Stonehenge Thoughts

Bluestone haulage for wimps

2012-01-30T17:42:00.000Z

I came across this photo today, in connection with a review of a new book about the Preseli Hills called "Ancient Wisdom and Sacred Cows" edited by Hefin Wyn (£14.95). No idea who the photographer was, but he was clearly dangling from a tree at the time.

The pic is of course an addition to our photographic history of the ill-fated Millennium Stone Pull in the year 2000. Very much a matter of stone-pulling for wimps. Note the great lengths of nylon rope, the compulsory gardening gloves for all pullers (to avoid chafing and blisters), the excellent asphalt road surface, the beautiful masonry bridge, and the extensive use of low-friction nylon netting to reduce the friction on the underside of the sledge. We were wimps, the whole lot of us! (Yes, I was one of them.........)

In the old days, our heroic ancestors needed none of this -- they just went ploughing straight across the sort of terrain we see in the top right of the photo. My God, they were tough in those days. And they were probably naked too, just for good measure......

Where is Rhosyfelin?

2012-01-28T18:24:00.002Z

I notice that some contributors to this blog are still uncertain where Craig Rhosyfelin (Pont Saeson) is located. (That's the site identified by Rob Ixer and Richard Bevins as the source for much of the Stonehenge foliated rhyolite debitage.)

My thanks to Jonathan Lee of Aberystwyth University for this splendid computer-generated topographic image -- it shows the coastline and the main relief features of NE Pembrokeshire very well. I have put onto the image the locations of Craig Rhosyfelin and Carn Meini. As you can see, Craig Rhosyfelin is well to the north of the Preseli Hills -- a nasty place for Neolithic stone-collecting expeditions, but quite a handy place for entrainment by a glacier flowing across the landscape from NW towards SE.

Unfinished projects

2012-01-27T18:22:00.003Z

I got a message from Tony about unfinished projects, which we have discussed at length before. He says: "...... Burl's "Stonehenge - a New History" (2006), page 107. He makes some good, reflective points there about what are indexed as 'unfinished projects', and proceeds to name quite a few from elsewhere in Britain, beyond Stonehenge'. That's one book I haven't got on my shelf, but in Burl's "Stonehenge" this is what he says on p 145 with respect to the early settings of posts:

Splendid fellow, Aubrey Burl. A man after my own heart. The image at the top of this post is another interesting example of an aborted project -- it's an image of an area just a km or so south of the town of Newport (Pembs) -- showing Carn Llwyd at the top (thought by the OU team in 1990 to be one of the sources of the Stonehenge bluestones), a very nice round house at the bottom (probably Bronze Age?) and a piece of a ridge and ditch (in the centre) that goes nowhere and does nothing. It looks as if it is a piece of a circumference of a large planned enclosure around a broad hill summit -- we have to assume that it's either Bronze Age or Iron Age, but it might be Neolithic. I've never heard anybody argue that this is what was planned, and that we are looking at a completed structure. So all we can do for now is speculate as to what it might have been intended for, and why it was abandoned.

OK -- I eat my words.....

2012-01-26T21:53:00.000Z

I have often said in the past that I think the dolerites, spotted dolerites and gabbros which are found outcropping in North Pembrokeshire are too coarse-grained to respond well to glacial abrasion processes and to reveal striations. I have based that assumption on the fact that all of the rock outcrops and the tops of erratic boulders projecting above the ground surface are weathered -- some subjected to weathering for 23,000 years or so, and some for far longer than that. These weathered surfaces are generally stained and pitted -- and although I have seen ice-moulded surfaces, none of these surfaces has carried striations. Rhyolites are a different matter -- I have seen striations, for example, on the outcrops at Carn Alw.

Well now -- one of my neighbours has been doing some landscaping with some heavy machinery, and this has involved cutting into a morainic mound and hauling out masses of boulders up to 3m long -- some of them probably weighing over 10 tonnes. Some of these boulders that have been thrown up into a great pile are shown in the top photo. On looking at the dolerite and gabbro boulders which have been buried up to 3m beneath the ground surface, and which have now been washed by the rain, you can see how beautifully smooth some of them are -- classic abrasion by fine-grained sediments on a rather fluid glacier bed. And there are striations! Lots of them...... When one ignores the damage done by heavy machinery, you can see quite deep gouges and abrasions even on the surfaces of some coarse-grained boulders -- the lower photo shows a boulder with two sets of striae, one set running up and down, and the other running across the face of the boulder beneath that patch of muddy turf.

OK -- revised opinion. There is in principle no reason why the spotted dolerites, dolerites, rhyolites and ashes used as orthostats at Stonehenge should not carry striations resulting from glacier transport. That would happen only if the stones were carried on the glacier bed -- although as I have argued on this site before, I doubt that that was the case. Again, if the surfaces of the stones have been exposed to the atmosphere for just a fraction of the 450,000 years that have elapsed since the Anglian Glaciation, the chances of striations surviving would be virtually zero.

Oh, for some cosmogenic dating of those bluestone surfaces at Stonehenge........

The Bluestone Argonauts -- did they sail or paddle?

2012-01-26T21:09:00.000Z

Above: the reconstructed Ferriby Boat called "Oakleaf"

Below: the Dover Boat

I have been quite intrigued recently, on going through some of the literature, to see that the experts seem to think that in the early Bronze Age there was no knowledge of sails or sailing techniques in Western Europe -- and that means the waters around the coasts of Britain. If that was the case, then there would certainly have been no sailing boats around in the Neolithic, when our heroic ancestors are supposed to have transported 82 bluestones over land and sea from Pembrokeshire to Stonehenge. Apparently the technical challenge which these earlier boatbuilders had not overcome was that of bedding a mast foot into the bottom or keel of a boat, so as to cope with the enormous stresses involved in catching and using the wind, often in rough sea conditions. So this famous illustration by Alan Sorrel is probably up the creek...

See my post dated 27 November 2011 on the "Bluestone Argonauts" and their sea-going vessels.
http://brian-mountainman.blogspot.com/2011/11/even-more-danger-marine-engineers-at.html

I recall that Herbert Thomas, the man who started this whole hare running, was no great believer in the marine transport of the stones, and many others have shared that view, on the basis that the technical challenge would have been far too great for the Neolithic tribesmen to cope with. Aubrey Burl shared that view, and analysed the maritime transport idea in some detail in more than one of his books. HHT thought that the stones must have been transported overland, all the way. It was Atkinson -- ably assisted by Alan Sorrell -- who enthusiastically promoted the idea of sea-going rafts and naked heroes braving the elements on a stormy shore..... By God, sir, they were a tough bunch in those days......

Not only do we have to cope with the technical challenge of making a seaworthy vessel large enough to take a stone weighing up to 8 tonnes (we have to assume that the Altar Stone travelled the same way as the others) -- but we also have the technical challenges associated with sails, ropes and paddles, and paddle fixings. Then there are the problems -- flagged up by Aubrey Burl -- on navigation and mental maps; and he quite rightly asks whether Neolithic tribesmen would have had the capacity to identify a source area in West Wales, to map out in their minds how to travel there and back on many different occasions, and to cope with all of the navigational hazards which we all know about around the Pembrokeshire Coast, in Carmarthen Bay, and in the Bristol Channel
-- areas of high seas, rapid tide races and currents, and very high tidal ranges.

I think that in this part of "The Great Stonehenge Story", more than in any other part, we are guilty of seeing as our heroes modern men in fancy dress.

That multi-million project...... whatever happened?

2012-01-26T08:22:00.000Z

I recall seeing (on one of the multitude of Stonehenge videos on YouTube) some interesting pictures of Mike Pitts with a tape-measure, earnestly measuring up Stonehenge and saying this was in preparation for some great project which would involve a full-scale reconstruction of the jolly old ruin, which would allow all sorts of people to study it properly, free (presumably) of all those nasty constraints placed on research by English Heritage. Was it a National Geographic video? Can't remember now......

Anyway, I was reminded of this when I came across this on the Ferriby Boats site:

"With projects such as a planned multi-million reconstruction of Stonehenge seeking to use full-scale replicas of the boats used to transport the bluestones from Wales, the experiment needs to continue." said John Davis, the Trustee who, with the support of local shipping businesses, helped bring the replica to the Humber. "The assessments made after initial trials on The Solent need developing into a more detailed evaluation of the boats' handling and load carrying abilities."

http://www.ferribyboats.co.uk/

http://www.archaeology.co.uk/the-timeline-of-britain/the-dover-bronze-age-boat.htm

So not only did we have plans (in 2009?) for the great reconstruction job, but also a reproduction of the great stone-collecting voyages (assumed to have involved all those nice Ferriby-type boats) back in the Neolithic.

Does anybody know more about this project, and what happened to it?

Preseli in the conflict zone

2012-01-24T17:07:00.000Z

Preseli in the conflict zone again -- this time it's not a conflict between archaeologists and geomorphologists, but between the Irish Sea Glacier and the local Preseli Ice Cap.

I published the top map some time ago, as my current best estimate of where the Irish Sea Glacier skidded to a halt in the Devensian Glaciation. I did suggest at the time that because there are ice-smoothed rock surfaces on the summit ridge of Carningli, and because there is a lot of fresh till and an erratic spread over the ridge and down onto the south side, the glacier might have crept over the ridge and extended down towards the Gwaun Valley.

Anyway, look at the cosy fit between my suggested southern ice limit and the northern edge of the Preseli Ice Cap, as modelled by Henry Patton and others. My dotted area is not that different from the proposed ice-covered area. I find that rather satisfying -- a nice convergence between desktop studies and fieldwork.

There are still a couple of big questions here. First, what was the role of the proposed "Glacial Lake Brynberian" in the sequence of events here? Second, was the maximum extent of the Irish Sea Glacier exactly in phase with the maximum extent of the Preseli Ice Cap? We are talking about a period of maybe 1500 years -- a very short time, geologically.

Watch this space. There will be developments.

Another Preseli Ice Cap Image

2012-01-23T18:22:00.001Z

This is another image of the Preseli Ice Cap, from the modelling work reported by Henry Patton and colleagues in 2011. This shows the picture as it MIGHT have been around 23,850 years ago, with cold-based (thin) ice over the main Preseli ridge and with a few small patches elsewhere as well. One of these patches is on Carningli -- assumed to have done nothing to the landscape. Danny McCarroll and colleagues have said:

“East of the proposed ice limit, the western Preseli Hills (Mynydd Carningli) show no evidence of glaciation” (McCarroll et al., 2010)

Oh yes they do, chaps. There are ice-moulded slabs on Carningli (very near the summit) and also morainic debris on the flanks of the upland. So the ice was maybe not so cold in the Devensian, and it was certainly capable of affecting the landscape in a number of different ways. But the complicating factor here is that the Irish Sea ice was coming in from the NW, and extending some way beyond the red line marked on the map. So there may have been some mixing of Irish Sea Glacier ice and local ice -- exactly as we see in Greenland today, where big ice streams exist right next to upland ice caps.

The red point shows the sampling point for the cosmogenic dates given by Mc Carroll and others -- as I have previously argued, those dates are wrong. I'm pretty sure they are INHERITED dates. More work needed. We'll get there in the end.

That's the nice thing about models -- they give you something to work on and argue about......

Devensian Sea Level

2012-01-23T12:08:00.003Z

In the Powerpoint presentation by Patton et al (2011) there is an excellent illustration of the current consensus regarding the Devensian sea-level curve. In the illustration (based on the famous Barbados sea-level curve) we see that global sea-level reaches its low point of about -120m around 26,000 years BP, assumed to be the global glacial maximum. In the UK and Ireland, it looks as if the ice sheet reaches its greatest extent a bit later; not everything is in phase, and here and there we see lags of a thousand years or more.

The map on the right shows the "dry land area" at the time of the Devensian "sea level low point" -- in green. But remember that it will not have been quite this simple. Isostatic effects associated with ice buildup will have depressed parts of the crust in western Europe, and so parts of this green area might have been flooded. There were complex interactions between eustatic (sea level) and isostatic (loading and unloading) effects.

Ice over All

2012-01-23T11:13:00.004Z

Some members of our faithful blogging community have difficulties with the fact that ice caps and ice sheets develop ice surface profiles that are sometimes quite independent of the shape of the ground underneath. So we effectively have a submerged landscape beneath a largely featureless ice expanse such as we see today in the centre of Greenland.

This is beautifully illustrated in the latest reconstructions of the Devensian Welsh Ice Cap by Hubbard et al (2011). Above there are two cross profiles -- the top one for North Wales and the lower one for Mid Wales. Note that there were a few small nunataks in North Wales (including Snowdon and Glyder Fawr) and that the ice surface was at about 1000m In Mid Wales the whole of the landscape was submerged, and the summit of the ice dome was at about 1200m.

In general, ice velocities are greatest where the ice is thickest -- and the ice flows in ice streams, often in deep river valleys or troughs. Where the ice is very thin -- near the mountain summits -- the ice temperatures will be low, and the ice will be "cold based" -- with very little or no erosion and with even quite delicate features like tors effectively protected.

Don't assume that this reconstruction is correct in every detail -- discussions are ongoing. But the evidence does seem to be converging, and with every year that passes, the models and the "ground truthing data" get closer together......

On Glacial Cycles

2012-01-23T10:54:00.000Z

This looks a bit daunting (from Patton et al, 2011) but it's really not that difficult. It shows the main glacial cycles -- known from work all over the world -- over the past million years or so. The interglacial phases (highlighted by nice yellow sunshine) are labelled I 1-11 and the glacials (marked with blue ice!) are numbered G 1-10.

The Devensian Glaciation is the most recent glacial episode, lasting from c 73,000 years ago to 14,000 years ago. The Anglian Glaciation -- which I have assumed to be the one responsible for the transport of the Stonehenge bluestones -- was around 450,000 years ago. But notice that there are several other big glaciations -- and we have very little idea what effects these episodes might have had in western Britain (in Eastern Britain things are a bit clearer). Phases G2 and G7 were particularly large glaciations, and the ice of the Irish Sea Glacier might well have been almost as extensive in those phases as it was during the Anglian.

One of the great implications of this pattern is that any erratics that we might find in the landscape have probably had multiple trips and zig-zag courses....

Source:
Modelling the dynamic instabilities of palaeo ice-sheets
Henry Patton, Alun Hubbard, Neil Glasser ,Tom Bradwell, Nicholas Golledge
IGES Presentation 2011

The Preseli Ice Cap

2012-01-23T10:06:00.003Z

I have drawn attention to the excellent work being done in Aberystwyth and elsewhere on ice cap and ice sheet modelling. I came across this interesting reconstruction for the extent of the Preseli Ice cap at the peak of the Devensian Glacation -- around 23,500 years ago. The authors (see below) suggest that the ice cap made brief appearances (for example around 25,000 yrs BP) and then grew to this extent around 23,500 yrs BP. Its life span might have been 2,000 years at the most. Notice that the ice is assumed to have been permanently cold-based, which means that it will have done very little to affect the landscape -- its role will have been largely protective. The authors assume that the whole of the Preseli ridge -- including all of the tors around Carn Meini etc -- was submerged beneath the ice.
If this model is correct, it means that Pont Saeson and Craig Rhosyfelin will have been very close to the northern edge of the little ice cap at the time of its maximum extent. This means that when the ice cap melted -- possibly catastrophically over a few centuries -- there will have been a very large volume of meltwater rushing along the gorge of the Afon Brynberian towards the confluence with the Nevern Valley.

A indicated in earlier posts, I'm not entirely happy with this model and its portrayal of the Irish Sea ice edge, but this is after all a computer-generated MODEL -- so it will be interesting to see how far the model and the hard evidence on the ground happen to converge........

Source:
Henry Patton, Alun Hubbard, Neil Glasser, Tom Bradwell, Nick Golledge: "Modelling the dynamic instabilities of the British-Irish Ice Sheet: The Welsh Ice Cap"
If you want to look at the animations created over the past few years, click on the links below and you should be able to download them.

26th July 2011 – INQUA – Bern, Switzerland. .pptx presentation [52mb] (Modelling the dynamic instabilities of the British-Irish Ice Sheet: The Welsh Ice Cap); animation .wmv file [2.4mb].
18th May 2011 – IGES departmental seminar – Aberystwyth University. .pptx presentation [99mb] (Modelling the dynamics of palaeo ice-sheets); model .mp4 file [13mb].

Those periglacial stripes are probably not periglacial

2012-01-22T15:03:00.000Z

I have devoted some space before to those strange features examined over the years by archaeologists and generally referred to as "periglacial stripes" -- and referred to, with delightful quaintness, as "geological stripes" or "natural Ice Age gullies" by EH. I've done a bit more digging into the literature -- a poor substitute for digging into the ground -- and I am increasingly convinced that they are not periglacial in origin.

Here are the latest EH statements about them -- probably guided by MPP and his team, who have most recently examined them:

Recent excavations and geophysical surveys have suggested the possible importance of geological features called periglacial stripes. They run parallel to the banks of the avenue and across the site of Stonehenge and align in places on the solstice axis. It is possible that these geological stripes may have been visible on the ground in early prehistory and could have led prehistoric people to believe that this was a special place.

http://www.english-heritage.org.uk/daysout/properties/stonehenge/history-and-research/history/
Outline of the main differences between the 1st edition of the
English Heritage Stonehenge guidebook (2005, reprinted 2007)
and the 2nd Edition (2011) (download as PDF)

v) The possibility that Stonehenge's location was chosen as a result of the
coincidental alignment with the solstice axis of natural landscape features
(periglacial stripes underlying the Avenue) coupled with the occurrence of a natural
sarsen (the Heel Stone) at the end of that alignment.

A new paragraph has been added discussing the discovery of the existence of
natural Ice Age gullies parallel to the Avenue, and the possibility that the Heel
Stone is a rare local sarsen found near where it now stands, both features
providing a coincidental alignment on the solstices. It is suggested that this may
have provided the impetus for the building work that followed.

Added mention of the natural "visible stripes" that are Ice Age landscape
features in the chalk parallel to the Avenue along the straight section leading up to
the monument. Changed emphasis in discussing the solstice axis from "this cannot
be a coincidence" to "this alignment is deliberate".

Beware of optical illusions on this LIDAR image --if you are not careful the low parts of the landscape can look high, and vice versa......

Vertical satellite image of the Avenue, running from Stonehenge (bottom L corner)

towards the NW

If the evidence is reliable that these stripes run parallel with the first part of the Avenue (shown in both of the illustrations above) and even run through or beneath the Stonehenge earthworks, then that clearly suggests a great age for the features. But we don't really know how extensive they are -- maybe somebody who knows the evidence on the ground can enlighten us on that. If you look very carefully at this illustration you can see a faint line outside the Avenue edge which is interpreted as one of the "periglacial stripes."

What we need here is a detailed topographic survey, but my impression is that these stripes (like the Avenue) point towards the midsummer solstice or sunrise position on the horizon (have I got that right?) but that they do NOT run down the maximum slope inclination towards Stonehenge Bottom. If there is one thing we do know about periglacial stripes it is this: they always run down the maximum inclination of the slope. I have seen a lot of such stripes in my time, in Antarctica, Greenland and Iceland, and I do not recall a single one that was aligned diagonally down a slope.

In the absence of a detailed survey all I can do is speculate about this -- and to say that if these stripes really are periglacial in origin, they should be running from Stonehenge down towards the road junction we can see on the LIDAR image.

Far be it from me to suggest that something perceived as "natural" in origin should now be re-classified as "probably man-made" -- but that is exactly what I am doing!!

EH updates on Stonehenge bluestones

2012-01-22T14:26:00.000Z

EH has made a number of changes to the Stonehenge Guidebook (2011 edition) -- nothing very exciting, but if anybody is interested, there is a PDF available which details all the changes, point by point. On the bluestones, there are new mentions of the recent TD/GW and MPP work, with mandatory mentions of the worlds of the living and the dead, and of the healing powers of bluestones "as a reason for going to the effort of transporting them from Preseli." It's strange how wacky theories, without a shred of evidence to support them, get turned into truth and orthodoxy. EH needs to take some responsibility for that, and the organization should be ashamed of itself. In spite of the ongoing debate about the mode of transport of the bluestones, EH has steadfastly set its face against any mention of the glacial transport hypothesis. Well, as I have said before, with the Olympics coming up, and a need to pull in as many punters to Stonehenge as part of the national recovery plan, they clearly don't want to say anything that might cast doubt upon the Gospels as written by the Apostles. Certainty above objectivity, any day.....

Location of Preseli Hills has been changed from "west Wales" to just "Wales". Caption to the
first map has been changed from "Map showing a likely route" to "Map showing one
possible route" from the Preseli Hills to Stonehenge.

Discussion of the bluestones "original setting" of "an incomplete circle of
paired stones", the dismantling of it prior to the inner sarsen structure's construction
and the later reintroduction of the bluestones, has all been removed. This has been
replaced by a paragraph noting that the sarsen structures do not appear to have
been moved once erected whereas the bluestones have been rearranged more
than once. It notes that the stone settings were built between about 2500 and 2000
BC.

........... two additional potential reasons for its construction are
also outlined. These are: its use as a cremation cemetery from the earliest
monument coupled with the idea that the stones represent long dead ancestors
compared to timber circles which represented the houses of the living; and, a
possible belief in the healing powers of bluestones as a reason for going to the
effort of transporting them from Preseli.

http://www.english-heritage.org.uk/daysout/properties/stonehenge/history-and-research/history/

Outline of the main differences between the 1st edition of the English Heritage Stonehenge guidebook (2005, reprinted 2007) and the 2nd Edition (2011)
(download as PDF)

When did Craig Rhosyfelin come into existence?

2012-01-21T12:41:00.000Z

This is an interesting question: when the large chunk (or chunks) of rock was/were taken from Craig Rhosyfelin by one process or another, and transported towards Stonehenge, did the landscape look anything like the landscape of today? The provenancing of some of the Stonehenge rhyolite debitage to "within a few metres" at Rhosyfelin seems to be based on the assumption that the landscape is unchanged, and that the pronounced spur sticking out into the valley of the Afon Brynberian was there at the time of rock extraction. I have questioned that assumption, and have wondered how accurate any provenancing can be, given sampling bias and other factors -- but putting that question to one side, I'm increasingly convinced that the landscape in and around this valley has changed quite substantially during the past 500,000 years.

On the top photo above, the MPP dig site is shown with the circle, on the flank of the rocky spur of Craig Rhosyfelin. On the lower photo, that site is in the bottom R corner, and we see the deep valleys of the Brynberian and Nevern rivers. Both are flowing partly in deep gorges, and I think most geomorphologists would agree with me that these are Pleistocene features, created at a time of deglaciation, with great volumes of meltwater flowing either under the ice or beyond the wasting ice edge, and trying to find its way towards lower land. This is at the same time as the creation of the huge meltwater channels of the Gwaun - Jordanston system mentioned in earlier posts.

So if these are meltwater channels created for the most part at the end of the Anglian Glaciation, it follows that they were not there (and neither was Craig Rhosyfelin) at the time when thick ice was flowing across the landscape and entraining large blocks of foliated rhyolite. So what did the landscape look like prior to the arrival of the ice? Probably there would have been a shallower valley here, and probably there was a substantial crag of rock -- rather like the tors of Carnedd Meibion Owen -- standing proud of an undulating land surface. Subsequently, after the erosion of this high crag, meltwater got to work, creating the main valley and the subsidiary valley on the northern flank of the rock.

A Whin Sill erratic cluster in the Stevenage area?

2012-01-21T11:47:00.000Z

In the middle of our recent discussions about erratic clusters, I was reminded of this rather interesting paper by Olwen Williams-Thorpe and others from 1999:

"Geochemical provenancing of igneous glacial erratics from Southern Britain, and implications for prehistoric stone implement distributions" by Olwen Williams-Thorpe, Don Aldiss, Ian J. Rigby, Richard S. Thorpe, 22 FEB 1999, Geoarchaeology , Volume 14, Issue 3, pages 209–246, March 1999

http://onlinelibrary.wiley.com/doi/10.1002/%28SICI%291520-6548%28199903%2914:3%3C209::AID-GEA1%3E3.0.CO;2-7/abstract

The main point of the paper was the link between erratics and stone implement distributions, on the assumption that Neolithic and even later people would instinctively have made use of whatever handy erratic material they found lying around in their neighbourhoods. Leaving that on one side, this is another excellent example of the increasingly accurate provenancing that can now be done -- this time using geochemical methods. The "cluster" of four Whil Sill erratics found near Stevenage, about 360 km from their source area and close to the southern limit of glaciation, is intriguing. (The box on the map shows the area examined by the authors -- and from which they collected 16 erratics for detailed examination.)

Of course, far-travelled erratics are not at all uncommon -- one of the most common and distinctive erratic types found on Pembrokeshire beaches is Ailsa Craig microgranite, which has come from the Firth of Clyde, near the original source area of the Irish Sea Glacier.

In the article, the authors discuss the possibility of "selective" erosion of the Whin Sill by overriding ice and the possibility of a zig-zag transport route over several glacial episodes. It's an interesting discussion, which obviously has a bearing on our debate with respect to Craig Rhosyfelin and Stonehenge.

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

Abstract

Sixteen basic and intermediate composition igneous glacial erratics from Anglian (pre-423,000 years) deposits in Hertfordshire and Buckinghamshire, southern Britain, were selected for chemical and petrographic analysis in order to determine their original source outcrops. Major and trace element compositions suggest that seven samples (plus two uncertain) originated in the Lower Carboniferous volcanics of the Scottish Midland Valley (SMV), four came from the Upper Carboniferous quartz dolerite association which crops out in Scotland, northern England (Whin Sill) and extends to Norway, and one came from the northern England Cleveland Dyke. One sample of altered dolerite is ambiguous but has some similarity to the Old Red Sandstone (Devonian) age lavas of the SMV, and one meta-basalt sample may be from southwest Scotland or Scandinavia. These results identify specific outcrops which provided glacial erratics within currently accepted ice trails in the United Kingdom, and provide the first supporting evidence based on geochemistry, rather than petrography, for these ice movements. The distribution and provenance of glacial erratics are of importance in archaeological studies, because erratics provided a potential source of raw material for stone implement production. There is a marked geographical correlation between the distribution of prehistoric stone implements of quartz dolerite in the United Kingdom, and directions of ice movements from quartz dolerite outcrops within Britain. This correlation lends support to the hypothesis that prehistoric man made extensive use of glacial erratics for implement manufacture, as an alternative to quarrying at outcrops and subsequent long-distance trade.

On Faceted Stones in Nature

2012-01-21T10:42:00.002Z

The pic which I recently published -- with what Rocky refers to as "eight faceted faces" -- has raised some interesting issues -- the most interesting of which is the means by which we recognize rock surfaces as having been shaped in some way by human beings in prehistoric times -- before the advent of metal tools like wedges, chisels, hammers and crowbars. As far as I am concerned, the photo showed a piece of rock which appears to have fractured along a number of intersecting joints or planes of weakness -- which suggested to me that there had been no human intervention of any sort.

If you look at the pic above -- from one of the dolerite pinnacles close to Carn Meini -- it is very common for elongated blocks to have 5 or 6 facets. Look closely (click to enlarge) and you will see that there are lines of quartz crystals running across the blocks in places. These are also weakness lines, and cause transverse breakages. You can see that one big chunk or flake is about to break away from one of the pillars.......

If we contemplate the hypothesis of that other rock having been fashioned by Neolithic rock workers, how would they get surfaces as smooth as that by working just with stone axes and maybe wooden wedges? And why would they want to lever out a slab with that particular shape anyway, when there are thousands of other flattish (and elongated) slabs littering the landscape? I just don't see any logic in it........

The Age of the Landscape

2012-01-20T09:29:00.002Z

Top map: the area of North Pembrokeshire which has been most affected by glacial processes (thanks to Prof David Bowen)

Middle photo: Part of the area of thick fluvuioglacial sands and gravels, between Newport and Cardigan (the two gravel pits are Trefigin and Pantmaenog)

Lower photo: Part of the Gwaun-Jordanston meltwater channel system, at the western end of the Gwaun Valley. The big channel at the bottom of the photo is the Nantybugail Channel -- it can also be picked out on the map.

There have been several comments recently on this blog about the age of the landscape and the age of land surfaces, with some contributors apparently rather keen on the idea that a few thousand years ago there are valleys where there were once hills, and that some low-lying areas have suddenly been uplifted. Well, let's get one thing clear -- the landscape of Pembrokeshire (and this goes for most of the British landscape) is for the most part very old indeed. I'm talking about a landscape which has not changed much over millions of years, apart from superficial vegetation change and the introduction of new features created by massive civil engineering projects (motorways, water supply reservoirs, ports and harbours, airports etc).

The only places where we have had dramatic changes are around the coast, where cliff falls, landslides etc triggered off by marine erosion (especially on high-energy coasts) can occur, and where high rates of sedimentation can change the outlines of embayments and estuaries. In Pembrokeshire, for example, we can see how some Iron Age promontory forts have been largely whittled away by coastal erosion over the course of 2,000 years or less. But right next door there may be a bit of coast that has incredible stability and longevity, where there is less exposure to wave attack.

We know from coastal and valley sediment sequences that most of inland Pembrokeshire hasn't changed much for more than 2 million years. In other words, the basic pattern of hills, valleys and plateau areas is the same now as it was then. But in the north of the county (see map at top) glaciation has wrought major changes in both surface altitudes and in the arrangement of rivers and valleys. The big meltwater channels to the south of Fishguard -- and including the Gwaun Valley -- appear to be NEW features created initially underneath the ice -- maybe during the Anglian Glaciation around 450,000 years ago. The valleys (which are in places more than 100m deep) have been modified during subsequent glaciations. There have also been major changes in the drainage pattern in the Teifi and Nevern Valleys, and in the interfluves where meltwater channels have been created subglacially and by overflowing lakes. Some old valleys have been abandoned, and filled with glacial deposits, and other new valleys have replaced them. Glacial, fluvio-glacial and lake deposits are is some places hundreds of metres thick. There are hummocky moraine deposits, kame terraces and eskers -- two of which are currently exploited for sands and gravels for the building industry.

How old are these landscapes of sedimentation? For the most part, Late Devensian, which means c 20,000 years old. So these are Pembrokeshire's "young" landscapes. Further to the south, in South Pembrokeshire, we seem to be looking at landscapes which may be well over ten million years old.....

Worked rocks -- what do they look like?

2012-01-19T22:51:00.002Z

One of our contributors, who wishes to remain anonymous, has sent these fantastic images of a "worked rock" close to one of the lower crags of Carn Meini -- the supposed source of at least some of the spotted dolerite orthostats at Stonehenge. The upper image shows the "end on" view, and the lower one the "side view."

Sorry folks, but I don't see any signs of working here -- these angular features are very common in the volcanic rock exposures throughout this area -- both on bedrock outcrops and on detached slabs and smaller stones.

So what criteria should we use in order to identify genuine human working and to distinguish it from features that are entirely natural?

100,000 hits

2012-01-17T15:12:00.002Z

I've just noticed that we have gone through the 100,000 hits barrier! Here is the site meter -- this includes only genuine external hits, and excludes my own visits for reviewing comments, putting up new posts, editing etc. It's interesting that there are now well over 500 page view hits per day, coming from an average of 243 site visits per day. Visitors spend an average of over 5 mins per visit, which is I suppose nothing short of miraculous, given the short attention span of the modern human being. Obviously those who read and contribute to this blog are made of sterner stuff, and are serious in their pursuit of knowledge!

Viewing this blog

2012-01-17T14:36:00.000Z

http://brian-mountainman.blogspot.com/view/magazine

There are now so many entries on this blog that it can get confusing, even if you are using the search facility on the site. Even if you use the Blogger magazine format, it can take a very long time to load, with a lot of scrolling required. However, if you have the patience to load the whole blog into the magazine format, you will have ALL entries on a single page which you can scroll up and down -- I recommend that you save this as a web page onto your desktop, and it should then always be there, intact. You can see all the entries adjacent to a thumbnail of the key illustration. Makes it much easier to use. Enjoy!

This will not automatically be updated with new entries -- for that you need to use a web browser like Firefox or Safari, as usual.

I am reminded of this because some recent contributors and readers appear to be unfamiliar with quite long and detailed posts and discussion threads in 2008-2011.

In case you missed it......

2012-01-17T13:12:00.000Z

It occurs to me that there are so many new readers on this blog that some of you, at least, may have not penetrated as far back in the records as 2008. This is the article which I produced with Lionel Jackson for "Earth" magazine -- minus the illustrations.

http://www.earthmagazine.org/earth/article/1a1-7d8-c-1f

As you will see, there is a speculation (a very reasonable one, we think) relating to the movement of two parallel ice streams.

Richard Bevins to talk at Aberystwyth

2012-01-17T09:31:00.000Z

In case anybody in the Aberystwyth area is interested:

Talk: 'Geological evidence for the origins of the Stonehenge Bluestones'
The inaugural event for the West Wales Geological Society will be presented by Dr Richard Bevins, Keeper of Geology at the National Museum of Wales.

'Richard, in partnership with Dr Rob Ixer (University of Leicester) and Dr Nick Pearce (Aberystwyth University) have been working on the rhyolite component of the Bluestones which leads them to believe it is of Welsh origin'.

Event Details
•    Date: 9th February 2012
•    Time: 1900
•    Cost: Members - Free. Non-members - £1.00
•    Location: Room A6, Llandinam Building, Aberystwyth University.
•    Parking: Aberystwyth Arts Centre

Whilst it is not necessary to register for this event, it would be useful for the society to anticipate numbers. Therefore, to register, use this link and contact the WWGS at info@westwalesgeolsoc.org.uk.

Ice streams

2012-01-16T17:29:00.001Z

Above: two distinct ice streams in the ice sheet edge, NW Greenland.

Lower pic: two ice streams separated by a zone of more sluggish ice in Wilkes Land, Antarctica. The ice embayment coincides with the zone of sluggish ice -- on either side of it the ice is moving much faster, and has pushed out across the coast in distinct tongues.

A number of people have asked recently what an ice stream is. I have put in various posts before on this topic -- I suggest you do a search via the search box. An ice stream is simply a stream of ice within an ice cap or ice sheet which is moving more rapidly than the surrounding ice. That may be because there is a rock trough below and a large input of ice from further up-glacier; there may then be ice melting on the bed and a subsequent acceleration in ice velocity.

"Streamlines" are simply the recreated ice flow directions, conventionally shown by arrows. Note that you can also recreate streamlines for ice flow in areas affected by an ice cover, even though you are not dealing with an area covered by an ice stream.

An ice stream may be highly crevassed -- and there is often another crevassed zone on the flanks of the ice stream where sluggish flanking ice is literally ripped apart.

Within the ice stream ice movement directions (and hence directions of erratic transport) will be rather consistent. In the intervening areas (which are sometimes "ice shed" areas) ice movement directions may be highly eccentric and variable. High rates of ice evacuation in an ice stream will lower the ice surface there, and cause ice from the intervening areas to flow towards the ice stream. If the ice stream slows down, or if accumulation patterns vary, ice movement directions may literally be reversed in these zones. Erratic movements in these areas will be very erratic indeed.......

The Irish Sea Glacier must have been an ice stream, flanked by ice-covered terrain on either side. There must also have been big ice streams in the Moray Firth region and in the Firth of Forth. This is the BRITICE recreation for 23,000 years ago -- in the Devensian Glaciation:

One of the areas we have been talking about recently -- Aberdeenshire -- was in effect squeezed between these ice streams. No wonder that geomorphologists have difficulty in determining exactly how and when erratics have been moved.......

See also:
http://brian-mountainman.blogspot.com/2009/10/on-bristol-channel-ice-stream.html

More geology on the way......

2012-01-15T12:34:00.001Z

Spotted on Rob Ixer's academic blog site -- from December. More on the rhyolites on the way........ not sure if the paper is fully published yet. It is available online for subscribers.

Provenancing the rhyolitic and dacitic components of the stonehenge landscape bluestone lithology: New petrographical and geochemical evidence. Bevins, Richard E. / Ixer, Rob A. / Webb, Peter C. / Watson, John S., Journal of Archaeological Science, In Press, Accepted Manuscript, Dec 2011

Abstract

The source of the bluestone component found in the Stonehenge landscape has long been the subject of great interest and considerable debate. The bluestones are a mix of lithologies, the standing orthostats being predominantly dolerites, variably ‘spotted’, with only four of them being of dacitic and rhyolitic composition and the Altar Stone being sandstone. However in the 1920s the spotted dolerites were sourced to outcrops which comprise tors in the summit regions of the Mynydd Preseli in north Pembrokeshire, west Wales. There were also speculations about the possible sources of the dacitic and rhyolitic components, ideas which were elaborated on in the early 1990s when the original petrological provenancing was supplemented by whole-rock geochemical analysis. Most recently, new petrographical investigations have been combined with zircon geochemical data to determine the possible source of one type of rhyolite, the so-called ‘rhyolite with fabric’, found abundantly as débitage in the Stonehenge landscape (but not composing the four orthostats) to outcrops in the vicinity of Pont Saeson, especially a large craggy outcrop called Craig Rhos-y-felin, located in low ground to the north of the Mynydd Preseli. In order to test this provenance whole-rock geochemical analysis has been undertaken on samples of débitage from the Stonehenge landscape and from the Pont Saeson area, including Craig Rhos-y-felin. These data are then compared with other new and existing geochemical data for dacitic and rhyolitic lithologies recovered from the Stonehenge landscape, including the four orthostats, as well as geochemical data from outcrops of the same lithologies from the two main volcanic horizons exposed across north Pembrokeshire, namely the Fishguard Volcanic Group and the Sealyham Volcanic Formation, both of Ordovician age. This study concludes that previous, 20th century, attributions of provenance to a number of dacitic and rhyolitic outcrops in the north Pembrokeshire have been in error whilst the new data for the Pont Saeson rhyolite accords well with elemental contents recorded in the ‘rhyolite with fabric’ lithology from the Stonehenge landscape débitage. This study therefore endorses the proposal that the Pont Saeson area is indeed the source of the ‘rhyolite with fabric’ lithology recovered from numerous sites in the Stonehenge landscape, and is the only reliable provenance for any of the dacitic and rhyolitic bluestone material collected to date. It also serves to endorse the use of zircon chemistry as a provenancing tool in archaeopetrological investigations.

List of the recent articles:

"Provenancing the rhyolitic and dacitic components of the stonehenge landscape bluestone lithology: New petrographical and geochemical evidence". Bevins, Richard E. , Ixer, Rob A. , Webb, Peter C. , and Watson, John S., Journal of Archaeological Science, 2012, pp

“Craig Rhos-Y-Felin, Pont Saeson is the dominant source of the Stonehenge rhyolitic ‘debitage’”, by RA Ixer & RE Bevins, Archaeology in Wales 50 (2011), 21–31

“Stonehenge rhyolitic bluestone sources & the application of zircon chemistry as a new tool for provenancing rhyolitic lithics”, by RE Bevins, NJP Pearce, & RA Ixer, Journal of Archaeological Sciences 38 (2011), 605–22

“The petrography, affinity and provenance of lithics from the Cursus Field, Stonehenge”, by RA Ixer & RE Bevins, Wiltshire Archaeological & Natural History Magazine 103 (2010) 1–15

“The detailed petrography of six orthostats from the bluestone circle, Stonehenge”, by RA Ixer & RE Bevins, Wiltshire Archaeological & Natural History Magazine 104 (2010), 1–14

On the nature of evidence

2012-01-14T21:04:00.002Z

First photo:: direct evidence of erratic transport and displacement : Conwaybreen, Svalbard

Second photo: indirect evidence of erratic transport and displacement: Easter Aquhorthies (in the centre, a reddish granite block, probably from Bennachie, a few miles to the west of the site.) The fact that the large recumbent stone might have been levered up or "adjusted" on the site, or even moved a short distance by the monument builders, is immaterial to the argument.

Above: The distribution of the key recumbent stone circles in NE Scotland.
There are reputed to be at least 99 of them.

Erratic transport directions and other glacial features, NE Scotland (BRITICE Project). Note that erratic occurrences exist at the points of the arrowheads.

On this blog, we have been wasting a vast amount of time recently in trying to elucidate what certain people mean by "evidence". Without getting too deeply into epistemology, philosophy and the scientific method, and without pondering too deeply as to the meaning of "truth", time to make a few simple points.

In glacial geomorphology, when we are trying to interpret the impact of glaciation on the UK landscape, we are dealing with "circumstantial evidence". However, interpretation is informed by direct knowledge of what glaciers do and how they work, in the field, in places like Greenland and Iceland. I have been to both those places, and have observed glaciers at close hand -- I hope it can therefore be assumed that I know what I am talking about when I form opinions about what has happened in the UK. If I am right, my evidence will be accepted by my peers. If I am wrong, one of my peers will come along and falsify my hypothesis through the provision of more reliable circumstantial evidence, well founded in field observations elsewhere, where processes are observable and measurable.

It is not enough for somebody from another discipline to come along and say "I don't believe you because I don't accept your evidence, or because you have not proved your case." The burden of proof is then upon him to produce sufficient new evidence, acceptable to the peer group, which will move things to a new conclusion.

Within the glaciated areas of Britain, the default position must be that large boulders and slabs of rock that might be labelled as "erratics" -- if found in areas downglacier of source areas -- must be assumed to have been moved by ice, simply because direct observation and direct evidence shows that that is what happens when glaciers flow across a landscape. There is nothing contentious in that. (That is true even if such large erratics have been incorporated into man-made monuments, since it seems to be a general rule that the builders of such monuments preferentially used the large stones that were readily to hand, rather than fetching them from a long way off.) This field evidence is simple, well-established, and not seriously liable to challenge -- and if anybody does wish to make a contentious claim (for example that the large erratic stones have been moved by human beings rather than ice) the burden of proof rests upon him to come up with powerful new evidence. In the case of NE Scotland, this would mean that he would have to overturn the interpretations incorporated into the BRITICE map and the published field evidence on which those interpretations are founded.

So when I look at large glacial erratics in a landscape which has been repeatedly affected by glacial processes, and call them glacial erratics because that is what my accumulated experience tells me, I will accept a challenge from another glacial geomorphologist who thinks he or she has better evidence than mine. But I will not accept a challenge from an archaeologist who knows nothing of glacial geomorphology and who simply says "I do not accept your evidence." Such a challenge is intellectually dishonest; it fails to accord me the respect that I deserve as a specialist in this field; and it is a waste of everybody's time.

By the same token, I am not an archaeologist, and if I wish to say something contentious or to challenge a well-founded hypothesis based on sound direct or indirect evidence, the burden of proof rests upon me to come up with something better, and to marshall my evidence in support of what I am saying.

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

From Wikipedia

Evidence in its broadest sense includes everything that is used to determine or demonstrate the truth of an assertion. Giving or procuring evidence is the process of using those things that are either (a) presumed to be true, or (b) were themselves proven via evidence, to demonstrate an assertion's truth. Evidence is the currency by which one fulfills the burden of proof.

Many issues surround evidence, making it the subject of much discussion and disagreement. In addition to its subtlety, evidence plays an important role in many academic disciplines, including science and law, adding to the discourse surrounding it.

An important distinction in the field of evidence is that between circumstantial evidence and direct evidence, or evidence that suggests truth as opposed to evidence that directly proves truth. Many have seen this line to be less-than-clear and significant arguments have arisen over the difference.

Circumstantial evidence directly supports the truth of evidence, from which the truth of the assertion may be inferred.

Evidence in science

Main article: Scientific evidence
In scientific research evidence is accumulated through observations of phenomena that occur in the natural world, or which are created as experiments in a laboratory or other controlled conditions. Scientific evidence usually goes towards supporting or rejecting a hypothesis.

One must always remember that the burden of proof is on the person making a contentious claim. Within science, this translates to the burden resting on presenters of a paper, in which the presenters argue for their specific findings. This paper is placed before a panel of judges where the presenter must defend the thesis against all challenges.

When evidence is contradictory to predicted expectations, the evidence and the ways of making it are often closely scrutinized (see experimenter's regress) and only at the end of this process is the hypothesis rejected: this can be referred to as 'refutation of the hypothesis'. The rules for evidence used by science are collected systematically in an attempt to avoid the bias inherent to anecdotal evidence.

Burden of proof

Main articles: Legal burden of proof and Philosophic burden of proof
The burden of proof is the burden of providing sufficient evidence to shift a conclusion from an oppositional opinion. Whoever does not carry the burden of proof carries the benefit of assumption. Whoever bears the burden of proof must present sufficient evidence to move the conclusion to their own position. The burden of proof must be fulfilled both by establishing positive evidence and negating oppositional evidence.

There are two primary burden-of-proof considerations:

• The question of on whom the burden rests.
• The question of the degree of certitude the proof must support. This depends on both the quantity and quality of evidence and the nature of the point under contention. Some common degrees of certitude include the most probable event, reasonable doubt, and beyond the shadow of a doubt.
Conclusions (from evidence) may be subject to criticism from a perceived failure to fulfill the burden of proof.

See also:
Epistemology

See also:
The Burden of Proof
http://brian-mountainman.blogspot.com/2011/12/on-burden-of-proof.html

Rob's Podcast

2012-01-14T14:01:00.002Z

Thanks to Rob for providing a link to this interesting podcast. It's good to hear things explained carefully and clearly, after all that hype. There are just a couple of things on which Rob might have been more careful. There are not 80 bluestones at Stonehenge -- there are around 43, including both standing stones and stumps. And the natural rock at Rhosyfelin does not naturally break up into long columns or orthostats. It breaks up for the most part into smallish angular fragments as seen in the pic above -- with occasional larger blocks.

www.cbc.ca/quirks

Sourcing Stonehenge

It has long been known that many of the so called "bluestones" that are part of the prehistoric monument Stonehenge, come from Wales. The bluestones, which are either buried or just above ground, are found in a ring inside the iconic standing stones. Now Dr. Robert Ixer, a geologist from The University of Leicester has been able to pinpoint the source of a subset of these bluestones. By analyzing rock flakes from these stones at Stonehenge and comparing them to samples from a large region of Wales, he's found a match to a specific outcrop in Pont Saeson in North Pembrokeshire, Wales. This means these bluestones traveled hundreds of kilometres from Wales to the Salisbury Plain, site of Stonehenge. Just how this happened is one of the enduring mysteries of Stonehenge.

Related Links
Dr. Ixer's paper is not available online. It was published in Archaeology in Wales 50, by the Council for British Archeology
National Museum of Wales press release
BBC News story
National Geographic article

That 99% -- the National Museum Press release

2012-01-14T13:28:00.000Z

This is the original National Museum of Wales press release which was picked up, chewed over, regurgitated, and generally abused by the media. On the whole it is pretty straightforward, but it's now clear that the nonsense about 99% of the rhyolite debitage at Stonehenge coming from Craig Rhosyfelin can be traced straight back to the press release:

"Their recent discovery confirms that the Stonehenge rhyolite debitage originates from a specific 70m long area namely Craig Rhos-y-felin near Pont Saeson. Using petrographical techniques, Ixer and Bevins found that 99% of these rhyolites could be matched to rocks found in this particular set of outcrops."

The authors should have insisted that this form of wording was not used -- because ultimately they are the only people whose reputations suffer from slapdash phraseology. They should have referred to "99% of the rhyolite fragments collected from the debitage at specified excavation sites." That, my dear Doctor Watson, is a very different thing.

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

News 19 December 2011

New geological discovery paves the way for further insight into the transport of Stonehenge rocks

http://www.museumwales.ac.uk/en/5/?article_id=728

A new paper in Archaeology in Wales, produced by Dr Rob Ixer of Leicester University and Dr Richard Bevins of Amgueddfa Cymru – National Museum Wales confirms, for the first time, the exact origin of some the rhyolite debitage found at Stonehenge. This work could now lead to important conclusions about how stones were transported from Pembrokeshire to Stonehenge.
Over a period of nine months, Bevins and Ixer have been carefully collecting and identifying samples from rock outcrops in Pembrokeshire to try and locate the provenance of rocks that can be found at what is today, one of the world’s most iconic archaeological sites.
Their recent discovery confirms that the Stonehenge rhyolite debitage originates from a specific 70m long area namely Craig Rhos-y-felin near Pont Saeson. Using petrographical techniques, Ixer and Bevins found that 99% of these rhyolites could be matched to rocks found in this particular set of outcrops. Rhyolitic rocks at Rhos-y-felin are distinctly different from all others in South Wales, which gives almost all of Stonehenge rhyolites a provenance of just hundreds of square metres.
Yet, the story progresses. Along the Rhos-y-felin crags, the rhyolites are distinctly different on a scale of metres or tens of metres. This has enabled Bevins and Ixer to match some Stonehenge debitage samples to an even more precise locality at the extreme northeastern end of the area.
What this means is that the area is now small enough for archaeologists to excavate to try and uncover evidence for associated human activity so providing another strand of the story of how the stones from Pembrokeshire reached Stonehenge.
Dr Richard Bevins of Amgueddfa Cymru said:
“Many have asked the question over the years, how the stones got from Pembrokeshire to Stonehenge. Was it human transport? Was it due to ice transport? Thanks to geological research, we now have a specific source for the rhyolite stones from which to work and an opportunity for archaeologists to answer the question that has been widely debated. It is important now that the research continues.”
In addition the level of work carried out at Rhos-y-felin confirms that the four remaining above surface rhyolite and dacite orthostats at Stonehenge do not come from Rhos-y-felin and work is in hand to determine if their source can be identified.
Dr Rob Ixer of Leicester University added:
“Being able to provenance any archaeologically significant rock so precisely is remarkable, to do it for Stonehenge was quite unexpected and exciting. However, given continued perseverance, we are determined that we shall uncover the origins of most, if not all of the Stonehenge bluestones so allowing archaeologists to continue their speculations well into a third century.”
Date: 19 December 2011

Rope technology

2012-01-14T12:59:00.000Z

Now here's a thought. All of the human transport technologies are dependent upon the existence and plentiful supply of rope -- often in great lengths. It appears that rope has been around for a long time -- in short lengths -- and maybe of questionable strength. It could be made with vegetable fibres or animal products -- see below. The technique is well known too -- slow, laborious and fun for an amateur experimental archaeologist or self-sufficiency freak, but adequate for production on a semi-industrial scale?

SO what evidence is there that really strong ropes, in sufficient quantities for hauling large numbers of very large stones either over land or sea, actually did exist in the Neolithic?

-----------------------------
From Wikipedia:

The use of ropes for hunting, pulling, fastening, attaching, carrying, lifting, and climbing dates back to prehistoric times. It is likely that the earliest "ropes" were naturally occurring lengths of plant fibre, such as vines, followed soon by the first attempts at twisting and braiding these strands together to form the first proper ropes in the modern sense of the word. Impressions of cordage found on fired clay provide evidence of string and rope-making technology in Europe dating back 28,000 years.[3] Fossilized fragments of "probably two-ply laid rope of about 7 mm diameter" were found in one of the caves at Lascaux, dating to approximately 15,000 BC.[4]

The ancient Egyptians were probably the first civilization to develop special tools to make rope. Egyptian rope dates back to 4000 to 3500 B.C. and was generally made of water reed fibres[5]. Other rope in antiquity was made from the fibres of date palms, flax, grass, papyrus, leather, or animal hair. The use of such ropes pulled by thousands of workers allowed the Egyptians to move the heavy stones required to build their monuments. Starting from approximately 2800 B.C., rope made of hemp fibres was in use in China. Rope and the craft of rope making spread throughout Asia, India, and Europe over the next several thousand years.

In the Middle Ages (from the 13th to the 18th centuries), from the British Isles to Italy, ropes were constructed in so-called Ropewalks, very long buildings where strands the full length of the rope were spread out and then laid up or twisted together to form the rope. The cable length was thus set by the length of the available rope walk. This is related to the unit of length termed cable length. This allowed for long ropes of up to 300 yards long or longer to be made. These long ropes were necessary in shipping as short ropes would require splicing to make them long enough to use for sheets and halyards. The strongest form of splicing is the short splice, which doubles the diameter of the rope at the area of the splice, which would cause problems in running the line through pulleys. Any splices narrow enough to maintain smooth running would be less able to support the required weight.

Leonardo da Vinci drew sketches of a concept for a ropemaking machine, but it was never built. Nevertheless, remarkable feats of construction were accomplished without advanced technology: In 1586, Domenico Fontana erected the 327 ton obelisk on Rome's Saint Peter's Square with a concerted effort of 900 men, 75 horses, and countless pulleys and meters of rope. By the late 18th century several working machines had been built and patented.

Some rope continues to be made from natural fibres such as coir and sisal, despite the dominance of synthetic fibres such as nylon and polypropylene which have become popular since the 1950s.

See also:

http://www.instructables.com/id/Make-rope-out-of-dead-plants----with-no-tools/?ALLSTEPS

The Bluestones of Stonehenge -- a glacial erratic assemblage

2012-01-12T14:00:00.000Z

The Bluestones of Stonehenge -- a glacial erratic assemblage

A well-placed spy, who is obviously a Times reader, informs me that this is in the paper today. This is what was sent. Not sure whether the published version was identical........... but fair play to the Editor for at least accepting that there is a bit of a debate going on here!

---------------------------------------------------
Letters to the Editor
The Times

10th January 2012

Re: Back to the Bluestones of Stonehenge 7th January 2012

Sir

The geological points made by Dr Olwen Williams-Thorpe in Norman Hammond's latest article are supported by research in the fields of glaciology and geomorphology. It has been known for many years that the ice of the Irish Sea Glacier flowed across Pembrokeshire, up the Bristol Channel and into Somerset. When it crossed the English coast it was flowing broadly eastwards. We do not know whether the ice reached Salisbury Plain, but glaciological modelling by the BRITICE project shows that this was quite possible. It is entirely reasonable to assume that the 30 or so rock types represented in the "bluestone assemblage" at Stonehenge are glacial erratics, since they seem to have come almost exclusively from the west.

I concur with Dr Williams-Thorpe when she says that the recent work by Ixer and Bevins at Craig Rhosyfelin is an exciting development, showing that very accurate provenancing of some of the bluestones is now possible. However, their research has no archaeological significance, and tells us nothing about the mode of transport by which certain stones (or broken rock fragments) found their way from Pembrokeshire to Stonehenge.

Thank you for giving space to this timely debate.

Dr Brian John
Past Lecturer in Geography, Durham University
Author, "The Bluestone Enigma"

Trefelin
Cilgwyn
Newport
Pembrokeshire
SA42 0QN
Tel 01239-820470

The Mythology of Old Keig

2012-01-12T10:47:00.000Z

I have been following up the material on these recumbent stone circles in Scotland, which are, as Chris reminds us, reputed to be "monuments placed with care and accuracy." Well, they are either that, or else monuments created around conveniently located large glacial erratics. The myth about Old Keig is especially interesting, as Geo has reminded us, since over and again in the literature it is flagged up as a prime example of a RSC in which the recumbent stone (weighing in this case 53 tonnes) has been moved from the Don Valley, about 10 km away, including one steep uphill section, by our heroic ancestors. That would mean the stone has been moved from the SE towards the NW -- in precisely the opposite direction to the assumed movement of ice at the peak of the Devensian Glaciation.

So how sound is all of that scientifically? I'm not at all sure. For a start, the sourcing of the stone is not as certain as we might assume. The stone is made of a "sillimanite gneiss" which Gordon Childe (1933), who did the original dig, assumed might have come from "the Don valley between Kemnay and Tillifourie." All he said was that "similar rocks" were to be found there. No stronger than that. But as far as I can see, that has been taken to be a definitive piece of provenancing, and has been used ever since in every succeeding paper or article. I need to check that out, and am trying to look at the relevant material........

But far from being a tidy piece of provenancing, Childe also added (and this is conveniently forgotten) that "there are also areas of gneisses shown on the 1-inch map both to the west and to the north." So he was admitting that the stone might have come from the west or the north. This is confirmed when you look into the geology of the region. Sillimanite gneiss seems to pop up all over the place, in a number of different geological formations -- and I am not at all sure whether these various examples of the rock type have been identified and differentiated to high modern standards.

Two recent maps showing reconstructed ice directions across NE Scotland. Old Keig is a short distance to the west of Iverurie, in an area affected by ice that has flowed from the west and the north-west.

There is one other feature of the Childe field report from 1933 -- and that is a clear impression that the superficial deposits in and around the site are made up of thin glacial till and areas of fluvioglacial sands and gravels. The descriptions are difficult to interpret -- especially since Childe, like many archaeologists before and since, leaned towards an assumption that everything in the area (including the deposits beneath and around the big stone) was created because of human interference.

I'm trying to obtain more info about the geology of that famous recumbent stone and the sediments of the neighbourhood -- all info (convenient or otherwise) gratefully received. But for the time being it will be just as well to reserve judgment on how that 53 tonne monster might have been moved, and where it came from..........

SOME RELEVANT MATERIAL
----------------------------------------------
"At Old Keig a recumbent stone circle situated on a slight crest on a ridge, and within a narrow windbelt. A recumbent stone, 16ft long on top, 6ft thick, 6 3/4ft high, two flankers, the westerly 5 1/4ft above the turf, the easterly 9 1/2ft, and a third orthostat, 9 1/2ft high, to the east, survive. "

"The circle is located on a very slight crest on rising ground with distant, sometimes magical, views over the Howe of Alford. The site was probably levelled and the enormous recumbent, which weighs 53 tons and is the largest known (4.9m by 2.1m by 2.0m) dragged from somewhere in the Don valley about 10km away. The last 1km would have been uphill at a gradient of 1:14, requiring well over 100 people."

http://canmore.rcahms.gov.uk/en/site/17530/details/old+keig/

Grid Reference: 57° 15' 48.7" N, 2° 40' 5.51" W.

http://www.ancient-wisdom.co.uk/scotlandoldkeig.htm

PDF available:
TRIAL EXCAVATIONS AT THE OLD KEIG STONE CIRCLE, ABERDEENSHIRE.
BY PROFESSOR V. GORDON CHILDE, B.LITT., P.S.A.ScoT.

"The Recumbent Stone is not of local origin. Similar rocks occur in
the Don valley between Kemnay and Tillifourie, and there are also
areas of gneisses shown on the 1-inch map both to the west and to the
north."

Refs

Atkinson, R J C (1962) 'Fishermen and farmers', in Piggott, S The prehistoric peoples of Scotland, London
Page(s): 17, 181

Burl, H A W (1973a) 'The recumbent stone circles of North-East Scotland', Proc Soc Antiq Scot, vol.102
Page(s): 60, 61, 63, 66-70, 72, 76, 78

Burl, {H} A {W} (1976a) The stone circles of the British Isles, London and New Haven
Page(s): 172, 174, 179-183, 352 Held at RCAHMS E.7.BUR

Burl, {H} A {W} (1979a) Rings of stone: the prehistoric stone circles of Britain and Ireland, London
Page(s): 17, 22-4,_32, 138-9 Held at RCAHMS E.7.BUR

Burl, {H} A {W} (1995) A Guide to the Stone Circles of Britain, Ireland and Brittany
Page(s): 105

Childe, V G (1933a) 'Trial excavations at the Old Keig Stone Circle, Aberdeenshire', Proc Soc Antiq Scot, vol.67
Page(s): 37-53 illust, plans

Childe, V G (1934a) 'Final report on the excavation of the stone circle at Old Keig, Aberdeenshire', Proc Soc Antiq Scot, vol.68
Page(s): 372-93 illust, plans

Coles, F R (1901) 'Report on the stone circles of the North-East of Scotland, Inverurie District, obtained under the Gunning Fellowship, with measured plans and drawings', Proc Soc Antiq Scot, vol.35
Page(s): 211-14

Henshall, A S (1963a) The chambered tombs of Scotland,, vol.1 Edinburgh
Page(s): 37, 39, Held at RCAHMS E.7.1.HEN

Kilbride-Jones, H E (1935a) 'An account of the excavation of the stone circle at Loanhead of Daviot, and of the standing stones of Cullerlie, Echt, both in Aberdeenshire, on behalf of HM office of Works', Proc Soc Antiq Scot, vol.69
Page(s): 168-214

Logan, J (1829c) Archaeologia, vol.22
Page(s): 201

Ralston, I (2009) 'Gordon Childe and Scottish Archaeology: The Edinburgh Years 1927-1946', European J Archaeol, vol.12
Page(s): 74

Shepherd, I A G (1986a) Exploring Scotland's heritage: Grampian, Exploring Scotland's heritage series Edinburgh
Page(s): 156, no. 97 Held at RCAHMS A.1.4.HER

Welfare, A (2011) Great Crowns of Stone: The Recumbent Stones Circles of Scotland: Gazetteer and Appendices, in S Halliday Edinburgh
Page(s): 422-7

Recumbent stone circles

2012-01-11T12:58:00.002Z

Old Keig recumbent stone and flanking stones. The recumbent stone is reputed to weigh 53 tonnes.
Thanks to: http://www.odysseyadventures.ca/trips/scotland/scotlandtrip_orkneys.htm

Thanks to Geo for bringing up this topic. More interesting than I had anticipated! I have been looking up some of the references on Old Keig and the other recumbent stone circles (RSCs) of Aberdeenshire, and I had forgotten what an interesting group of monuments they are. According to some sites, there are scores of these circles in a restricted area -- representing a specific cultural tradition.

Aberdeen CC says:
The Recumbent Stone Circle (RSC) is Aberdeenshire's unique contribution to the tradition of erecting rings of standing stones which was current in certain parts of Britain and Ireland during the third and second millennia BC.
Up to 99 examples have been recorded, with diameters ranging from 18.2 m to 24.4 m.
The distinctive feature of the RSC is the massive slab, laid recumbent on its side in the south-western or southern arc of the ring, and flanked by the two tallest stones of the circle. The recumbents average 24 tons in weight and were carefully levered and chocked-up to ensure that their upper surface was as level as possible.

One thing that occurs to me immediately is that the location of these recumbent stone circles has been determined by the presence of a large and convenient glacial erratic. Some of the web sites and printed materials do not mention glaciation, and they do not mention erratics -- and it is assumed that the big recumbent stones have all been moved into position, as have the smaller standing or flanking stones. Now why would the builders want to go to all that bother? As in the case of Garn Turne and all the cromlechs in Wales, you put your monuments where the biggest stones happen to be located. In the case of the cromlechs, you use these big stones as capstones, and move in the pillars or supporting stones from round and about in the neighbourhood. Perfectly sensible.

Garn Turne, a burial mound or "megalithic monument" in which a massive slab of bedrock has simply been levered up along one edge, so as to serve as a capstone. In this case the slab weighs c 60 tonnes. it is often referred to as a "collapsed capstone" but it is doubtful that it ever was higher up than it is today...........

This is from an earlier post of mine:

There was some very interesting work reported by Colin Richards on the cromlechs / dolmens of the area. There has been a big dig at Garn Turne (the one with the enormous capstone) -- and he reckons that here, as at Pentre Ifan and Carreg Samson the stones that have been used as capstones were originally embedded in the ground and have been lifted up onto supporting pillars without being moved very far, if at all. He thinks they may not have been at the centre of earth or stone mounds at all, but that they were megalithic monuments in the true sense of the word, in the same sense that the trilithons at Stonehenge are "monuments". He also thinks that they are very old -- maybe as old as the dolmens of Brittany, some of which go back to 4,500 BC. I like the "use what's on the spot" idea -- and that of course is exactly what Steve Burrow says in his book.
http://brian-mountainman.blogspot.com/2011/09/credit-where-credit-is-due.html

One thing that comes into the frame with respect to the Aberdeenshire RSCs is the evidence for glacial action in the landscape. We still do not know with any degree of accuracy exactly what happened in the Devensian, let alone the earlier glacial episodes, but this is a reconstruction by Chris Clark and others:

In general, it looks to me as if most of the RSCs are in an oscillating ice shed area, where ice movement in virtually any direction might have occurred.....

Here is an enlargement of the relevant bit of the BRITICE master map, showing erratic routes in the Devensian in NE Scotland:

Another bluestone experiment

2012-01-10T23:01:00.000Z

This is an historic photo from the archives -- from 1986. It shows a very pleasant young lady from a Japanese TV station -- just prior to the lighting of the great bluestone bonfire.

(NB folks -- I am really into experimental archaeology! There's more to life than glaciers. Not only do I help to pull that blasted chunk of bluestone in the year 2000 that ends up on the floor of Milford Haven; but I also undertake research into how easy it is to quarry chunks of bluestone from the native rock by using fire and water ..... impressive, eh?)

Just joking. But it was quite entertaining, and I even got paid a few quid for doing it. We placed a large bluestone boulder into the middle of the bonfire, sent the whole thing up in flames, and then when the pile of logs had been reduced to a pile of glowing embers with a bluestone in the middle of it, we got as close as the heat would allow us, and threw several buckets of cold water onto the stone. Lo and behold, it split. The TV crew went away happy.

That all goes to show that "quarrying" is possible, if you have plenty of logs, the means of making fire, and buckets of cold water! When it comes to the practicalities (or the necessity) of using this method for splitting monoliths from the cliff face at Carn Meini, that's a different matter.....

The Times revisits the bluestone issue

2012-01-10T20:25:00.002Z

Last Saturday The Times revisited the bluestone issue, with another short article from Norman Hammond. It is based almost entirely on an interview with Olwen Williams-Thorpe. What she says appears to me to be eminently sensible..... and let's hope that a few archaeologists read the article.

Back to the bluestones of Stonehenge

Norman Hammond
The Times, Sat 7th January 2012

One of Britain’s leading geoarchaeologists has challenged the recent claim that the“glacial theory” for the origins of Stonehenge’s bluestones is “out cold” (The Times, Dec 17, 2011).
Because of variability in the bluestones’ composition, numerous sources were involved, says Dr Olwen Williams-Thorpe, making human transport so complex as “to look supremely unlikely”.

She calls the work of Dr Rob Ixer and Dr Richard Bevans, who have pinned the source of several of the stones to a single outcrop in Pembrokeshire, as, “an important step forward in bluestone research, applying the most precise petrographic analysis to the stones”, but says that this does not in fact negate the idea that Ice Age glaciers transported the rocks eastwards from Wales.
“Studies indicate glaciation east of the Bristol Channel and probably further into southern England.

This offers a far more likely explanation for the mixed bag of Welsh bluestones at and around Stonehenge than the increasingly contorted special pleading invoked by the human transport supporters,” she says, noting that in some of these scientific models, “the ice may only have been present over Cornwall, Devon and Somerset for around 1,000 years”.

Dr Williams-Thorpe, who worked on the first modern analysis of bluestone origins more than 20 years ago, underlines “the great variety of bluestone types” and points out that “none of the four remaining rhyolite orthostats above ground (those numbered as SH 38, 40, 46 and 48) matches the source at Pont Saeson, near Newport, that has been pinpointed by Drs Ixer and Bevans.

“The Open University’s geochemistry work has pointed to various north Pembrokeshire outcrops as the probable source area for these orthostats, but we did not find exact petrographic matches in our work. Quite apart from the rhyolites, there are of course at least three Preseli outcrop sources for the spotted and unspotted dolerites; and then there are the several types of sandstone bluestones.
“These come from varied sources, the exact localities of which are uncertain but likely to be in west or south Pembrokeshire, perhaps even the Brecon Beacons. So, if it is human transport, we are looking at many different and dispersed outcrops all regarded as “special” or “magical”, with transport of stones north from Pont Saeson, south from the Preseli Mountains, from west and south Pembrokeshire and possibly from Brecon — all sort of routes and mechanisms would have to be invoked.”

Back to the bluestones of Stonehenge | The Times
http://www.thetimes.co.uk/tto/life/courtsocial/article3278922.ece

This nonsense is official -- so it must be true.....

2012-01-05T17:15:00.000Z

On the Culture 24 web site, sponsored by the Dept of Education, Arts Council England, MLA Museums etc, we find the following nonsense:

"Archaeological investigators from National Museum Wales say "99%" of rhyolite rocks found at Stonehenge can be matched to ones found in a 70-metre stretch of land in North Pembrokeshire."

How wrong can you get? This wasn't a National Museum of Wales investigation -- it was a bit of cooperative work involving Rob Ixer and Richard Bevins. They weren't archaeological investigators - they were (and still are) geologists. They did not say that 99.9% of rhyolites at Stonehenge can be matched to Rhosyfelin. They said that at least 99.9% of the rhyolite DEBITAGE (from those parts of the site from which flakes and fragments have been collected) could be matched to samples collected in the Rhosyfelin area -- and they specifically said that the rhyolite orthostats at stonehenge are NOT from this locality.

This would be funny, if it were not for the fact that this site is heavily used by teachers and students, who presumably accept that what is on the site is authoritative and accurate. Oh dear oh dear.....

Source:

Stonehenge rocks pinpointed to Pembrokeshire in National Museum Wales investigation

By Culture24 Reporter | 04 January 2012

http://www.culture24.org.uk/history%20&%20heritage/archaeology/megaliths%20and%20prehistoric%20archaeology/art371879#.TwVwxlN9jIc.twitter

Stonehenge and the importance of heroic failures

2012-01-05T13:45:00.000Z

While I am thinking beautiful thoughts, here is another one: Could it be that the uniqueness and iconic stature of Stonehenge is explained quite simply by the fact that it was a heroic failure?

I have argued over and again on this site that Stonehenge was never finished -- and many others have also come to that view, including a well-known geologist who referred to it as a "jerry-built shambles." I won't go over all the arguments here again -- but it's worth reminding ourselves that there ought to be around 160 stones at Stonehenge, instead of the 90 or so that we know about; that there are large "empty segments" in the structure where there appear to be neither stones, stumps nor sockets; and that it stretches credibility to extremes to suggest that no less than 70 large stones have been removed or destroyed by rival tribes, Romans, farmers, stone collectors and treasure hunters over the years.

I believe that even EH is beginning to come round to the view that the concept of the "immaculate Stonehenge" propounded by Anthony Johnson and many others is at fault; and that while we have to admit that the aspirations and ambitions of the Stonehenge builders were mightily impressive, we also have to accept that either their technologies or their manpower resources were inadequate to finish the job. As I have often argued, the frequency of changes in the stone settings (cf all those intersecting sockets) also argues for indecisive leadership and a shortage of stones. I think the stones were all gathered up from the neighbourhood of Stonehenge, and that the builders ranged further and further afield in their stone collecting trips and eventually reached a point at which the cost was greater than the benefit -- at which time the project ground to a halt.

So Stonehenge was a one-off, a glorious failure, which was why no other Neolithic tribal groups sought to either copy it or improve upon it. The word got round that those mad people on Salisbury Plain had tried to build this crazy edifice but had given up on it. We are normally told that the builders of Stonehenge were revered and respected by other tribes, to the extent that they even brought tribute stones of their ancestors to the site -- so as to become a part of the great enterprise. Hmmm.......

Here is another view. The builders of Stonehenge were looked on by their neighbours as a bunch of crazy idiots, admired in some way for their sheer audacity, but genuinely pitied and held up for ridicule at the same time................

So it is because Stonehenge failed that it is unique. If it had succeeded, it would have been copied. And because it is unique, it has become one of the great iconic structures of prehistory.

On technological development

2012-01-05T13:18:00.000Z

"Technology includes all tools, machines, utensils, weapons, instruments, housing, clothing, communicating and transporting devices and the skills by which we produce and use them." (Bain, 1937)

I have been pondering on the fact that the Stonehenge bluestone "human transport enterprise" -- if it ever happened -- must have been one of the most extraordinary aberrations in prehistory. And yet people actually do believe in it -- so fervently that it has become an article of faith within British archaeology. That is also extraordinary.

It is in the nature of technological development -- in the field of prehistory -- that things start small, then develop and become mainstream, and then maybe fade away as other technologies take their place. I know that Colin Renfrew, Tim Darvill and many others have pondered on this in the context of cultural diffusion, parallel development, innovation and so forth. If we look at the history of the wheel, or of road building, or canals, or the making of stone tools, or house construction, or even pyramid construction, we can see in the prehistoric record the "beginning of things" followed by development and increasing sophistication, followed by an acme or zenith, and then decline. (If not a decline, a time at which no further development occurs, either because the raw material will not allow it, or because the cost / benefit equation is all wrong, or because something better comes along to replace it.) So a technology is not actually forgotten about, but put to one side. In that process, the skills involved may well be lost. What proportion of the population today knows how to make a stone axe?

So why is it that there is NO evidence for the seriously long-distance (or even moderately long-distance) transport of big stones from a source area to a megalithic monument site either before Stonehenge or after it? According to all the rules, the technology needed for moving big stones must have developed gradually, maybe spreading out from a core area or maybe happening simultaneously in different places. But there is no evidence for any of that, anywhere in Britain. And once Stonehenge was up and running (if we believe that it was ever finished), why did that stone-moving technology not spread to other areas, or become duplicated or improved? So why did it not happen on a smaller scale well away from Stonehenge, around the time of the Neolithic / Bronze Age transition? If Stonehenge was constructed by a big and powerful tribal group, why was the behaviour of that group not mimicked by smaller groups elsewhere, who were maybe intent upon increasing their status?

To my mind this lack of a "technology development history" is one of the most powerful arguments against the human transport theory. The theory just does not make sense, and is best forgotten about.

Note: The Pyramids: Monolithic, smooth sided pyramids did not just suddenly appear in Egypt. There was an evolutionary period, leading to the great pyramids of Giza that began with simple mastaba tombs, expanded into step pyramids, which led to experimentation, some of which failed miserably, and culminating with the perfected structure. In addition, the decorative themes associated with pyramids also evolved over time.

Stonehenge -- a breeding ground for pseudoarchaeology?

2012-01-05T09:21:00.004Z

I was rambling about, looking something else up, when I was taken to this page on Wikipedia:
http://en.wikipedia.org/wiki/Pseudoarchaeology

It struck a chord with me -- especially in the light of my recent post called "Does Stonehenge make all men mad?" and many earlier posts on the scientific method. What struck me is that the article's authors have clearly considered that most pseudoarchaeology is outside of academia, with its disciples or practitioners considering that they are being victimised and marginalised by an archaeological establishment that is complacent and which blocks alternative or radical views. It seems to me that within the Stonehenge debate, at any rate, the pseudoarchaeology is INSIDE academia, with the radicals and the subversives who are arguing for scientific rectitude all being on the outside. How dangerous is that?

From the Wikipedia article:
Pseudoarchaeology: Lack of scientific method

Academic critics have pointed out that pseudoarchaeologists typically neglect to use the scientific method. Instead of testing the evidence to see what hypotheses it fits, pseudoarchaeologists "press-gang" the archaeological data to fit a "favored conclusion" that is often arrived at through hunches, intuition, or religious or nationalist dogma.[17][18]

Comment: the Rhosyfelin "quarry mania" is absolutely typical of this. See my previous posts on the Newport lecture evening and all the hype surrounding it -- with reference to a group of archaeologists who had decided what they were looking at well before they even turned up to look at the evidence on the ground. That's classic pseudoarchaeology, and when it starts within academia, we should not be surprised when the media makes matters worse.

Different pseudoarchaeological groups hold a variety of basic assumptions which are typically unscientific: the Nazi pseudoarchaeologists for instance took the cultural superiority of the ancient Aryan race as a basic assumption, whilst Judeo-Christian Fundamentalist pseudoarchaeologists conceive of the Earth as only being 10,000 years old and Hindu Fundamentalist pseudoarchaeologists believe that the Homo sapiens species is much older than the 100,000 years old it has been shown to be by archaeologists.[19] Despite this, many of pseudoarchaeology's proponents claim that they reached their conclusions using scientific techniques and methods, even when it is demonstratable that they have not.[20][21]

Comment: This is interesting too -- as a number of authors have noted, HH Thomas's original hypothesis about the human transport of the bluestones was motivated at least in part by the desire to show the world that "our British Neolithic ancestors were at least as smart as the German Neolithic ancestors, and were probably even smarter...." Nationalistic hogwash, of course, but understandable when seen in the context of the First World War. And that sort of nationalistic jingoism and pride may well explain why the archaeological establishment never properly examined the HHT theory when it was first propounded. In effect, there was lack of scrutiny.

Academic archaeologist John R. Cole believed that most pseudoarchaeologists do not understand how scientific investigation works, and that they instead believe it to be a "simple, catastrophic right versus wrong battle" between contesting theories.[22] It was because of this failure to understand the scientific method, he argued, that the entire pseudoarchaeological approach to their arguments was faulty. He went on to argue that most pseudoarchaeologists do not consider alternate explanations to that which they want to propagate, and that their "theories" were typically just "notions", not having sufficient supporting evidence to allow them to be considered "theories" in the scientific, academic meaning of the word.[23]

Comment: I can understand what Cole is getting at here. As I have argued on this blog many times before, archaeologists are nowadays very good at using archaeological techniques but they are not always good at understanding how science works. Some of them might be called technologists rather than scientists. They promote ideas that are essentially faulty, they do not test their hypotheses properly, and they concentrate on the propagation and promotion of their theories rather than on falsification and balanced debate.

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

http://brian-mountainman.blogspot.com/2010/09/pseudoarchaeology-at-stonehenge.html

Salon Report on Rhosyfelin paper

2012-01-03T10:29:00.001Z

The Kellaway map of Irish Sea Glacier streamlines. I doubt that any geomorphologists or glaciologists would argue with this map, apart from the suggestions for Somerset and Wiltshire!

A report has appeared in SALON, and while not so biased and garbled as some others in the media, the author (Chris Catling, the Editor?) cannot resist referring to "the probable quarry site." Further, if Ixer and Bevins are correctly quoted, they cannot resist suggesting that the new work now tips the balance towards the "human transport theory" and away from the glacial transport theory.

I do find it rather wearying that archaeologists and geologists persist in the belief that a narrow range of stones at Stonehenge would support the human transport thesis, whereas "the use of different rock types from disparate parts of Wales to create the first stone circle at Stonehenge would support the thesis that the stones were carried by natural means, such as the Irish Sea Glacier." How many times do I have to repeat that that is not how glaciers work? Glaciers do not simply collect up stones from here, there and everywhere, mix them up and then dump them in one place. Glaciers entrain, transport and deposit debris on streamlines, and if stones from disparate sources are entrained and carried they can only come from a narrow band of country coinciding with the streamlines themselves. We know pretty accurately what the streamlines of the Irish Sea Glacier looked like. It is not at all unusual (as I have shown many times on this blog) for glaciers to entrain clusters of boulders from one very limited location and to dump those boulders tens or even hundreds of kilometres away, in another location --- with or without an erratic train joining the two points together. How many times do I have to repeat that, in order for people to understand it?

=========================
Stonehenge bluestones: natural or human transport?

SALON - the Society of Antiquaries of London Online Newsletter
Salon 268: 3 January 2012

In an important new paper published in the journal Archaeology in Wales, our Fellows Rob Ixer, of Leicester University, and Richard Bevins, of Amgueddfa Cymru — National Museum Wales, report on the latest stage in their work to pin down the precise origin of the rhyolitic bluestones that formed the first stone circle at Stonehenge. Having already published a paper in the Journal of Archaeological Science suggesting that the crags of the Pont Saeson area of Pembrokeshire (on the northern flank of the Preseli hills, some 6.5km from Newport) were the likely source, they have now refined their chemical and petrographical techniques to the extent that they have been able to identify a specific outcrop as the probable quarry site.
‘We assumed that we might be able to pin down the source to an area of several hundreds of square metres’, Rob Ixer said, ‘but we can now pin it down unequivocally to an area of a few square metres, namely to a small single outcrop or couple of outcrops at Craig Rhos-y-felin’. The outcrop is some 70m long and has many tall, narrow slabs up to 2m high as the dominant feature, splitting off from the parent rock in blocks that are reminiscent of the Stonehenge bluestones.
The site was found by comparing the chemical properties of stone taken from outcrops in Wales and the west of England with the distinctive bluestone debitage (the waste created by shaping and dressing the stones) excavated in 1947 and subsequently stored in a box at Salisbury Museum. ‘I have always wanted’, Rob Ixer told our Fellow Norman Hammond, Archaeological Correspondent of The Times, ‘to tell this story under the tabloid heading “Old shoebox held key to Stonehenge mystery”.’
Drs Ixer and Bevins also say that their recent work is tipping the balance in the debate about whether or not the stones are glacial erratics. In the ‘nature versus human transport debate’, the higher the number of stones that can be demonstrated to have come from one site, and not from any other, the more likely it is that human agency accounts for their quarrying and transport to Stonehenge. Vice versa, the use of different rock types from disparate parts of Wales to create the first stone circle at Stonehenge would support the thesis that the stones were carried by natural means, such as the Irish Sea Glacier.
Rob Ixer told Current Archaeology magazine that ‘this is the first time that any lithics from Stonehenge have been so clearly provenanced but it will not be the last’. Meanwhile, the hunt continues for the source of four standing Stonehenge orthostats (SH38, SH40, SH46 and SH48) that have been tested and found not to have any petrographical match for any rhyolitic lithology at Pont Saeson — so the story of how and from where the bluestones got to Stonehenge still has some way to run.

Happy New Year!

2011-12-31T22:48:00.001Z

Slabs of sea ice in pressure ridges in McMurdo Sound, Antarctica.

From the brilliant "Glaciers Online" web site.

Phil's Contraption

2011-12-31T15:55:00.000Z

http://prehistoric-technology.blogspot.com/2011/07/moving-stonehenge-bluestones-st-fagans.html

Thanks to Phil Morgan for drawing my attention to his contraption -- basically a rocking A-frame -- which was demonstrated last July at the Welsh Folk Museum at St Fagans, on a sort of experimental archaeology day.

There is a short writeup and photo on Andy Young's blog site.

You can see how it works -- the reinforced A-frame rocks on its base, and by pulling it forward you can drag along a sledge with a heavy weight (or a bluestone) by a few feet at a time. Then you reposition the rocker by pulling on the rear rope, and once it's in position you pull on the front rope again. And the sledge moves forward again. As Andy says, this might be practical for moving heavy stones on a building site -- but I would have serious doubts about the utility of the technique over a long distance, and in rough terrain.

Those "periglacial stripes"

2011-12-30T16:48:00.000Z

A discussion on these famous "periglacial stripes" seems to be bubbling up again -- and purely by chance I came across these two pics -- from 1956 and 1958, I think -- from the excavations in the Avenue. The top photo shows the supposed periglacial features in cutting C48, and the lower photo shows what seems to be a cross-section of one of the stripes, as exposed in the side of cutting C40.

I don't recall ever seeing a plan or map of these features -- does anybody know of one?

The photos are from the Atkinson collection, on the EH web site.

For earlier discussions of these features, and some analogies from the Arctic, just type in "periglacial stripes" into the search box on this blog.

The Stonehenge Cave

2011-12-30T16:39:00.000Z

I had forgotten about this picture --it shows what Stone 60 was like in 1958 before the "cave" was filled with concrete in order to stabilize the stone. This is one of the Atkinson series, from the EH web site.

How depressing -- I suppose I must have looked a bit like that in 1958 -- except that I didn't smoke....

The Silbury Hill bluestones (again)

2011-12-29T20:12:00.000Z

Further info about the Silbury Hill bluestone fragments. Thanks to Rob for drawing this to my attention -- it's in British Archaeology, Jan/Feb 2012. Click to enlarge.

The Cursus Great Pits

2011-12-29T13:49:00.002Z

David Keys has drawn my attention to this piece published online on the Independent web site. It's a longer version of something we discussed on this blog a while ago. What interests me in particular is the "great pits" in the Cursus and the proposed link with the heelstone.

http://www.independent.co.uk/life-style/history/secret-history-of-stonehenge-revealed-6268237.html

Secret history of Stonehenge revealed
Ancient site may have been place of worship 500 years before the first stone was erected

David Keys

Independent, Saturday 26 November 2011

Extraordinary new discoveries are shedding new light on why Britain’s most famous ancient site, Stonehenge, was built – and when.

Current research is now suggesting that Stonehenge may already have been an important sacred site at least 500 years before the first Stone circle was erected – and that the sanctity of its location may have determined the layout of key aspects of the surrounding sacred landscape.

What’s more, the new investigation – being carried out by archaeologists from the universities’ of Birmingham, Bradford and Vienna – massively increases the evidence linking Stonehenge to pre-historic solar religious beliefs. It increases the likelihood that the site was originally and primarily associated with sun worship

The investigations have also enabled archaeologists to putatively reconstruct the detailed route of a possible religious procession or other ritual event which they suspect may have taken place annually to the north of Stonehenge.

That putative pre-historic religious ‘procession’ (or, more specifically, the evidence suggesting its route) has implications for understanding Stonehenge’s prehistoric religious function – and suggests that the significance of the site Stonehenge now occupies emerged earlier than has previously been appreciated.

The crucial new archaeological evidence was discovered during on-going survey work around Stonehenge in which archaeologists have been ‘x-raying’ the ground, using ground-penetrating radar and other geophysical investigative techniques. As the archaeological team from Birmingham and Vienna were using these high-tech systems to map the interior of a major prehistoric enclosure (the so-called ‘Cursus’) near Stonehenge, they discovered two great pits, one towards the enclosure’s eastern end, the other nearer its western end.

When they modelled the relationship between these newly-discovered Cursus pits and Stonehenge on their computer system, they realised that, viewed from the so-called ‘Heel Stone’ at Stonehenge, the pits were aligned with sunrise and sunset on the longest day of the year – the summer solstice (midsummer’s day). The chances of those two alignments being purely coincidental are extremely low.

The archaeologists then began to speculate as to what sort of ritual or ceremonial activity might have been carried out at and between the two pits. In many areas of the world, ancient religious and other ceremonies sometimes involved ceremonially processing round the perimeters of monuments. The archaeologists therefore thought it possible that the prehistoric celebrants at the Cursus might have perambulated between the two pits by processing around the perimeter of the Cursus.

Initially this was pure speculation – but then it was realized that there was, potentially a way of trying to test the idea. On midsummer’s day there are in fact three key alignments – not just sunrise and sunset, but also midday (the highest point the sun reaches in its annual cycle). For at noon the key alignment should be due south.

One way to test the ‘procession’ theory (or at least its route) was for the archaeologists to demonstrate that the midway point on that route had indeed a special relationship with Stonehenge (just as the two pits – the start and end point of the route – had). The ‘eureka moment’ came when the computer calculations revealed that the midway point (the noon point) on the route aligned directly with the centre of Stonehenge, which was precisely due south.

This realization that the sun hovering over the site of Stonehenge at its highest point in the year appears to have been of great importance to prehistoric people, is itself of potential significance. For it suggests that the site’s association with the veneration of the sun was perhaps even greater than previously realized.

But the discovery of the Cursus pits, the discovery of the solar alignments and of the putative ‘processional’ route, reveals something else as well – something that could potentially turn the accepted chronology of the Stonehenge landscape on its head.

For decades, modern archaeology has held that Stonehenge was a relative latecomer to the area – and that the other large monument in that landscape – the Cursus – pre-dated it by up to 500 years.

However, the implication of the new evidence is that, in a sense, the story may have been the other way round, i.e. that the site of Stonehenge was sacred before the Cursus was built, says Birmingham archaeologist, Dr. Henry Chapman, who has been modelling the alignments on the computerized reconstructions of the Stonehenge landscape

The argument for this is simple, yet persuasive. Because the ‘due south’ noon alignment of the ‘procession’ route’s mid-point could not occur if the Cursus itself had different dimensions, the design of that monument has to have been conceived specifically to attain that mid-point alignment with the centre of Stonehenge.

What’s more, if that is so, the Stonehenge Heel Stone location had to have been of ritual significance before the Cursus pits were dug (because their alignments are as perceived specifically from the Heel Stone).

Those two facts, when taken together, therefore imply that the site, later occupied by the stones of Stonehenge, was already sacred before construction work began on the Cursus. Unless the midday alignment is a pure coincidence (which is unlikely), it would imply that the Stonehenge site’s sacred status is at least 500 years older than previously thought – a fact which raises an intriguing possibility.

For 45 years ago, archaeologists found an 8000 BC Mesolithic (‘Middle’ Stone Age) ritual site in what is now Stonehenge’s car park. The five thousand year gap between that Mesolithic sacred site and Stonehenge itself meant that most archaeologists thought that ‘sacred’ continuity between the two was inherently unlikely. But, with the new discoveries, the time gap has potentially narrowed. Indeed, it’s not known for how long the site of Stonehenge was sacred prior to the construction of the Cursus. So, very long term traditions of geographical sanctity in relation to Britain’s and the world’s best known ancient monument, may now need to be considered.

The University of Birmingham Stonehenge area survey - the largest of its type ever carried out anywhere in the world – will take a further two years to complete, says Professor Vince Gaffney, the director the project.

Virtually every square meter in a five square mile area surrounding the world most famous pre-historic monument will be examined geophysically to a depth of up to two metres, he says.

It’s anticipated that dozens, potentially hundreds of previously unknown sites will be discovered as a result of the operation.

The ongoing discoveries in Stonehenge’s sacred prehistoric landscape – being made by Birmingham’s archaeologists and colleagues from the University of Vienna’s Ludwig Boltzmann Institute – are expected to transform scholars’ understanding of the famous monument’s origins, history and meaning.

In praise of "Geology Viewer"

2011-12-28T23:19:00.000Z

This is another amazing web site which I have referred to before -- it's a free service from BGS -- available just by clicking on either of the links below:

http://maps.bgs.ac.uk/geologyviewer_google/googleviewer.html

http://www.bgs.ac.uk/discoveringGeology/geologyOfBritain/viewer.html

You just need to click on the Geology Map viewer, and you can see either the satellite imagery of Britain (zoom in as close as you like), or a location map, or a composite image that incorporates the geology map at a maximum scale of 1:50,000. That's satisfactory for most purposes. Also, you can put your cursor on any point of interest and a label will come up which gives you the name of the geological formation at that point.

Thoroughly recommended.

On the significance -- or otherwise -- of >99.9%

2011-12-28T11:19:00.002Z

Amid all of the recent media frenzy relating to the Rhosyfelin paper (Ixer and Bevins 2011), Rob has encouraged us to concentrate on the paper itself rather than on the hype and nonsense appearing in sections of the media. That's fair enough, although as I have pointed out some of the hype and misunderstandings must be down to ambiguities in the press release which flagged up the importance of the paper to an outside world which has never been particularly well informed. So as a service to our faithful blogging community, not all of whom have access to the paper itself, I have escaped from the Christmas mayhem for a little while and -- while others snooze -- have had a good look through the article. I have copied a few key extracts at the base of this post. Some of the main points to come from the article are as follows:

1.   At the Pembrokeshire end, 39 samples were investigated from the Pont Saeson - Brynberian - Crosswell area. Within this total, 12 were from Pont Saeson - Craig Rhosyfelin, collected in June 2011. A further 20 samples were collected in 1978. A further 7 samples were collected in 2010 by BJ, MPP and others. To be more specific, 19 out of the 39 samples were from Craig Rhosyfelin, and seven from Pont Saeson -- the area around SN 1158 3599 9 (near the bend in the river, about 200m SSE of the Rhosyfelin rocky spur ).

2. At the Stonehenge end, samples (an unspecified number) were analysed from excavations in the Stonehenge Avenue, Trench 44 and 45, the Aubrey Holes, from around the Heelstone, and the Darvill - Wainwright 2008 Stonehenge excavations. We don't know how many fragments from the Stonehenge layer were collected and how many were rejected. Neither do we know what proportion of the fragments were sarsen, or flint, or dolerite, or spotted dolerite, or other rock types, or rhyolite. We do not know how typical of the Stonehenge Layer the sampled areas actually are. So there is a strong bias in the collection of the samples. All we do know is that within the collection of RHYOLITE fragments from the sampled locations the link between those chips and flakes and the Craig Rhosyfelin outcrops seems to be strong.

3.   The samples taken from near Pont Saeson appear to match very closely a rhyolite sample taken from the Cursus Field (Ixer and Bevins 2010).

4. The samples taken from Locality 8 near the tip of the Rhosyfelin rocky spur match very closely with two Stonehenge samples -- one fragment from near the Heelstone, and another from the Darvill-Wainwright 2008 excavation.

5. The four standing Stonehenge rhyolite bluestones numbered SH38, SH40, SH46 and SH48 do not match any of the rhyolites found at Pont Saeson or Rhosyfelin. However, some rhyolite fragments at Stonehenge do match standing stone SH48. Source unknown. Work is ongoing on these other rhyolites.

6. In the Pont Saeson - Craig Rhosyfelin area, the peculiar foliated rhyolites described in this paper seem to occur over an area of "a few hundred square metres."

7. There is a suggestion that orthostats SH46 and SH48 might match with lithic-crystal tuff outcrops lower down the valley and about 300m NW of Craig Rhosyfelin.

8. According to the authors, in excess of 99.9% of of the Stonehenge rhyolitic ‘debitage’ can be petrographically matched to the rhyolitic rocks found around Craig Rhosyfelin and Pont Saeson. It is largely because of that statement that the media have become obsessed with the idea that the source of the bluestones has now been found. However, as I have pointed out before on this blog, the >99.9% figure is meaningless, since we have no idea how many rhyolite fragments have been examined, how they were distributed in the Stonehenge Layer, how close together the collection points were, and what degree of selection was employed in the collection of samples during the respective digs. Percentage figures like this should never be used without a full presentation of the numerical data from which they are supposedly derived.   In any case, we have no idea which rhyolites occur in the Stonehenge Layer in those large segments of Stonehenge that have not been excavated, and in the soils of the area around Stonehenge, and what their frequency may be.

9. There seems to be an assumption that the stump of orthostat SH32e could be an exact match with the samples from Locality 8 in the Rhosyfelin geological sampling exercise. However, we should bear in mind that no samples from that stump have been examined, and that the suggestion is based entirely upon an examination of the photographs in the Atkinson collection. Clearly some real science is needed on this matter........

10. I take issue with the authors over their suggestion that the narrowing down of rhyolite sources to a very small area, and in one case to within a few square metres, "is perhaps suggestive of human agency" in the transport of the bluestones.    They argue that "a large number of different rock types from disparate areas" would suggest a glacial or "natural transport mechanism" -- but they imply that their research is not helpful to those who argue for glacial transport. They also seem to think that the "transport problem" now needs to be solved by archaeologists -- inevitably through a search for Neolithic quarries at Craig Rhosyfelin.   I disagree with that too, as I have told Rob many times. In my view the problem needs to be solved by reference to glaciology and geomorphology.

My reading of the evidence presented? It looks as if this is a classic case of glacial entrainment, with rhyolitic and related rocks picked up by overriding ice from a stretch of the Afon Brynberian valley which is about 500m long and maybe 100m wide, from north to south. That's an area of 50,000 sq m. The provenancing of one or two of these rocks to a very small area on the ridge of Craig Rhosyfelin is an excellent and exciting geological development. It also appears that the stones from this locality (which may or may not have been orthostats or pillars) have been largely destroyed and redistributed as flakes or fragments -- although it may be that stump 32e is all that is left of one of them. In my view none of this work has any archaeological significance -- and it has no bearing on the bluestone transport debate. I can understand why Rob has reiterated several times on this blog that the transport issue is one that he treats with sublime indifference -- and assume that the hints about human agency were inserted into the paper in deference to the fact that it was published by an archaeological journal!

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

SOME EXTRACTS

The local geology:

In the Pont Saeson area the Fishguard Volcanic Group
comprises a strongly foliated to foliated and lensoidal
rhyolitic rock the like of which is not seen elsewhere in
the outcrop of the group across the 32 km of strike section
from Pen Caer in the west to Crymych in the east. These
very distinctive rhyolitic rocks can be traced for no more
than 150 m from the northeasternmost end of Craig Rhosy-
felin. The foliation strikes quite consistently at between
040-050°, dipping to the northwest at between 40-80°
(Figure 2). Whilst the fabric is macroscopically typically
planar in thin section it can be seen to be lensoidal where
there are included, typically flattened, ovoid lithic clasts
which are usually 2 – 3 cm in maximum length (Figure
3), although larger elongate clasts up to 5 cm can be
located. These clasts are microtonalite. The main rock
is commonly traversed by thin (mm scale) quartz veins
which are tightly folded, with their folds being axial
planar to the foliation.

Field sampling:

Twelve accurately located in situ samples from Pont
Saeson (and especially Craig Rhos-y-felin) were collected
in June 2011. The sampling locations are shown in Figure
1. .... Polished sections were made of each of the twelve samples. These samples
augmented the original twenty in situ samples collected
by Bevins in 1978, during a reconnaissance study of the
Ordovician rocks of the Pont Saeson area. Due to this
the 1978 samples were not collected with the degree of
accuracy of the 2011 samples. These older samples are
provenanced therefore more generally at two locations
with grid references centred on SN 1166 3615 and SN
1158 3599. Additional samples from Craig Rhos-y-felin
collected by Mike Parker Pearson (2010) and Brian John
(2010) were also studied in order to be certain that the
full range of lithologies had been sampled.

In total thirty-nine lithics were investigated including nineteen from
Craig Rhos-y-felin and seven from the rhyolitic outcrops
centred on SN 1158 3599. Following a thorough
macroscopical description, detailed ‘total petrography’
as defined by Ixer (1994) and Ixer et al (2004) was
undertaken on the polished thin sections using both
transmitted and reflected light.

at the Stonehenge end:

These were compared with polished thin sections
of macroscopically similar rocks (groups A-D) from
the excavations of the Stonehenge Avenue, Trench 44
and 45, Aubrey Holes and the April 2008 Stonehenge
excavations.

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

Almost all (>99.9%) of the Stonehenge rhyolitic ‘debitage’
can be petrographically matched to rhyolitic rocks found
within a few hundred square metres at Pont Saeson and
especially to those found at Craig Rhos-y-felin. However,
it is possible in a few cases, where the petrography of
these Welsh in situ rocks is so distinctive, to suggest an
even finer provenance to within square metres, namely to
individual outcrops.

NB this statement:

One sub-crop, however, namely Craig Rhos-y-felin
Locality 8 appears to be the unique origin of the highly
distinctive Jovian fabric (an extreme combination of a
foliation with a strongly associated lensoidal fabric) seen
within some of the Stonehenge rhyolitic ‘debitage’. The
outcrop is situated at the extreme northeastern end of
Craig Rhos-y-felin.

Two Stonehenge samples have been matched with Craig Rhosyfelin Locality 8

Stonehenge Heel Stone area 1979 SH 79+520
M/L2 31.5.79 Excavated by Pitts (1982).
Rhyolite with fabric. 37.0gms after sectioning.

Stonehenge Excavation STH08 Context 3
G/2 Find No. 738 Excavated by Darvill and
Wainwright 2008.
Rhyolite with good planar fabric. Weight 72gms A
classical example of Group C.

(The 3 samples were deemed to have a common origin.)

Conclusions

Detailed collecting and identification of in situ rocks
from Pont Saeson and comparison with Stonehenge
material allows for a number of important conclusions.
The overwhelming majority of the Stonehenge rhyolitic
‘debitage’, namely that belonging to Groups A-C, can be
sourced from the Pont Saeson area and perhaps entirely
from Craig Rhos-y-felin, but from more than one site on
the crags.

The four standing Stonehenge orthostats SH38, SH40,
SH46 and SH48 offer no petrographical match for any
rhyolitic lithology at Pont Saeson.

In essence therefore Pont Saeson area may be the
dominant origin for the rhyolitic ‘debitage’ (Groups A-C)
but is eliminated as the source of any of the four standing
Stonehenge orthostats (SH38, SH40, SH46 and SH48).
It may be possible to go further. In 2011 Ixer and
Bevins stated that buried orthostat SH32e could also
originate from the Pont Saeson area and if that were so
“it would be the first non-preselite bluestone orthostat
to be precisely provenanced”. Examination of the Craig
Rhos-y-felin outcrops and comparison with photographs
of SH32e in excavation strengthens this belief and,
sometime when SH32e is re-examined and its foliation
described in detail, it should be possible to exactly match
the artefact to sub-crops at Craig Rhos-y-felin.

As importantly, the three macroscopically different
rocks (Groups A-C), originally assumed to have different
geographical provenances, are now shown to have a single
geographical origin. The number of discrete geographical
sources for the Stonehenge bluestones is of much
significance in the nature versus human transport debate,
with a large number of different rock types from disparate
areas supporting a natural transporting mechanism
whereas a restricted number of geographical origins is
perhaps suggestive of a human agency.

Ixer and Bevins (2010) declared that “The discovery of
the stilpnomelane lensoidal rhyolites is the first time that
a non-dolerite bluestone has been clearly provenanced, it
will not be the last”. It should be noted that the envisioned
provenance area was several hundreds of square metres.
This statement has proved to be correct and can now be
strengthened to state that ‘This is the first time that any
lithics from Stonehenge have been unequivocally assigned
to an area of a few square metres, namely to within a very
small single outcrop or couple of outcrops; it may not be
the last’.

It is now possible to attempt a focussed archaeological
examination of these restricted areas with some scientific
justification. These areas should include Locality 3 but
especially Locality 8 at the termination of Craig Rhosy-
felin.

Bedd Arthur

2011-12-24T12:29:00.000Z

I thought this might be of interest. It's Bedd Arthur (the grave of King Arthur), near the tor called Carn Bica and not very far from Carn Meini. It's often referred to as a stone circle or even a stone oval -- but it's not really either of those. The standing stones of which it's built are very small, not much above knee height, and all of them seem to lean in towards the middle. I have always thought of it as a destroyed long barrow which might at one time have held a cromlech or burial chamber at its heart. I think those stones have been entirely removed -- unless they are buried beneath the turf. I think the remaining standing stones might have rested on the surface of the now-removed mound.

I'm not aware that this site has ever been excavated. It's not far from the "Neolithic tomb" excavated by TD and GW last summer, which was widely flagged up as having held the remains of the splendid fellow who drew up the plans for Stonehenge......

Things are not always what they seem...

2011-12-24T11:38:00.002Z

And while I am in geomorphology mode, here's another splendid pic from "Glaciers Online" -- if you look across the ice-covered bay towards the skyline, you'll see a magnificent "pseudo-moraine" near Cape Roberts, Antarctica. It's actually an ice-pushed ridge on the shoreline -- it must be an incredibly steep shoreline, with very deep water close inshore, because a tabular berg has come trundling in, breaking up the sea ice, and pushing up this considerable ridge of shoreline debris. If, after the passage of 20,000 years, somebody turns up here and assumes that this is a terminal moraine ridge, which marks the maximum extent of a glacial advance, he or she would very definitely be barking up the wrong tree.

The granite obelisk

2011-12-24T11:16:00.001Z

In a spirit of goodwill at this Christmas season, and specially for Kostas, here is a splendid picture from the wonderful "Glaciers Online" web site. It shows a granite obelisk in the Victoria Dry Valley in Antarctica -- it couldn't have been put there by Neolithic tribesmen from Wiltshire, since nobody reckons that they strayed THAT far from home, no matter how good their coracles were, but I suppose it could have been put in place by a super-race of Emperor Penguins, who are known for their incredible achievements (David Attenborough and all that).

On the other hand we could go for the boring explanation and say that this isn't far from a glacier snout, and that this is an unusual morainic block projecting up from an extensive area of moraine which has (mostly) been covered at a later date by aeolian or windblown deposits. Very mundane. Sorry Kostas -- I couldn't find any nice pictures of blocks like this which are tastefully arranged in circles or rows......

Happy Christmas!

The National Geographic gets it more or less right...

2011-12-23T14:42:00.004Z

I never thought I'd ever say this, but this appears to be quite a well-balanced report on the National Geographic web site.... and I like the bit about the sheep farm - makes it all sound very rural. And "it's official" ?!! What does that mean? Has HM Office of Provenancing now given the official seal of approval?

Apart from the inevitable over-simplification here and there, we can live with this.

It's Official: Stonehenge Stones Were Moved 160 Miles

Ancient bluestones match outcrop near Wales sheep farm, experts say.

Dave Mosher

National Geographic Magazine

http://news.nationalgeographic.com/news/2011/12/111222-stonehenge-bluestones-wales-match-glacier-ixer-ancient-science/

Published December 22, 2011

Some of the volcanic bluestones in the inner ring of Stonehenge officially match an outcrop in Wales that's 160 miles (257 kilometers) from the world-famous site, geologists announced this week.
The discovery leaves two big ideas standing about how the massive pieces of the monument arrived at Salisbury Plain: entirely by human hand, or partly by glacier.
As it looks today, 5,000-year-old Stonehenge has an outer ring of 20- to 30-ton sandstone blocks and an inner ring and horseshoe of 3- to 5-ton volcanic bluestone blocks.
The monument's larger outer blocks, called the Sarsen stones, were likely quarried some 20 to 30 miles (32 to 48 kilometers) away in what's now England, where sandstone is a common material.
The origin of the bluestones, however, has weighed heavy on the hearts of archaeologists. Rocks resembling the material under a microscope haven't been found anywhere relatively near Stonehenge—at least until now.

[[ That of course is untrue -- we have all known since 1922 that many of the stones have come from the eastern Preseli area. It's the PRECISE provenancing that's new.....]]

Pinpointing the stones' origins is crucial to understanding how so many heavy hunks of rock made their way to the open plain where Stonehenge now stands.
"There's no way of explaining how these stones were transported without knowing where they came from," said study co-author Robert Ixer of the Univ of Leicester in the U.K.

Stonehenge Source Near Sheep Farm
For about two decades, Ixer and study co-author Richard Bevins, of the National Museum of Wales, have searched for the origins of the bluestones in outcrops around Wales.
As late as two years ago, the pair thought the blocks couldn't have come from the country—no samples from Welsh outcrops matched the Stonehenge blocks.
But not all of the samples collected over 20 years had yet been prepared for examination under a microscope. To be absolutely certain, the geologists began slicing up their remaining rocks.
The very first one—a chunk of rock collected in Wales 20 years ago—was a perfect match to the Stonehenge bluestones. The geologists spent the next two years checking a piece of Stonehenge bluestone against other outcrops around Wales.
"We sampled extensively and did not find anything that came anywhere close," Ixer said.
The rocky outcrop fingered by the duo's analysis is called Craig Rhos-y-Felin, which is now located on private land near a sheep farm.
The site is a long, bush-covered set of crags the size of four double-decker buses.

Next Step: Search for Tool Marks
The new find leaves two prominant theories for how the Welsh rocks got to Salisbury.
Humans could have quarried the site and dragged the blocks on wooden rafts. Or a giant glacier may have chiseled off the blocks and ferried them about a hundred miles (160 kilometers) toward Stonehenge, with humans dragging them the rest of the way.
If humans did the digging, archaeologists might detect marks left by tools or some other evidence. But if signs of human quarrying are lacking, the glacier idea might gain the upper hand.
"If we could find a quarry site," Ixer said, "we could tell if mankind was involved" in carving out the blocks.
But settling the issue, Ixer says, isn't up to geologists such as himself: "I have never betted in my life" and will not start now, he said.
"We need archaeologists. If they can show the rocks were quarried, that would suggest those rocks were transported by man."

[[We might add to that: "We also need geomorphologists. If they can show that the rocks were quarried by overriding ice, that would suggest that those rocks were transported by a glacier." It's interesting that the geologists hardly ever mention their earth science colleagues in this context, or admit that they have a real contribution to make. What was I saying about "geology in the service of archaeology"....?]]

Is the Glacial Theory now frozen out?

2011-12-22T10:07:00.001Z

In the recent "exclusive" report of the Pont Saeson (Rhosyfelin) work, the Times reporter Norman Hammond quoted Rob Ixer as follows:

“The glacial theory is frozen out by this new evidence,” Dr Rob Ixer of Leicester University told The Times. If the stones had been transported east of the Bristol Channel by glacial action, a much wider range of sources would be expected. The pinpoint sourcing that has now been done argues strongly for human quarrying and transport of the bluestones.........."

That particular line has been used in headlines and as the underpinning of other media reports all over the world -- in the press, on TV and on radio, and in countless articles on the internet. Rob has not denied the quote attributed to him, and it's clear that this position is shared by Richard Bevins, who continues to speculate about the "Newport Bay route" for bluestone transport, and by other commentators like Mike Pitts, Mike Parker Pearson and Geoff Wainwright. On the telly the other night Mike Pitts more of less quoted the Times piece word for word -- and he has taken the same line on his own blog.

OK -- let's accept that the publication of an article like this will be trumpeted from the battlements by the authors and by their departmental media people. That's accepted -- everybody wants to be loved and famous! And of course the word "breakthrough" is over-used in such circumstances -- to demonstrate the value of a piece of work you have to "overturn" or "destroy" some pre-existing theory. And the handy theory that is supposedly destroyed in this case is the glacial transport theory -- add some nice metaphors, and away you go!

But let's stand back and look at this in the cold light of day. What has the new work actually done, with respect to the glacial transport theory? If anything, it enhances the theory rather than damaging or destroying it. My reasoning is as follows:

1. As I have said before, this is not a piece of archaeological work. It is a piece of straight geology -- an interesting and detailed exercise in provenancing. It's not a breakthrough at all, in the sense that since Herbert Thomas made the initial identification that many (not all) of the Stonehenge bluestones came from the Carn Meini area, there has been a gradual homing in on the precise locations from which the stones were taken, either by ice or human agency. The biggest leap forward was by the big Open University team project in the late 1980's, involving Olwen Williams-Thorpe, Rob Ixer and many others who used much more sophisticated techniques than were ever available to HHT around 1920. Geologists have been getting closer and closer to matching individual stones to individual outcrops in the field -- such is the way with science. There is a sort of continuum. And now we have the claim that much of the rhyolite debitage (NB -- not the TOTAL debitage) at Stonehenge can be traced to Rhosyfelin. No single stone has been provenanced with this accuracy -- we are just talking about lumps and chips found in the ground. The fact that the work is now reported in an archaeological journal is neither here nor there -- the work tells us NOTHING about how the stones were moved.

2. Some commentators on the new research (including senior academics) have suggested that the provenancing (or "pinpoint sourcing") of some fragments of Stonehenge bluestone to a POINT rather than a district somehow enhances the human transport theory and diminishes the glacial transport theory. That of course is utter nonsense, for the reasons given above.

3. While not diminishing or questioning the quality of the research by Rob and Richard, I have to say that I have read the paper carefully, and still have a few matters that cause me to feel uneasy. Because the paper was published in an archaeology journal, was it refereed by archaeologists rather then geologists? Perhaps the Editor will tell us -- because a paper like this should very clearly have been refereed by specialists in the same field as the authors. There are some other things that need to be said too. The "rhyolite debitage" referred to by the authors can only be the debitage that happens to have been examined (and collected) in assorted digs over the years -- the authors cannot know what lies beneath the surface in those parts of Stonehenge that have not been excavated. So there could be a strong bias at the Stonehenge end of this research. There could also be a strong bias at the Rhosyfelin end of the research. The authors claim to have tied down the "source area" for the foliated rhyolites to within a few metres -- but you can only make a statement like that if you can demonstrate that there is no chance that identical rocks are found elsewhere in the district. There are rhyolite outcrops in many different places in the Pont Saeson - Brynberian - Felin y Gigfran - Crosswell area. Some of them appear to be roughly on the same alignment as the sampled Rhosyfelin outcrop. Have ALL of those outcrops been sampled and eliminated as possible sources? Perhaps Richard can tell us.

4. Then there is this point: "If the stones had been transported east of the Bristol Channel by glacial action, a much wider range of sources would be expected." Come along now, chaps, let's get real. How many sources would you like? We are up to 32, at the moment, I think, and still counting....... and a point which is not often made is that all of the foreign stones that we know about in the "Stonehenge total assemblage" appear to have come from the west. That in itself is a persuasive argument for glacial transport.

5. Finally, let's look at the location from which the "destroyed foliated rhyolite orthostat" is supposed to have come. (One or more? It doesn't really matter.) It is in a river gorge, on the flank of a rocky spur where a smaller channel runs down into a larger one. A very difficult and constrained location. Why would anybody want to quarry large orthostats from a place like this, either from a practical standpoint or from a ritual one? You are just making enormous trouble for yourself -- since before you can do anything with your stones you have to get them up and away from this wretched river valley -- which would, by the way, also have been densely wooded during the Neolithic. The large hole in the ground which MPP and his team kindly opened up showed one large stone and many smaller stones, in exactly the positions where we would expect them to have accumulated over many years of rockfalls and scree development. But according to glacial theory this is one of many locations where, during the Ice Age, basal shearing could have occurred at the base of the Irish Sea Glacier as it flowed across the area. If there was shearing, there could also have been entrainment. I have gone over this many times before, so I'm not going to repeat it all again!

All in all, I cannot see any logical basis for the idea that the glacial transport theory has now been "frozen out" -- but I don't suppose that anything I say will halt or slow down the mad Quarry Hunt, since rational thought seems to be a thing of the past.

Craig Rhosyfelin sampling points

2011-12-21T11:17:00.000Z

For those who might not have access to the original paper, I'm sure that Rob and Richard will not mind me sharing this image which shows the Craig Rhosyfelin sampling points which they used in their identifications of the foliated rhyolites:

Full reference:

“Craig Rhos-Y-Felin, Pont Saeson is the dominant source of the Stonehenge rhyolitic ‘debitage’”, by RA Ixer & RE Bevins, Archaeology in Wales 50 (2011), 21–31

In praise of "Where's the Path"

2011-12-21T10:59:00.001Z

I think I might have mentioned this one before, but the incredible application called "Where's the Path" allows you to examine the landscape in great detail, using the latest satellite imagery, and to view it on a split screen with the OS map to the left. You can choose what sort of images you want to look at, either side by side or full screen. And in some ways, most useful of all, your pointer on the screen is always given a precise grid ref (ten-figure) and geographical coordinates in a box at bottom right. This is the application which Rob Ixer and Richard Bevins used for fixing the locations of their Rhosyfelin sampling points.

You can zoom in and out of either image (right and left) and so the two images in the split screen do not always cover identical geographical areas -- but that does not matter greatly, because the cursor point is always in the right place, on both images. (And of course grid north is slightly different from true north.....)

Thoroughly recommended.....

http://wtp2.appspot.com/wheresthepath.htm

The Daily Mail bluestone punt

2011-12-20T16:42:00.000Z

Have added the latest illustration to my lexicon, here:

http://brian-mountainman.blogspot.com/2011/11/even-more-danger-marine-engineers-at.html

More Media Madness ... modified

2011-12-20T15:47:00.001Z

Want a picture of Craig Rhosyfelin? What the hell -- this one of Carn Meini will do -- it's near enough, isn't it, and nobody will know anyway........

The "news" about the geological work at Craig Rhosyfelin (which readers of this blog knew about many months ago) has now been picked up by the global media, including papers in NZ, Australia and North America. For all I know, the story is also making the headlines in Japan and China........

It's great to have a real science story attracting attention, but I do wish that there would be a bit more respect for the things that Rob Ixer and Richard Bevins actually say in the article. All over the place we are having this story portrayed as "source of the Stonehenge bluestones (all of them) finally identified" -- and one article which I looked at actually seemed to suggest that all of the Stonehenge stones (including the sarsens) had now been fixed to a place of origin at Craig Rhosyfelin.

Even the august Today (BBC R4) programme this morning suggested that the origin of the bluestones (ie all of them) had now been narrowed down, and that from this point on all that needs to be done is for the quarry sites to be properly identified, and for the precise mechanisms of transport (rolling, sledging etc) to be worked out. Incompetence, from top to bottom.......

As for the Times headline thundering to the world that "the glacial transport theory has now been frozen out" -- that is total rubbish too, as I have pointed out. My thanks to Olwen Williams-Thorpe for sending a copy of a letter she submitted to the Times, making the same point. The letter may or may not have been published, but if it wasn't, it should have been:

Sir

Re: 'Bluestones glacier theory is now frozen out' Times 17/12/11

It is incorrect and misleading to suggest that new evidence on bluestone provenance 'freezes out' the glacial transport theory. Norman Hammond's article omits important information. There are many
bluestone rock types at Stonehenge that do not match the Pont Saeson outcrop. The arguments in favour of glacial transport therefore remain: varied bluestones, many sources, and glaciers capable of removing large erratics from Pont Saeson and other areas.

Dr Olwen Williams-Thorpe
Senior Visiting Fellow of the Open University

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

.............and now the ITV Ten O'Clock news caps the lot, with the most garbled report you are ever likely to see. First of all, they say that the new work relates to ALL of the Stones at Stonehenge, then they show a picture of Carn Meini and say it is Craig Rhosyfelin, and then they repeat the nonsense (with Mike Pitts's help) that the glacial transport theory is somehow diminished by the new evidence. Oh dear -- Richard and Rob, with the aid of your press release you have indeed unleashed a whirlwind of incompetent nonsense, which no doubt you could have prevented if you had worded things differently. What the hell -- who cares about the truth when there is a good story to be told?

Happy Christmas!

2011-12-20T09:54:00.001Z

According to Mr Blogger there have been 85,000 hits on the site now, so there must be a sizeable community of followers / occasional visitors out there. Thank you all for your interest and support, and above all else, for your contributions! So from me to you in this festive season:

Impossible? Apparently not..... (modified)

2011-12-19T17:26:00.002Z

On one of the discussion threads recently somebody said that it was impossible for morainic features to cross one another. Well, it's not impossible. I have seen morainic features that intersect, in response to shifting ice edge positions -- for example around the snout of a small glacier. Here is another interesting example from Bruarjokull in Iceland. What we have here is a fluted (ground moraine) feature running from the foreground and to the left of the girl, and crossing it at right angles is a crevasse fill -- typical of something that forms in a heavily crevassed and dirty glacier that is wasting rapidly. Neither of these features on the ground has anything to do with a previous ice edge position.

Also, notice the scatter of erratics in the background -- the definition on this pic is very good -- just click on it for enlargement.

Postscript

I'm not going to get sucked into one of those interminable exchanges with Kostas here, but as an aid to universal enlightenment here is a map of Wisconsin moraine positions in Illinois. Note that there are many intersections of moraines.

The reason for these intersections is that when an ice sheet edge is retreating across a landscape it is very rare for the whole ice edge to retreat at the same rate. Indeed, there may be short-lived advances during the course of an overall retreat. These small advances will of course have different dynamics in them -- and the ice streams may come from different directions from those of the earlier ice sheet. So moraines get truncated and overridden. Hence intersections. Perfectly simple.

Now the Daily Mail joins the fun.....

2011-12-19T12:05:00.000Z

The Times "exclusive" published the other day has now turned into a feeding frenzy, with all of the media getting in on the act. I wonder what the press release from the National Museum and Leicester Univ actually said? Anyway, another article, this time from the Daily Mail -- and another rubbish headline. Why can't reporters and sub-editors try to develop at least some respect for the truth? In the quote below Richard Bevins does at least acknowledge that there is a "glacial transport" theory out there, but why he keeps on referring to a "Nevern Estuary" human transport route as a possibility is beyond me, unless maybe he is just saying what the archaeologists want to hear.....

Stonehenge riddle unravels: Geologists pinpoint exact Welsh outcrop where 'Bluestones' came from

Quote: "Dr Bevins explains that his finding could help explain the method used to take the stones to Stonehenge and the reason, because the site is small enough for archaeologists to excavate to try and uncover evidence of human activity.
He said: ‘It has been argued that humans transported the spotted dolerites from the high ground of Mynydd Preseli down to the coast at Milford Haven and then rafted them up the Bristol Channel and up the River Avon to the Stonehenge area.

‘However, the outcome of our research questions that route, as it is unlikely that they would have transported the Pont Saeson stones up slope and over Mynydd Preseli to Milford Haven.
‘If humans were responsible then an alternative route might need to be considered. However, some believe that the stones were transported by the actions of glacier sheets during the last glaciation and so the Pont Season discovery will need appraising in the context of this hypothesis.’

Indy report on foliated rhyolite research

2011-12-19T11:12:00.000Z

Shattered rockfall / scree debris beneath the rock outcrop at Craig Rhosyfelin. The "foliated rhyolites" here are claimed to match much of the rhyolite debitage at Stonehenge -- and Ixer and Bevins claim to be able to fix the source to within a few metres. Time will tell whether that claim is reliable or not.

Now the Independent has also reported on the Ixer / Bevins research, in a much more measured way. All in all, a pretty balanced report, apart from the headline, which should have read "Scientists discover one of many sources of rock used in Stonehenge's first circle." But I suppose that such a headline would have been deemed too boring...........

========================
Scientists discover source of rock used in Stonehenge's first circle

Discovery reignites debate over transportation of smaller standing stones

David Keys
http://www.independent.co.uk/news/science/archaeology/news/scientists-discover-source-of-rock-used-in-stonehenges-first-circle-6278894.html
Sunday 18 December 2011

Scientists have succeeded in locating the exact source of some of the rock believed to have been used 5000 years ago to create Stonehenge's first stone circle.

By comparing fragments of stone found at and around Stonehenge with rocks in south-west Wales, they have been able to identify the original rock outcrop that some of the Stonehenge material came from.

The work - carried out by geologists Robert Ixer of the University of Leicester and Richard Bevins of the National Museum of Wales - has pinpointed the source as a 70 metre long rock outcrop called Craig Rhos-y-Felin, near Pont Saeson in north Pembrokeshire. It's the first time that an exact source has been found for any of the stones thought to have been used to build Stonehenge.

The discovery has re-invigorated one of academia's longest running debates - whether the smaller standing stones of Stonehenge were quarried and brought all the way there from Pembrokeshire by prehistoric humans or whether they had already been plucked out of ancient rock outcrops and carried all or part of the way to Wiltshire by glaciers hundreds of thousands of years earlier.

Archaeologists tend to subscribe to the 'human transport' theory, while some geomorphologists favour the glacial one. The debate is solely about Stonehenge's early/smaller standing stones (often known collectively as 'bluestones') - not about the larger ones (most of the so-called 'sarsens') which were incorporated into the monument several centuries later.

The Leicester University and National Museum of Wales scientists' discovery - reported in the journal, Archaeology in Wales - does not solve the mystery of how Stonehenge's Welsh-originating stones ended up in England, but it does potentially open up the possibility of finding archaeological evidence of quarrying activity that could indicate a human rather than a glacial explanation (indeed that archaeological search has already been launched by archaeologists from Sheffield and other universities). Conversely, any lack of such evidence would help those scholars arguing in the opposite direction. As the geological research continues, it's likely that numerous other rock outcrops in various parts of Pembrokeshire will be positively identified as sources of other stones used to build early versions of Stonehenge. Over past decades, the approximate area they came from has been identified - and the ongoing research will almost certainly succeed in pinpointing additional exact sources.

But although the stone fragments from Stonehenge will allow the scientists to track down where the material originally came from, those same fragments represent an altogether different mystery.

Literally thousands of fragments of rock - almost certainly from monoliths used at or around Stonehenge - have, over the years, been found in or near the world famous monument.

These fragments (mostly less than 50 grams each) appear to have been deliberately chipped off ancient monoliths at some stage in antiquity - many of them probably in the Neolithic.

However, most of the fragments examined so far are from particular types of rock which were used for less than 10% of the early (i.e. Welsh originating) Stonehenge monoliths. The fragments - found not just at Stonehenge itself but also elsewhere in the Stonehenge landscape - tend to be of a different geological character to the vast majority of early Stonehenge standing stones (which are mostly made of a different type of Pembrokeshire-originating rock). Indeed the rock type from Craig Rhos-y-Felin (just pinpointed by the new scientific research) was probably used for just one of the Stonehenge monoliths (a now buried stone, last seen in the 1950s).

This suggests that there may have been other stone circles or other 'standing stone' monuments in the landscape which have now vanished, but could in the future be found by other scientists (from Birmingham and other universities) who are carrying out an ongoing program of geophysical survey work throughout that landscape.

A further unsolved mystery is why prehistoric people were chipping fragments off probable monoliths. It's possible that they were chipped off in order to give monoliths a better shape. Alternatively, some monoliths or other rock material may have been broken up and re-cycled as stone axes - potentially imbued with particularly high status or conceivably perceived as having magical powers.

The detective work, that the University of Leicester and the National Museum of Wales scientists had to carry out to pinpoint the precise Pembrokeshire source of many of these fragments, was extremely complex.

First of all the geologists needed to sort through thousands of tiny fragments of Pembrokeshire-originating rock found by archaeologists at and around Stonehenge over the past 70 years.

Then the two scientists began to look particularly closely at around 700 of them which were made of a specific type of volcanically-originating rock (geologically, dating back some 460 million years) known as 'foliated rhyolite'.

They then succeeded in tentatively locating the approximate area of north Pembrokeshire which those 700 fragments originated from.

This was subsequently confirmed by comparing the chemical signature of tiny crystals (each one-five-hundredths of a millimetre in diameter) in the Stonehenge fragments with similar rocks in north Pembrokeshire.

Finally, by examining the detailed inter-relationships between minerals in samples from Stonehenge and north Pembrokeshire, they succeeded in pinpointing the precise rock outcrop.

If the stones were brought to Stonehenge from Pembrokeshire by human effort, the location of the newly discovered source (Craig Rhos-y-Felin) has interesting cultural implications.

For the newly discovered source is around five miles away from a wider area already known to have been the source for some of Stonehenge's other monoliths.

If humans were responsible for quarrying and transporting the stones from Pembrokeshire, then it would suggest that Stonehenge's Neolithic designers were extremely choosy and very specific as to where they got their stones from.

Research over recent years by Tim Darvill of Bournemouth University and Geoffrey Wainwright, a former chief archaeologist at English Heritage, suggests that the Pembrokeshire stones may have had a particular ideological or magical significance.

The outcrops where some of the stones come from are thought to have been associated with sacred springs and local Welsh stone circles.

It's argued that, by importing those particular rocks the 160 miles from Pembrokeshire to Wiltshire, the builders of Stonehenge thought they were taking possession of more than just plain rock. They may have regarded them as extremely important - and could even have seen them as possessing supernatural powers.

The newly discovered source is also significant because of its location. It lies on low ground to the north of the Preseli Mountains. This would have made transport to Wiltshire much more difficult than it would have been for other Pembrokeshire rocks used in Stonehenge and, known to have come from the High Preseli several miles to the south.

Transporting the north Pembrokeshire stones by sea would have required sailing round St. David's Head, a particularly difficult and dangerous route for a Neolithic boat. Alternatively the prehistoric quarrymen and their colleagues would have had to haul the stones over the top of the nearby Preseli Mountains. However, if humans took the stones to Stonehenge, it is also possible that the stones had already been used to construct circles in Pembrokeshire - and were therefore moved from those locations to Stonehenge, rather than from the original sources themselves.

Where are the geomorphologists?

2011-12-19T10:37:00.000Z

A Geomorphologist holding forth on something or other.......

Several times on this blog I have bewailed the fact that geomorphologists do not seem to be gainfully employed these days on archaeological projects -- especially on those relating to Stonehenge. Where are they? What are they doing if they are not doing this? Well, I suppose many of the brighter young geomorphologists (and glaciologists) these days are working on big projects related to global climate change -- and that's fair enough. But there are plenty of geomorphologists coming out of the UK universities with good degrees -- and an ability to make meaningful contributions to the archaeology projects currently under way.

Have any geomorphologists been employed on the recent MPP team digs at Craig Rhosyfelin, Garn Turne, Bluestonehenge, Cursus etc, and the TD/GW digs on the Preseli Hills and at Stonehenge? We hear occasional rumours about somebody with geomorphological expertise being "consulted" -- but these shadowy figures are hard to find, and it's even harder to find anything in the literature which they have directly contributed to some of the ongoing debates. Of course, even if they are getting stuck in on some of these digs, they will be acting as "geomorphologists in the service of archaeology" -- and will therefore be subject to exactly the same pressures as the "geologists in the service of archaeology" (like Rob and Richard) who currently publish in archaeological journals. Of course, I would never accuse them of bias, but if you are publishing in archaeological journals, with archaeologists as editors, and for a readership of archaeologists, of course you do what you can to enhance the chances of your papers being accepted and published. And that means a few hints here, a few conclusions there, that you might not have put in had the papers been submitted to straight geology journals.......... And without saying anything at all about the quality of the papers concerned, I wonder whether the editors of the journals concerned actually use GEOLOGISTS as referees prior to acceptance?

What we are talking about here is a very subtle process which gradually poisons the academic debate. If geomorphologists are absent from the process of putting together research applications, from the dig sites and from the definitions of fieldwork protocols etc, and from the evening discussions by the dig teams, then bias will be introduced at the very earliest stages of a project. That is why I was so appalled and disappointed by the Newport presentations by the team responsible for the Rhosyfelin dig -- it was clear to me (and others in the audience) that nobody had been present to challenge internally the ruling hypothesis that drove the whole team forward. So what we ended up with was a tidy and interesting dig but BAD SCIENCE. This refers:
http://brian-mountainman.blogspot.com/2011/09/evening-of-fairy-tales.html
See my other posts on Craig Rhosyfelin also -- you can find them by using the search box.

So a word to archaeologists -- why aren't you employing geomorphologists on your digs? Are you really afraid that these guys might somehow disturb your comfortable convictions about the noble works of man? And a word to geomorphologists -- why aren't you getting involved in these big archaeology projects and seeking to convince project leaders that you have something to offer?

The provenancing of raw materials

2011-12-18T20:33:00.001Z

A nugget of copper and other minerals found in the USA -- possibly from the Lake Superior area

We have had a lot of discussion on this site about the dark arts of provenancing "raw materials" found in archaeological contexts. There is, for example, a whole branch of archaeology devoted to the classification and provenancing of stone axes -- and as we have noticed, there is a tendency (tackled head-on by Stephen Briggs and a few others) to say that if stone axes of a certain lithology occur frequently in finds in the UK, then there must have been an axe factory at the place where this rock type is found in the landscape. This of course is wishful thinking more often than not, because genuine "quarries" or "axe factories" are incredibly difficult to find. And as Stephen and Olwen Williams-Thorpe have argued, where glaciation has affected the landscape, it is quite possible, and indeed probable, that the makers of axes have utilised whatever raw materials they discovered in erratic assemblages or even in deposits of till, for example exposed on river banks.

This all makes sense -- if a technology was widely known, it could have been employed in hundreds or even thousands of different locations, at the places where "raw materials" were discovered. There is no need for a centralised "production facility" where ore and nodules were mined, smelted and fabricated into implements. (But of course archaeologists search for these sorts of places all the time, because they allow a strengthening of assumptions about cultural uniformity and organization.)

See also:
http://brian-mountainman.blogspot.com/2011/11/more-on-erratic-harvest.html
http://brian-mountainman.blogspot.com/2010/04/needed-more-erratic-hunters.html

The same argument applies with respect to the bluestones -- if they were "available" to the builders of a monument like Stonehenge in an erratic cluster or even in a scatter across an area of a few square miles, then obviously the instinct of the builders would be to use them -- in preference to anything found very far away.

There is a nice parallel discussion in Canada, where archaeologists have tended to assume that since Native American tribes used copper, and since copper ore is found in the ground around Lake Superior, then they must have mined the copper at the places of origin. Not necessarily so, say some geologists and archaeologists. Since copper nodules and lumps of ore (sometimes in large boulders) occur quite commonly in the glacial till and glacio-fluvial deposits further south, there is a strong chance that Native Americans simply used whatever they could find, maybe hundreds of kilometres away from the original source areas. So the heroic "trading" expeditions maybe never happened at all........

John Halsey has kindly allowed me to paste this message up onto the blog:

"I have only recently become aware of your support of the idea of glacial transport of bluestones. I would like to bring to your attention a "controversy" in North American archaeology that closely mirrors your interests, that is the transport of native copper nuggets and boulders from bedrock sources around Lake Superior to locations many hundreds of miles to the south. Acceptance of "drift" or "float" copper as it is commonly known, as legitimate sources of raw materials used by Native Amerficans to craft a wide variety of tools, weapons, and articles of decoration has been slow in coming. Many mainstream archaeologists continue to be fascinated with the idea of Argonaut-like voyages to strange and distant places to obtain this exotic material and discount the usage of drift copper as minor or non-existent. Attached is an expanded version of a paper I did seven years ago on the subject. I hope you find it of interest."

John R. Halsey, State Archaeologist of Michigan (retired). "Copper from the Drift."
(The paper is an enlarged version of a 2004 paper presented to various conferences in North America.)

Quote from RD Salisbury 1885:

The area over which copper is scattered is thus seen to be very great, perhaps not less than 450,000 square miles. If all the fragments came from Lake Superior, some of them must have been transported about 600 miles to the south, others, 150 or 200 miles, or perhaps more, to the west, and small specimens have been carried more than 100 miles east of the eastern limit of the locality from which the copper is supposed to have come. There is then an east-west distribution, accepting the testimony from Nebraska, of more than 700 miles, and a north-south distribution about 100 miles less (1885:47).

Quote from R Irving 1877:

Ancient implements of copper have been found very abundantly in Wisconsin...It is evident enough, however, that there is a direct connection between the abundance of copper implements, and the abundance of drift copper fragments, which in ancient times were probably much more plenty on the surface than now, and which by pounding could yield any and all of the implements ever found (1877:619-620).

Does Stonehenge really make all men mad?

2011-12-18T00:32:00.000Z

Thanks to Tim for drawing my attention to these pieces -- the Times article (or some of it) and Mike Pitts's comments on his own site. I am amazed -- the work at Rhosyfelin does NOTHING to enhance the human transport theory, and it does NOTHING to increase the likelihood of Neolithic quarries being found. Have all of these people lost the capacity for rational thought? More on this in due course.....

If Rob is correctly quoted here, I am appalled. And if he is misquoted, I wonder what he proposes to do about it?

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

Saturday, 17 December 2011

Bluestones theory is now frozen out

The Times

Bluestones theory is now frozen out
Norman Hammond, Archaeology Correspondent
December 17 2011 12:01AM
http://www.sarsen.org/2011/12/bluestones-theory-is-now-frozen-out.html

The long-running debate about the origin of the Stonehenge “bluestones” and how they got to Salisbury Plain some four millennia ago has taken another turn: a precise quarry source for much of the Stonehenge rock has been pinned down to a few square metres in southwestern Wales. This supports the notion that the bluestones were taken by human agency all the way from Pembrokeshire to Wiltshire, rather than helped along their way in the Ice Age by glacier transport.
“The glacial theory is frozen out by this new evidence,” Dr Rob Ixer of Leicester University told The Times. If the stones had been transported east of the Bristol Channel by glacial action, a much wider range of sources would be expected. The pinpoint sourcing that has now been done argues strongly for human quarrying and transport of the bluestones, whatever the motivation and precise route employed.........
Three major rock types and two minor ones can be identified within the “bluestone” range using both the entire stones and waste chips known as debitage which result from trimming the slabs on site at Stonehenge. The three major groups, originally thought to be from different geographical sources, can now be shown to be from the same locale.
The area of the new find lies at Pont Saeson on the northern flank of the Preseli Mountains, long known as the general source of the bluestones, some 6.5 kilometres (four miles) from Newport in north Pembrokeshire. The discovery follows the use of zircons included in the rocks to identify an area near Pont Saeson as one likely source of Stonehenge material by Dr Ixer and his colleague Dr Richard Bevins of the National Museum of Wales.
“Almost all — 99.9 per cent — of the Stonehenge rhyolitic ‘debitage’ can be petrographically matched to rhyolitic rocks found within a few hundred square metres at Pont Saeson and especially to those found at Craig Rhosyfelin.
“However, it is possible in a few cases, where the petrography of these Welsh in situ rocks is so distinctive, to suggest an even finer provenance to within square metres, namely to individual outcrops,” Ixer and Bevins report in Archaeology in Wales.
...
The outcrop itself is some 70 metres long and has many tall, narrow slabs up to two metres (6.5 feet) high as the dominant feature, splitting off from the parent rock and reminiscent of the Stonehenge bluestones. One of the Stonehenge shafts, known as SH32e, can be matched very closely to this outcrop, and must have been quarried there, not transported by a glacier.
....
The dispute over natural versus human transportation for these elements of an early and important phase of Stonehenge now seems to be settled —as Ixer says, the glacial theory is out cold.

May be more.......

Archaeology in Wales Vol. 50 pp 21-31

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

Bluestones – proof for human transport to Stonehenge?

http://mikepitts.wordpress.com/2011/12/17/bluestones-proof-for-human-transport-to-stonehenge/

Norman Hammond’s piece in Today’s Times (“Bluestones theory is now frozen out”) highlights the work by Richard Bevins and Rob Ixer on the precise origins of the Stonehenge bluestones. This is landmark stuff, and worth trying, briefly, to summarise.

There’s a lot of stone debris under the ground at Stonehenge, and more in the area around. For much of the 20th century the former was known as the “Stonehenge layer”. William Hawley associated it with the original dressing of megaliths (hence, any pits found below it were said to be older than the standing stones), while Richard Atkinson thought it derived from destruction of the stones, and was largely post-medieval or modern. As I found at my small excavation on the roadside in 1980, at least some of this debris almost certainly is prehistoric. At the time, I claimed it was contemporary with the carving of the stones. Mike Parker Pearson and Tim Darvill would now like to associate it with prehistoric stone destruction; on available evidence, I think it’s impossible to be certain either way. However, while the debris across the site is likely to have a variety of different origins, most of it, at least, probably does come from stones used for megaliths. So it’s an extremely important resource for understanding Stonehenge.

At last, we have some substantial modern studies of this material. Hammond quotes the most recently published, by Ixer and Bevins in Archaeology in Wales. Other articles include theirs in the Wiltshire Archaeological Magazine, and one they authored with Nick Pearce in the Journal of Archaeological Science (see references). They bring an important insight: the great bulk of the non sarsen stones at Stonehenge (but not all), come from a very restricted region in Pembrokeshire, south-west Wales. So restricted, that Ixer at least is confident in saying that this alone points to human transport as the only likely mechanism for the stones having got to Stonehenge.

The best known type of bluestone is the spotted dolerite, of which all the stones in the surviving inner arrangement at Stonehenge are composed. These are long known to have originated in the Preseli Hills. Ixer and Bevins have also examined specimens of the other main class, rhyolitic tuffs.

The work began principally with a study of the stone fragments picked up on the surface or excavated in test pits near the Cursus, just north of Stonehenge. Though several different types of rhyolitic rock were represented, they found that most “had a restricted and distinctive petrography both in terms of their mineralogy and textures”, and that “this petrography was unusual for south-west Wales, being only recognised from the Pont Saeson area”. In subsequent fieldwork, building on Bevins’s extensive knowledge of the area, they located outcrops at Pont Saeson, in a deep valley on the northern edge of the famous Preseli Hills. In the JAS article, they reported that some rhyolites from Stonehenge were the same as samples from Pont Saeson (on Craig Rhos-y-felin), and further detailed work confirming this is reported in the Archaeology in Wales article. The location is so precise, we have every reason to think that actual quarries should now be found, opening up exciting fieldwork possibilities.

References

“Craig Rhos-Y-Felin, Pont Saeson is the dominant source of the Stonehenge rhyolitic ‘debitage’”, by RA Ixer & RE Bevins, Archaeology in Wales 50 (2011), 21–31

“Stonehenge rhyolitic bluestone sources & the application of zircon chemistry as a new tool for provenancing rhyolitic lithics”, by RE Bevins, NJP Pearce, & RA Ixer, Journal of Archaeological Sciences 38 (2011), 605–22

“The petrography, affinity and provenance of lithics from the Cursus Field, Stonehenge”, by RA Ixer & RE Bevins, Wiltshire Archaeological & Natural History Magazine 103 (2010) 1–15

“The detailed petrography of six orthostats from the bluestone circle, Stonehenge”, by RA Ixer & RE Bevins, Wiltshire Archaeological & Natural History Magazine 104 (2010), 1–14

The Times pronounces on the bluestones

2011-12-17T20:58:00.001Z

Craig Rhosyfelin, where the "precise quarry source" for the Stonehenge bluestones has been found, according to somebody who presumably knows about these things. So there we are then......

A little bird told me that there was an article in The Times today in which the glacial transport theory is definitively rejected on the basis of new geological evidence from a "precise quarry source" -- and that presumably means Craig Rhosyfelin. All I can find on the Times web site is what I have pasted below -- apparently it is in the Court and Social part of the Newspaper.... ??!!! Interesting, to say the least -- so this will be very scientific, then.

The Times wants to charge me for seeing the article in full, and I am disinclined to pay. If anybody has seen it, I'll be very interested to hear more....

Bluestones theory is now frozen out

Norman Hammond

The Times
Published: 17 December 2011
Court & Social

...long-running debate about the origin of the Stonehenge “bluestones” and how they got to...precise quarry source for much of the Stonehenge rock has been pinned down to a few...motivation and precise route employed. Stonehenge’s “bluestones” are not the...

Erratic mysteries

2011-12-16T20:20:00.001Z

Erratic boulder, Blido, Sweden (click to enlarge)

I'm often asked why, if the bluestones at Stonehenge are glacial erratics, they aren't covered with scratches (striations) and glacial facets which would demonstrate for all to see that they have been transported in or on glacier ice. Partly, that's because dolerite does not striate very easily -- it's very coarse, and because the component crystals are quite large, when glacial abrasion occurs on a dolerite surface the rock crumbles rather than becoming smooth. On the other hand rhyolite does smooth reasonably well, and I have seen striations on some ice-smoothed surfaces, on Carn Alw for example. But there is not a lot of rhyolite exposed above the surface at Stonehenge. Some sandstones can smooth and accept striations -- maybe the two sandstone stumps in the bluestone circle may give some clues as and when anybody gets to look at them. Ashes are sometimes too soft -- but given the right circumstances maybe we could find glacial scratches on the smoothed faces of some Stonehenge monoliths.

To give us some idea how complex are the effects of glacial transport on contained erratics, have a look at the boulder above. We dug it up last year from the thick till near our summer cottage in Sweden. This boulder has at least nine facets on it -- the seven that I have labelled, and two that we can't see. Number 1 probably shows the original shear face -- probably this boulder was sheared off the bedrock roughly along a weak contact between pink rock and bluish-grey rock. (I hesitate to give them names -- the pink rock is thought to have been Pre-Cambrian granite originally, but there has been tremendous metamorphism since it was originally emplaced. The bluish-grey rock is altered too.) You can click to seee the other facets more clearly -- they are all sheared or fractured faces of different ages. It's difficult to give them relative dates. Note that some are VERY rough, while others have been subject to varying degrees of abrasion and smoothing. The smoothest facet of all is Number 6 -- beautifully abraded, with very clear striations and also chatter-marks or pressure fractures created by tools being forced down onto the rock surface. If a tool is very big and the pressure exerted is very large too, then the whole boulder will be split or fractured, and thence reduced in size. And we will have another facet on the boulder. If this process goes on for long enough, the boulder is reduced to a collection of smallish bits and pieces, gravel and sand. If the boulder is protected, it can be carried for hundreds of kilometres without further modification.

This is typical of what happens to a boulder being carried at the base of a glacier. Boulders carried englacially or supraglacially are affected by a different set of processes.

Stonehenge "Light Art"

2011-12-11T14:38:00.001Z

http://www.marcbb.co.uk/portfolio-set.php?set=72157620663692985

Some fantastic photos have been published on Marc Bowyer-Briggs's web site. He is a professional photographer who was given permission for a very brief visit -- and there's a nice portfolio on the web of some of his artistic creations. Enjoy!

The Sandstone Bluestones

2011-12-10T09:56:00.001Z

The traditional Stonehenge Plan -- click to enlarge

It's often erroneously stated that all of the bluestones at Stonehenge are igneous, and that they all come from the Carn Meini area. Well, that just ain't so. We know about the Altar Stone (numbered 80 on this plan and overlain by fallen sarsens) -- but there are two other sandstones as well -- numbered 40g and 42c. Their positions are marked in yellow on the plan. There is probably no significance in their locations -- although it has often been said that in the final settings of bluestones the hardest dolerites were chosen for the bluestone horseshoe, and the softer and more variable rhyolites and ashes (and sandstones) were left in the outer bluestone circle. I have argued before that this, of course, was never completed, because the builders ran out of stones.

What do we know about stones 40g and 42c? Not a lot, apart from the fact that they are both buried stumps, and are labelled as "micaceous sandstone" -- probably of Palaeozoic age, and probably from somewhere in South Wales. Sampling is urgently needed -- English Heritage, are you listening?

If you are a romantic soul who likes to think that the bluestones were chosen because of their magical or healing properties, then the sandstone bluestones become a bit of a problem. Maybe they were replacements for igneous bluestones lost in transit? Or maybe they were deemed to be magical not because of their petrographical characteristics, but because of WHERE they came from? Then again, they might just be glacial erratics, picked up like all the other stones from the general neighbourhood of Stonehenge?

Brit Arch letter published

2011-12-08T18:40:00.002Z

I'm grateful to Mike Pitts, the editor of British Archaeology, for publishing this letter which I sent through to him back in September. A faithful reader of the magazine has now informed me that it's been published.

This is the letter which I submitted:

Erratic Professors

On two occasions within the last twelve months or so, I have heard
eminent professors holding forth in defence of their ideas about the human
transport of bluestones from Pembrokeshire to Stonehenge. On both
occasions it was stated that the Irish Sea Glacier had never reached the
English side of the Bristol Channel. On the contrary, it is fully
accepted by geomorphologists and glaciologists that during the Quaternary
Period, this great glacier crossed the Bristol Channel on at least one
occasion, and affected the coastlands of Somerset, Devon, Cornwall and the
Scilly Isles. This is based on our best understanding of scores of
papers published, over many years, by field geomorphologists, in the
specialist peer-reviewed literature. What we do not know, at present, is
exactly when the most recent glaciation of these coastlands occurred, and
how far to the east and south the ice edge might have progressed. The
directions of ice movement, insofar as we understand them, suggest that
glacier ice crossed Pembrokeshire broadly from NW towards SE, and that
erratic boulders from Pembrokeshire were entrained and transported
eastwards within the ice. We know where some of those boulders were
dumped, but other erratic transport routes are still to be ascertained.
This information clearly has a direct bearing upon the ongoing discussions
about the origins and transport of the "bluestone assemblage" at
Stonehenge, involving at least 24 different rock types.

Brian John, Newport, Pembrokeshire

I gather that there has been some slight editing, and a new title has been used: The Irish Sea Glacier. That's fair enough.....

If the letter encourages archaeologists to think about the real situation, rather than some mythical and misleading one perpetrated by senior academics, all well and good.

PS. I would normally put a link in here to "British Archaeology", but given what has happened today with the Bournemouth University blog site (trojan horses etc) I will delay until I am sure that the problem is solved, and add a link later....

Please take care

2011-12-08T15:00:00.001Z

One of our regular contributors has reported a virus attack on his computer which seemed to coincide with opening up the page for the last post -- on Seeing Beneath Stonehenge. I have checked my computer carefully, and everything seems to be working as it should, including the links. But I use an Apple Mac and I'm aware that PCs are much more vulnerable........

So please check that all is well, and that you have all appropriate virus protection measures in place -- just in case.

Brian

PS. It appears that the Bournemouth blog link contains a trojan horse. I have now wiped it off -- but if anybody has it downloaded onto their computer, please beware.

Seeing Beneath Stonehenge? Not quite.....

2011-12-08T10:43:00.001Z

Thanks to Stonehenge News for drawing attention to this new site, made by the Sheffield University team with lots of collaboration, and with assistance from Google. Google Under-the-Earth is an app which can be downloaded if you already have Google Earth -- it allows you to zoom around, getting rather giddy in the process, as you look at the Stonehenge landscape.

The new site (with various YouTube videos as well) gives you access to a lot of info from the recent Sheffield Univ projects led by MPP and his team, including carefully photographed scans of the trenches, and various animations as well. The key project is the Stonehenge Riverside Project. So as a teaching resource, I can see this as very valuable. I'm not sure what else it gives us -- and it certainly doesn't allow us to see beneath Stonehenge in the sense of allowing us to see exactly where the pits, stumps and other subterranean features are to be found..........

------------------------------------------------
Hidden dimension of Stonehenge revealed
by stonehengenews

A project directed by academics at the University of Sheffield has made the archaeology of the world-famous Stonehenge site more accessible than ever before.

Google Under-the-Earth: Seeing Beneath Stonehenge is the first application of its kind to transport users around a virtual prehistoric landscape, exploring the magnificent and internationally important monument, Stonehenge.

The application used data gathered from the University of Sheffield´s Stonehenge Riverside Project in conjunction with colleagues from the universities of Manchester, Bristol, Southampton and London. The application was developed by Bournemouth University archaeologists, adding layers of archaeological information to Google Earth to create Google Under-the-Earth.

The unique visual experience lets users interact with the past like never before. Highlights include taking a visit to the Neolithic village of Durrington Walls and a trip inside a prehistoric house. Users also have the opportunity to see reconstructions of Bluestonehenge at the end of the Stonehenge Avenue and the great timber monument called the Southern Circle, as they would have looked more than 4,000 years ago.

The project is funded through Google Research Awards, a program which fosters relationships between Google and the academic world as part of Google's ambition to organise the world's information and make it universally accessible and useful.

Professor Mike Parker-Pearson from the University of Sheffield's Department of Archaeology said: "Google Under Earth: Seeing Beneath Stonehenge is part of a much wider project led by myself and colleagues at other universities - the Stonehenge Riverside Project - which began in 2003. This new Google application is exciting because it will allow people around the world to explore some of the fascinating discoveries we've made in and around Stonehenge over the past few years."

Archaeological scientist Dr Kate Welham, project leader at Bournemouth University, explained that the project could also be the start of something much bigger:

"It is envisaged that Google Under-the-Earth: Seeing Beneath Stonehenge could be the start of a new layer in Google Earth. Many of the world's great archaeological sites could be added, incorporating details of centuries' worth of excavations as well as technical data from geophysical and remote sensing surveys in the last 20 years." she said.

Dr Nick Snashall, National Trust Archaeologist at Stonehenge said: "The National Trust cares for over 2,000 acres of the Stonehenge Landscape. Seeing Beneath Stonehenge offers exciting and innovative ways for people to explore that landscape. It will allow people across the globe, many of whom may never otherwise have the chance to visit the sites, to share in the thrill of the discoveries made by the Stonehenge Riverside team and to appreciate the remarkable achievements of the people who built and used the monuments."

You can download the application from the Google Under-the-Earth: Seeing Beneath Stonehenge site. The tool is easy to use and requires Google Earth to be installed on your computer.

Notes for Editors:
Google Under-the-Earth: Seeing Beneath Stonehenge was created at Bournemouth University by Dr Kate Welham, Mark Dover, Harry Manley and Lawrence Shaw. It is jointly directed by Dr Kate Welham and Professor Mike Parker Pearson at the University of Sheffield.

To find out more about the University of Sheffield's Department of Archaeology, visit: Department of Archaeology

The Stonehenge Riverside Project was a joint collaboration between Universities of Bournemouth, Bristol, Manchester, Sheffield and University College London. It was led by Professor Mike Parker Pearson, University of Sheffield, and co-directed by Professor Julian Thomas, University of Manchester, Dr Joshua Pollard, University of Southampton (formally University of Bristol), Dr Colin Richards, University of Manchester, Dr Chris Tilley, University College London and Dr Kate Welham, Bournemouth University.

This project has been supported by: The Arts and Humanities Research Council, the British Academy, the Royal Archaeological Institute, the Society of Antiquaries, the Prehistoric Society, the McDonald Institute, Robert Kiln Charitable Trust, Andante Travel, University of Sheffield Enterprise Scheme, the British Academy, the National Geographic Society, with financial support from English Heritage and the National Trust for outreach. The project was awarded the Bob Smith Prize in 2004 and the Current Archaeology Research Project of the Year award for Bluestonehenge in 2010.

Sponsored by 'The Stonehenge Tour Company'

Dugout boats found in Cambridgeshire Fens

2011-12-05T14:19:00.001Z

http://www.guardian.co.uk/science/2011/dec/04/bronze-age-archaeology-fenland

A nice article in The Observer and on Guardian Online about the finds in the Fens........ they all seem to date from the Bronze Age. Lots of artifacts including some rather unexpected ones, preserved under 4m of organic muds. (What did I tell you, Geo? These things are there -- they turn up eventually...........often purely by chance.)

There are 6 dugout boats on the site, including one which is over 8m long. The pic above shows one of the boats being revealed. The boats seem to be quite crude, and are not thought to have been suitable for sea voyages -- but they were clearly OK for sculling around in the sheltered lagoons and swamps of the environment at the time.

Bluestone Rock Types

2011-12-03T11:37:00.000Z

About a year ago I published this updated list of the 31 or so different "bluestone" rock types that are now recognized in the Stonehenge area. Thanks to Rob Ixer and Richard Bevins and their collaborators, the geology is moving on apace, and this list probably now needs revision -- especially in the light of the work relating to Pont Saeson / Craig Rhosyfelin. All comments gratefully received on the accuracy of this list, and corrections that need to be made. I'll do my best to keep this list as authoritative as possible.......

Stonehenge Bluestone Types

1. Unspotted dolerite ---- monoliths 45 and 62. Carn Ddafad-las?

2, Spotted dolerite -- densely spotted. Monolith 42 -- Carnbreseb? 43?

3. Boles Barrow dolerite -- spotted? But similar to stones 44 and 45? From Carnmeini / Carngyfrwy area?

4. Rhyolite -- stones 38, 40, ignimbrite character. Ash-flow tuffs (dacitic). Not Carnalw ? May be from different sources?

5. Rhyolite -- stones 46 and 48, rhyolitic ash-flow tuffs. Carnalw area? Same source?

6. Rhyolite fragment from a different source from the above types

7. Laminated calcareous ash -- stumps 40c, 33f, 41d

8. Altered volcanic ash -- stump 32c, 33e?

9. Rhyolite -- another type -- stump 32e. Related to Pont Saeson samples?

10. Micaceous sandstone -- stumps 42c, 40g (Palaeozoic -- South Wales origin?)

11. Rhyolite -- lava -- stone 46

12. Rhyolite -- flinty blue -- different lava? stone 48

13. Spotted dolerite with whitish spots --stones 33, 65, 68, stump 70a?, stump 71?, 72

14. Spotted dolerite with few spots -- stone 31, 66?

15. Spotted dolerite with pinkish spots -- stones 150, 32, 34, 35A, 35B (one stone), 39 (?), 47, 49, 64, 67, 69, 70

16. Spotted dolerite -- moderate spots -- stone 37, 61, 61a?

17. Unspotted dolerite -- stone 44 -- different from stones 45 and 62

18. Very fine-grained unspotted dolerite -- stone 62

19. Silurian sandstone -- Cursus -- fragments

20. Devonian sandstone -- Altar Stone -- Devonian Senni Beds -- Carmarthenshire or Powys

21. Sarsen sandstones -- various types -- packing stones and mauls

22. Jurassic oolitic ragstone -- Chilmark?

23. Jurassic glauconitic sandstone -- Upper Greensand?

24. Gritstone unspecified fragments (Maskelyne, Judd)

25. Quartzite unspecified fragments (Maskelyne, Judd)

26. Greywacke unspecified fragments (Maskelyne, Judd)

27. Granidiorite -- Amesbury long barrow 39

28. Quartz diorite -- ditto

29. Hornblende diorite -- ditto

30 Flinty rhyolite -- fragments from Pont Saeson

31. Rhyolite fragments -- with titanite-albite intergrowths (source unknown)

The Burden of Proof

2011-12-02T16:42:00.001Z

Another in my series of philosophical (sort of!) musings, to go with the posts on Occam's Razor, Pseudoscience, the Hutton Principle of Uniformity and the Popper arguments about falsification. You can look those up on the Search facility.

My thanks to Geo for kicking off a rather interesting line of debate on one of the other posts. (here) This is all to do with the burden of proof applicable to the two sides of the bluestone transport debate. I have argued for years that the "human transport hypothesis" has been given the status of a rebuttable presumption -- ie the media, the great British public and the archaeological establishment have conspired to presume that the hypothesis is correct, and have placed the burden of proof on people like me to provide evidence to show that it is not. Now according to law that is plain daft, because a rebuttable presumption is supposed to be underpinned by prima facie evidence -- and this hypothesis has no such evidence associated with it. Quite the reverse -- we can say that the hypothesis is counter-intuitive, since nothing like it can be demonstrated either earlier or later than the assumed "bluestone expeditions" and since no indisputable evidence has ever been adduced in support of it. On the contrary, the evidence that we DO have about British megalithic structures shows that people did not carry stones over great distances, but used whatever was closely at hand.

What should the "default hypothesis" be here? Without any doubt at all, it should be the glacial transport hypothesis. We do not have any "killer facts" relating to bluestone transport by ice onto Salisbury Plain, but we do have evidence of ice flow from Preseli at least as far east as Somerset, of the transport of far-travelled erratics by the Irish Sea Glacier, and of glacial and related deposits in many "convenient" locations in the published literature. The overall story is strong, and consistent -- the evidence stacks up. Therefore, in my humble opinion, M'Lud, the rebuttable presumption has to be that glacier ice carried the stones from Preseli to Stonehenge. THAT should be the working hypothesis, to be tested according to normal scientific principles:

A linearized, pragmatic scheme for the scientific process:

    • Define a question : How did spotted dolerite from the Carn Meini area get from Preseli to Stonehenge?
    • Gather information and resources (observe). Abundant and consistent scientific literature.
    • Conjecture -- Form an explanatory hypothesis. Glacier ice was responsible.
    • Test the hypothesis by performing an experiment and collecting data in a reproducible manner
    • Analyze the data. It confirms and strengthens the hypothesis.
    • Interpret the data and draw conclusions that serve as a starting point for new or modified hypothesis
    • Publish results for peer review. that's what this Blog is all about....
    • Retest (frequently done by other scientists). Yes please.

The default position has to be that natural processes, rather than human ones, were responsible for the transport of the stones. We are not talking about "beyond reasonable doubt" here, but a high probability in accordance with the evidence already to hand. If somebody wants to come along and assert something different, then the burden of proof is placed upon him. He carries the evidential burden. His evidence must be even stronger that that underpinning the default position. To quote one of the pieces below "He who asserts must prove...."

So that is why I will not accept for a moment the proposition that the human transport thesis does not need to be underpinned by evidence, on the grounds that our ancient ancestors trod so lightly on the land that they did not leave any traces of their enterprises behind.

Get real, you guys! We are talking science here, not fairy tales..... so go forth and dig, and come back to us with anything you find.

I rest my case.

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

Some info from the web

Burden of Proof

In civil litigation the standard of proof is either proof by a preponderance of the evidence or proof by clear and convincing evidence. Both are lower burdens of proof than beyond a reasonable doubt (used in criminal cases). A preponderance of the evidence simply means that one side has more evidence in its favor than the other, even by the smallest degree. Clear and convincing evidence is evidence that establishes the truth of a disputed fact by a high probability. Criminal trials employ a higher standard of proof because criminal defendants often face the deprivation of life or liberty if convicted while civil defendants generally only face an order to pay money damages if the plaintiff prevails.
http://legal-dictionary.thefreedictionary.com/burden+of+proof

Burden and Standard of Proof -- Presumptions
Introduction
The allocation of the burden of proof in both civil and criminal trials turns on the
decision as to who should bear the risk of losing the case. That allocation is decided
by common law and by statute. In criminal trials the ‘presumption of innocence’
means that the burden of proof will be on the prosecution, unless this is reversed by
some express or implied statutory provision. Here the law of evidence safeguards
what in some other jurisdictions is a matter of individual civil rights backed up by a
tenet of the constitution.
In answering questions in this area, you must understand the difference between the
legal and the evidential burden and the occasions where they are separately allocated. It
is helpful to see the evidential burden primarily as an aspect of the sensible proposition
that there must be a degree of evidence on asserted issues before they can be a matter
for the trial. It is for the judge then to decide whether the assertion can go before the
jury. Thus the prosecution has to adduce enough evidence of the guilt of the accused
for the judge to be satisfi ed that there is a case to answer. In other words, it has the
evidential burden. Here, the prosecution also has the legal burden on the same matter
and this is the normal state of affairs directed at convincing the jury of the defendant’s
guilt beyond reasonable doubt (the criminal standard). The tricky areas are those
where there is a divorce of the legal and evidential burden. These arise primarily in
situations where the prosecution cannot be expected to put up evidence to anticipate
every specifi c defence the accused may present. Thus in order to plead self-defence the
accused will have to provide some evidence to enable the court to consider the matter.
The legal burden stays with the prosecution.
It is somewhat misleading to refer to a single burden of proof in a trial. The
burden may relate to several different specifi c facts in issue. Burdens may be allocated
between the parties in relation to these different facts in issue. This is particularly
so in civil cases but may also occur in criminal cases. In civil cases the principle ‘He
who asserts must prove’ means that the burden may shift according to who is trying
to establish a relevant fact in issue. In criminal cases the presumption of innocence
means that as a general principle the burden of proving actus reus and mens rea lies on
the prosecution.

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

In many situations, one side has the burden of proof resting on it. This side is obligated to provide evidence for its position. The claim of the other side, the one that does not bear the burden of proof, is assumed to be true unless proven otherwise. The difficulty in such cases is determining which side, if any, the burden of proof rests on. In many cases, settling this issue can be a matter of significant debate. In some cases the burden of proof is set by the situation. For example, in American law a person is assumed to be innocent until proven guilty (hence the burden of proof is on the prosecution). As another example, in debate the burden of proof is placed on the affirmative team. As a final example, in most cases the burden of proof rests on those who claim something exists (such as Bigfoot, psychic powers, universals, and sense data).
http://www.nizkor.org/features/fallacies/burden-of-proof.html

Reverse burden of proof.....

Rebuttable presumption
From Wikipedia, the free encyclopedia
Both in common law and in civil law, a rebuttable presumption (in Latin, praesumptio iuris tantum) is an assumption made by a court, one that is taken to be true unless someone comes forward to contest it and prove otherwise. For example, a defendant in a criminal case is presumed innocent until proved guilty. A rebuttable presumption is often associated with prima facie evidence.

Hot news from America

2011-11-30T19:18:00.000Z

Hot news from America (well, not actually all that hot -- but news travels slowly across the Atlantic) -- apparently the two Profs (GW and TD) are now so convinced that the "important person" who may or may not have been buried beneath that little pile of stones on Carnmeini has something to do with Stonehenge that they are directing further research at the problem of how he did it, and when, and why. They say that this splendid fellow "played a crucial role" since he was buried on top of a "ceremonial stone circle." So there we are then. There is probably a research proposal in the pipeline as we speak. How on earth they propose to demonstrate all of this is a closely guarded secret -- but maybe they have a direct line to the spirits of the ancestors or to Gwlad y Tylwyth Teg?

From the latest edition of the American Welsh Newspaper called NINNAU:

ARCHAEOLOGISTS ARE researching the grave of an important figure they believe may have played a crucial role in the construction of Stonehenge. The burial chamber is located above a ceremonial stone circle in the Preseli hills in west Wales, where it is believed bluestone was quarried before being taken to Stonehenge. More research will be done to establish if the important person buried there played a role in the moving of bluestone 190 miles from West Wales to the Wiltshire monument. The find has been made by Professors Tim Darvill and Geoffrey Wainwright, who have spent the last IO years trying to establish how and why the blue- stones - or spotted dolerite - were transported from the Preseli hills to Stonehenge.

Bluestone Transport Lexicon

2011-11-29T14:16:00.000Z

Many thanks for the kind comments -- on and off the record -- about the pictures I have posted which purport to show how bluestones were transported across land and sea. The two pages are here:

http://brian-mountainman.blogspot.com/2011/11/danger-engineers-at-work.html
http://brian-mountainman.blogspot.com/2011/11/even-more-danger-marine-engineers-at.html

I have already added a few pics since the original posts were made -- and if anybody knows of any I have missed, please let me know. I will be happy to incorporate them.

New pics added

2011-11-27T18:23:00.002Z

I have added some new pics to the post called "Danger -- engineers at work"......... Enjoy!

Even more danger -- marine engineers at work

2011-11-27T16:38:00.001Z

By popular request, here is my gallery of wacky transport systems designed for carrying 82 bluestones from Pembrokeshire to either the mouth of the Somerset Avon or the Hampshire Avon. There are almost as many proposed transport routes as boat designs.........

This is the daddy of them all - Alan Sorrell's famous illustration done for the 1959 edition of Atkinson's book on Stonehenge. It's a simple sailing and rowing raft -- shown here with 2 bluestones lashed in place. I suppose the original idea was to show that sea-based transport was possible, but since this raft is about to be shipwrecked in a severe storm, I suppose it might have demonstrated for many people that this sort of transport was impossible, rather than possible. However, undeterred, we have a veritable host of others who have entered the fray.

Atkinson -- triple wooden punts with a stone strapped to a top decking

Len Saunders -- simple raft with a bluestone pillar "underslung" -- at the water-line

The Ferriby Boat -- built of wooden planking. Strictly Bronze Age, but some think the technology was available in the Neolithic too

The "curragh pontoon" used during the Millennium Stone fiasco. These specially built curraghs were first fitted with decking to take the stone, but when this proved unstable, a rig was built so that the stone could be slung in a harness below the water line.

Castleden's idea -- triple dugouts with a top decking lashed on, for the support of the stone

Single curragh with underslung stone, lifted off on a rising tide

Blunt-stern curragh, wide enough to take a bluestone sitting in the bottom of the boat

(Michael Bradley)

And now the greatest of all -- Robert Langdon's reed boat -- a catamaran made of reeds -- with the Stonehenge harbour in the background. No comment.

And here's the latest, courtesy of the Daily Mail -- the two-man bluestone punt, just perfect for shifting very large lumps of stone from Milford haven all the way up the Bristol Channel to the mouth off the Avon. No doubt the stout fellows used punting poles at least 50 feet long. And the practicalities? Maybe the newspaper should consult t maritime transport engineer next time.........

Seahenge and Stonehenge

2011-11-27T10:45:00.000Z

A number of people have asked for a post on Seahenge, Norfolk -- presumably on the basis that it might give us some insights into the age and purpose of Stonehenge. I must admit to ignorance re this site, except that I do recall all the fuss that went on at the time of its excavation -- with our friend Geoff Wainwright at the centre of it....... Anyway, for better or for worse, the site was cleared, and the timbers are now preserved and on display in the Lynn Museum.

For those who are interested in drawing parallels with Stonehenge and otherwise discussing the significance of Seahenge, over to you.....

This info is from the Lynn Museum website:
Seahenge
Prehistoric timber circle from Holme

In the summer of 1998 the shifting sands of Holme beach on the
north Norfolk coast revealed something extraordinary. Preserved in
the sand were the remains of a unique timber circle dating back
over 4000 years, to the Early Bronze Age. Although discovered on
a modern beach, the circle was originally built on a saltmarsh,
some distance inland.
The discovery captured the imagination of archaeologists and
public alike and the site soon became known as ‘Seahenge’. The
timbers came from a circle 6.6m (21 ft) in diameter, comprising 55
closely-fitted oak posts, each originally up to 3m (10 ft) in length.
At the centre of the circle was a great upturned tree stump.
Scientific dating methods showed that the trees were felled in the
spring or early summer of 2049BC. Whilst we can never be certain
why the site was built, it was probably used following the death of
an important person, with a body laid out on the upturned stump
so birds and animals could pick the bones clean. They were
removed for burial elsewhere. We do know that after only a short
period of time, the entrance to the circle was sealed.

John Speed's ruinous Stonehenge

2011-11-26T15:03:00.000Z

I found this delightful illustration of Stonehenge (top pic) -- from the John Speed Atlas, dated to 1611 but incorporating bits of artwork which might well have been completed up to a decade earlier.

It's instructive to compare the illustration with the Lucas de Heere illustration, first published around 1575 but maybe drawn around 1550. So there may be a 50 year gap between the two portrayals of the ruinous old site.

It's often assumed that the Speed illustration is simply copied from the de Heere picture -- but I'm not quite sure. The wondrous mountains in the background are clearly very fanciful, and suggest that the artist may never have been near the site -- but note the subtle differences between the illustrations. In each one there are only ten lintels in place, but in the Speed picture there is a fifth bluestone, leaning at a crazy angle. In each picture there are fewer than 30 standing sarsens, with seven or so leaning or fallen.

As we all know, the "immaculate Stonehenge" is supposed to have had a total of about 160 stones on the site -- about 80 bluestones and about 80 sarsens. Vast numbers are missing in these early illustrations -- well before the "seventeenth century stone collecting mania" which we hear about in the literature as an explanation for missing stones. If there were so few stones here on the site in the Sixteenth century, I think it fair to assume that they were never there in the first place.

Danger -- engineers at work

2011-11-26T13:04:00.009Z

Dick Parry's rollers

Cliff Osenton's supporting frame and log rollers

Richard Atkinson's sledge 1958

Cuban "wedge sledge" -- Len Saunders

Bruce Bedlam's roller

Garry Levin's wickerwork roller

Bruce's balls

The Millennium Stone sledge 2000 -- used on roads with low-friction netting

Above -- Alan Sorrell -- 1958 for Atkinson et al -- rack and rollers, and lots of strong men with very long ropes.......

The Millennium Stone Pull, 2000. Note the vast amounts of low friction Netlon being used to enable the sledge to slide properly. On this day (when I was involved!) the sledge went out of control on the hill you can see in the background, and this pic was taken shortly after the crash. There weren't enough people with braking ropes at the back.

Luckily nobody was hurt....

Rodney Castelden's ox sledge and bogey -- needing 24 oxen for the haulage of a sarsen. Presumably the haulage of bluestones would have needed fewer oxen and a simpler rig?

The "conveyor stone" system, in which a row of bluestones acts as a "firm roadway" for other stones to be moved along from the back of the row to the front, through the use of rollers. Nice idea, but on rough terrain, with rough and irregularly shaped stones....?

Phil Morgan's Contraption. Basically a rocking A-frame capable of moving a bluestone on a sledge forward by a few feet at a time. Tested July 2011 at St Fagan's.

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I have been pondering on what a splendid cottage industry we now have in the UK, involving enthusiastic teams of engineers and presumably underwritten by substantial quantities if public money. Not that I'm complaining -- I'd rather see money spent on this than on Trident submarines, for example. But just think of the thousands and thousands of hours of intellectual effort have gone into all of this -- not to mention the sweated labour (usually involving groups of students.)

There are a number of interesting themes coming through here.

One -- some of the experiments don't use stones at at all, let alone irregular stones such as those in the bluestone assemblage at Stonehenge.

Two -- there is frequent "cheating" especially through the use of modern ropes, used in great lengths both for lashing rollers and frames together, and for pulling sledges along. OK -- so what these guys are doing is attempting to "establish a principle" that works -- but can you really imagine Bruce Bedlam's roller working, for example, with Neolithic ropes made of twisted bramble stalks or animal gut? Hmmm.......

Three -- the use of asphalt roadways or hard surfaces is rather too common for comfort. And on the Millennium Stone pull, in which I was involved, the organizers had to resort to the use of low-friction nylon netting to facilitate the movement of the sledge with its bluestone, and used just asphalt roadways and good farm tracks for the haulage route.

Four -- there are some other wonderful impracticalities, the most wonderful of which is Bruce Bradley's ballbearing and railway track idea, which requires not only a trackway with a near-perfect groove cut in it, but also large quantities of IDENTICAL stone or wooden ballbearings. Now that's something I really DO object to taxpayer's money being used for......

Five -- too many flat and even fields and rolling chalk downs for comfort. One or two of the trials did involve haulage up slopes, but not one of the tests thus far has come anywhere near replicating the assumed haulage of stones across a heavily-wooded landscape with peat bogs, rocky outcrops and stone litters, sticky clay depressions, steep slopes, waterlogged woodland clearings, cataracts and streams with alternating torrents and shallows. Some of the experimenters need to come to Pembrokeshire and have a look round.... I will be happy to act as a local guide, just in case the natives prove to be hostile and choose to target them with spears and arrows......

SO WHEN IS SOMEBODY GOING TO DO AN AUTHENTIC EXPERIMENT, USING NEOLITHIC MATERIALS AND A PROPER LUMP OF SPOTTED DOLERITE OR RHYOLITE, ACROSS AUTHENTIC TERRAIN?

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Sorry guys -- you have had fun, and some of your techniques might have worked on Salisbury Plain, but I have seen nothing yet, in all the info about these engineering experiments, to convince me that large numbers of bluestone pillars could have been moved for one mile through the Neolithic jungles of central Pembrokeshire, let alone for the epic journey so beloved of EH and miriads of otherwise sensible people. The more I think about it, the more convinced am I that ALL of the stones used at Stonehenge were gathered up and transported across a relatively limited area of Salisbury Plain. Even there, the Neolithic terrain would have been far more difficult than it is today, so that might well have placed a real constraint upon the maximum distance across which the haulage of stones was worthwhile.

Secret history of Stonehenge revealed -- again, and again, and again.....

2011-11-26T11:42:00.000Z

Haven't we heard all this a thousand times before? Well, yes we probably have. This is a piece from David Keys in "The Independent" -- no doubt based upon a University of Birmingham press release. It's almost impossible to say whether this is saying anything new, or not. All of these research teams feel that they have to flag up their "findings" with maximum hype, and I recall that not long ago Mike Pitts had a real go at this particular team for -- shall we say -- over-egging their latest pudding to a considerable degree. Anyway, it's good to see that work is still going on -- and I do like the thought that a wide survey across the Stonehenge landscape might reveal previously unknown sites, stone or post holes and even buried stones made of sarsen or bluestone.......... and who knows, they might even find a moraine or another cluster of erratics!

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Secret history of Stonehenge revealed

Ancient site may have been place of worship 500 years before the first stone was erected

David Keys
Saturday 26 November 2011

http://www.independent.co.uk/life-style/history/secret-history-of-stonehenge-revealed-6268237.html

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Extraordinary new discoveries are shedding new light on why Britain’s most famous ancient site, Stonehenge, was built – and when.

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Current research is now suggesting that Stonehenge may already have been an important sacred site at least 500 years before the first Stone circle was erected – and that the sanctity of its location may have determined the layout of key aspects of the surrounding sacred landscape.

What’s more, the new investigation – being carried out by archaeologists from the universities’ of Birmingham, Bradford and Vienna – massively increases the evidence linking Stonehenge to pre-historic solar religious beliefs. It increases the likelihood that the site was originally and primarily associated with sun worship

The investigations have also enabled archaeologists to putatively reconstruct the detailed route of a possible religious procession or other ritual event which they suspect may have taken place annually to the north of Stonehenge.

That putative pre-historic religious ‘procession’ (or, more specifically, the evidence suggesting its route) has implications for understanding Stonehenge’s prehistoric religious function – and suggests that the significance of the site Stonehenge now occupies emerged earlier than has previously been appreciated.

The crucial new archaeological evidence was discovered during on-going survey work around Stonehenge in which archaeologists have been ‘x-raying’ the ground, using ground-penetrating radar and other geophysical investigative techniques. As the archaeological team from Birmingham and Vienna were using these high-tech systems to map the interior of a major prehistoric enclosure (the so-called ‘Cursus’) near Stonehenge, they discovered two great pits, one towards the enclosure’s eastern end, the other nearer its western end.

When they modelled the relationship between these newly-discovered Cursus pits and Stonehenge on their computer system, they realised that, viewed from the so-called ‘Heel Stone’ at Stonehenge, the pits were aligned with sunrise and sunset on the longest day of the year – the summer solstice (midsummer’s day). The chances of those two alignments being purely coincidental are extremely low.

The archaeologists then began to speculate as to what sort of ritual or ceremonial activity might have been carried out at and between the two pits. In many areas of the world, ancient religious and other ceremonies sometimes involved ceremonially processing round the perimeters of monuments. The archaeologists therefore thought it possible that the prehistoric celebrants at the Cursus might have perambulated between the two pits by processing around the perimeter of the Cursus.

Initially this was pure speculation – but then it was realized that there was, potentially a way of trying to test the idea. On midsummer’s day there are in fact three key alignments – not just sunrise and sunset, but also midday (the highest point the sun reaches in its annual cycle). For at noon the key alignment should be due south.

One way to test the ‘procession’ theory (or at least its route) was for the archaeologists to demonstrate that the midway point on that route had indeed a special relationship with Stonehenge (just as the two pits – the start and end point of the route – had). The ‘eureka moment’ came when the computer calculations revealed that the midway point (the noon point) on the route aligned directly with the centre of Stonehenge, which was precisely due south.

This realization that the sun hovering over the site of Stonehenge at its highest point in the year appears to have been of great importance to prehistoric people, is itself of potential significance. For it suggests that the site’s association with the veneration of the sun was perhaps even greater than previously realized.

But the discovery of the Cursus pits, the discovery of the solar alignments and of the putative ‘processional’ route, reveals something else as well – something that could potentially turn the accepted chronology of the Stonehenge landscape on its head.

For decades, modern archaeology has held that Stonehenge was a relative latecomer to the area – and that the other large monument in that landscape – the Cursus – pre-dated it by up to 500 years.

However, the implication of the new evidence is that, in a sense, the story may have been the other way round, i.e. that the site of Stonehenge was sacred before the Cursus was built, says Birmingham archaeologist, Dr. Henry Chapman, who has been modelling the alignments on the computerized reconstructions of the Stonehenge landscape

The argument for this is simple, yet persuasive. Because the ‘due south’ noon alignment of the ‘procession’ route’s mid-point could not occur if the Cursus itself had different dimensions, the design of that monument has to have been conceived specifically to attain that mid-point alignment with the centre of Stonehenge.

What’s more, if that is so, the Stonehenge Heel Stone location had to have been of ritual significance before the Cursus pits were dug (because their alignments are as perceived specifically from the Heel Stone).

Those two facts, when taken together, therefore imply that the site, later occupied by the stones of Stonehenge, was already sacred before construction work began on the Cursus. Unless the midday alignment is a pure coincidence (which is unlikely), it would imply that the Stonehenge site’s sacred status is at least 500 years older than previously thought – a fact which raises an intriguing possibility.

For 45 years ago, archaeologists found an 8000 BC Mesolithic (‘Middle’ Stone Age) ritual site in what is now Stonehenge’s car park. The five thousand year gap between that Mesolithic sacred site and Stonehenge itself meant that most archaeologists thought that ‘sacred’ continuity between the two was inherently unlikely. But, with the new discoveries, the time gap has potentially narrowed. Indeed, it’s not known for how long the site of Stonehenge was sacred prior to the construction of the Cursus. So, very long term traditions of geographical sanctity in relation to Britain’s and the world’s best known ancient monument, may now need to be considered.

The University of Birmingham Stonehenge area survey - the largest of its type ever carried out anywhere in the world – will take a further two years to complete, says Professor Vince Gaffney, the director the project.

Virtually every square meter in a five square mile area surrounding the world most famous pre-historic monument will be examined geophysically to a depth of up to two metres, he says.

It’s anticipated that dozens, potentially hundreds of previously unknown sites will be discovered as a result of the operation.

The ongoing discoveries in Stonehenge’s sacred prehistoric landscape – being made by Birmingham’s archaeologists and colleagues from the University of Vienna’s Ludwig Boltzmann Institute – are expected to transform scholars’ understanding of the famous monument’s origins, history and meaning.

Milford Haven -- the great bluestone hunt

2011-11-25T17:29:00.001Z

One of the interesting sections in that film (see previous posts) was to do with the great efforts made by the film's producers to find bluestones on the bed of Milord Haven, in order to validate a find made around 1970 by a diver called Pinot Antoniassi (correct spelling?). When diving in the Haven in association with a big project to deepen and widen the deepwater channel used by oil tankers, he discovered what he thought were 3 bluestones, in about 30 feet of water off Angle Bay. He assumed that these "bluestones" had slipped off a raft or other Neolithic vessel when rough water was encountered near the mouth of the Haven. The find made great headlines in the local press at the time, and perpetuated an old myth about "lost bluestones" on the bed of the Haven. Well, went the theory, for all the stones that made it following the hazardous voyage from Milford Haven, there must have been many more that were lost -- and where better to be lost than just off Angle Bay, where the swells from the open sea were first encountered by the voyagers?

For the film, a team of divers did a lot of sonar scanning work, and looked through the sedimentary records associated with the channel deepening project, before coming up with a list of 21 sites where large stones seemed to be sitting on the sea floor. They homed in on the best of these, near the edge of the deepwater channel. They dived down, found the stones, and saw immediately that they were not at all pillar-shaped, but very irregular, with jagged edges. They seem to have decided immediately that they were not "lost bluestones" at all, but probably shattered boulders of bedrock which were by-products of the blasting work in the channel. At any rate, in order to keep the interest of the viewing public alive, they took a large sample off the biggest stone and brought it ashore. Prof Bowen must have known it was local Carboniferous Limestone the moment he set eyes on it, and he could have tested it with a few drops of acid, but of course in a dramatic gesture he had to cart it all the way up onto Carn Meini, where (for the cameras) he compared it with a lump of spotted dolerite and declared it to be a red herring, or a lump of Carboniferous Limestone, or whatever -- much to the disappointment of all concerned.

So that was that. An interesting episode, but singularly unhelpful to the cause of those who believe in heroic Neolithic seamen taking 80 or more stones out of Milford Haven and across the Bristol Channel. Almost as chaotic, one might think, as the great Millennium Stone Fiasco of the year 2000, in which many enthusiastic folk (including me) tried to deliver a lump of bluestone from Mynachlogddu to Stonehenge. That one ended up on the floor of Milford Haven too........ but that's another story.

Stonehenge -- secrets of the stones

2011-11-25T15:45:00.000Z

This has recently been posted on YouTube -- but as far as I can make out, it was first shown in 1998. I'm not sure who made it, or where it was shown. It lasts for almost 50 mins, and there is a lot of interesting info in it......

By the way, there is at least one more programme with exactly the same name.

Those famous Chlorine 36 dates

2011-11-25T15:35:00.000Z

I've been looking at the film called "Stonehenge -- Secrets of the Stones." Thanks to Pete for drawing attention to it. I'll put up another post with a YouTube link on it, in case anybody is interested.

One of the interesting sequences in the film (produced in 1998) is the bit featuring Prof David Bowen, who wanders about in the monument patting sarsens and apparently thinking that they are bluestones, and then produces two lumps of stone which he wants to date, using the chlorine 36 technique. He says that the stones have come from the 1958 dig -- so presumably they have come from the collections made in the Richard Atkinson excavations of that year. God only knows where they came from on the site, and what their history might be. That would be quite enough to put most people off, but not Prof DB.

Look at the stones in these pics. The smaller one is obviously a piece of spotted dolerite -- but what is the other one? Looks like a bit of Chilmark stone to me -- please correct me if I'm wrong. Could it be a piece of volcanic ash? Or a piece of rhyolite? Anyway, we don't hear anything more about the big lump on the TV programme -- but the smaller one ended up being crushed to a powder in the USA (at Purdue University) and subjected to Chlorine 36 dating. The date apparently came out as showing that the stone was first exposed to the atmosphere around 40,000 years ago. On that basis the good Professor says -- on the film -- that "there is no way that this rock could have been transported by glacier ice from Preseli to Stonehenge." He says that the last ice sheet that might have affected this area was in existence about 650,000 years ago -- goodness knows where he got that date from........

This finding was widely purported in the media to demonstrate conclusively that glaciation could not have moved the bluestones to Stonehenge. of course, it does nothing of the sort. It does not even support the human transport theory.

Prof Bowen's dating exercise -- also involving other dates, with two from Carn Meini, has been heavily criticised by other geologists. It is in my view entirely useless -- we do not know where the sample came from either at Stonehenge or at the place of its origin. fUnless you know precisely where a sample came has come from, ie what its exposure to cosmic radiation and weathering might have been over many thousands of years, you can say NOTHING reliable or scientific about the age of the stone surface you are purportedly dating. And to say anything sensible, you need at least two different dating techniques, based on the characteristics of the rock.

This was pointed out by Olwen Williams-Thorpe and others some years ago. I'm a bit confused, because there is another date (for the big sample in the picture?) that was published in 1994 --- around 14,000 years BP. Other dates for rock surfaces at Carn Meini were 5,400 BP and 4,900 BP. Which rock surfaces? Chosen because they looked fresh, or because they looked old? facing east or west? On top of a cliff or in the shadow of a cliff? We have no idea................

PLEASE will somebody do some sensible cosmogenic dating one day, to help us to understand what has gone on at Stonehenge?

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Antiquity, Volume: 69 Number: 266 Page: 1019–1020

Chlorine-36 dating and the bluestones of Stonehenge

Olwen Williams-Thorpe, D. Graham Jenkins, Judith Jenkins and John S. Watson

http://findarticles.com/p/articles/mi_hb3284/is_n266_v69/ai_n28663881/

Chlorine-36 dating and the bluestones of Stonehenge

by Olwen Williams-Thorpe, D. Graham Jenkins, Judith Jenkins, John S. Watson

Chlorine-36 dating has important potential for archaeology, but recent Chlorine-36 dates on `bluestones' of Stonehenge have been misinterpreted. Professor D.Q. Bowen of the University of Wales, Cardiff and colleagues have dated a fragment of igneous rock reported as having been found at Stonehenge (exact type unknown, but not a spotted dolerite) at 14,000[ or -]1900 years, and surfaces of outcrops at Carn Menyn in Preseli at 5400[ or -]400 and 4900[ or -]400 years (Bowen et al. 1994; Bowen 1994: 211). This information has been interpreted as indicating that the bluestones of Stonehenge could not have been transported to the site of Stonehenge by ice, because the ice sheets were extensive enough only at c. 400,000 years or earlier, when the fragment and outcrop were apparently still buried or covered, and not exposed for ice transport (Bowen 1994: 211; Hawkes 1994; British Archaeology News 1995).
Chlorine-36 dating gives an estimate of the length of time that a rock surface has been exposed to the atmosphere, by measuring the amount of Chlorine-36 produced by exposure of the rock to cosmic radiation. If the rock or surface has been covered or buried, the date obtained will reflect the reduced time of exposure to air. Thus a Chlorine-36 date may reflect either recent exposure of a surface due to processes such as frost shattering, or an original exposure date. This difficulty of interpretation is why Chlorine-36 dating is normally done on boulders or lava surfaces whose erosional history is known (e.g. Phillips et al. 1991).
Professor Bowen and colleagues have obtained a date of c. 14,000 years exposure time for the fragment from Stonehenge. However, it is not possible to tell if this is an original exposure date, or if the fragment was brought to Salisbury Plain by ice 400,000 years ago or earlier, and was subsequently buried within superficial deposits on Salisbury Plain for part of its history. Or it could have been broken off a larger erratic lying on Salisbury Plain, by natural processes such as frost shattering. The rock type of this fragment is unknown, and the sample now completely destroyed (Professor D.Q. Bowen, in discussion at the meeting of the Lithic Studies Group, Cardiff, 28 January 1995), so it may be nothing to do with the bluestone monoliths.
Carn Menyn loses material from outcrop surfaces every year through frost shattering. This will reduce the date obtained on an outcrop. A date of 5000 years could represent a preserved quarried surface (in which case it might be expected to show quarry marks), or it could be a frost-shattered surface. Even if it is a quarried surface, its relevance to Stonehenge is questionable, because the bluestones were erected there about 4000 years ago.
Thus, even if it is considered that the bluestones were moved by human transport, the Chlorine-36 dates do not tell us at what era that movement might have taken place.
The article in British Archaeology suggests that dating a monolith surface of a bluestone at Stonehenge will resolve the problem. Unfortunately, it will not. At least some of the bluestones were dressed and the argument continues about which, and how many were altered in this way. Some have also been damaged by tourists. A dressed or damaged bluestone will give a Chlorine-36 date reflecting total exposure time - for example, about 4000 years if it is dressed but not subsequently damaged. A variety of older dates could be obtained, depending on whether the bluestone was removed from Wales by a glacier as an erratic, buried for part or all of its glacial transport, or broken up by erosional processes in post-glacial times.
We welcome further evidence in the Stonehenge debate, but are concerned about misinterpretations. Chlorine-36 dating might help the debate by obtaining large numbers of dates on Preseli outcrops (to give a mean date of oldest exposed surfaces). Dates on monoliths at Stonehenge could be useful if obtained for undressed and undamaged surfaces, but even these would be subject to interpretation. In the meantime, Chlorine-36 dates give no evidence either for or against glacial transport of the bluestones of Stonehenge.

References

Bowen D.Q. 1994. Late Cenozoic Wales and south-west England, Proceedings of the Ussher Society 8: 209-13.
Bowen, D.Q., F.M. Phillips & D. Elmore 1994. Chlorine-36 dating British ice-sheets, Abstracts of the American Geophysics Union, 1994 Fall Meeting: 226. British Archaeology. 1995.
Dating gives clue to Stonehenge riddle, British Archaeology 1 (February).
Hawkes, N. 1994. Stonehenge dating dispels icesheet theory, The Times: 5 December 1994.
Phillips, F.M., M.G. Zreda, S.S. Smith, D. Elmore, P.W. Kubik, R.I. DORN & D.J. Roddy. 1991. Age and geomorphic history of Meteor Crater, Arizona, from cosmogenic [Cl.sup.36] and [C.sup.14] in rock varnish, Geochimica et Cosmochimica Acta 55: 2695-8.

The Bluestone Transport Myth -- how it all began

2011-11-25T10:21:00.002Z

Yesterday I gave a talk in Cardigan (about my novels, not about Stonehenge) and a gentleman came up to me and gave me a copy of a translation from an article written (in Welsh) by Prof OT Jones in 1966. He thought I might be interested in it -- too right!! I had never seen it before, and indeed I had no idea that the article existed.

The article is reproduced above -- click to enlarge.

Jones was one of the team which was doing the original geological survey of Pembrokeshire in the years before the First World War, and in this article he describes a trip by Thomas, Cantrill, Dixon, Jones and Evans to the Preseli Hills in 1908. The geologists were involved in an erratic hunt, trying to track down the source of the spotted dolerites which they had found scattered across the countryside in SE Pembs and Carmarthenshire. The found the source area around Carn Meini, and Jones describes "thousands of blocks lying loose on the ground and extending along the hilltops towards the road to Maenclochog." Note this statement: "..... there was no argument that it was from this spot (Carn Meini) that the stone had been carried by ice towards the southern part of the county." Note too that this was strictly a geological expedition -- there is no mention anywhere of archaeology or indeed of any use of the stones in prehistoric structures.

Jones describes how HHT later received a "parcel... containing a large number of specimens" of rock with a request that the source area might be found. These specimens had been collected at Stonehenge -- and neither HHT nor OTJ was in any doubt that they matched the spotted dolerites they had seen at Carn Meini some years earlier. Thomas visited Stonehenge and looked at the bluestone monoliths, and although he was convinced that the majority had come from Carn Meini he spent 3 years checking to see if there might be other source areas in Ireland, Wales, England or Brittany. He didn't find any, but he did satisfy himself that the rhyolites at Stonehenge had come from Carn Alw -- and that association of the two rock types both at Stonehenge and on the Preseli Hills convinced him of the "match" between source area and final resting place. "This settled the matter absolutely" wrote Jones -- of course, as we now know, it did nothing of the sort, but this was after all a long time ago. He was also convinced by HHT's identification of the Altar Stone as coming from the Cosheston Sandstone beds on the shores of the Daugleddau (the inner reaches of Milford Haven.)

What interests me about this historic document is that HHT and OTJ and the other geologists at the time saw no archaeological significance in any of the work they were doing -- and that there was no question in their minds but that large numbers of spotted dolerite boulders and slabs had been picked up by glacier ice and carried southwards and eastwards. We still don't know why, or when, HHT moved from that relatively simple position to propose that the stones "could not possibly" have been moved by ice over a distance of 200 km or so, from their source area to Salisbury Plain...............

Altar Stone location

2011-11-21T19:00:00.000Z

For those who are not familiar with the plan of Stonehenge, the Altar Stone is the flattish standing stone at the focal point of the bluestone horseshoe -- number 80 on the plan, and nestling beneath the tallest trilithon on the artists recreation.

I'm not saying I accept any of this -- but that is the EH version..........

The Altar Stone - where the glacier left it?

2011-11-21T10:32:00.001Z

Desperate Dan wanted a nice colour pic of the Altar Stone -- and thanks to the wonders of modern technology, here we are:

Many thanks to Rob Ixer for this -- that's him pointing to the stone. Note that the stones here are in exactly the same positions as they were in 1867 -- in spite of all of the reconstructions, excavations and stone stabilisations that have occurred over the years -- and especially in 1958.

The Altar Stone is such a strange shape, and is so solidly embedded into the ground, that one wonders whether it ever has been moved from anywhere else. Now here's an idea -- could it be that the only stone at Stonehenge which is in its original position (ie after dumping by the glacier) is the Altar Stone? And could it be that this stone was invested with such significance (because it was strange) that it became the focal point for the erection of the succession of stone settings which we now know as Stonehenge?

Another picture of the Altar Stone -- not sure where I found it! But it shows up well here.

Stonehenge Thoughts

Bluestone haulage for wimps

Where is Rhosyfelin?

Unfinished projects

OK -- I eat my words.....

The Bluestone Argonauts -- did they sail or paddle?

That multi-million project...... whatever happened?

Preseli in the conflict zone

Another Preseli Ice Cap Image

Devensian Sea Level

Ice over All

On Glacial Cycles

The Preseli Ice Cap

Those periglacial stripes are probably not periglacial

EH updates on Stonehenge bluestones

When did Craig Rhosyfelin come into existence?

A Whin Sill erratic cluster in the Stevenage area?

Abstract

On Faceted Stones in Nature

The Age of the Landscape

Worked rocks -- what do they look like?

100,000 hits

Viewing this blog

In case you missed it......

Richard Bevins to talk at Aberystwyth

Ice streams

More geology on the way......

Abstract

On the nature of evidence

Rob's Podcast

That 99% -- the National Museum Press release

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News 19 December 2011

New geological discovery paves the way for further insight into the transport of Stonehenge rocks

http://www.museumwales.ac.uk/en/5/?article_id=728

Rope technology

The Bluestones of Stonehenge -- a glacial erratic assemblage

The Mythology of Old Keig

Recumbent stone circles

Another bluestone experiment

The Times revisits the bluestone issue

This nonsense is official -- so it must be true.....

By Culture24 Reporter | 04 January 2012

Stonehenge and the importance of heroic failures

On technological development

Stonehenge -- a breeding ground for pseudoarchaeology?

I was rambling about, looking something else up, when I was taken to this page on Wikipedia:http://en.wikipedia.org/wiki/Pseudoarchaeology

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See also my previous post from 2010, which attracted no comments at the time!

http://brian-mountainman.blogspot.com/2010/09/pseudoarchaeology-at-stonehenge.html

Salon Report on Rhosyfelin paper

Happy New Year!

Phil's Contraption

Those "periglacial stripes"

The Stonehenge Cave

The Silbury Hill bluestones (again)

The Cursus Great Pits

In praise of "Geology Viewer"

On the significance -- or otherwise -- of >99.9%

Bedd Arthur

Things are not always what they seem...

The granite obelisk

The National Geographic gets it more or less right...

Apart from the inevitable over-simplification here and there, we can live with this.

Ancient bluestones match outcrop near Wales sheep farm, experts say.

Is the Glacial Theory now frozen out?

Craig Rhosyfelin sampling points

In praise of "Where's the Path"

The Daily Mail bluestone punt

More Media Madness ... modified

Happy Christmas!

Impossible? Apparently not..... (modified)

Now the Daily Mail joins the fun.....

Stonehenge riddle unravels: Geologists pinpoint exact Welsh outcrop where 'Bluestones' came from

Indy report on foliated rhyolite research

Where are the geomorphologists?

The provenancing of raw materials

Does Stonehenge really make all men mad?

The Times pronounces on the bluestones

The Times wants to charge me for seeing the article in full, and I am disinclined to pay. If anybody has seen it, I'll be very interested to hear more....

I was rambling about, looking something else up, when I was taken to this page on Wikipedia:
http://en.wikipedia.org/wiki/Pseudoarchaeology