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Monday, 23 December 2013

Chips off the old block


The main sites referred to in the latest paper -- mostly debitage sites

"Chips off the old block: the Stonehenge debitage Dilemma", by Rob Ixer and Richard Bevins, Archaeology in Wales 52 (2013), pp 11-22
https://www.academia.edu/5464937/Chips_off_the_old_block_The_debitage_Dilemma

Another new paper from the "provenance hunters" Rob Ixer and Richard Bevins -- this time published in "Archaeology in Wales". To quote the authors at the outset:

Within this century there has been a renewed interest in the lithology of the Stonehenge bluestones, both for the standing orthostats and also for the vast numbers of broken bluestone material, now referred to as debitage. Increasingly it has been recognised that there are a number of interesting problems associated with this debitage found within the ‘Stonehenge Landscape’, most notably their original geographical provenance, their internal Stonehenge provenance (matching debitage to parent orthostat), the reason for their presence and finally explanations for the apparent mismatch between the lithologies of the (above-ground) bluestone orthostats and the debitage both in terms of type and numbers. A fundamental initial step in answering most of these questions is to try to match debitage fragments from well constrained contexts to their parent orthostat.

So the debitage (c 4000 rock fragments and c 100 thin sections examined) is the focus here.

The authors also state, with respect to origins:

In relation to the explanation for the debitage, amongst the main anthropogenic contenders are the following: (a) that it is wastage from the dressing of the orthostats, (b) that it is true debitage associated with the later reuse of the orthostats as ‘quarries’ for axe manufacture, (c) that it is made up of ‘knock-offs’ from later souvenir hunters or amulet collectors. The favoured non-anthropogenic explanation is that some of it comes from (glacial) erratic background material, some of which was not incorporated into the Stonehenge stone settings (John, 2008). Of course, it is quite possible that all of these explanations are partly correct; they are not mutually exclusive.

With resepect to the main Stonehenge bluestone lithologies, they say:

The main bluestone orthostat lithologies are either spotted or non-spotted dolerite (the authors suggest 3 groups -- BJ) but within the outer bluestone circle there are 12 non-dolerite bluestones (used here in the sense of any non-sarsen, proven or potential, Stonehenge orthostat material), including both standing orthostats (SH38, 40, 46 and 48) and buried stumps (32c, 32e, 33e, 33f, 40c, 40g, 41d, 42c) (Atkinson, 1979). Of these, 32e is described as a rhyolite, 40c as a calcareous ash, 40g and 42c as micaceous sandstones and 32c, 33e, 33f and 41d as altered, dark olive-green ash (Atkinson, 1979; Thorpe et al 1991). In addition the Altar Stone is a calcareous sandstone of probable Devonian age and unlike any other lithic from Stonehenge (Ixer and Turner, 2006). 

The bluestone debitage comprises spotted and non-spotted dolerite, a restricted set of rhyolite and rhyolitic tuffs, informally known as ‘rhyolite with fabric’ and more formally as Rhyolite Groups A –E (Ixer and Bevins, 2011b), a variety of argillaceous and calcareous tuffs (informally known as ‘volcanics with sub-planar texture’), and a numerically far smaller group of sandstones including (Lower) ‘Palaeozoic sandstone’ and ‘micaceous sandstone’. Other non-bluestone lithologies are very rare and mainly restricted to disturbed or modern contexts and are not discussed further. 

The authors are circumspect, but from previous work there appear to be at least 15 different lithologies in the frame.  There appear to be nine different rhyolites -- represented in the orthostats and in the debitage.  The Altar Stone (Devonian sandstone) is unique among the orthostats, and there are just 3 debitage fragments that appear to match it.  All the other sandstone debitage fragments are from other sandstones -- probably Lower Palaeozoic, and possibly from North Pembrokeshire........

Rhyolite orthostats 38, 40 and 46 appear to be different, and unusual in that there appears to be no debitage related to them.  Orthostat 48 (made of Group E rhyolite) does have some debitage related to it.  There are abundant fragments of debitage in Rhyolite Groups A-C -- assumed to have come from Craig Rhosyfelin, but as yet no related orthostat has been found.  The authors speculate in this paper, not for the first time, that there may be a match either in stump 32d or 32e.

The conclusion of the paper is as follows:

Although the evidence is very incomplete the hypothesis is, that, for the non-dolerite bluestones, above-ground orthostats have no debitage and so have suffered little systematic removal of material, (the recent observation by Abbott and Anderson-Whymark (2012, 25) that the bluestone circle bluestones are largely undressed partially supports this suggestion) whereas the most abundant classes of debitage belong to (now buried) ‘slighted’ orthostats and are the result of a purposeful destruction possibly by those with an axe to grind. But here is the rub; most of the ‘slighted’ orthostats comprise ashes, tuffs (‘volcanics with sub-planar texture’) and sandstones, ‘soft’ lithologies that would be difficult to work into tools. These proposals can, should and will be further tested.

As for the future, the authors say:

Sampling that would provide longer term provenancing data should begin with buried orthostats SH40g and SH42c, noted by Atkinson as micaceous sandstone. This would allow comparison of these two orthostats with the Altar Stone and with the (Lower) ‘Palaeozoic sandstone’ debitage to determine if either is the parent for any of the sandstone debitage. This should then be followed by sampling buried orthostats 32c, 33e, 33f and 41d, noted by Atkinson as altered, dark olive-green ash. This would allow comparison of these with two or more classes of ‘volcanic with sub-planar texture’ debitage, again to establish any relationship. Finally, sampling the remaining standing and buried dolerite orthostats would allow for new petrographical and geochemical analyses to complement the on-going programme of sampling in situ Preseli sources.

All in all, another interesting piece of work, confirming the very large number of lithologies represented among the bluestone orthostats and the bluestone debitage, and confirming the point that much of the debitage has not apparently come from the dressing of stones still present in the bluestone settings.  Quite reasonably, the authors therefore suggest that many stones might have been completely smashed up, and that the debitage comes largely from those.  I would have liked more discussion of non-anthropogenic origins for the debitage -- maybe we would have had it if the paper had been submitted to a geological journal instead of an archaeological one.  From where I stand, I still see an assemblage of erratic materials that have come largely from West wales.  I also see considerable areas of the Stonehenge landscape that have not yet been excavated -- and I assume that new and undiscovered rock types may well be represented in these areas.  The number of lithologies represented in the Stonehenge landscape seems to be going up all the time, and there is a lot of provenancing still to be done.  And EH must get up off its backside and accept that if some of the major problems surrounding the bluestones ever are going to be answered, there MUST be a proper sampling programme on the bluestone orthostats themselves.  ALL OF THEM!

Saturday, 21 December 2013

MPP's lunchtime lecture


This is one of the slides Prof MPP used in his lecture.  He claimed that the provenance of one of the rhyolite monoliths at Stonehenge had been fixed to an accuracy of 1 m by Richard Bevins and Rob Ixer, and he claimed that the white dot on the photo shows a recess from which the stone came.  Well, I see a fissure, that's for sure -- but I am afraid I see no recess from which a 2-tonne or 4-tonne monolith might have been taken.  Neither do I accept, from the evidence presented, that the foliated rhyolite fragments in the debitage at Stonehenge have been provenanced with that level of accuracy.

Prof MPP's lunchtime lecture at UCL was put onto YouTube on 10th December.  Here is the link:

Unravelling the mysteries of Stonehenge 

http://www.youtube.com/watch?v=81owUAZJ4Qk

All credit to him for covering a lot of territory in about 30 mins.  Not a lot in the talk that was new -- and MPP employed his usual technique of making it appear that all sorts of things are self-evident when in reality they are highly contentious.  Thus it was presented as self-evident that Stonehenge was a "place for the ancestors"; that Durrington Walls contained the settlement camp for the builders of Stonehenge; that the bluestones were in the Aubrey Holes before they were taken and used in other settings; that the so-called "periglacial fissures" determined the alignment of the Avenue and the precise positioning of the stone monument; that Neolithic monuments were preferentially built in concordance with natural features or astronomical alignments;  that if there was a religion in the Neolithic it was a "religion of place"; that Craig Rhosyfelin was the site of a Neolithic bluestone quarry; and that the catchment of the River Nevern was so special that it encouraged the collecting of monoliths for the building of a revered stone circle at Castell Mawr which was then transported lock stock and barrel to Stonehenge shortly after 5,000 years ago.  All of those things are worthy of debate -- but MPP is a man who likes to decide what his story is on the basis of very thin evidence indeed.

That all having been said, there were a few interesting snippets in the talk:

1.   A very comprehensive set of data from the teeth and bones of animals in the Durrington Walls "barbeque middens" (more than 70 samples) suggests that the animals (mostly cattle and pigs) came from all over the UK -- including Scotland, Cornwall and the Midlands -- but not from Pembrokeshire.  Prof MPP made one rather spurious connection between one pig tooth and South Wales generally, but that was not convincing.  One does need to ask why, if Pembrokeshire was so special that people carted 82 bluestones from there to Stonehenge, there are apparently no animal remains that have come from the same area as the stones?  After all, by this theory hundreds if not thousands of men must have made the journey with the precious stones -- if people travelled with their animals from everywhere else, why did the Pembrokeshire travellers not do the same?

2.  The organic samples from Craig Rhosyfelin which are going to be used for radiocarbon dating were sent off to the laboratory on the very day of the lunchtime lecture.  So they will be available in 2014.  They may tell us if and when there might have been human activity at Rhosyfelin -- but whether they tell us anything about "quarrying activities" is another matter entirely.  Human occupation of the site does not indicate that there was any quarrying going on; in my view it is much more likely that this sheltered location was a favoured camping / hunting site, maybe over many centuries.

3.  It is now apparent, according to the good Prof, that the bluestones were not dragged or rolled or trundled, or even taken by boat, from Castell Mawr to Stonehenge.  They were CARRIED by large groups of men using long poles on either side and a sort of sling holding the stone in the centre.  In answer to a question, MPP said that 50 men -- 25 on each side -- could easily carry a monolith weighing 2 tonnes across country, on the land route that he now favours.  If you have enough replacement gangs to take over when one group tires, there is logistically no problem.  That is apparently all perfectly fine in India, and therefore it is fine in Neolithic Britain as well.

So there we are then.


Thursday, 19 December 2013

Mysterious new bluestone site

There is an interesting brief report on Tim Daw's site (thanks, Tim!) about a new site "close to Stonehenge" where spotted dolerite fragments have been found in surface spoil from rabbit burrows.  Here is Tim's note and a link to a photo of what he has found:
 
http://www.sarsen.org/2013/12/bluestone-chips-paper-by-ixer-and.html

"I discovered this surface scatter in the spoil from animal burrows, the black round object is from a rabbit, last summer.  Over two hundred chips have been seen so far on the surface. It is close to Stonehenge, in the landscape but not within the Stonehenge Triangle. I have of course informed the archaeologists at Stonehenge, and can't tell anyone else the location. Sorry."

We await further info when Tim is ready to give it to us.  In the meantime, this is a bit more evidence that there may be quite widespread "bluestone debitage" across the Stonehenge landscape -- and it's worth recalling that there are thousands of acres of terrain that have never been properly investigated for "extraneous" or erratic stones that have arrived, somehow, from somewhere else.

Tuesday, 17 December 2013

Miniature bluestone trilithons?

Thanks to Mike Pitts for a fascinating preview of some of the displays to be revealed to the world when the new Stonehenge Visitor centre opens tomorrow.  More photos on Mike's blog:

http://mikepitts.wordpress.com/2013/12/17/the-new-stonehenge-centre/

One thing that caught my eye -- a recreation of one of the early bluestone settings, with a miniature bluestone trilithon in the middle of the picture.  I have often wondered whether some bluestones might have been used as lintels, either supported by other bluestones or as lintels perched on top of the sarsens.  It's good to see that some variations in traditional thinking are beginning to appear.......  the old order breaking down?

Monday, 16 December 2013

Search problems

Some followers of this blog might have noticed that there are major problems worldwide just now with the Blogger search box.  Since Google took over Blogger something strange has happened.  Many blogger users have found that their searches don't work at all.  I have tried to install a "workaround" -- but it's not very satisfactory.  When I try to use it myself, it just provides an endless syream of complete blog entries, rather than a list of the blog titles -- which is what it did rather well in the past.

Please be patient -- a lot of bloggers are hassling Blogger -- and I hope they will get the problem fixed before too long.......

Monday, 9 December 2013

Bancywarren geology lesson


How about this for a geology lesson?  Faulted fluvioglacial sands and gravels at Bancywarren, north of Cardigan.  These sands and gravels were emplaced during a Devensian ice ADVANCE -- that's a bit counter-intuitive, since big fluvioglacial sequences are normally laid down during ice wastage phases.

The faults are so sharp here that the mass of sand and gravel must have been frozen by permafrost when the faulting took place.  The structures here are very different from those formed by settling / compaction / loading when the mass of fluvioglacial material is in a semi-liquefied state.  So what we have here is an example of a frozen body of sediment which has been subjected to pressure either from the side (eg by an advancing ice front) or by a great weight of ice or other sediments exerting pressure from above.


Thursday, 5 December 2013

New two-part TV blockbuster planned for Stonehenge



Oh dear -- I get a sinking feeling...... I wonder who they are talking about here:  "October has gained exclusive access to an international team of scientists conducting an archaeological project at Stonehenge......." ??

BBC, CBC unite for “Stonehenge” co-pro  

Adam Benzine

http://realscreen.com/2013/12/04/wcsfp-13-bbc-cbc-unite-for-stonehenge-copro/

BBC2, France 5, the CBC, Smithsonian Channel, Australia’s ORF and ZDF Germany are among the broadcasters uniting for Stonehenge Empire, a two-part doc looking at Britain’s ancient Stonehenge site.

The 2 x 60-minute production is being made by UK indie October Films with Canada’s Lightship Entertainment and Austria’s Interspot Film.

October has gained exclusive access to an international team of scientists conducting an archaeological project at Stonehenge, and the two-parter will combine new archaeological evidence from the international survey, drama reconstructions and CGI, to produce “the most complete and interconnected picture of the how the whole site looked in its heyday; revealing Stonehenge to be a Neolithic Valley of the Kings,” the indie promises.

The partners unveiled the project at the World Congress of Science and Factual Producers in Montreal today (December 4). It is being executive produced by Adam Bullmore, Terence McKeown and Heinrich Mayer-Moroni.

The series was commissioned by Martin Davidson for BBC2; Sue Dando for CBC; Chris Hoelzl for Smithsonian Channel in the U.S., Perrine Poubeau for France 5; Andrew Solomon for ORF Austria; and Georg Graffe for ZDF Germany. The coproduction was set up by Lilla Hurst at Drive.

In a statement, October creative director Adam Bullmore said: “Stonehenge Empire will dramatically change the way we understand Stonehenge and the prehistoric culture that flourished around it.

“Instead of seeing Stonehenge as an extraordinary achievement of an otherwise relatively primitive, prehistoric people, it will reveal Stonehenge as the epicenter of a truly remarkable and highly sophisticated ancient civilization.”

Davidson, the BBC’s commissioning editor for history and business programming, added: “This is a really exciting project which will, using drama, CGI and the latest archaeological discoveries, allow us to properly understand the achievements and character of the people that built it; people who mastered deep mining, sophisticated engineering, textile manufacturing, ship-building, ‘micro’ gold-working, metallurgy, glass making, overseas trade and complex astronomy and mathematics.”

Read more: http://realscreen.com/2013/12/04/wcsfp-13-bbc-cbc-unite-for-stonehenge-copro/#ixzz2mcasvXRF

Tuesday, 3 December 2013

The Sheyenne ice disk -- an amazing wonder!!


A little video has been getting huge numbers of hits on assorted news sites -- showing a slowly rotating disk of ice fragments on the Sheyenne River in North Dakota, USA.    As the enthusiastic reporter keeps on telling us -- it is "an amazing wonder" --or, if you prefer it,  "a wondrous amazement" ...........

It is certainly very strange -- I've never seen anything like it before.  Apparently it's not very big -- just about 50 ft across.  And it rotates very slowly in an anti-clockwise direction.  It's not made of solid ice at all -- it's just an aggregation of small ice fragments which appear to have become trapped in a rotating eddy in the river during very cold freezing conditions.  There are even growth rings on it -- you can see these if you look closely.  Apparently if you throw a stone into the ice disk it just goes straight through and splashes into the water beneath.

Very ephemeral and very freaky.  Not sure how long it lasted.  It's probably gone by now......

Monday, 2 December 2013

Force of circumstances

 

Stonehenge, Pembrokeshire and the Ice Age


Sorry folks, but I'm feeling very groggy at the moment, with one of those nasty flu bugs.  High temperatures, splitting headache and persistent cough --  grrr.

I had two Stonehenge lectures planned -- one for tomorrow (3rd Dec) in Moylgrove Village Hall, and the other for Thursday (5th Dec) in Carmarthen.  I had hoped that things would ease off, but this wretched bug is very persistent, and there is sadly no prospect of me being able to stand up in front of an audience and talking -- rather than coughing -- for an hour or so.  So my wife tells me I am going nowhere for the rest of this week -- and I have to obey orders.....

I hope to be able to rearrange both talks for the coming months.  Watch this space.........

Ding Dong Dolerite.........

The acoustic experiment under way, with all seriousness, at Stonehenge.  Photo -- George Nash.

Amazing revelations from the Daily Mail -- that igneous rocks make a ringing sound when you hit them with a hammer.................... er, no further comment required.  Even Tim Darvill, when plonked in front of a vide camera and asked to make a comment, found it difficult to keep a straight face.  And in case you wondered, no, it isn't April 1st today............
------------------------------

Stonehenge 'was a prehistoric centre for rock music': Stones sound like bells, drums, and gongs when played


    • Rocks make metallic and wooden sounds, in many different notes
    • Monoliths were moved by Stone Age man from Wales to Stonehenge
    • Researchers believe their musical make-up could be why they were moved

By Sarah Griffiths and Amanda Williams

Stonehenge may have been built by Stone Age man as a prehistoric centre for rock music, a new study has claimed.

According to experts from London's Royal College of Art, some of the stones sound like bells, drums, and gongs when they are 'played' - or hit with hammers.

Archaeologists, who have pondered why stone age man transported Bluestones 200 miles from Mynydd Y Preseli in Pembrokshire, South West Wales to Stonehenge, believe this discovery could hold the key.

The 'sonic rocks' could have been specifically picked because of their 'acoustic energy' which means they can make a variety of noises ranging from metallic to wooden sounding, in a number of notes.

Research published today in the Journal of Time & Mind reveals the surprising new role for the Preseli Bluestones which make up the famous monument, and which were sourced from the Pembrokeshire landscape on and around the Carn Menyn ridge, on Mynydd Preseli, South-West Wales.

Bluestones were used in the village of Maenclochog - meaning bell or ringing stones - until the 18th century.

English Heritage allowed archaeologists from Bournemouth and Bristol universities to acoustically test the bluestones at Stonehenge, effectively playing them like a huge xylophone

A significant percentage of the rocks on Carn Menyn produce metallic sounds - like bells, gongs or tin drums - when struck with small hammerstones. Such  sonic or musical rocks are referred to as 'ringing rocks' or 'lithophones'.

The Landscape & Perception project drew upon the comments of the early 'rock gong' pioneer, Bernard Fagg, a one-time curator of the Pitt Rivers Museum, in Oxford.

He suspected there were ringing rocks on or around Preseli and suggested that this was the reason why so many Neolithic monuments exist in the region – with the sounds making the landscape sacred to Stone Age people.

Stonehenge may have been the built by stone age man as a prehistoric centre for rock music, a new study has claimed

English Heritage allowed archaeologists from Bournemouth and Bristol universities to acoustically  test the bluestones at Stonehenge, effectively playing them like a huge xylophone.

To the researchers’ surprise, several were found to make distinctive if muted sounds, with several of the rocks showing evidence of having already been struck.

The stones make different pitched noises in different places and different stones make different noises - ranging from a metallic to a wooden sound.

The investigators believe that this could have been the prime reason behind the otherwise inexplicable transport of these stones nearly 200 miles from Preseli to Salisbury Plain.

There were plentiful local rocks from which Stonehenge could have been built, yet the bluestones were considered special.

The principal investigators for the Landscape & Perception project are Jon Wozencroft and Paul Devereux. Wozencroft is a senior lecturer at the RCA and the founding director of the musical publishing company, Touch.

Jon Wozencroft told MailOnline it was 'amazing' to find that the stones used in the monument make the noises that the researchers hoped for.

'It was a really magical discovery and refreshing to come across a phenomenon you can't explain,' he said.

The researchers have looked into geological reasons as to why some rocks make noise and others do not and one theory is that the amount of silica in the rocks could explain why in the future.

'Walking around Mynydd Y Presel you can't tell which stones will make sounds by sight, but in time you get a sort of intuition by the way they are positioned,' he said.

The researchers had feared the musical magic of the stones at Stonehenge might have been damaged as some of them were set in concrete in the 1950s to try and preserve the monument and  the embedding of the stones damages the reverberation.

Mr Wozencroft said 'you don't get the acoustic bounce' but when he struck the stones gently in the experiment, they did resonate, although some of the sonic potential has been suffocated.

In Wales, where the stones are not embedded or glued in place, he said noises made by the stones when struck can be heard half a mile away.

He theorised that stone age people living in Wales might have used the rocks to communicate with each other over long distances as there are marks on the stones where they have been struck an incredibly long time ago.


Read more: http://www.dailymail.co.uk/sciencetech/article-2515159/Why-Stonehenge-prehistoric-centre-rock-music-Stones-sound-like-bells-drums-gongs-played.html#ixzz2mJb2EmNQ