.  They are all figments of somebody or other's rather fertile imagination, and on examination they are all seen to be completely natural and unsurprising -- and even boring and commonplace.

As for the radiocarbon dates, they confirm intermittent occupation and burning (either in camp fires or for woodland clearance) but they do nothing else.  They seem to be isolated in the sense that they cannot be tied incontrovertably to specific activities.  They are certainly interesting and important for the elucidation of a settlement history, but they do NOTHING to support the idea that there is a QUARRYING history here.

So after all the sound and fury, I still think that large chunks of the Rhosyfelin crags were entrained by over-riding ice, probably during the Anglian glaciation, and sent on their way towards Stonehenge without any assistance from our Neolithic friends.  I thought MPP was completely wrong in 2011, and I still think he is wrong in the extraordinary story he has fabricated for this site.

What we have here, I think, is a classic example of a group of fieldworkers moving in on a site with a pre-formed or predetermined ruling hypothesis, and then spending four years describing what they expected to see, in rather colourful terms, while failing to describe calmly and rationally what they were actually looking at.  It could all have been so different, had they bothered to include a glacial geomorphologist in their digging team or even in their group reviews of progress.  Instead of that, they have apparently spent their time in a bubble, impervious to sage advice from outside, freely given, by me and a lot of other people who actually do know what they are talking about.  Should we blame a National Geographic funding contract for at least a part of this situation?  I suspect so........ since in the media all that matters is a good story.

Prof MPP's 2015 lecture: Rhosyfelin




Just back from Prof MPP's lecture at Castell Henllys education centre, with the not very subtle title "Stonehenge and its bluestone quarries."  So the audience had a pretty fair idea, before he even started speaking,  that there was not going to be much discussion about the pros and cons of the quarrying hypothesis.........

Where to begin?  I have to admit that when MPP had finished I said nothing, because if I had disputed almost everything that had been said in the talk (as I wanted to), with an audience of people who do not even know Rhosyfelin and Carn Goedog, the process could have taken several hours and would certainly have become rather animated!! So I let a few others ask rather innocuous questions, and we all went on our way........

There is so much to say that the process will take several posts, some on Rhosyfelin and others on Carn Goedog.

Key points to start with, which I had already picked up from some of my spies prior to the lecture:

1. The famous 8-tonne proto-othostat never was intended for Stonehenge.  Some charcoal found beneath it was radiocarbon dated to the Early Bronze Age, so the big stone could not have been emplaced in the Neolithic.  MPP now thinks it was intended to be a standing stone in a local Bronze Age stone setting, but that it was rejected by the quarrymen because a large chunk broke off it.

2.  Apparently assorted geomorphologists who have visited the site with MPP have informed him that the rock face is artificial rather than natural.  I do not have a clue which geomorphologists these might have been,  but all I can say is that those who have visited the site in my company have been unanimous in stating that they see NO traces of human involvement in the shaping of the rock face.  It is, in their view and mine, entirely natural.

3.  MPP admits there never was a quarry settlement here.  There are assorted radiocarbon dates, and traces of food supplies such as hazel nuts, but the signs are that there has just been intermittent occupation of a camp site here during the Mesolithic, Neolithic and Bronze age, and maybe even later.

4.  No traces of artefacts, tools or other things associated with quarrying have been found, and there are no post holes that might indicate permanent settlement or ritual use of the site.

5.   MPP claims to know EXACTLY where a Stonehenge rhyolite bluestone was taken from, and blames Rob Ixer for this wonderfully precise bit of provenancing.  He showed a pic of himself standing on the exact spot.  (As we have said many times on this blog, it's not THAT precise, if the primary literature is anything to go by, for all sorts of reasons including a quite inadequate density of sampling points.)

6.  MPP claims that 2 or 3 rhyolite bluestones may have been taken from here to Stonehenge, but God knows where that particular piece of reasoning came from.

7.  A big new pit has been opened up on the floor of the valley, in the river gravels, and MPP claims that this has revealed a corridor or routeway along which bluestones were trundled or carried away down the valley, travelling northwards.  From the slides he showed, this was just as fantastical as the "revetment" or quayside which we have already discussed......

8.  The oldest radiocarbon date from the site seems to be one of c 7,500 yrs BP, from charcoal in the stained colluvial layer described in a recent post.  That means that there was some occupation here in the Mesolithic, possibly involving burning of the woodland.

9.  The clay-rich till found beneath the "proto-orthostat" is interpreted as a "clay-rich binding agent used for stabilising packing materials" used to support the weight of the stone.  Oh dear oh dear......

10.  In the whole lecture there was no mention of till, fluvio-glacial gravels, stratified slope deposits or any other sedimentary layer, and no mention of any natural processes or features. 

Before I start to get really rude, I'd better go to bed.  And you ain't heard nothin' yet.  Just wait till I get round to describing what has been said about Carn Goedog........

Meltwater channels: Afon Teifi and Afon Nyfer catchments




Many thanks to Neil Glasser for sending me a copy of this interesting paper, which we have not previously discussed on this blog.  The paper looks at the meltwater channels in the Cardigan - Newport area, and confirms what I have been saying for 45 years or more -- that the channels cannot be attributed to one glacial episode -- the Late Devensian.  They are far more interesting than that, and this paper reveals just what complexities there are -- identifying different channel types and using contained sediments as one of the means of working out relative ages and origins.  Many of the channels are originally subaerial and fluvial, formed in conditions when there was no glacier ice anywhere in the vicinity -- as one would expect. Then we have the effects of at least two glacial episodes -- the Anglian and the Late Devensian -- with channel segments and sometimes whole channel systems being modified when used by large volumes of meltwater.  Sometimes the water flowed subglacially, and sometimes in the open.  Many of the channels are humped -- I would have liked the location of the humps to have been shown more clearly on the above map.  But it's a great map -- and a very useful reference for future work.

The authors have concentrated on a classification of channel types and on explanations of the phases of erosion which have given them their present forms.  What the authors don't do, however, is tie these channels (or even segments of them) in to the ice bodies responsible, and the directions of ice movement or hydrostatic gradients within the ice.  That's for another paper, maybe.  But the interesting thing, as far as I am concerned, is that the channels have alignments that are very "inconvenient" when we try to relate them to the current consensus on the movement of the Irish Sea Glacier across this area, both in the Anglian and Devensian glacial episodes.  The ice is supposed to have moved from NW towards SE across this area on both occasions -- maybe N-S during some phases.  But these channel systems, like the Gwaun-Jordanston channel system further to the west, are aligned for the most part E - W -- and that would mean that prevailing meltwater flow would have been against the hydrostatic gradient in the ice......  and that would break the most basic of the physical rules.

https://www.qra.org.uk/top-50-quaternary-websites/        See p 52
http://brian-mountainman.blogspot.co.uk/2012/02/those-meltwater-channels.html

So the possibility exists that these channel systems  -- all of them -- were originally created at a time when Welsh ice covered this area, moving approximately east - west, with meltwater flow during a deglaciation or ice wastage phase then following the normal rules of physics and flowing westwards with assorted swings influenced by pre-existing topography.  Alternatively, if Welsh ice was not involved, it is possible that pre-existing (pre-glacial?) channels were such significant features of the landscape that they directed subglacial meltwater flow during a phase -- or several phases -- of very rapid ice wastage.   That would only work if the collapse of the Irish Sea Glacier in Cardigan Bay was truly catastrophic.  Somebody else needs to work all that out..........  maybe with some modelling thrown in.

So where did that huge volume of meltwater go?  One last thought on this -- could that extraordinary chasm in Ramsey Sound have anything to do with it?


I have done several posts about Ramsey Sound and the images kindly provided by Dr Paul Evans.  There is talk of catastrophic floods being responsible for the draining of impounded lake water through the Straits of Dover -- could it be that the Ramsey Sound trough was formed in a similarly catastrophic fashion, by meltwater that had been forced westwards along the North Pembrokeshire coast (off the present coastline) and which then found a convenient escape route southwards between the mainland and Ramsey Island?


Glasser, N. F., Etienne, J. L., Hambrey, M. J., Davies, J. R., Waters, R. A. & Wilby, P. R. 2004 (August): Glacial meltwater erosion and sedimentation as evidence for multiple glaciations in west Wales. Boreas, Vol. 33, pp. 224–237. 

Abstract

This article presents the results of a geomorphological and sedimentological investigation of former glacial meltwater drainage in the region of the lower Afon Teifi, one of the major rivers of southwest Wales. Former drainage characteristics in the region are reconstructed concentrating on palaeo-drainage routes associated with successive Pleistocene glaciations and their role in the Quaternary evolution of the lower Teifi. Mapping of these features throughout a c. 100 km2 area reveals a complex evolution in the establishment of the present-day drainage system, with evidence for the following surface channel types: (i) type 1 channels of primary subglacial origin cut during the late Devensian (late Wisconsinan/late Weichselian) glaciation; (ii) type 2 channels representing either pre-late Devensian subaerial fluvial run-off, unconnected to the course of the preglacial Afon Teifi, or originating as subglacial chute channels; (iii) type 3 channels developed as subglacially modified pre-late Devensian tributaries of the Afon Teifi. Two further features are also described: (iv) type 4 channels are drift- plugged abandoned preglacial courses of the Afon Teifi, and (v) type 5 channels formed as lateglacial and post- late Devensian gorges which bypass type 4 channels. A relative chronostratigraphy based on channel geomorphology and sedimentology reveals an evolutionary sequence considerably more complicated than identified in previous studies, with extensive modification of the lower Afon Teifi region by glacial meltwater during at least two periods of Pleistocene glaciation.

Tuesday, 15 September 2015

Rhyolite groups A-C



On reading through "Chips off the Old Block" by Rob Ixer and Richard Bevins, I was reminded of this statement, in the Conclusions part of the text:

"If the parent orthostat for the rhyolite groups A-C were sampled and it proved to be either SH32d or SH32e then it would demonstrate that widespread and abundant debitage is directly associated with an orthostat, is the partial result of the destruction of that orthostat and has not been introduced into the Stonehenge Landscape for other reasons or by other processes including glacial ones."

A number of things.  I'm still confused by the numbering of these stones.  On the Atkinson photos, 32e (closest to stone 33) looks like a dolerite stump, whereas stones 32c and 32d do indeed look like  rather flaky rhyolites.  Is there a definitive ruling somewhere as to which stone is which?

Second, can somebody please explain what the differences are between the foliated rhyolites in Groups A, B and C?  They are mentioned in several of the key papers, but I am still confused. Presumably they are all foliated rhyolites ......... but if they are different enough to be in different petrographic categories, how can lots of fragments in all 3 groups have come from the same stone?

Third, I don't follow the logic in the argument that if the fragments in the debitage can be related to the destruction of a big stone, that somehow rules out the introduction of debris into the landscape by glacial or other processes.  Surely it is perfectly feasible for debris from a large stone or super-erratic to have been scattered about in the landscape prior to the selection and introduction of a small part of it into a stone hole? At that point it became an orthostat or a standing stone.   You have no way of knowing how big or small that stone might have been prior to its selection and use......  and of course, if it was destroyed later on, there would have been the introduction of even more flakes and debris into the debitage.
  
Update

I found this classification in the Craig Rhosyfelin paper:

A. Dark/black, sharp, flinty rhyolite ± joint planes. Rare, pale-coloured, flinty rhyolite is probably weathered dark rhyolite.

B. Rhyolite with a planar fabric. Rare, extreme examples of this group initially were classed as ‘slate/phyllite’.


C. Rhyolite with a pronounced planar and lensoidal fabric ± joint planes.

I'm still confused.  Are these three categories now deemed to be redundant, and have they been rolled into one?  But they sound rather different from one another...... and that being the case, how can they all have come from one stone?


Monday, 14 September 2015

UK's Top 50 Quaternary Sites



Hot off the press!  Published today -- a new booklet from the Quaternary Research Association which is a fantastic teaching resource.  The top 50 Quaternary sites in the UK -- well, actually they got such a response from contributors that there are 80 sites, but the more the merrier......

Feel free to browse happily -- it's amazing what a diversity of Quaternary sites we have in this country.  Probably most of your favourites are in there somewhere.  There is a handy list which you can browse through, with hyperlinks to those sites you want to look at.  Mercifully, the descriptions are short and pretty non-technical.

https://www.qra.org.uk/top-50-quaternary-websites/

Solifluction sediments and colluvium at Rhosyfelin

This photo from 2011 shows the stratified solifluction deposits in which the "proto-orthostat" was embedded when it was discovered.
 

Colluvial and other deposits on the valley floor near the outer tip of the spur. At the base, fluvioglacial and glacial deposits (light grey). Above, dark grey finer-grained sediments, grading upwards into buff / cream coloured colluvium with iron-staining increasing upwards. Above that, an irregular junction with dark brown colluvium and modern soil.

Dr Simon Carr taking samples from the stained layer during a recent visit.

Interbedded with the rockfall debris and overlying the till and fluvioglacial deposits at Rhosyfelin, there is a layer of slope deposits up to 2.5 m thick. It's quite variable and very interesting indeed, and is difficult to interpret both with respect to age and origins.

The material exposed adjacent to the large slab is reminiscent of the “upper head” or stony solifluction layer found above Devensian glacial and fluvioglacial deposits in West Wales coastal sections. Exposures cut in the sediments in 2012 showed that more than 5m from the rock face there is a clear contact between the till and the overlying pseudo-stratified slope deposits. Within the latter there are at least five different but discontinuous layers, with a c 10 cm sandy/silty layer at the base. Above that, there are some layers of fine-grained sediments and others made up predominantly of elongated stones and flakes less than 10 cm in length. In addition to an abundance of sharp-edged local rhyolite fragments there are some large slabs and boulders and also, in the lower layers, rounded and sub-rounded erratics derived from upslope glacial materials. There are many signs of root penetration through this sequence, and the fine-grained layers contain many streaks of peaty organic debris. These materials have moved downslope predominantly from the NW, W and SW. The big flat-topped "proto-orthostat was embedded in this sediment layer when it was discovered. There do not appear to be any ice wedge casts which might suggest the presence of permafrost at the time of accumulation or at a later date, but in lower horizons there are some signs of bedding disturbances possibly attributable to frost-heave processes.

Further downslope, where the surface gradient decreases, the stones in this layer become less abundant, and it is predominantly made up of colluvial gravels, sands, silts and clays. Resting directly on the fluvioglacial deposits on the edge of the Afon Brynberian floodplain, there are at least three bands which are difficult to correlate precisely with the layers at the upslope end of the dig site. That having been said, there do not appear to be any discontinuities or unconformities that might show a long break in sedimentation.

At the base (close to the valley floor water table) there is a blue-grey layer at least 30 cm thick. It is clay-rich but incorporates bands of gravels which appear in places to have been deformed either by loading or frost-heave processes.

Above that is a layer up to 80 cm thick made up of sands, silts and clays but with some gravel and stone inclusions. There is no sharp junction between this and the underlying grey-blue sediment; texturally the two bands appear to be related. In this deposit there are occasional fragments of charcoal, suggestive of either natural / accidental burning of woodland or scrub in the vicinity, or else human occupation. This layer is buff- or cream-coloured at its base, but passing upwards iron-staining becomes more and more prominent, until the sediment has a distinct foxy-red colour similar to that on the till surface elsewhere on the site. It is noteworthy that the iron-enriched band transgresses the junctions between stratigraphic layers, suggesting that it is a pedogenic feature related more to water table oscillations than to age. (Iron "pans" are common in podzol soil horizons across north Pembrokeshire.)

Finally there is a grey-brown surface layer made of accumulated fine-grained slope materials, passing upwards into modern soil. There is a high content of organic matter, and more fragments of charcoal. This layer is up to 80 cm thick on the lower part of the site.

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

This layer with many internal variations has to be post-glacial because it sits directly on till and fluvio-glacial gravels. But how old is it? Does it represent the whole period between c 18,000 years ago (when the last of the ice may be assumed to have melted away) and the present day? Or could there be a lot of sediments missing, and could it be of much more recent date?

Radiocarbon dates from some of the charcoal inclusions might help with the dating process: but one technique that might be particularly useful is OSL dating (optical thermoluminescence dating) which is best used on sediments that at the time of formation were exposed to daylight. The solifluction deposits might not be very suitable for sampling, but the colluvial deposits might be;   advice is needed on this.

Somebody's reading all this stuff........


I switched on the computer earlier on and found that there was a nice round figure on the counter.  Almost as exciting as watching the mileometer on a car gradually passing the 100,000 mile mark........

So a pure fluke.  But it's always good to know that there are a few readers out there.  What also interests me is that so few actually contribute to our discussions.  Maybe they look at the comments pages, and get put off by all that metaphysical / folk music stuff........  no matter, I rather like all you strange, crusty, eccentric, and expert contributors who make up our little community!  Obviously, or I would have gone off and done something else long ago.  So thank you all for what you bring to our common pursuit of the truth.

Show, don't tell.........



One of the great guiding principles of science is "Show, don't tell........"  That was something drummed into me when I started on my doctorate research, all those years ago, and the principle won't have changed in the years that have passed.

Everybody who has been required to submit a doctorate thesis will have been instructed by his / her supervisor to conduct research in a meticulous fashion, with good recording, and to them write a thesis more or less as follows:  Background to the problem >> statement of the problem itself >> working hypothesis to be tested >> presentation of evidence from the lab or from the field >> synthesis and summary of major results >> relevance to the problem being tested >> conclusions re confirmation or rejection of the working hypothesis.  At the end of it all, you only get your PhD or D Phil if you have moved forward the sum total of human knowledge in a meaningful way and have demonstrated a capacity for clear and independent thought.

Peer-reviewed scientific papers should of course follow the same route.  That is not to say that all peer-reviewed papers are honest and truthful -- you just have to look at "Retraction Watch" to see how much scientific fraud and corruption there is out there, especially in those areas where huge commercial interests are involved -- such as pharmaceuticals or agrichemicals.  But powerful media interests can also lead to results being skewed, and to research being slanted towards the establishment of the spectacular or the newsworthy rather than towards the truth.  So we need to be concerned about the recent news that the National Geographic Magazine is being taken over by James Murdoch and Fox.

https://www.washingtonpost.com/lifestyle/style/national-geographic-magazine-shifts-to-for-profit-status-with-fox-partnership/2015/09/09/7c9f034e-56f0-11e5-8bb1-b488d231bba2_story.html

That's seriously scary, given what the new owners have done in the past to pretend that climate change is a myth, and given Fox's role in that infamous trial a few years ago which established the principle in American law that media organizations are not obliged to tell the truth.  The truth, according to the judge in that case, is whatever you deem it to be...........  just think for a moment what the implications of that statement actually are.........

What got me thinking about all of this was a poem read out by "the canal boat laureate" Jo Bell, at a very pleasant PENfro Festival literary lunch yesterday.  Not everybody knows that Jo used to be an archaeologist (before she received enlightenment) and that she has actually written poems that are to do with her past.  I was very much struck by these lines:

"Record what you can see
And not what you expect......"

She suggested that that piece of sound advice should apply to poetry as well as to archaeology and other disciplines.  Well, on this blog I have always tried to show rather than tell, by putting evidence in front of anybody who may be interested, for critical comment and respectful debate.  What I have always had a big problem with, on the matter of the Rhosyfelin "Neolithic Bluestone Quarry" and on other matters, is that certain archaeologists have done a lot of telling and not a lot of showing.  And I have grave concerns that for much of the time they have been recording "what they expected" rather than "what they could see."  Come hell or high water, this is a Neolithic Quarry, and if it takes us ten years, this is what we will show........  We are now in the fifth year of the digging programme at Rhosyfelin, and we have not seen a single piece of "showing" and evidence presentation in print in a seasonal dig progress report or anything else.  Just not good enough, guys......  simply from the point of view of your own self-interest and academic reputations, to get this far into a project without any of your ideas being scrutinized and tested, except by those who are within the "bubble", is downright foolhardy.

By the same token I have to admire the geologists -- particularly Rob Ixer and Richard Bevins.  On some matters I find their evidence less than convincing, but that's the way of the world.  At least they have published, and their papers are out there, freely available for the rest of us to scrutinize.  And we have had some good knockabout fun with them, on this blog, thanks to our mysterious friend Myris.

How long will it be, I wonder, before hard evidence gets in the way of a rather good story?

Sunday, 13 September 2015

Stonehenge DEBU (date of earliest bluestone use)



Following up on Tony's recent comment about the relevance of Bluestonehenge, I too have looked at Wikipedia for guidance!  (Yes, I know that's a naff thing to do, but most Wikipedia entries are pretty reliable, since nonsense tends to be kicked out and replaced by people who consider themselves to be experts!)

So here's what the entry says:

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

The monument has been tentatively dated to between about 3000 and 2400 BC, although radiocarbon dating of antler tools found at the site has only provided an approximate date of 2469 to 2286 BC for the dismantling of the stones.[5] Tests on an antler pick found at the bottom of a stonehole have so far failed due to inadequate collagen in the sample.[6][7]

Excavation revealed several stone settings that are thought to have been erected some time between 3400-2500 BC, due to two flint chisel arrowheads in a style commonly used during that period being found. It is estimated that there may have been as many as 27 stones in a circle 33 feet (10 m) wide. Charcoal was found in some holes, suggesting that burning may have taken place there.[8] One suggestion is that the henge was a site for cremations.[7] Within the stone circle there were imprints of the bases from the original stones, which have been compared to the bluestones located in Stonehenge and have been found to have matching dimensions.[original research?]

The name "Bluestonehenge" is derived from the discovery of small stone chips in some of the stone settings. These bluestones are also found in Stonehenge and consist of a wide range of rock types originally from Pembrokeshire West Wales, some 150 miles (240 km) away.[2][9] Archaeologist Mike Parker Pearson suspects that any bluestones in the circle may have been removed around 2500 BC and incorporated into Stonehenge, which underwent major rebuilding work at about that time.[7]

The stone circle settings were surrounded by a henge, comprising an 82-foot-wide (25 m) ditch and outer bank which appears to date from approximately 2400 BC.[7] Unlike Stonehenge, there do not appear to be any significant solar or lunar orientations within the monument.[8]

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


So MPP appears to be convinced that the bluestones were moved some time after 5400 yrs BP and were in place here by 5,000 - 4,400 yrs BP --  up to 27 bluestones?  They were then moved to Stonehenge around 4400 yrs BP for incorporation into the monument.....

So this would, if correct, give us a DEBU (date of earliest bluestone use) of between 5,400 and 5,000 yrs BP.  The problem is, as we have pointed out many times on this blog, there there does not appear to be a shred of evidence to support this theory apart from some putative stones holes that appear to have contained stones which later appear to have been taken away.

Saturday, 12 September 2015

When were the bluestones first used at Stonehenge?





With Prof MPP no doubt planning to reveal his 20 or so Rhosyfelin radiocarbon dates to the world on Wednesday next, it's worth reminding ourselves of the sequence of events as currently understood.  

The piece below was posted on this blog back in Oct 2011 -- shortly after the Rhosyfelin dig started.   The interesting point to come from the chronology assessments is that Prof MPP favours a very early (Middle Neolithic) use of bluestones at Stonehenge, around 5,000 years ago, in Stage 1, when they were placed in the Aubrey Holes.  The evidence for that seems a bit scanty, but one line of argument is that the holes were of  remarkably similar dimensions to the Q and R holes which were (by common consent?) later used for a bluestone setting.  Another argument is that the holes were too big for timber posts and therefore held stones of bluestone size (rather than of sarsen size -- sarsen monoliths would have required much bigger holes).  Then there is the evidence of crushed chalk and other debris, suggesting a great pressure exerted from above -- and the cremation evidence, which is somewhat equivocal.

On the other hand, my understanding is that Darvill and Wainwright argued that the bluestones did not get used at Stonehenge until Stage 2, when they were placed in the Q and R holes around 4,500 years ago, in the Late Neolithic.  They propose that this happened after the erection of the sarsen trilithons but before the erection of the sarsen circle.  

There seems to be more agreement about what happened after that.  In Stage 3 (c 4350 yrs ago) (Copper Age) there may have been some rearrangement of the bluestones inside the trilithons.  In Stage 4 (c 4,100 yrs ago) (Early Bronze Age) the bluestones are thought to have been taken from the Q and R holes and placed in their "final" positions, first in the outer bluestone circle, and then in the bluestone oval or horseshoe.  In Stage 5 (c 3600 yrs BP) (Middle Bronze Age) the Y and Z holes were dig, maybe with the intention of putting bluestones into them, but in the event nobody ever got round to doing it............

That is the chronology as far as I understand it from Prof MPP's 2012 book.  So, if you believe in the human transport theory,  the favoured story is that the bluestones were carried from Wales in the Middle Neolithic, around 5,000 years ago.  Of course, as we have said many times before, the presence of that dolerite boulder in Boles Barrow pushes the "earliest bluestone use date" back to around 5,500 years ago. 

All comments on the accuracy of the above will be welcomed! 

===================== 

Did the Aubrey Holes hold 56 bluestones?

Sunday, 9 October 2011

 

   

I found this report from 2008 on the research council web site -- and it struck me that the discovery in Aubrey Hole 7 of "crushed and compacted chalk" by MPP and his team is about the only evidence we have that the holes once held bluestone pillars. The report says that a similar feature was also found in 3 other Aubrey Holes in earlier excavations. But how do we know that this compaction was not simply done by a ramming device, with the purpose of creating a firm base in the hole for whatever was due to be placed in it? (eg cremated remains). No bluestone fragments, as far as I know, have been found in the Aubrey Holes -- so the pillars (if there were any) could well have been small sarsens rather than bluestones. But MPP builds up a large hypothesis here -- not for the first time -- on what seems to me to be very flimsy evidence. He even speculates now that the stone circle of 56 bluestones had a diameter of 87m -- and that that stone circle might well have been carried from Preseli, where it was previously set up at Waun Mawn. He also says that when the Neolithic transport gangs had carried that stone circle lock, stock and barrel (or maybe minus the 3 stones that are still there) from Waun Mawn to Stonehenge, and put them all up in the Aubrey Hole setting, they later dismantled the whole thing and moved the stones in towards the centre of the monument, where they were supplemented by another batch of stones from the wild west (bringing the total up to 82), and then built into the later bluestone circle and horseshoe settings.

Type in 'Waun Mawn" in the search box for my previous posts on this topic.......

Does anybody know of any other evidence that supports this wacky theory, or is is just as wild as I think it is?

==========================
From the AHRC web site -- a report of a project funded with £500,000.

Changing the meaning of Stonehenge 

09 Oct 2008 
AHRC-funded excavation of Aubrey Hole  could change Stonehenge’s meaning

A new excavation of Stonehenge, funded by the Arts and Humanities Research Council, has revealed that an Aubrey Hole – one of a circle of pits surrounding the stones at Stonehenge – had probably held a standing stone.
The excavation of Aubrey Hole 7 was directed over one week in August 2008 by Mike Parker-Pearson, Mike Pitts and Julian Richards for the Stonehenge Riverside Project. The project, sees a collaboration involving five UK universities and over 200 archaeologists, and is funded by a £500,000 research grant from the AHRC.
Professor Mike Parker-Pearson at the University of Sheffield says, “If all 56 pits had held stones, this would have been one of the first and largest stone circles in the country, made of Welsh bluestones in 3000BC. A recent claim that these stones arrived at Stonehenge in 2300BC would then relate to the time when the bluestones were moved into the centre of the site 700 years later. Stonehenge’s history as envisaged since the 1950s is overturned.”
The pit had already been excavated twice: when discovered in 1920, and again in 1935 when all the cremated human bone found earlier at Stonehenge was reburied. Recovery of this bone for modern examination was the prime goal of the new dig (the bone was in excellent condition, and study will begin over the winter).
Another reason was to look at the Aubrey Hole itself – the first to be seen open since 1950. It was believed that these pits had been dug for oak poles, but Parker-Pearson had revived an old interpretation that they had held bluestones: the evidence of crushed and compacted chalk had been recorded in 1920 in three of the pits. He says, “Aubrey Hole 7 had crushed chalk on its base indicative of a standing stone. This had been missed by archaeologists twice before: it seems likely that similar evidence still survives in other Aubrey Holes. We propose that very early in Stonehenge’s history, 56 Welsh bluestones stood in a ring 285 feet 6 inches (87m) across”. He concludes, “This has sweeping implications for our understanding of Stonehenge.”
The new evidence from Aubrey Hole 7 suggests megaliths were present throughout Stonehenge’s existence. The first three radiocarbon dates for human cremation burials, obtained in May from the only bones then available for study, range between about 3000 and 2300BC. Contrary to claims made in the recent BBC Timewatch film, which promoted a theory of Stonehenge as a healing centre built after the practice of cremation burial had ceased, standing stones and burial of the dead may have been prominent aspects of Stonehenge’s meaning and purpose for a millennium.
Ends.
Media Contact: Emi Spinner, Communication Officer,  tel: 0117 9876 770 / 07854 005662


Editors Notes

Arts & Humanities Research Council: Each year the AHRC provides approximately £100 million from the Government to support research and postgraduate study in the arts and humanities, from archaeology and English literature to design and dance. In any one year, the AHRC makes approximately 700 research awards and around 1,000 postgraduate awards. Awards are made after a rigorous peer review process, to ensure that only applications of the highest quality are funded. Arts and humanities researchers constitute nearly a quarter of all research-active staff in the higher education sector. The quality and range of research supported by this investment of public funds not only provides social and cultural benefits but also contributes to the economic success of the UK.

Aubrey Holes

56 pits named after the 17th century antiquarian John Aubrey, were discovered by archaeologists in 1920. Thirty four were excavated 1920–1924 and two in 1950. They average about 3.5 feet across (1.1m) and 3 feet deep (0.9m) – similar to pits in the centre of Stonehenge known to have held bluestones. Their contents included mostly undistinguished artefacts, and pockets of cremated human bone and ash.
The pits’ purpose has been much debated. The original excavators first thought they were dug to hold small standing stones (the Welsh bluestones): the great Egyptologist Sir Flinders Petrie suggested they were a war indemnity paid by a Welsh tribe. But debate followed on whether they had held stones or wooden posts. After the 1950 excavation of two pits, they were believed to have been only for the placement of ritual deposits, with no stones or posts. In the 1960s astronomers suggested they may have held markers to predict eclipses. Since 1995, the standard interpretation has been that, when first dug, they held tall oak posts that had no astronomical function.


Cremation at Stonehenge

About 60 finds of cremated human bone are recorded at Stonehenge, representing some 50 people. Most of what survives has now been recovered in the excavation of Aubrey Hole 7. All such remains had originally been buried in or near Aubrey Holes or the ditch beyond. Pitts has suggested that in total, the cremated remains of some 240 people were buried at Stonehenge. This is by far the largest cemetery of this era we know of in Britain.
After the 1920s excavations had ended, no institution wished to curate the cremated bone, and in 1935 Wiltshire archaeologists William Young and Robert Newall buried them in Aubrey Hole 7. A lead plate with an inscription briefly describing the event was found in August. Today we expect to be able to learn a great deal from these remains, identifying sex, age and health of the individuals, and with a new process we can radiocarbon date them.


Bluestones

The great majority of researchers agree that almost all the bluestones were brought to Stonehenge by people from a small area of Pembrokeshire around the Preseli Hills. There are no stone chips at the bottom of the Aubrey Holes, but large numbers elsewhere on the site. It may be that 56 stones were brought to Stonehenge as natural boulders around 3000BC, and erected in the Aubrey Holes. Only later were some of them (not all) carved to shape, and further bluestones must have been brought to Stonehenge either then or before.
The total weight of all original bluestones at Stonehenge was around 260 tons. The total weight of the sarsens (the larger stones, brought from some 20 miles away) was around 1,700 tons.


BBC Timewatch

These new claims conflict with those made by Timothy Darvill and Geoffrey Wainwright, who excavated at Stonehenge in April. In a BBC broadcast on September 27, they said the first bluestones arrived at Stonehenge in 2300 BC, by which time cremation burial had ceased.
We cannot support the 2300 BC radiocarbon date. It was obtained from a single cereal grain, which most archaeologists would find unacceptable. Items this small can be moved by burrowing animals – Charles Darwin showed the burying power of earthworms specifically at Stonehenge in 1877. It also conflicts with other radiocarbon dates and the known sequence of megalithic construction at the site, which together place the first erection of bluestones in the centre of Stonehenge at an unknown date before 2470 BC.
There are currently only three radiocarbon dates for cremation burials. It is statistically unlikely that the last burial that took place at Stonehenge is amongst those dated, so the most recent date of 2470–2300 BC should not be read as dating the end of that tradition.


Stonehenge Riverside Project

Responsible for major excavation within the Stonehenge world heritage site over the past five summers. Directors are Mike Parker Pearson (Sheffield University), Joshua Pollard (Bristol University), Colin Richards and Julian Thomas (Manchester University), Christopher Tilley (UCL) and Kate Welham (Bournemouth University).
Website at www.shef.ac.uk/archaeology/research/stonehenge

Thursday, 10 September 2015

Lower Palaeozoic sandstone at Stonehenge


I found this illustration in one of Rob Ixer's publications.  It's rather pixellated, but it shows an erratic fragment (size not known) of a buff-coloured Lower Palaeozoic sandstone found at or near Stonehenge.  The geologists seem pretty certain that it is from the Lower Palaeozoic, which means that it's probably Ordovician or Cambrian,  or could be Silurian (there are some Silurian sandstones in Pembrokeshire, in the central part of the county and on Skomer Island).  At the moment the money seems to be on NW Pembrokeshire as a source, and we await with interest the next Ixer / Bevins geological paper which might shed light on the provenance of this fragment and some other related fragments from Stonehenge.

Rhosyfelin and "spot provenancing"



 This is the "exact spot" from which a Stonehenge rhyolite bluestone orthostat is supposed 
to have been taken.......


Is it possible for geologists to provenance rock fragments found in one place to a locality a great distance away, with an accuracy of "a few square metres"?

As readers of this blog will know, Prof MPP claims to know exactly where at least one Stonehenge bluestone has come from, and he has pointed the spot out to many visitors to the Rhosyfelin dig site.  OK, you might say, he's just repeating what the geologists have told him.....

But hang on a minute.  If you read the papers by Ixer and Bevins rather carefully they are for the most part rather circumspect, and they are very cautious about making claims that might be difficult to sustain under close scrutiny.  So who's responsible for the hype here?  This is important, because the story of this "precise provenancing"  has been picked up by the media and by all sorts of august institutions like the Pembs Coast National Park and the Dyfed Archaeological Trust -- so the truth does become rather important.  So what are the facts?

Well, we have (according to a mysterious source) about 40-60 thin sections of rock samples from the Rhosyfelin - Pont Saeson area, and we can probably assume that there are an approx equal number of thin sections from the "foliated rhyolite" debitage in the Stonehenge area.  So do the matches match the hype?  Here we have a problem, because very few of these "Jovian fabric" slides have been published.  No problem with that, since no researchers ever publish ALL their data, and as Myris has reminded us, they try to publish slides that are "typical" or "representative" of the group as a whole.

The slides I have been able to find are reproduced below, with full acknowledgement to Richard Bevins and Rob Ixer and their colleagues.

 Rhosyfelin Location 8, near the tip of the rocky spur

 
 Point PS8 from Pont Saeson
 
 Point PS10 from Pont Saeson

 
OU18, from the Avenue at Stonehenge

 
Jovian fabric from Stonehenge samples -- sample STH08-738

 
Jovian texture -- sample from near the Heel Stone at Stonehenge

The top thin section -- actually representing the rocks at the tip of the spur at Rhosyfelin -- is the crucial one here, and what we need is something from Stonehenge that matches it almost exactly. 

The sample from the Heel Stone fragment is not all that good a match, because the black blobs look rather like tadpoles on that one  (excuse the scientific language.......).  The closest match is that of Sample STH08-738, but even that is not all that close, because the black blobs are less frequent and there is a sort of melted or fluidized look to the slide which is absent in the one from Rhosyfelin.  And the larger phenocrysts (right word?) are more prominent and texturally distinct at Rhosyfelin than they are in the Stonehenge sample.

Could the Heel Stone sample have come from another part of the Rhosyfelin crags, or is it matched to something further away?   Could OU18 have come from Pont Saeson PS10?  They do look rather similar.......

What we don't know at present is the extent of lateral variation in texture along a foliation plane, or the extent to which samples taken from the rock face at Rhosyfelin are representative of those rocks a metre or two "behind" the rock face, or higher up or lower down.  Maybe that info will be forthcoming in a future paper?

So on the evidence currently before us, M'Lud, I suggest that the case is not proven.  I do not see anything in the Stonehenge samples to convince me of an identical match.  Neither do we know how big a variation there is in the Stonehenge material.  Could the samples all have come from one or two stones that have been broken up, or could they have come from a much wider range of material in the Stonehenge landscape and transported by ice from the Rhosyfelin - Pont Saeson neighbourhood? Now there may well be other samples hidden away that we have not yet been shown.  But I suspect that if there had been "better" Stonehenge samples, we would have seen them by now.  On the principle of "Show, don't tell" may we have a look at any other thin sections that might help to convince us that there really is a match to "within a few square metres" between something at Stonehenge and something at Rhosyfelin?