The great Millennium Stone Pull

Came across this picture in my photo album -- which reminded me just how idiotic this whole theory about the human transport of the stones actually is. If HH Thomas had not dreamt up the whole silly notion, just think what a lot of human effort might have been spared -- millions of words in print, endless debates on blogs and forums, vast sums spent on reconstruction projects, and the same old stuff going round and round, with people in general fascinated by the idea of ancient tribesmen invested with extraordinary engineering skills, stupendous imagination, and incredible social and economic motivation -- not to mention the navigational and maritime skills used in treacherous coastal waters with high tidal ranges, mudflats, storm waves and roaring currents.

I thought for a long time that it was a fine thing to engage in some of the Stonehenge blogs, on the basis that discussion would lead all of us eventually to the truth........ but no matter how one attempts to address the real issues of engineering and motivation, and no matter how much one tries to debate the glacial ("alternative") theory, people will insist on going right back to square one and asking "I wonder how they did it?" and coming up with endless theories, apparently without ever stopping to ask the questions "Did they do it?" and "Is it necessary to speculate on this anyway?"

The picture above shows how difficult it was to control one smallish bluestone on a sledge, on a moderate slope, during the "Millennium Stone" pull in the year 2000. With the aid of netlon (low-friction netting), modern ropes, asphalt roadways and help from cranes, JCBs and modern boats, the project was still a shambles that left the stone on the bed of Milford Haven.

Here's a proposal -- forget about the human transport altogether. Pretend that the daft idea had never even been thought of. And concentrate all the formidable brain power of the people of the planet (well, a little bit of it anyway) on solving the riddle of how natural processes carried some of the Stonehenge "bluestones" from West Wales to Somerset and Wiltshire. Jim Scourse and Chris Green have declared -- in print -- that it was "impossible" for natural processes to have been responsible for this entrainment and transport. Not a word one should use lightly........

Those undistinguished outcrops

Carn Llwyd, not far from the coast and above the town of Newport. This little outcrop is so insignificant that if you are a few hundred metres away you hardly notice it at all. It is well down the slope on the northern flank of Carningli.

Happy Christmas everybody!! Escaping from the grandchildren for a few minutes, while the turkey cooks to a turn, I retired to the sanctuary of my study and pondered on undistinguished outcrops. It's worth flagging up again just how significant the new findings from Rob Ixer and Richard Bevins are. The new discoveries from the source area of many of the Stonehenge bluestones suggests not only that the stones were not preselected by rock type (ie nobody went out hunting for spotted dolerite) but that they were also not preselected from prominent outcrops. The idea that the stones were taken from Carn Meini (a) because the crags were made of the mystical or magical spotted dolerite which reminded the gatherers of the night sky, or which had healing properties; and (b) because the crags were prominent on the skyline, and were therefore treated with awe or invested with great significance, is now shown more than ever to be pure fantasy. The stones are not just made up of many different lithologies (some of which, like volcanic ashes, are soft and crumbly) but they also come from some places which are not at all prominent in the landscape. Examples of such source areas are Carn Clust-y-ci and Carn Llwyd near Newport, and Pont Saeson near Brynberian. At the latter place there are no prominent rock outcrops at all -- just some exposures of bedrock on the flanks of a wide river valley.

Unless anybody can dream up some wildly wacky reason for stones to be gathered up from such a place and dragged all the way to Stonehenge, we might as well dispense with the human transport theory once and for all, and concentrate on the REAL problems -- ie

(1) what were the glaciological conditions responsible for the entrainment, transport and dumping of the stones?

(2) exactly when did this happen? and

(3) where were the stones dumped, and how far did they need to be carried from their "discovery points" to the Stonehenge monument?

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

Key source of info:
British Archaeology
news
Important revision to Stonehenge bluestone theory

In the News pages of the Nov/Dec 2009 issue of British Archaeology, it is reported that new petrographical work by Rob Ixer (University of Leicester, Department of Geology) and Richard Bevins (National Museum of Wales) had suggested that some of the Stonehenge bluestones had not come from Pembrokeshire, but (in Ixer's words) from "a far wider and, as yet, unrecognised area or more likely areas". As the magazine was being printed, however, Bevins was out in the field, and found an apparent source for the rocks in question north of the Preselis. Ixer and Bevins have kindly written this interim note on this latest development.

Stilpnomelane-bearing rhyolites/rhyolitic tuffs at Stonehenge are most probably from the Preseli Hills region.
by Rob Ixer & Richard Bevins

".......rocks from undistinguished outcrops in the low ground north of Mynydd Preseli, close to Pont Saeson".
"...... but a search for their associated source rocks must no longer be restricted to the prominent outcrops on the Preseli Hills."

http://www.britarch.ac.uk/ba/ba109/interim.shtml

Stonehenge and the Olympics

Now that considerable doubt has been thrown on the "authorized" version of the Stonehenge story -- and especially the bluestone chapter -- I wonder how much of that story will be modified on English Heritage web sites and publicity material? I suspect that the fairy tales about Neolithic tribesmen and their heroic efforts (not to mention their amazing navigational skills) in transporting the bluestones from A to B are actually too valuable to ditch, especially with the London Olympics not very far away. Stonehenge, great national treasure that it is, will be marketed for all it's worth, and the more heroic tribesmen figure in the story, the better the foreign visitors will be pleased, and the the more foreign exchange will jangle into the EH cash-boxes. They will have been charged by the Government with maximising their income during and around the Olympics, so that public funding can gradually be pulled, and I predict that they will do virtually nothing to jeopardise their chances of doing that, by "watering down" the authorized story of expressing doubts about the truth of any of it........

I will have a look at some of the current EH material, and report back.......

Glaciation of the Mendips

The Mendips -- glaciated or not?

I've always been intrigued that many geologists and geomorphologists have argued that the Mendips have never been glaciated. For some reason they want to maintain the pretence that ice coming in from the Bristol Channel skidded to a halt just a few kilometres inland from the present coast, somewhere around Court Hill. The main inland sites with good evidence of glacial deposits are Kennpier, Nightingale Valley, Weston-in-Gordano, and Yew Tree Farm, none of which is more than 5 km from the coast. These deposits are variable, and include flow tills and fluvioglacial gravels. So nobody can doubt that this area was glaciated by ice coming in from the west.

But then things get a bit silly. Because these deposits indicate ice-edge or ice-marginal conditions, some quite senior geomorphologists have argued that they show us the maximum inland extent of the ice. There is nothing to suggest that this was a true TERMINAL MORAINE, and indeed we know that the ice DID extend much further inland on at least one occasion. There are clear traces of glaciation at Bath University / Bathampton Down, Hampton Rocks Cutting, Newton St Loe, and Stidham Farm on the River Avon. So the ice extended at least 35 km to the east of Kennpier, Court Hill and the other sites mentioned above. Much of the Avon Valley must have been glaciated. To the south of the Mendips, the ice reached at least as far inland as Greylake. Maybe there were two lobes of ice, one pushing up the Avon Valley and the other pushing in from Bridgwater Bay into the Somerset Levels. But it is almost inevitable, given this scenario, that the Mendips were also glaciated; and indeed the deep gorges of the Mendips speak of huge volumes of glacial meltwater carving into the Carboniferous Limestone bedrock. Some authors have argued that the gorges were cut by water from snowmelt under periglacial conditions, but I just do not think that snowpatches, even over many thousands of years, could have provided the water volumes necessary. We need a full ice cover across the Mendips -- and that is indeed what the glacial modelling suggests.

Bluestone monoliths

Callum and Finley -- bluestone monolith in Tycanol Wood, Pembs

Bluestone monoliths or orthostats cause great excitement in Wiltshire, but they are all over the place in Pembrokeshire. This one is on the north side of the Preseli Hills, and is made (like many others in the area) of bluish dolerite. Probably it is local, from the Fishguard Volcanic series of rocks. Such rocks have been used since the Neolithic, usually very close to their places of origin, for cromlechs, standing stones, lintels and window sills, headstones for graves, and (as here) as gateposts. It is virtually impossible to say which of these stones are prehistoric and which are modern -- the collection and use of the stones goes on to this day.........

And forget about the idea that there was a "bluestone quarry" -- stones have been collected from the litter or scatter of elongated stones right across the North Pembrokeshire landscape. The collectors -- now as in the Neolithic -- have been opportunists and pragmatists driven by utilitarian motives rather than sacred or ritual ones.

Clay-with-flints and Chalky till

Back to the UK. Been pondering on the ancient deposits that sit on the chalk in Eastern England. The map shows that in Hertfordshire there is a south-western zone with "clay-with-flints" (brown) on the interfluves (implying that these deposits are very old, and are indeed older than many of the river valleys) and a north-eastern zone (light blue) with Chalky Till. This is a greyish colour (see the photo above) and contains chalk, flint, and erratics from the north. It has all the characteristics of a typical till laid down by a wet-based glacier -- supposedly in the Anglian Glaciation. Does the distribution of this till actually give us the extent of the maximum glaciation in this area?

OK -- on to the "clay-with-flints" (which occurs quite frequently on Salisbury Plain and on the higher Chalk Downs. Here is the Wikipedia entry:

Clay-with-Flints was the name given by W. Whitaker in 1861 to a peculiar deposit of stiff red, brown or yellow clay containing unworn whole flints as well as angular shattered fragments, also with a variable admixture of rounded flint, quartz, quartzite
and other pebbles. It occurs in sheets or patches of various sizes over a large area
on the north to Sussex on the south, and from Kent on the east to Devon
on the west. It almost always lies on the surface of the Upper Chalk, but in Dorset
it passes on to the Middle and Lower Chalk, and in Devon it is found on the Chert-Beds of the Selbornian group (A. J. Jukes-Browne, The Clay-with-Flints, its Origin and Distribution, Q.J.G.S., vol. lxii., 1906, p. 132).

Many geologists have supposed, and some still hold, that the Clay-with-Flints is the residue left by the slow solution and disintegration of the Chalk by the processes of weathering; on the other hand, it has long been known that the deposit very frequently contains materials foreign to the Chalk, derived either from the Tertiary rocks or from overlying drift. There is evidence against the view that the deposit is mainly a Chalk residue, This shows that many patches of the Clay-with-Flints lie upon the same plane and may be directly associated with Reading Beds. He concludes that the material of the Clay-with-Flints has been chiefly and almost entirely derived from Eocene
clay, with addition of some flints from the Chalk; that its presence is an indication of the previous existence of Lower Eocene Beds on the same site and nearly, at the same relative level, and, consequently, that comparatively little Chalk has been removed from beneath it. Finally, I think that the tracts of Clay-with-Flints have been much more extensive than they are now. Clay-with-flint is a nutrient rich substance unlike chalk.(bc. cit. p. 159).

It is noteworthy that the Clay-with-Flints is developed over an area which is just beyond the limits of the ice sheets of the Glacial epoch, and the peculiar conditions of late Pliocene and Pleistocene times; involving heavy rain, snow
and frost, may have had much to do with the mingling of the Tertiary and Chalky material. Besides the occurrence in surface patches, Clay-with-Flints is very commonly to be observed descending in pipes often to a considerable depth into the Chalk; here, if anywhere, the residual chalk portion of the deposit should be found, and it is surmised that a thin layer of very dark clay with darkly stained flints, which appears in contact with the sides and bottom of the pipe, may represent all there is of insoluble residue.

A somewhat similar deposit, a congbomirat de silex or argile a silex, occurs at the Paris basin, in the neighborhood of Chartres, Thimerais and Sancerrois.


So what are the relationships of these two deposits? Both are highly variable -- and the Clay-with-Flints has -- in some instances -- been interpreted as a glacial deposit because it contains so much erratic material. Mostly, however, it is interpreted as a residue or remnant of younger (Tertiary) rocks that once capped the Chalk and which have subsequently been eroded away.

More on erratic trains

Some of the boulders in the erratic train are 16m in diamater.

Thanks to Lionel Jackson for bringing this to my attention. There are more examples here of "erratic trains" -- this time strung out in the lowlands of Tierra del Fuego, and traceable back into the mountains of the Cordillera Darwin. The thousands of boulders in the erratic trains are largely unmodified by glacial abrasion, and they sit on top of moraines -- so they are interpreted, like the Foothills Erratic Train in North America, as having come from valley side avalanches descending onto moving glacier ice. The ice has carried them away on the glacier surface and has "attenuated" or strung them out -- so that what might have been a cluster to start with has been transformed into a linear feature. Interesting info, which might help us in our attempts to work out what the glacier dynamics were when the erratics were transported from Wales to the eastern side of the Bristol Channel.

Reference:
Enigmatic boulder trains, supraglacial rock avalanches, and the origin of “Darwin’s boulders,” Tierra del Fuego
by Edward Evenson et al
GSA Today, v. 19, no. 12,pp 4-10

Finding the GBG ice edge

The two maps above show ice movements during earlier glaciation(s) of eastern England, with "British" ice from the north pressured eastwards by Scandinavian Ice coming in from where we now have the North Sea (which was not there at the time). Note that the ice edge is almost as far south as London.




These two UK maps are of limited use, since they relate to the Last Glaciation. There is now great dispute as to where the southernmost Devensian ice limit might have been, following the discovery that till on the Scilly Islands is of this age. (Thanks to Clark, Gibbard and Rose)

Lessons from Jameson Land?

Jameson Land, East Greenland. On the satellite image, Jameson Land is the large unglaciated area to the east of the broad Scoresby Sund -- which carried the ice from a number of the East Greenland Fjords. The undulating landscape of central Jameson Land is very different from that of the "fjordland" to the west and north.

Ah - happy days! I walked across part of this area and worked here in 1962. Been pondering a bit on how we might find parallels between this area and Salisbury Plain -- a lot of geomorphology is done by analogy, in which we seek guidance to what happened in one landscape by reference to what can be observed elsewhere, in similar terrain or where glaciological circumstances might have been similar.

Jameson Land might give us clues -- because instead of seeing evidence here of streaming ice and deep erosion, we appear to have a landscape which has been effectively protected by stagnant or sluggish cold-based ice. Lena Hakansson, who has studied this area, says that: "... local ice with limited erosion potential covered and shielded large areas for substantial periods of the last glacial cycle." Local ice -- that's interesting, and maybe something that gives us a guide to what might have happened over the Mendips, Dartmoor and Exmoor. But there are erratics and some exposures of till in Jameson Land -- these appear to be much older.

There are plenty of erratics on Salisbury Plain, as shown in earlier posts on this blog. Till is usually observed in river cuttings or road excavations. But because Salisbury Plain is made of chalk, the effects of fluvial erosion are very limited. What we have are coombes or dry valleys, but few exposures or cuttings to tell us whether there are any thick sediments present, and how they may be distributed. We know about the "clay-with-flints" and occasional river terraces made of gravels, but otherwise there appear to be no records of anything that might be referred to as unequivocal "till" or boulder clay. I wonder what's lurking beneath the surface, waiting to be discovered?

Glaciation "impossible" on the Wiltshire Downs?

Crusoe Glacier, Axel Heiberg Island, N Canada. I visited this glacier more than 40 years ago -- very impressive, with relatively clean ice, and in places a vertical ice cliff simply sitting on the tundra (which of course is permanently frozen).

I have been looking again, in the big Cunliffe/Renfrew "Science and Stonehenge" book (1997), at the chapters written by Jim Scourse and Chris Green. I am still amazed, as I was when I first read them. Seldom have I encountered such certainty, and without accusing them of pandering to the wishes of their sponsors and most influential readers (ie the archaeology establishment) I wonder why and how they can have brought themselves to the point of using the word "impossible" with respect to the glaciation of Salisbury Plain, or even a part of it. These chapters, which we might call "the Gospels according to St James and St Christopher", have of course been heavily cited by the likes of Darvill, Wainwright, Parker-Pearson and Pitts -- who say, repeatedly, that if "their experts" tell them that glaciation this far east was impossible, then it WAS impossible. My two learned friends are frequently referred to as either geologists or glaciologists -- they are neither, since (like me) they are geomorphologists. Their opinions are no more reliable than mine...........

What I find intriguing -- and somewhat irritating -- is the manner in which they waste a great deal of time going after some of the extreme and peripheral issues raised in the writings of Geoff Kellaway -- and spend very little time addressing the key issues:

1. Why is there no evidence in support of the human transport hypothesis?
2. Why are there so many rock-types represented at Stonehenge, and so many variations in "bluestone" size and shape, varying from substantial monoliths down to small stones and fragments?
3. If you are looking for "evidence of glaciation" as a geomorphologist, surely it is there, before your very eyes, in this complex and varied assemblage of "foreign stones"?
4. If the ice of the Irish Sea Glacier did (as they admit) extend across the Bristol Channel coast and into Somerset, would it not be more logical to assume that the "foreign" stones at Stonehenge (and elsewhere) were erratics, dumped somewhere to the west of Stonehenge?

They seem to have major problems on these points, and they do not address them properly. I'm not saying they are wrong in everything they say -- but I do challenge some of their assumptions. They say that if the Plain was glaciated, there should be glacial sediment sequences and "depositional landforms." I disagree. They say that if the chalk scarp had been overridden by ice from the west, there would be "glacio-tectonic structures." I disagree. They say that glaciological theory makes it impossible for glacier ice to have carried erratics from Preseli to Stonehenge. I disagree. They say there is an inconsistency between "observational and theoretical data.... and the regional geological data." I disagree.

The answer, when it comes (and it will come) will be partly down to the collection of field data and partly down to a better understanding of what happens on a chalk downland when it is affected by cold-based dry ice. It is patently obvious that Salisbury Plain was not affected by warm-based and "wet" ice carrying huge amounts of debris; if it had been, there would be glacial sediment sequences, moraines and other features all over the place. But I prefer to look, for my parallels or analogies, at the northern parts of Canada, the Dry Valleys of Antarctica, and maybe parts of North Greenland, where polar-based ice affected the landscape without doing very much to it at all. This is where our debate should concentrate...... and all contributions will be gratefully received!

Hobgoblin musings

This simple map shows the locations of the bluestones and the sarsens on the site today. Missing stones everywhere -- if they were ever there in the first place.....

On another blog site, a fellow who calls himself "Hobgoblin" has been examining the implications of the latest geology findings by Rob Ixer and Richard Bevins. This is the site:

http://thehobgoblin.blogspot.com/2009/11/new-stonehenge-bluestone-mystery.html

And this is his commentary:

"So where does this leave the bluestone transportation debate?

The Stonehenge sarsens, the largest used in the Great Trilithon estimated at 50 tons, were brought 25 miles from the Marlborough Downs, which was a significant achievement in its own right. Transporting 4 ton bluestones 160 miles by human effort from South Wales to Salisbury Plain certainly seems plausible. There were also a small number of limestone blocks and slabs used in the construction of Stonehenge brought to the site for the specific purpose of packing material to support the much larger sarsen uprights. The limestone quarries have been identified as Chilmark, 12 miles west, and 3 miles southeast at Hurdcot.

The number of different rock types found amongst the bluestone group at Stonehenge is cited as significant evidence of glacial deposits, with debate continuing for the location of the exact quarry sites seen as the basic flaw in the argument for human movement of the bluestones, in other words identifying the quarry site(s) will prove the human agency method. According to Ixer & Bevins's revision statement were are still looking at Preseli as the geological provenance for the majority of bluestone. Anyone familiar with the Preseli mountains will be aware that there is ample loose bluestone over a number of peaks in the mountain range and would therefore not need to be quarried but pieces the appropriate size simply collected with minimal effort for use in the monument requiring later minimal dressing prior to erection. The bluestone constructions at Stonehenge were built and rebuilt maybe as many as five times over a 400 year period. We do not know if all the bluestones were brought at the same time, but it is quite conceivable that different working parties, possibly generations apart, collected from different sites in the Preseli mountains. As Rob Ixer told BA, had “different groups [of people] brought different stones?”

As Anthony Johnson states in his recent work on Stonehenge:

“...as there appear to be so relatively few bluestone finds outside Stonehenge and its immediate environs, with no extensive distribution across the Plain or its river valleys, a glacial derivation is considered unlikely. The glaciation theory has to address why the people building the earliest stone monument appear to have selected only exotic stones; if Salisbury Plain had been littered with a variety of rocks, including local sarsen, was the intention to gather material suitable to build the first stone circle, or primarily an exercise in prehistoric field geology?

It is far easier to envisage the bluestones collected at the source (i.e. where they outcrop), than to see them as having been selectively chosen from the surrounding landscape. There is a another important point to consider here: whilst a variety of large exotic rocks and even hammer-stones and mauls was used in the packing of the sarsen uprights, implying that stone for this purpose was in short supply, none was bluestone; had it been generally present within a local glacial assemblage it would undoubtedly have been collected and utilised.” [1]

It would appear the building materials for Stonehenge were carefully selected from various sources for specific purposes, far from being a “rag bag mix of glacial erratics”.

With all due respect, Mr Hobgoblin, I think I have to part company with you on a great deal of that. Some people may think the sarsens were transported 25 miles from the Marlborough Downs, but I certainly don't, and nobody has ever produced evidence in support of that theory. Pure speculation. And to use that as a basis for saying "Well, if they could do that, then moving little bluestone blocks from Wales would have been easy" is to get into circular reasoning territory. To say that the Preseli area was littered with blocks which could be "simply collected with minimal effort for use in the monument" is sheer fantasy. You are talking about incredibly rough terrain, dense woodland, bogs, steep slopes, and fast-flowing streams -- this terrain was vastly different from the gentle grasslands of Salisbury Plain. And I disagree with Anthony Johnson -- there is no evidence that the builders of the earliest stone settings at Stonehenge only used "exotic" stones (bluestones). We do not know that. At least two of the bluestones were sandstones -- left as stumps now under the turf. We only have traces of 43 "exotic" bluestones. Those who want there to have been 80 or more have to explain where all the others are -- I have argued in my book that they may not have been there -- ever. Even if they were present at one time, it is likely that they were small sarsens, maybe later removed and incorporated into later stone settings, or used as lintels in the sarsen circle or on the trilithons.

When was the GBG?

Because the stratigraphy in many of the key sites in Somerset and Avon is difficult to interpret (and difficult to date, in spite of a plethora of modern techniques) the date of the glacial and fluvio-glacial deposits is a matter for conjecture. The latest thinking seems to be that the GBG (Greatest British Glacation) occurred in Oxygen Isotope stage 16 -- ie about 650,000 years ago. That places it before the Devensian Glaciation (the last glaciation, which peaked about 20,000 years ago) and even before the "Anglian Glaciation" -- and puts it into a period known as the Cromerian in the UK. That was a long period of oscillating climate which may have included several glacial and interglacial episodes.

The two maps above show (above) the "conservative" ice limit -- which is certainly too conservative, since we know of glacial traces outside it -- and (below) the "extreme" limit that seems, on present evidence, to accord best with the glaciological modelling. But on this map, there is a lot of "ground truthing" to be done -- ie it must, if it is to withstand scrutiny, be matched up with field evidence of erratics and maybe other ground features. Best of all, some sections have to be discovered in Somerset in which the stratigraphy of glacial and non-glacial deposits can be examined. Watch this space.....

Where are the geomorphologists?

Salisbury Plain -- glaciated or not?

I still count myself as a geomorphologist, although I retired from teaching the subject many years ago. Seeking to understand the lumps and bumps, dips and dales in the land surface is still a fascinating business, and I have tried -- over the past three years or so -- to apply the principles of geomorphology to sorting out the "bluestone question." I should have thought that professional geomorphologists -- and there are plenty of them -- would have been jostling to get in their comments on the bluestone debate. OK -- they have lots to do on the teaching front, and they all have their own pet research projects to follow through -- but surely the bluestone mystery is one of THE great mysteries which has still has to be answered? And it's a classic one in which the earth sciences -- in this case geology, geomorphology and glaciology -- have a huge amount to offer, as against the fanciful theorizing of the archaeologists. We do actually have evidence on the ground, as I have tried to point out in the book and on this blog. But those geomorphologists who have had something to say (including James Scourse, David Bowen and Chris Green) have strangely simply put up the shutters and said "No glaciation on Salisbury Plain. End of story." -- without using their critical faculties to address the manifold shortcomings of the human transport theory. Can it be that they -- like the archaeologists -- are simply afraid of rocking the boat?

The Bluestone Enigma -- the video

I put this little video onto the site in the Spring -- here it is again if anybody hasn't seen it. It's on YouTube, but the quality leaves much to be desired. It makes many of the key points of my argument -- very briefly indeed. If you need more info, you'll have to buy the book, or work through some of the entries on this blog!

Stonehenge Disloyalty

I've been getting a fair bit of stick on one of the other discussion sites on the grounds that I have shown a "lack of respect" to Stonehenge by calling it a tumbledown old ruin, an unfinished jerry-built disaster and various other things. Apparently I am supposed to show it due reverence, and to accept that it is a masterpiece of ancient engineering with wondrous spiritual qualities.........

I'm constantly intrigued that for some, Stonehenge is not just an icon but also something akin to an altar or a cathedral. OK, people can invest Stonehenge with whatever degree of sanctity they choose, but I part company with them when they say that it is somehow disrespectful -- and maybe sacriligious -- to ask serious questions about how it was built, how the stones were transported, and whether it was ever actually finished. And to talk about glaciers and erratics is somehow to question at a fundamental level man's capacity for original thinking, his aspirations and his technical abilities -- and even his spirituality. The epic story of the Neolithic tribesmen targetting and fetching all those bluestones from Wales has taken on a sort of religious significance, and is invested with the same sort of assumed truth that fundamentalist Christians apply to the books of Genesis and Exodus. People WANT to believe it. And when I come along and question the fundamentals of their belief system, they become FURIOUS!!! Strange old world...... a world in which rational assessments of evidence become all but impossible.

Bluestones everywhere

Normanton Barrows from the air

I've been reminded that there are many other bluestone occurrences on Salisbury Plain besides those mentioned in the last post. In the big OU study published in 1991 there are about 30 mentions of bluestone fragments / flakes / pieces found in locations outside Stonehenge. Among the barrows mentioned are Amesbury 51, Amesbury 4, Amesbury 39,Stoke 28, Heytesbury 1 (Boles Barrow), Lake, Winterbourne Monkton, Cursus, Fargo Plantation, and about 20 fragments mentioned by Julian Richards. Some fragments appear to be flakes from axes, but many are not. Included are spotted dolerites, rhyolites, unspotted dolerites, diorite, granodiorite and other bits unidentified. Much work is still to be done on these fragments and pieces. Are they all related to the working of bluestones at Stonehenge? That's very doubtful indeed -- as it is also doubtful that the fragments are all bits or roadstone or "surface litter." Many of the pieces are in barrow soil or fill -- and are not in positions where they might be placed if they were being treated with reverence because of some special "quality."

I think we are beginning to answer those who keep on saying "If the bluestones are erratics, why aren't there bluestones all over the place on Salisbury Plain?" Well, there apparently ARE bluestones all over the place........

Bluestone scatter on Salisbury Plain......

I reported earlier on Geoff Kellaway's conviction that there is (or was) a scatter of bluestones and bluestone fragments (of all sorts) on Salisbury Plain. I've seen a number of references lately to bluestone fragments in the Normanton Barrows complex to the SW of Stonehenge. Now I came across this, in Julian Thomas's 1999 book "Understanding the Neolithic." On p 179 he says: "... bluestone fragments in several Beaker and Early Bronze Age graves, such as Amesbury 51 and Fargo Plantation........ and Amesbury 4......"

Does anybody know anything about these fragments?

The other sandstones

With ref to the recent discussion on the Altar Stone, I just recalled that there are 2 (at least) other sandstone monoliths in the bluestone circle at Stonehenge -- numbered 40g and 42c. They are conveniently forgotten about, because they are just represented as stumps, buried beneath the turf and now no longer visible.

Where have they come from? Well, four sandstone fragments (that may or may not be linked directly to these stumps) have been examined by Dr RG Thomas, Dr Rob Ixer and Dr Peter Turner -- and it turns out that they are not the same as the Altar Stone sandstone, and not from the Cosheston Beds. They may be Silurian sandstones, from western Pembrokeshire, Ceredigion or mid-Wales.

More thoughts on ice movement

(This map has been tweaked since the original posting. I had the ice-shed over Mid Wales too far to the east. I have now shifted it westwards, closer to the Cardigan Bay coast -- which of course wasn't there at the time.......)

I'm still waiting to see how the models of the Greatest British Glaciation (GBG) turn out, but I'm more and more convinced that the contact zone between the Welsh Ice and the Irish Sea ice must have had "waves" or wobbles in it. As the Irish Sea Ice was thinning on its way up the Bristol Channel, I think it would have been pressurized by the sheer weight of ice coming off the Welsh Uplands -- the mid Wales plateau and the Brecon Beacons. The ice would have been flowing fastest in the main troughs -- the valleys of the Tywi, Tawe, Neath, Rhondda, Cynon, Taff, Usk and Wye. A vast amount of ice must also have poured over the interfluves. This must have pushed the contact zone out from the present coastline of South Wales.......

This is a suggestion, but may explain the relative paucity of Irish Sea Till on the coasts of Gower and in the vale of Glamorgan. On the map the black line is the reconstructed ice limit for the last (Devensian Glaciation) which is not really relevant for the GBG except insofar as it shows where the main outlet glaciers were. The red arrows show Welsh Ice movement directions; the orange arrows show the movement of Irish Sea Ice; and the suggested contact zone is shown in blue.

At various stages of the glaciation the pressure of Welsh ice may have pushed the Irish Sea ice even further to the south.

The entrainment zone which I have postulated for the Dinas Head - East Preseli area may just have operated for a short time -- maybe that was displaced also at the peak of glaciation, with or without any entrainment going on.

Comments, anybody?

New map of suggested ancient glaciation

This map was made for an article by Lionel Jackson and myself in Earth Magazine -- strangely, the colours have gone mad. And the key has disappeared. Never mind -- you can still see the postulated ice cover, the postulated erratic train transportation route, and the Mynydd Preseli source area for some (indeed the majority) of the bluestones for which we still have physical evidence at Stonehenge.

Some of the evidence for glacial traces in the South-West is to be found here:

http://www.brianjohn.f2s.com/enigma4.html

The references to the relevant scientific papers are in the book!

Who wrote the script?

Been pondering on who might have written the script for that Hidden Histories programme (or at least, that bit of it which dealt with the Presely / Stonehenge link). I've concluded that it was written by somebody who was not familiar with the Stonehenge literature, or with the debate about the origins and transport of the bluestones. There was such an emphasis on the "ground-breaking" nature of these "exciting revelations" from our friend Wainwright that this must have been written by a publicist or public relations person working for the Royal Commission. Or was the script written by Wainwright himself? I wonder....

In case you missed it.......

One of the supposed "healing springs" at Craig Talfynydd. The rock here is not blue (even when fresh), and is not spotted dolerite.

That programme is on BBC iPlayer, here:

http://www.bbc.co.uk/iplayer/episode/b00nv5kv/Hidden_Histories_Series_2_Episode_1/

Frankly, I'm amazed that Dr Toby Driver and the Royal Commission should have allowed themselves to be suckered into involvement in that programme, and to have apparently signed themselves up to all that rubbish about sacred springs and healing stones, quarries, sledges and rafts. Are they incapable of independent thought, and so in awe of senior academics that they are incapable of noticing that there is not actually any EVIDENCE to support anything that Prof Wainwright said to the camera? Sheer fantasy, from top to bottom.

"New light from the Preseli Hills...." ?? Nonsense.
"... 80 bluestone monoliths...." ?? Nonsense.
"... we know the precise outcrop..." ?? Nonsense.
"Evidence of quarrying lies all around..." ?? Nonsense.
"...a number of springs are known to this day as having medicinal properties..." ?? Nonsense.
"Quite common for monuments to be built of stone from elsewhere..." ?? Nonsense.
And the Banc Du settlement? What on earth has that got to do with bluestones or Stonehenge? Nothing at all.

Here is a link to the Banc Du description:

http://www.coflein.gov.uk/en/site/308024/details/BANC+DU%2C+ENCLOSURE/

Oh dear oh dear. This is getting tiresome.

Oh dear oh dear........

That programme on BBC2 Wales -- Prof Wainwright talking to Toby Driver, going over all that tired old stuff again. Bluestone quarry at Carn Meini, blue rock, sacred springs, sledges and rafts, and all the rest of it. No questions, no uncertainty -- just pontification. I'm surprised that the Royal Commission allowed itself to be swept up in all that nonsense without demonstrating at least some capacity for critical thought. A lot of what was said was demonstrably untrue -- and the commentary was appallingly reverential and portentious. I'm also surprised that Richard Edwards, who is generally a good and careful film-maker, should have allowed all that Wainwright fantasizing to go out on air without any of it being questioned. Just goes to show how the media just LOVES a wacky story -- and to hell with the truth.

The Key to Stonehenge

Tonight (3 Nov) at 7.30 on BBC Two Wales -- the first part of a new series on Hidden Histories. Made with the cooperation of the Royal Commission on Ancient and Historical Monuments............. The first part deals with the Preseli-Stonehenge connection -- the advance blurb says that the programme will reveal how the key to Stonehenge lies in the Preseli Hills. Hmmm -- I wonder what we will get? Not more Darvill-Wainwright fantasy, I hope......

Suggested bluestone entrainment zone

This is a suggestion for the alignment of the "entrainment zone" along which erratics seem to have been entrained into the ice prior to transportation towards Somerset and the Salisbury Plain. Note that the strip (a probable contact zone between Irish Sea Ice and Welsh Ice) is only 2-3 km wide. From what the geologists are telling us, all of the likely sites from which erratics have been picked up by the ice are within this strip. I'll try to create a map which shows exactly where these known sites are. Watch this space.......

Stonehenge Visitor Centre

Met a lady today who has just been on a visit to Stonehenge -- she reported that she was very surprised to see my "Bluestone Enigma" for sale there, quite prominently displayed. Well that's heartening! Of course I knew it was there, but I had deep suspicions that it might have been kept in a deep cupboard somewhere, to prevent the public from encountering unorthodox and even polluting ideas from somebody who talks of glaciers and erratics rather than heroic tribesmen and Neolithic engineering. So -- credit where credit is due.....

New search facility

Since this blog now has a lot of entries, I have added a search facility. Seems to work OK -- feel free to try it out!

Bluestones all over the place.....

Bluestone at Porthleven -- the Giant's Quoit

If we use the term "bluestone" as meaning anything that isn't sarsen (which is the only meaning we can give to the term) then of course we find bluestones all over the place. There are bluestones at Court Hill, in the glacial deposits; at Fremington, in glacial deposits; on the Scilly Isles; in fissures in the limestone on the Mendips; in the Bath area; at Stanton Drew; and as isolated boulders here, there and everywhere. Some of these have been incorporated into megalithic structures. Much more info is in the book! And I'm sure more info will emerge.

The Court Hill erratics could have come from the Gower (Carboniferous Limestone) or from the Vale of Glamorgan (Lias and Trias) or from the ORS which is very extensive in the Brecon Beacons and SE Wales. I'm not sure that anybody has done sufficiently detailed work on the erratics in the glacial deposits of SW England to decide on how far-travelled they are -- it's difficult with sedimentary rocks. (Just look at the long debate about the origin of the Altar Stone!)

Erratics in glacial deposits at Court Hill

Ah -- discovered some info. The 24m sequence of tills at Court Hill contains erratics up to .5m -- as observed, That doesn't rule out larger erratics also, still buried in the deposits. Sources: Carboniferous Limestone, Pennant Sandstone, Carboniferous chert, Triassic Sandstone, Mercia Mudstone, Old Red Sandstone, Greensand chert and flint.

Much of this material could be fairly local, but of course these rock types are also represented in South Wales -- so could have been introduced from the South Wales valleys. No coal as far as I know!

What might the ice stream have carried?

Stones from the Brecon Beacons?

Thanks again, Ed. This is all very intriguing -- I really want the geomorphologists and glaciologists in on this. We do actually have a pretty mottley collection of stone types or provenances at Stonehenge -- 27 or so at the last count? Some of them are Preseli igneous rocks, but others aren't. There are some fragments still unidentified. And the Altar Stone is a pretty large erratic, identified by Kellaway a long time ago as coming from the Senni Beds in the Brecon Beacons -- and now that identification has been confirmed by other geologists too. So that must be one "South Wales" erratic carried southwards by Welsh ice and then eastwards by Irish Sea ice. Did all of this happen in one glacial episode, or two, or three? Still great problems and mysteries! I have touched on these in my book.

The best glacial deposits are at Court Hill, at the western edge of the Mendips -- tills 24m thick. I need to check out what the erratic assemblage is.

How tight were the bends in the ice movements? It's all speculation at the moment. As you might have observed, I have played about with a few variations on the theme, and am still none the wiser.....

Why no bluestones at Stanton Drew?

Thanks for the comment, Ed. This is all very hypothetical -- since we need hard evidence -- but I would speculate that the ice that passed north of the Mendips did not actually carry bluestones as we conventionally label them. These stones, from Pembs, including all the igneous stones, were transported South of the Mendips. I'll be interested to see what comes up re the geology of the Stanton Drew monuments.

Not sure I would agree that there is "ample evidence" of the Stonehenge bluestones having been used elsewhere prior to inclusion in the monument. Most of the markings etc could equally well be explained by constantly changing priorities -- with a limited number of stones being used here, there and everywhere as the designers and builders faffed about from one generation to another. Some lintels were later used as standing stones, and vice versa. The number of empty and intersecting sockets is truly amazing.

How important is Stanton Drew?

Been thinking about these ice streams again.

On checking up on Stanton Drew, I found another paper by Geoff Kellaway, published in the Survey of Bath and District No 17 (2002), called "Glacial and tectonic factors in the emplacement of bluestones on Salisbury Plain." There is a lot in the paper that I find difficult to accept. However, one thing is very interesting. He argues strongly that the bluestones which were used in the stone settings at Stonehenge were all stolen or removed from earlier stone settings -- monoliths, dolmens, long barrows -- as part of the Stonehenge enterprise. That would of course accord with the MPP theory of the Bluestonehenge stones being removed (with reverence or irreverence) from that place to Stonehenge itself. Geoff argues that the reason for this "stone stealing" was that the bluestones always were in short supply, and that they never had enough of them to finish the job (whatever that might have been....)

He thinks the Boles Barrow bluestone was "the one that got away" -- maybe because it was a bit too far from Stonehenge for the builders to bother with. He also thinks there were bluestones (large and small) all over the place, including the Stonehenge neighbourhood, the Cursus, the Boles Barrow area, and Normanton Barrows. He says that Cunnington found a piece of bluestone in the Normanton barrow that had previously been examined by Stukeley. He also reminded us of Cunnington's conclusion that "these pieces (of bluestone) were scattered about on the plain before the erection of the tumuli under which they have been found."

Interesting stuff! Bluestones from Pembs south of the Mendips, and other erratic assemblages to the north? Geoff refers to "the Stanton Drew moraine." I'd like to know what the evidence for that may be............. Geoff says that the ice that crossed the Stanton Drew site came from the NW -- it crossed Broadfield Down, eroding the Lower Lias. It carried boulders of Upper ORS from the Failand Ridge, and entrained masses of Triassic conglomerate and Lower Lias breccia from Winford and Felton, and also picked up slabs of Dundry Freestone. The builders of Stanton Drew used a litter of boulders of all these rock types -- they were opportunists and foragers who (naturally enough) simply wanted to minimise effort.

I'd like to get some other opinions on all of this..... if all of the Stanton Drew stones are demonstrably from the W and the NW, and none of them from other compass directions, then Geoff may be onto something here.

On the Bristol Channel Ice Stream

Thinking aloud (sort of) here -- and wondering whether we are starting to move towards a better understanding of what happened when the Anglian (??) Irish Sea ice stream came in from the west and penetrated the coastal zones of Devon and Somerset.

Look at the two maps above. The modelled ice streams have to match up with evidence on the ground -- insofar as it is reachable, given that in a later glaciation (Devensian) ice came out from the valleys of the Coalfield onto the Gower, the Vale of Glamorgan and even out into the area now covered by the sea, Those advances obliterated much of what was there before. But maybe Geoff Kellaway wasn't far wrong with his suggestion of three components to the ice stream?

In reply to Ed

Hi Ed

I agree with you that the term "bluestone" is the cause of endless trouble. Some archaeologists seem to think it is a petrographic term. It is not -- it is used loosely to refer to anything, in the context of Stonehenge, that happens not to be sarsen. Most of the stones are not even blue. We would be better off without it, but sadly we are stuck with it.

Re the curved line used on the map, I'm not sure what you mean by "exaggerate".......... of course it is a guess -- we really have no idea how the junction between Irish Sea ice and Welsh ice may have run from Pembrokeshire towards the coasts of Devon and Somerset. It may have been smooth, or it may have had "kinks" in it, caused by streams out ice coming out of the South Wales Valleys -- the Towy, Taf, the smaller valleys coming off the coalfield, and then the Usk. They all held glaciers. I hope that some new modelling from Dr Alun Hubbard and his colleagues in Aberystwyth might give some more clues on this.

Why don't we find bluestones all over SW England? That's not how glaciers work. Entrainment, transport and deposition of erratics is very spasmodic and difficult to predict -- it depends to a large degree on the thickness of the ice, how it streams, and what the bed conditions were like. But I'm coming gradually to the view that dear old Geoffrey Kellaway wasn't far wrong when he suggested that the ice stream travelling up the Bristol Channel might have had three components -- one to the south comprising Scottish and Bristol Channel erratics, one in the middle with erratics from Pembrokeshire, and one in the north with erratics from the Welsh uplands and the Midlands.

How entrainment happens

This diagram shows a particular set of glaciological circumstance that would explain why the bulk of erratics entrained into the Irish Sea Glacier appear to have been "plucked up" and carried off in the body of the glacier from the northern flanks of the Preseli hills (both the main ridge and Carningli-Dinas Mountain).

Richard Bevins is searching for other rhyolite outcrops that might match with rhyolite fragments found at Stonehenge -- I wouldn't mind betting that another source area will be found in or near Tycanol Woods..........

Another bluestone source identified

This is getting more and more interesting. There's an important revision to the article recently published by Mike Pitts in British Archaeology -- arising from the discovery of a rock outcrop at Pont Saeson, between Brynberian and Crosswell, which matches up with one or more fragments found in the Stonehenge digs. The authors refer to "rocks from undistinguished outcrops in the low ground north of Mynydd Preseli, close to Pont Saeson." This is important for a number of reasons:

1. It provides yet another example of entrainment from a very narrow zone (it seems to be about 3 km wide) which runs from Dinas Head SE towards Carningli, then to Carnedd Meibion Owen, Brynberian, Carngoedog and Foeldrygarn. This seems to confirm the thesis put forward by Lionel Jackson and myself in EARTH magazine at the beginning of this year -- namely that the entrainment of erratics has occurred along a very narrow contact zone, probably between Irish Sea ice and Welsh ice. Very soon I shall plot all these known sources on a map.

2. The authors stress that this bluestone source is not at all prominent -- just an undistinguished outcrop in a valley on the north flank of Preseli. This appears to be another nail in the coffin for the idea that stones were collected by Neolithic stone collectors from prominent hill masses that were "auspicious" or prominent in the landscape. Carn Clust-y-ci and Carn Llwyd, on the flank of Carningli, two other bluestone sources, are pretty unimpressive too. We must be talking here of glacial entrainment, not human collection.

3. The idea that some of the bluestones might have come from North Wales now appears to be unpopular again! Again, this makes glaciological sense -- if the stones at Stonehenge really are glacial erratics, then they should come from one source area or maybe from a number of sources approx on the same line, which was the route followed by the moving glacier.


Details:
British Archaeology
http://www.britarch.ac.uk/ba/ba109/interim.shtml
-----------------------
Important revision to Stonehenge bluestone theory
------------------------------------------
Rob Ixer and Richard Bevins

The Stonehenge Bluestones -- a problem for earth scientists?

Yesterday I gave a seminar in Aberystwyth University -- to a mixed group of undergraduates, research students and staff from various disciplines including glaciology, geography, geomorphology and geology. It was a good opportunity to explore some of my ideas with them, and to deal with questions and comments. Afterwards I had the chance to talk with Dr Alun Hubbard and his colleagues about the new modelling work they are doing -- with a view to refining the parameters and the "model-building" techniques allowed by modern computing power. It looks promising -- and Alun assures me that it should be possible, on the basis of a reasonably accurate map of ice limits in Southern England (from published sources relating to till / moraine localities) to work out what the glacier responsible might have looked like........

This is exciting -- and as I have said before, the problem of bluestone transport will not be solved by archaeologists, but by earth scientists. I hope my talk will have encouraged some of them to get involved, and to start looking at the field evidence that may help us to crack this particular nut.

Archaeologists beginning to shift?

there are some subtle indications that maybe the UK's senior archaeologists (or some of them, at any rate) are beginning to shift their ground on the matter of glacial transport and glacial erratics. In Mike Pitts's piece in British Archaeology he did at least mention the fact that some people believe that the bluestones were transported for most of the distance between their source areas and Stonehenge by glacier ice -- so that's progress. Mostly, in past comment columns, the glacial theory is not mentioned at all. Then, it is rumoured that MPP actually showed one of my maps of the glacier occupying the Bristol Channel, in his lecture last Saturday on "Bluestonehenge." He probably didn't go so far as to admit that the glacier theory has some merit -- but we are getting there.......

And the fact that English Heritage has allowed "The Bluestone Enigma" to be sold through the Stonehenge Visitor Centre is progress too!

Response to post

Anonymous said...

"Richard and I have made no archaeological claim
we are just doing the petrography.
I long ago abandonned the transport problem as I have said for decades-find a true quarry site and the game is over until then a theories are just that.
I do not know who the stones arrived at Stonehenge and indeed try not to worry about that. It is an archaeological problem." Rob Ixer

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

Thanks for this, Rob.I appreciate why you and Richard would want to stick to the petrography, and to leave the debate about "transport systems" to others. It does get a bit hot at times! I also agree that the archaeologists are never going to provide definitive support for the human transport idea until they come up with some convincing evidence of a quarry site (or, more likely, given that we are dealing with around 25 different rock types) around 25 quarries! That looks increasingly unlikely -- and the Carn Meini "quarry", as the prime and favoured candidate, never has been at all convincing. But I part company with you on the statement that this is "an archaeological problem." This is far too important to leave to the archaeologists. That is why I am encouraging earth scientists to examine the geology, geomorphology and glaciology very carefully -- and to share their hypotheses in print. There is masses of evidence around the shores of the Bristol Channel, in SW England and around the Mendips -- it need to be reassessed and examined in the light of what we already know about glacier dynamics.

Mike Pitts on the Bluestones

Below I have pasted the article which is causing a great hullaballoo (how does one spell that word?) in archaeological circles. It was written by the Editor of British Archaeology. Mike Pitts, and was based in part of information provided by geologists Rob Ixer and Richard Bevins. Sadly, like all "popular" articles, it contains inaccuracies. Jim Scourse and Chris Green are geomorphologists, not geologists. Geoff Kellaway's Christian name is Geoffrey, not George. The "shift" of the key spotted dolerite location from Carnmeini (Carnmenyn) to Carngoedog is not new -- this was proposed long ago by the OU team which published its big report on the bluestones in 1991. And I will beg to differ with whoever said that the problem of how the stones were moved from their source areas to their locations on Salisbury Plain is "an archaeological problem." From where I stand, this is a problem that needs to be sorted by geomorphologists, glaciologists and geologists -- and this is increasingly apparent from the new evidence of multiple sources and multiple lithologies being represented in the bluestone assemblage of Salisbury Plain.

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

Missing Stonehenge circle did not come from Preselis
British Archaeology
November December 2009|7

A new theory about the Stonehenge
bluestones is set to divide geologists
and archaeologists, and open new
inquiries into how and why the famous
stones reached Stonehenge.
The site’s megaliths are traditionally
classed into two groups, sarsens (a local
sandstone) and bluestones. While the
former, at an estimated total weight of
1,700–1,800 tonnes, outscale the 250-
odd tonnes of the latter, the bluestones
have dominated debate. The issues of
where they came from and how they
reached Stonehenge, have polarised
into two widely divergent views:

•Most derive from the Preseli Hills
in Pembrokeshire, south-east Wales,
and were taken to Wiltshire by the
builders of Stonehenge around
3000–2500bc

•Alternatively, they come from a
variety of sources in south Wales, and
reached Salisbury Plain as glacial
erratics during the ice age, thousands of
years before Stonehenge was built.

Most prehistorians believe people
moved the stones. This was what
geologist Herbert Thomas proposed,
when he first identified the Preselis as
the origin in 1920: a view endorsed by
geologists including Christopher
Green and James Scourse, and recently
by archaeologists Timothy Darvill and
Geoffrey Wainwright, who claim to
have found quarry outcrops and “sacred
springs” at the source of the megaliths
around Carnmenyn.

Geologist George Kellaway
proposed in 1971, by contrast, that the
bluestones had been transported by a
glacier. This view has been supported
by archaeologist Aubrey Burl, and (in a
differing glacial interpretation) an
Open University team of geologists
including Olwen Williams-Thorpe.
Last year the latter wrote on a BBC
Timewatch blog that the bluestones
“are a rag-bag mix… from all over south
Wales”, and Brian John published The
Bluestone Enigma (see Books, page 55).

Now geologists Rob Ixer (University
of Leicester) and Richard Bevins
(National Museum of Wales) are
proposing a third option. They say
many bluestones came not from
Pembrokeshire, but from “a far wider
and, as yet, unrecognised area or more
likely areas” – perhaps north Wales
(Snowdonia, the Llyn Peninsula and
Anglesey), or even beyond. The wellknown
spotted dolerite, is a Preseli
rock, they say – but Carngoedog was
the likely source, not Carnmenyn.

These conclusions derive from a new
study of thousands of Stonehenge rock
specimens: from near the west end of
the Cursus earthwork (where a lost
bluestone circle has been proposed),
collected in 1947 and excavated by the
Stonehenge Riverside Project in
2006/08; and from Stonehenge,
excavated by Mike Pitts in 1979/80 and
Darvill and Wainwright in 2008.

The geologists also found the Cursus
bluestones, which are all rhyolitic and
mainly tuffaceous (with no Stonehenge
dolerites), had significant mineralogical
differences from visually similar rocks
at Stonehenge. The Darvill and
Wainwright excavation produced
significant amounts of a type of
rhyolite or rhyolitic tuff “not recorded
in north Pembrokeshire and noticeably
absent in the Mynydd Preseli area”.

How the stones were moved, Ixer
told British Archaeology, “is an
archaeological problem”, though he
wondered if “different groups [of
people] brought different stones?”
Ixer and Bevins’s detailed study will
be published in the 2009 Wiltshire
Studies. In WS 2006, Ixer and Peter
Turner suggested that the Stonehenge
Altar Stone (the largest bluestone)
came from an unidentified source far
from Milford Haven – the traditional
attribution said to indicate where the
Preseli stones were taken downriver
and out to sea by neolithic gangs.

More on tribute stones etc

A small update. Apparently the piece in the journal wasn't actually written by Rob and Richard -- but by the Editor, Mike Pitts, on the basis of info provided. That may explain the emphasis on "the third option" and the reluctance to endorse the glacial erratic theory.......

But whoever wrote it, the article makes a very valuable contribution to the debate, and I appreciate the fact that Mike Pitts was willing to give space to it, given that some of his senior colleagues will not be best pleased.

Apologies to Rob and Richard for assuming that they wrote the piece (there was no attribution on it), and for originally assuming that their opinions may have been influenced by the people they were working for. Rob assures me that that was not the case, and of course I accept his assurances.

Above is a rough map that shows suggested ice movement directions of the two ice streams -- one sweeping south of the Mendips, and the other (with many more erratics from sources in southern Wales and the Marches) coming in towards Salisbury Plain from the NW. This will no doubt be replaced by better maps as the glacier modelling proceeds.

The Bluestones -- tribute stones, petrified ancestors, or simply erratics?

Rob Ixer has kindly sent a copy of the new article from British Archaeology -- entitled "Missing Stonehenge Circle did not come from the Preselis." This refers not to the "new" circle at the end of the Avenue, near the River Avon, but to another assumed missing circle at the far western end of the Cursus, where there has also been a lot of recent excavation. He and Richard Bevins have identified many rhyolite fragments from the digs in that area -- many of them apparently not from the Preseli area at all. They are not sure where the fragments have come from.......

Interestingly, Rob and Richard have not plumped for the glacial theory in preference to the human transport theory, but have suggested a third option, namely that the stones were carried to the Stonehenge area "by different groups of people." This has been suggested for a while by Mike Pitts and other senior archaeologists who have been trying to come to terms with the fact that the bluestones are from well over 20 different locations. The geologists say that the question of how the stones were moved is "an archaeological problem." I would disagree with that. It is a geomorphological/glaciological/geological problem -- in the solution of which archaeologists do not have much of a role.

So are these stones "tribute stones" or "dead ancestors"? In one scenario, Mike Pitts has suggested that the Stonehenge ritual landscape was so important across the UK, and the tribal groups that controlled the area were so powerful, that other tribal groups from far and wide travelled to Stonehenge with "tributes" in the form of large stones which could then be set up on the developing monument. It may have been required or expected of them, in view of their status as subservient tribes, acknowledging the power of their masters. A nice theory? Hmmm -- I'm not convinced. Sounds like special pleading to me -- and there is no evidence for this sort of thing ever having happened in the British Neolithic or Bronze Age, as far as I know. Also, we seem to be obtaining evidence now of stones and fragments of all shapes and sizes -- would these "tribute payers" have carried with them some big stones, some little ones, and a few flakes from here, there and everywhere? You could build up a mighty fantasy here -- and archaeologists will probably do just that. Another problem is that there seems to be no evidence of stones that have come from the east or south. If stones were brought to Stonehenge as tributes, one would have thought that they would be carried from east, west, north and south. So far as we know, they only come from the W and NW -- and that happens to be where the ice came from. No -- they still look like erratics to me.

The dead ancestors theory? That's even more wacky - and designed to bolster the Parker Pearson theory that Stonehenge was a place of the dead. He will probably argue that Stonehenge was a place where rituals were centred on ancestor worship and ceremonies designed to send the dead off to Paradise or some such place -- and that as this "ancestor" cult developed tribes came from tens and maybe hundreds of kilometres away, bearing with them the likenesses of their ancestors in the form of stone pillars, to be incorporated (with due ceremony) into Stonehenge. Sorry, but again this takes fantasy to absurd lengths. And again, why did these dead ancestors all come from the west, with none of them coming from the other points of the compass?

This is all ridiculously elaborate, and for my money the new evidence simply confirms that what we had on or near Salisbury Plain was an assemblage of glacial erratics, of all shapes and sizes, from many different locations, conveniently available for picking up and incorporation into the monuments of people who enjoyed working with stone.

Now the geologists join the fray

This is a major development, with two senior geologists presenting their evidence in print. The article is in the new edition of British Archaeology, dated 9th October. Needless to say, I feel very chuffed, and don't feel quite as lonely as I did yesterday!

Rob Ixer and Richard Bevins have studied thousands of rock specimens from recent excavations at Stonehenge. They conclude that many bluestones came not from Pembrokeshire, but from a far wider area, perhaps north Wales (Snowdonia, the Llyn Peninsula and Anglesey), or even beyond. The well-known spotted dolerite is a Preseli rock, they say – but the likely source was not Carnmenyn (where archaeologists have recently claimed to have found quarries) but nearby Carngoedog.

The photo above is of Carngoedog -- identified quite a long time ago as the most likely source of the majority of the spotted dolerites, but of course studiously ignored by Profs Darvill and Wainwright and most of the other key archaeologists working in the UK.

More about ice on Salisbury Plain

Been looking at Alun's model again. There is a lot of controversy about it -- not least relating to the extensive ice shown over the uplands of Devon and Cornwall. Some people will not accept that there was ever any ice cover over dartmoor and Exmoor -- but other geomorphologists beg to differ. Personally, I have no problem with a cover of thin cold-based ice maybe 100-200m thick, moving very sluggishly -- the landscape effects will have been minimal.

It gets much more interesting when we look at Somerset and Wiltshire. The ice is shown as covering the site of Stonehenge -- again this would have been thin, sluggish ice. But I'm quite intrigued by the idea that there was a divergent ice flow over Somerset, with ice coming in from the west and then being split into two streams, one on either side of the Mendips. The southern stream, which (according to this model) reached its greatest extent near Yeovil and Sherborne, must have travelled from the NW towards the SE. The northern stream, affecting the Bath area and pressing down towards Stonehenge, would have moved approx WNW - ESE. The southern ice stream -- simply on the basis of reconstructed ice movement directions -- would have been the one most likely to have carried Pembrokeshire erratics. The northern one might have carried more material from Mid Wales and the Marches. That opens up all sorts of exciting possibilities relating to the origins of the "unknown" rock fragments that have been showing up in some recent digs on Salisbury Plain.

What is most interesting about this new work is that it pretty well confirms what dear Geoffrey Kellaway said almost 40 years ago -- and for which he has been vilified by senior archaeologists (not to mention geologists and geomorphologists) ever since.......