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

Sunday, 31 March 2013

Those "periglacial" stripes -- solutional rills?


This is a still from the recent TV film which we have already discussed at length.  It's a somewhat fanciful artistic representation of the two famous "periglacial stripes" which, according to MPP,  led Stonehenge to be created here rather than somewhere else.  the trouble is that there are not just two of them.  Photos show that there are scores of them, quite close together, meandering slightly and with ridge crests often about 50cm above the trough bottoms. 

I have already shown this map of the contours around Stonehenge:


Unfortunately, it doesn't show the detailed contours (25 cm interval) for the key part of the Avenue, so all we have to go on are the comments from Charly and Mike that the "grooves" or stripes do not run directly downslope, but DIAGONALLY.  This seems to be confirmed on this LIDAR image which I recently came across, in the Field and Pearson Stonehenge Report from 2011.


If you look very carefully at the "grain" showing up on the image (click to enlarge) you'll see that the Avenue is aligned a few degrees away from the direct downslope orientation.

One would need to examine these troughs and ridges quite carefully to try and work out their origins (Simply to call them "periglacial stripes" is highly misleading, since it tells us nothing about the actual PROCESSES involved.)

My money is still on these stripes, which may cover a large part of the landscape beneath the regolith or soil layer, being solutional rills which owe their orientations partly to some structural control in the chalk bedrock.  It may be that the presence of a permafrost table might have played a part in this, by preventing the downward passage of surface water and concentrating flow close to the ground surface but maybe within the soil layer.  Much more work to be done -- but please can it be done by a geomorphologist rather than an archaeologist?

Source of image:

Research Report Series 105-2011
STONEHENGE WORLD HERITAGE SITE
LANDSCAPE PROJECT
STONEHENGE DOWN AND THE TRIANGLE
ARCHAEOLOGICAL SURVEY REPORT
David Field and Trevor Pearson



Ice Requiem

Here is my latest blockbuster -- wonderful images and a serious message.

Enjoy!!

Ice caves

Three more stunning images of the interior of ice caves.  The top one is of a meltwater tunnel on Skaftafjell, Iceland.  Not sure where the others are from.....  Acknowledgement to Robbie Shone for the middle photo.

For no other reason than that these images are fantastic!

Saturday, 30 March 2013

More on bluestone shapes

Rodney Castleden's Stonehenge Plan -- showing an accurately measured arrangement of stones before lots of them went missing, started falling over and getting in the way.    The black symbols show stones still in place.  White symbols show stones fallen or missing.  Note that neither of the circles is perfect, and the same is true of the horseshoes.  Castleden thinks that the surveying and setting of the stones at Stonehenge was all somewhat approximate.  He thinks that mathematical accuracy was neither desired nor achieved, with some stones almost a metre away from their "perfect" positions.

Rodney Castleden's "panorama view" from the centre of the monument, looking along the MSSR line and taking in a span of 180 degrees.  The trilithons to right and left are the end trilithons of the sarsen horseshoe.  Note the "scruffy assortment" of bluestones visible here in the bluestone circle -- but note that only 4 of them are standing today.  The other shapes are assumed.

Anthony Johnson's reconstructions also show the use of random stones of various lithologies, shapes and sizes in the bluestone circle.  he says:  "... we find, especially in the circle, stones of all shapes and sizes used in seemingly random way, almost a "garden ornament" phase........ the idea that something meaningful or precise can be read from the plan of this disparate collection of reused stones is untenable."  This has been known for a very long time --  Atkinson stated that apart from 2 fallen lintels found in the circle (numbered 150 and 36) "ALL bluestones of the circle are in their natural state and none show any sign of deliberate tooling or dressing."  So where did this myth of the hunt for pillars and columns come from?  Answers on a postcard please.........


There was clearly a much greater degree of selection when it came to the bluestone horseshoe.  For a start, all of the 11 remaining stones (some standing, some fallen) are made of dolerite -- spotted and unspotted -- rather than rhyolite or volcanic ash or anything else.  We can't be sure that the missing stones were also made of dolerite, but it's a possibility.  Another possibility is that other softer stones were used, and that they have been destroyed deliberately or have been broken down by natural processes.  In the above photo we see bluestones 62 and 63 -- one a tapered pillar and the other a pillar, assumed by Castleden to be the "preferred" female and male shapes which supposedly alternated when the horseshoe was originally created.  As most commentators have pointed out, a lot of smoothing and shaping went on on these dolerite stones -- with mortice and tenon and tongue and groove features still causing archaeologists to scratch their heads as to the whys and wherefores.......

The spectacular groove cut along the length of bluestone 68. What was the groove for?   Stone 66 might have had a long tongue on it, but only a part of that stone remains.  Maybe the two fitted together at some stage.....

Back to the bluestone circle chaos.  Below is another picture, this time showing some of the bluestones of the circle. 

 
This gives a good representation of the jumble of stones used in the circle.  (These are stones 46, 47, 48 (fallen), 49 and 31.)  The more one looks into this, the more one is convinced that the builders of Stonehenge were simply making use of a pretty random collection of stones of many lithologies and many shapes and sizes, which were lying about somewhere in the neighbourhood.  Having assembled the stones together in one place, they used them many times in various settings -- we know this from the extraordinary "honeycomb" of stone holes revealed during various digs down through the years.  In the final settings, the rough and irregular stones were put into the bluestone circle. The hardest and most elongated were used in the bluestone horseshoe -- and some of them were shaped and smoothed.

What we still do not know, of course, is whether there ever were more than 43 bluestones on the site; whether the bluestone circle and the bluestone horseshoe ever were finished; and whether at some stages sarsens and bluestones were mixed together in various settings long since abandoned.



Thursday, 28 March 2013

Ice-moulded slabs on Carningli

Ice-moulded slab on Carningli.


This is a photo taken today of a beautiful ice-moulded slab on the south side of Carningli, near Newport in Pembrokeshire.  Just up the road from where we live......

To my great shame (I thought I knew every inch of the mountain) I had not spotted this before -- maybe because you sometimes miss things in the landscape if the light is not right.  Anyway, today the light was exactly right, and there it was, revealed in all its glory.

I don't know of any other process that can mould a rock surface like this apart from long-continued meltwater flow.  But in this location there is no evidence for a fluvioglacial origin for these features -- so overriding glacier ice it has to be.

I have dithered a lot in the past on the question of whether the Devensian ice of the Irish Sea Glacier flowed over Carningli, or round it, or just skidded to a halt somewhere on its northern flank.  However, this is near the western end of the craggy mountain, on the south-facing slope where there are great banks of scree, broken bedrock and occasional rock outcrops.  The ice here must have been flowing down the slope, from north to south -- there is now no doubt in my mind that the ice surface in the Devensian was above the summit of Carningli, and that ice flowed at least as far as the Gwaun Valley.  The abundant ice-moulded slabs on the summit ridge of the mountain, and on its flanks overlooking the town of Newport, all add to the evidence of quite intensive ice action, with the whole of the local landscape submerged beneath ice.

(There is still a chance that we are looking at Anglian glacial features here -- but that would mean they are 450,000 years old, and they look far too fresh.  Some more cosmogenic dating is needed........)

So this evidence matches that which I recently described in my post about the Gernos Fawr moraine on the SOUTH side of the Gwaun Valley, about 3 km due south from the photo location.

http://brian-mountainman.blogspot.co.uk/2013_02_01_archive.html






Wednesday, 27 March 2013

Another bluestone myth


The photo above shows an elongated "pillar" of spotted dolerite lying beneath a rock face at Carn Meini in eastern Preseli -- within the area deemed to be "the bluestone quarry" by Profs Darvill and Wainwright.  For many years this has been referred to by Stonehenge enthusiasts as "the one that got away'' or as a pillar stone quarried and then for some reason left behind.

There is quite a powerful myth -- going all the way back to HH Thomas and Richard Atkinson -- that the bluestones were quarried from here because of their unique spotted character (those large white specks) and because pillars or columns were easy to obtain since that is the way that the rock splits naturally from the rock face.  So the builders of Stonehenge were targetting a rock type here in West Wales which provided them with orthostats or pillars suitable for incorporation into a monument in which pillars were not just desirable but necessary.  Such is the myth.  But how reliable is it?

Here are some plans of the Stonehenge arrangements:





Click to enlarge and to examine them in detail.  Sorry that on each one the axis is aligned differently -- there is another ancient tradition of ignoring compass north on Stonehenge diagrams........

Now, lets forget about how many bluestones there might have been at some stage in the past, and concentrate on what we know for sure.  There are 43 bluestones known in the stone settings. As we can see, some are standing, and some are fallen.  Some are dolerite, some are spotted dolerite, and some are rhyolites and other rock types.

Here is my list of rock types, stone numbers, and identified fragments from the debitage, culled from the literature:

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)

When we look at the STANDING bluestones, we see that there are 10 of them -- numbers 46, 47, 49, 31, 61, 33, 34, 37, 72 and 37.  It is a moot point whether some of these deemed to be "standing" are complete and as they were, or whether they are broken or otherwise modified.

In the bluestone circle, only six stones are still standing straight.  Another 13 are leaning or have fallen.  Another ten have been found as stumps during excavations.  That makes a grand total of 29 bluestones in the bluestone circle.

In the bluestone horseshoe, six stones are standing, five are fallen, and there are two known stumps below ground level.  That makes 13 stones in total.

Let's now look at stone SHAPES.  Some of the stones are classic elongated pillars standing up to 2m above the ground surface:  stones 150, 61, 62, 63, 69 and 70 are the most impressive.  But then we have another distinct group of stones which are best referred to as slabs -- for example, stones 46,47, 31 and 37.  Rodney Castleden refers to some of these as tapering triangles, and suggests that they are the "female stones" which were originally placed in an alternating setting with the "male stones" which were tall and erect.  Not many other Stonehenge authors agree with that interpretation, and we may put it down to wishful thinking.......

Then we have all the other bluestones -- the fallen nondescript lumps of non-sarsen stones scattered all over the place, as we can see on the diagrams above, and the stumps about which we know very little indeed.  Some of the stumps might have been elongated pillars originally -- we just don't know.

So there are ONLY five or six elongated bluestone pillars at Stonehenge -- on that basis it is strange indeed that the "bluestone pillar" myth ever was developed.  There is hardly any sound evidence to suggest that elongated bluestone pillars were preferred and even targetted as desirable stones to collect and transport over great distances.

I rest my case, and restate my belief that the bluestones at Stonehenge (maybe just 43 of them, and maybe more to start with) were a mottley collection of stones of all shapes and sizes that just happened to be there.  The longest and slimmest ones were used to most spectacular effect, and some of them were even shaped carefully as lintels or as "tongue and groove" neighbours, but the rest were just used here, there and everywhere, because they were the only stones the builders had to work with.

Note: I think I have got my numbers right in the text above -- however, I will be grateful for any corrections from those who know the monument better than I do.


Sunday, 24 March 2013

Sea ice in Sweden


We just received this splendid photo from Inger's niece in Sweden.  It shows the sea ice as it is today -- thick enough to carry quite large vehicles.  The shore is on the outer side of one of the islands of the Stockholm Archipelago.  The ice is a bit disturbed and lumpy here, because of the slight rises and falls of the water in response to pressure changes -- there is no tide to speak of.  On the far horizon are the outer islands of the archipelago.  The ice is thinner out there because of greater exposure, wave action and stronger currents.  In fact you can see one stretch of open water in the top left of the photo.

Ice forms very easily here when temperatures are consistently sub-zero, because the salinity of the sea is very low.

It's amazing to think that in two months' time it will be high summer here, and we will be kayaking and swimming in the sea in precisely this area.......

Thursday, 21 March 2013

Is the bluestone myth based on scientific fraud?

HH Thomas -- hero or dastardly villain?  He was the man who "established" the links between Stonehenge and Carn Meini and Carn Alw in the Preseli Hills.  It now looks as if he might have been guilty of a calculated and successful scientific fraud........


When the Sublime Apollo sent this message (on the record)  this morning I was more than a little intrigued:

 This has just been accepted:  "Carn Alw as a source of the rhyolitic component of the Stonehenge bluestones: a critical reappraisal of the petrographical account of H.H. Thomas". Bevins and Ixer. (Apparently it will be in the Journal of Archaeological Science).  When this is out, read and weep.  It looks like he was a bit economical with the evidence - naughty man.

Spotted dolerite from eastern Preseli.  Rocks that look like this are found in a number of the tors and crags around and to the east of Cerrig Marchogion.


Banded rhyolite in an outcrop on the flank of Carn Alw.  Within these rhyolite outcrops there is considerable variation -- sometimes the rhyolite is smooth and almost glassy, and elsewhere it is very coarse and grainy to the touch.

I keep my ear to the ground, and I have no intention of weeping.  Of course I was aware that Rob and Richard were working on the rhyolites at Stonehenge and on Preseli, and also on the spotted dolerites which are at the core of the "bluestone myth."  On the spotted dolerites, we await developments -- but of course there have been earlier suggestions that Carn Goedog (and not Carn Meini) was  the real source of the spotted dolerite orthostats found at Stonehenge.  If that is proved by new research to be correct, that would be the end of the 'bluestone quarry" idea at Carn Meini, so beloved of Profs Darvill and Wainwright.

Back to the rhyolites.  HH Thomas was very keen on the idea that Carn Alw was the source of the main rhyolites at Stonehenge, because it is geographically quite close to Carn Meini.  But in the analysis of his thin sections, his selection of samples, and his reporting of research results, how selective was he with the truth?   It looks as if Rob Ixer and Richard Bevins are now going to suggest that he was indeed a "naughty man" who does not quite deserve the reverence which he is given by those who do not know much about geology.

This brings to mind two posts I pasted onto this blog in 2010:

Did HH Thomas cook the books?

http://brian-mountainman.blogspot.co.uk/2010/02/did-hh-thomas-cook-books.html

Two great hoaxes: Piltdown Skull and Bluestone Quarry?

http://brian-mountainman.blogspot.co.uk/2010/03/two-great-hoaxes-piltdown-skull-and.html

I paste these below, for convenience.  As things stand, it looks increasingly likely that the bluestone myth is based upon faulty or even fraudulent science.  Is this the REAL Stonehenge story of the century?

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

Sunday, 14 February 2010 

Did HH Thomas cook the books? 


I have come across a lot of fraudulent science lately, in other contexts, and this got me thinking about whether HH Thomas deliberately "cooked the books" when it came to his original stunning revelations about the link between Stonehenge and Preseli. Increasingly, I think that he did distort and select his evidence in order to prove his point. For example, we still do not know how many samples he took, and we do not know how many "inconvenient" stones he chose simply not to report on..........


This is an extract from THE BLUESTONE ENIGMA:

It was Herbert Thomas who speculated on a Preseli origin for the Stonehenge bluestones in 1908 and then went on to propose, in his famous 1921 lecture, that the bluestones were identical to rocks cropping out within one small area around Carn Meini. These bluestones, located within the bluestone circle and the bluestone horseshoe, comprise 43 stones, give or take a few. The best estimate is that there are 27 spotted dolerites (including at least two that are broken in half), three unspotted dolerites, five altered volcanic ashes, five rhyolites (of which two are ignimbrites and two are lavas), two micaceous sandstones and a greenish sandstone called the Altar Stone. The spotted dolerites are more variable than one might think; some of them have obvious and large spots of whitish or pinkish feldspar, and others have spots that are almost too small to see with the naked eye. The two micaceous sandstones and five volcanic ashes are just left as stumps, buried beneath the turf.

Most people believe that Herbert Thomas actually sampled the bluestones in the stone settings at Stonehenge. He did not do that. Instead, his work was based upon a visual examination of 34 in situ stones and an analysis of fragments and samples from assorted collections made by William Cunnington, Nevil Maskelyne and William Judd. His analytical method was called “standard transmitted light petrography” which involved a detailed examination of thin sections made from his samples. He also looked at thin sections made from samples taken from the tors in the Preseli Hills, although it is unclear whether any of the samples were his own. Again he seems to have depended largely upon samples collected by other geologists. Some of the samples came from bluestone fragments found in the soil during excavations.

His paper was remarkably vague and unsatisfactory in many respects; we have no idea, to this day, how many samples he looked at and whether he reported on ALL of his analyses. He was driven by the belief that all of the stones must have come from one small source area, as suggested initially by Sir Jethro Teall. So although some of his rock identifications were anomalous, he seemed unprepared to consider the possibility that they had come from other far distant sources. For example, he rejected the possibility of some dolerite samples having come from the Cader Idris district on the grounds that “this locality may be disregarded as a possible source.” There was no explanation for this curt dismissal. He was far too hasty in assigning a Preseli origin to some of the rhyolite samples to which he had access. He also avoided a proper discussion of the source of the Altar Stone, and he made no mention at all of the “inconvenient” micaceous sandstone bluestones (numbered 40g and 42c) or the equally inconvenient fragments of sandstones, grits, quartzites, greywackes, argillaceous flagstones and slates, and of the glauconitic sandstone listed by Judd in 1902. He was familiar with Judd’s work, but treated it with disdain, largely because Judd was convinced that the Stonehenge bluestones were erratics of glacial origin! Thomas’s results were not tabulated or itemised anywhere, and it is impossible to tell which of his assumptions and conclusions are based on which samples. In the grand tradition of Stonehenge studies, confidence and bluster were sufficient to overcome any shortcomings on the data front. The five pairs of thin sections which illustrated his article were obviously selected to give the best “matches” possible; but that is fair enough, since he, as an author, was seeking to make a case! And let’s not be too critical here. Thomas was writing in 1923 when the science of geology was anything but mature, and there is no doubt at all that his work was of great importance.

Thomas knew that his sampled stones could not all have come from one “quarry” because of the petrographic differences which his work revealed. There were at least seven different rock types. So the heterogeneity of the bluestones had to be explained. He did this by proposing that the stones were erratics gathered together in one small area (possibly around Cilymaenllwyd) and utilised there in an early and simpler version of Stonehenge.

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

 27 March 2012

Two great hoaxes: Piltdown Skull and Bluestone Quarry?



Some see a bluestone quarry -- others don't.
Some see a Missing Link -- others see a hoax.

There was a piece on the telly the other day about the Piltdown Man hoax of 1912. One thing struck me in the commentary -- namely the "fertile ground" which existed in Britain at the time, providing perfect conditions for the hoax to take root, to flourish and eventually (in spite of the reservations of some experts) to become part of mainstream thinking. This is what one web site says about the hoax:

"Perhaps the most famous hoax was Piltdown man. In 1912, at a time when Darwin's evolutionary theory was new, and people were looking for missing links between humans and apes, someone planted two fake skulls which came to be known as Piltdown Man.
The part medieval man, part Orang-utang fossil was found, in the very English village of Piltdown in Sussex. Piltdown man's scientific name, Eoanthropus dawsoni, reflected its finder's name Dawson. To get a flavour of those times, the British Empire was still riding high, and Germany had their Heidelberg man fossil, Britain was desperate for a more important ' missing link' between man and monkey."

The key to this is national pride, and a desire in Britain to demonstrate that whatever important discoveries there were in Germany, Britain had even better ones, showing the world what wonderful ancient civilizations we had here, and what brilliant archaeologists we had to uncover them and to expound new theories of evolution to the world...... OK, petty, nationalistic, xenophobic and even absurd, but that was the world around the time of the First World War. Germany had Neanderthal Man, and now Britain had the "Missing Link" -- even more important.

So what about HH Thomas and the bluestones? Well, I have suspected for some time that Thomas might have been guilty of simplification and selective citation of his samples and his rock identifications, in order to flag up the Carn Meini area as the source of the bluestones. I have also expressed my amazement in earlier posts that he "got away with murder" in that NOBODY seems to have seriously examined his evidence or questioned his wacky idea that the stones had been hauled by tribesmen all the way from Presely to Stonehenge in a totally unique feat of Stone Age long-distance transport. And why did people not scrutinize his theory more closely? Why, because there had been great discoveries about megalithic structures in Germany, and because British archaeologists were desperate to show that in these islands we had even more advanced prehistoric civilisations and even cleverer engineers and technicians.

Sounds absurd? I don't think so -- and a number of other authors have suggested that Thomas's idea was carefully put together around the time of the First World War as part of a national "feel good" strategy, and that the whole nation (and not just the archaeologists) just loved the idea when he announced it, and were disinclined to examine it carefully.

So Thomas became famous, then the bluestones became famous, and the "bluestone transport story" entered the mythology of Britain. It is still trotted out ad infinitum, even though there is even less evidence for it now than there was in 1920. And anybody who dares to question it, or to undermine our cosy assumptions about the extraordinary skills of our Neolithic ancestors, is likely to get short shrift from the archaeology establishment. Look at what happened to poor Geoffrey Kellaway.......

So was the Carn Meini / bluestone quarry / human transport story all a hoax? I think it's a distinct possibility. How much longer will it be before the whole mad idea about human transport is finally consigned to the scrapheap? Not long, I suspect, since the new geology being done by Rob Ixer and colleagues in the Stonehenge area is revealing so many new sources for the stones and fragments at Stonehenge that we are going to have to talk about 20 quarries all over western Britain, rather than one. And that would be to stretch things to a rather extraordinary degree......

All hoaxes have their day, and eventually bite the dust, leaving senior academics looking very foolish.

The dating of the Dartmoor Tors


 Greater Dartmoor, showing the locations used for the sampling of the granite tors for cosmogenic dating purposes.  In the north of the marked area, the whitish overlay shows the presumed extent of the Devensian ice cap.

The proposed extent of the Dartmoor ice Cap in the late Devensian. Seven samples were taken for cosmogenic dating from within this area assumed to have been covered by ice.


Many thanks to Yanni Gunnel for sending this article, which I have mentioned earlier on this blog. 

"The granite tors of Dartmoor, Southwest England: rapid and recent emergence
revealed by Late Pleistocene cosmogenic apparent exposure ages."
Yanni Gunnell, David Jarman, Régis Braucher, Marc Calvet, Magali Delmas, Laetitia Leanni,
Didier Bourlès, Maurice Arnold, Georges Aumaître, Karim Keddaouche.  in: Quaternary Science Reviews 61 (2013) pp 62-76


This is not something I know a lot about, but the article is well presented and carefully considered, and I find it convincing.  Here is the Abstract:

Dartmoor, in SW England, is a classic periglaciated granite upland adorned with a population of over 150 tors. The origin of the tors has been controversial, but their emergence by differentiation after stripping of regolith during Pleistocene cold phases is accepted. However, their actual age has been unknown, with possible scenarios ranging from preservation since the early Middle Pleistocene to relatively short-lived landforms in a maritime climate with high denudation rates. The latter is now
supported by 32 cosmogenic surface exposure dates from 28 tors across the whole upland. The distribution of apparent 10Be ages peaks strongly in the Middle Devensian (36-50 ka), which with corrections for weathering and limited ice shielding could be interpreted as Early Devensian. These ages are much younger than those found for three glacially unmodified Cairngorms tors, and somewhat younger even than glacially modified Cairngorms tors. The dates show little spatial variation. Although an ice cap has now been modelled in the heart of northern Dartmoor, tors here are of median age, suggesting that ice cover sufficient to shield tors from incoming radiation was of short duration. The few younger tor ages support the idea of continuing landform instability across the landscape, with weathering flakes redeveloping soon after inferred loss of top pillows by gelifraction or gravitational toppling. The few older tor ages have no systematic explanation, and may indicate inheritance from an earlier cycle of bedrock near exposure.
 

Since most tors are modest in height (typically 2-5 m), volumetrically insignificant, and often
in advanced stages of disintegration, the general impression is that they are evanescent features, which emerge and quickly disappear during every Pleistocene climatic downturn. Tor populations may thus flicker across the landscape rather randomly over the Quaternary. The remarkably consistent age of the present tor population could be associated with a stripping event at the start of the Devensian, but fuller analysis must await closer controls on tor denudation rates in different climatic phases, and on ice cover extent and duration. These results only date extant tor surfaces, not the landscape, but as the best available erosion pins they have evident value in exploring theories of the evolution of Dartmoor during the Quaternary.


Much of the paper is concerned with sampling procedures and correction factors -- but the results are interesting.  Of the 32 samples taken, the oldest was 117,000 yrs BP and the majority were clustered around 40,000 - 45,000 yrs BP -- in the Early Devensian.  The youngest date was around 9,000 yrs BP.   At face value, this means that the rock surfaces (if not the tors themselves) are surprisingly young -- much younger than the surfaces of tors in the Cairngorms, for example.  This means that the landscape is surprisingly dynamic, evolving quite rapidly under the influence of effective weathering processes. the authors do not think that the results contribute much to the debate on whether or not Dartmoor had its own ice cap.  as they say, such an ice cap would have been so short lived that it will not have skewed the cosmogenic readings very much at all.  Indeed, it may well be that while the ice cap was present, the rest of the ground surface on Dartmoor will also have been protected -- by perennial and seasonal snowfields.

What we still do not know is the extent to which the results are skewed as a consequence of granite weathering and erosion.  Are we looking here at artifices, or meaningful dates?  In an attempt to resolve this issue, the authors estimate or calculate rates of ground surface lowering or denudation.  The figures suggest that amid the dartmoor tors the ground surface is being lowered at rates between 76 mm per millennium and 6 mm per millennium.  Mostly the figures suggest between 10 mm and 25 mm per millennium.

All in all, an interesting contribution to our knowledge of what happened in the Ice age in SW Britain..... and I particularly like the idea of the "flickering" tors -- coming and going over a very long period of time depending on the upturns and downturns of the climate.

Wednesday, 20 March 2013

Devensian limit in West Wales


This represents my current thinking on the Devensian limit in West Wales, dated at around 20,000 yrs BP.  The yellow line shows the limit of the Irish Sea Ice Sheet.  The purple line shows the extent of Welsh ice at about the same time.  The orange arrows show the assumed directions of ice movement during earlier glacial episodes, for example in the Anglian and Wolstonian Glaciations. (The Anglian is assumed to have been a time of very extensive ice cover.  There is more doubt about the Wolstonian.)

Note that in the "unglaciated" part of Pembrokeshire in the Devensian, there may well have been a small ice cap on Preseli at the peak of the glacial episode, and also very extensive perennial snowfields elsewhere.  If you had flown across the landscape at the time in the Tardis, you might not have seen any clearly defined ice edges.

The dating of rock surfaces


This is a nice piece of rhyolite from an erratic (probably not very far-travelled) found on the flank of Carningli in Pembrokeshire.  Note the weathering crust, which is everywhere about 10mm thick and in places up to 15mm thick.  The crust is formed by a weathering process called oxidation, and it will continue to thicken for thousands of years -- maybe millions -- as long as there is free water in the environment.  the rock can be buried or exposed to the atmosphere -- it doesn't seem to matter very much.  Different rock types react to chemical weathering in different ways.

One factor which will influence this weathering crust is the annual rainfall received in the location in question:


This rainfall map of the British Isles shows degrees of dryness in brown and degrees of wetness in white and blue.  It stands to reason that for a particular rock type, weathering rates will be much higher in the wetter areas towards the west, and lowest in the areas coloured dark brown on the map.

This is all relevant because of the increasing use of isotopic / cosmogenic dating techniques which are being used on rock surfaces and even on thickly buried sediments.  There will be more to report on this quite soon......

If you are going to date a rock surface exposed to the atmosphere by measuring the amount of "cosmogenic bombardment" there has been, you need to be absolutely sure that the rock surface has been continuously exposed.  Even on exposed hill summits you can hardly ever be certain of that, for during warmer climatic intervals there may have been peat or other vegetation covering the rock, and during cold periods snow or ice might have covered the same surface -- thus shutting off cosmic rays.  You will get the highest "cosmogenic imprint" close to the surface, and this will decrease with every mm you penetrate into the solid rock.  Sometimes, if an author has not told us exactly how he took his samples, our confidence in his dates may be seriously compromised.......

Another big factor which can lead to the distortion of results is the breaking down of material on the rock surface  -- by the processes of physical weathering.  Frost action, salt spray, mineral contraction and expansion related to temperature changes, and even biogenic effects can break up rock surfaces and lower them by millimetres or centimetres per century.  In carbonaceous rocks like limestone or chalk, solution processes will come into play, and rock surfaces can be lowered even more rapidly, especially if rainwater and groundwater remain aggressive and unsaturated.   If you are dating a surface that has been lowered by any these processes, you will almost always get a falsely young result.

What does all of this mean?  In my view it means that great caution needs to be exercised in interpreting cosmogenic and other dates from "exposed" rock surfaces -- at least until such time that we have a much greater understanding of the correction factors that should be employed in the calculations.  Secondly, wherever possible, at least two different techniques should be employed -- if they bring up broadly comparable dates, this will greatly increase our confidence that we are learning something meaningful.



Tuesday, 19 March 2013

The joy of Geology


This is for Rob!  When I studied geology, I never did get the hang of that optical mineralogy stuff, but I quite liked the sedimentology and the fossils.

As I was clearing out some stuff from my study cupboard today, I came across these samples collected many years ago.  I thought they were rather splendid, and worth sharing.  Nothing whatsoever to do with either Stonehenge or the Ice Age........

 The "tuning-fork" graptolite is Didymograptus murchisoni -- found in the Ordovician rocks (dark grey or black shales -- old sea floor deposits) of the area.  The big one on the left of the photo is 7 cm long.

The most famous location for seeing these is Abereiddi, on the North Pembs coast west of Fishguard.  That's where I collected these samples.  The fossils are thought to be  circa 480 million years old.

Sunday, 17 March 2013

Stones from west and east? And north? And south?


 This illustration from the recent Channel Four documentary shows the 56 hypothetical bluestones in position in the Aubrey holes, before they were moved into various settings within the outer sarsen circle.

 There have been a number of reports (like the one below) which have quoted MPP as saying that "stones were taken from west and east" and brought to Stonehenge as ancestral totems or symbols of dead ancestors.  But hang on a bit.  Where are the stones from the east?  And, for that matter, where are the stones from the north and south?  Unless MPP is now counting the sarsen stones as ancestral totems as well, there is rather too much poetic license here.  As I have frequently pointed out, ALL of the bluestones seem to have come broadly from the west -- and since we know that that is where the ice of the Anglian glaciation came from, I have persisted in the belief that the stones are most logically interpreted as glacial erratics -- either carried all the way to Stonehenge or left scattered about somewhere to the west of the monument.

If the stones used in the bluestone settings really were memorial stones celebrating the memory of the ancestors, WHY ARE THERE NONE FROM THE OTHER DIRECTIONS OF THE COMPASS?  It beggars belief that the only people interested in making this grand gesture, and in carting stones over a great distance, across land and sea, were those who came from the west.  Why didn't all those splendid Scots who came all the way from Orkney (or wherever) with all their cattle bring some nice stones with them as well?  Will somebody please try to give me a reasonable archaeological / anthropological / geological explanation of this rather wondrous anomaly?
 
 ========================

From Stonehenge News:  "Parker Pearson believes Stonehenge was erected as a monument to the ancestors of all Britons. The aim was to unify the different peoples of the British Isles by honouring all their dead. Stones were taken from west and east and erected together to solidify alliances that had been struck up between these different people. "Stone is eternal and was used to represent the dead," said Parker Pearson. "That is the purpose of Stonehenge."

Observer regurgitates bluestone lies





A number of us who are Observer readers will have seen the big double-page spread today on Stonehenge -- another rather lazy piece of journalism by Robin McKie, whom I have had cause to mistrust on a number of previous occasions.  Anyway, he bases his piece rather unquestioningly on the Channel 4 documentary of the other day, and it's difficult to discern whether he has actually bothered to talk to any of the protagonists. 

He cites Tim Darvill:  "The sick and wounded would come here (ie to Stonehenge) for cures from the monument's great bluestones, which had been dragged from Wales to Wiltshire because of their magical healing properties."  Hmm -- a little circumspection and even inquiry might have been appropriate there, for a start....... but McKie seems not to have heard of glaciers or glacial transport.

Then he cites Darvill again:  "Darvill points to the quarries in the Preseli Hills in Wales, the source of Stonehenge's bluestones. "These are all associated with sacred springs today," he said.  "That association is a very ancient one....."    WHICH quarries?  ALL of the bluestones?  And as I have pointed out many times before, the springs in the general neighbourhood of Carn Meini have NO traditions of sanctity attached to them, and there are NO associated ancient traditions at all.   I have checked this with a number of local historians, and they all agree with me on this.  Sheer fantasy -- why does Tim Darvill carry on repeating this absolute nonsense?  Answers on a postcard please......

------------------------
Stonehenge remains a mystery as scientists ask: was it a health spa, or a cemetery?

Robin McKie, The Observer, Sunday 17th March 2013
http://www.guardian.co.uk/culture/2013/mar/16/stonehenge-conflicting-theories-spa-cemetery

Archaeologists back conflicting theories on Britain's greatest prehistoric monument

It already attracts more than a million visitors a year. Yet these numbers could be dwarfed once Stonehenge, one of the world's greatest prehistoric monuments, completes its radical facelift
Over the next year, the nearby A344 will be closed and grassed over. A new visitor centre will be built a mile and a half from the monument and tourists will be encouraged to explore the ancient landscape around the 5,000-year-old complex.
The makeover falls short of plans, since scrapped, that would have seen all major thoroughfares in the area diverted through tunnels. Nevertheless Stonehenge should be returned to something like its past glory, it is hoped, and then attract even greater numbers of visitors seeking to understand the purpose of this vast, enigmatic edifice.
For centuries, historians and archaeologists have speculated about the reason for the monument's construction. Suggestions have ranged from the proposal that it was built by Merlin to commemorate knights slain in a battle against Saxon invaders to the idea that Stonehenge was a highly sophisticated astronomical observatory.
Earlier this month, the latest salvo in the debate was fired by archaeologists, led by Professor Michael Parker Pearson, of University College London, who published research indicating that the original Stonehenge was a graveyard for a community of elite families. "This was a place for the dead," Parker Pearson said.
The notion – that Stonehenge is essentially a large funerary temple created between 3000 and 2500BC – does not find favour with every scientist, however. Indeed, the other main group of UK researchers investigating the site – archaeologists led by Professor Tim Darvill of Bournemouth University – believe the place was an ancient Lourdes. The sick and wounded would come here for cures from the monument's great bluestones, which had been dragged from Wales to Wiltshire because of their magical healing properties. "This was a place for the living," Darvill said.
Such divergence of views would seem to suggest we are as far from understanding the purpose of Stonehenge as we have ever been. English Heritage historian Susan Greaney counselled caution, however. We should not place too much emphasis on our ignorance about the monument, she said. "We know who built it and when they built it and have a good idea how they built it. It is only its ultimate purpose that still remains unresolved," she said.
Detailed radiocarbon dating of Stonehenge has shown that work on its construction probably began with the huge circular ditch that still surrounds the monument. Inside several dozen bluestones were erected along with various timber posts and other structures. It was a relatively modest construction by the standards of the remains we can see today. Then, around 2600BC, the site was transformed. A ring of giant upright stones called sarsens were erected and capped with huge rock lintels. Inside five huge trilithons – pairs of rock columns capped with a single slab – were erected and many of the magical bluestones from Wales that had been erected near the edge of the monument were moved inside this inner sanctum. Crucially, the rays of the setting midwinter sun and the rising midsummer sun would shine through the heart of the monument and down the avenue that leads into it.
Over succeeding centuries, the bluestones were rearranged for purposes that still mystify scientists. In short, Stonehenge is not one monument, built at one moment in history, but many built and rebuilt over many centuries. By that definition, it had no single purpose but had many. Even today it performs many functions – as a touristattraction, a religious site (for Druids), and a place for scientific study, for example.
As to the identity of the builders of Stonehenge's great rings of sarsens and trilithons, that appears to be far less of a mystery. Work at the nearby site of Durrington Wallsindicates it was occupied by thousands of individuals at exactly the time the great stone rings of Stonehenge were being erected. The remains of the cattle they slaughtered have been studied and by careful analysis of the chemical makeup of their teeth, their place of origin in Britain has been determined. Remarkably, the animals appear to have been brought to Wiltshire from almost every part of the country. Even more intriguingly, most were killed during two peak periods: midwinter and midsummer.
"People were coming from all over the country at these times," said Parker Pearson. "It was partly a religious festival and partly a construction site: a combination of Glastonbury and a motorway building camp. The crucial point is that this was the first and only time in British prehistory that the country was united in a common cultural activity."
The issue is: what was that common cultural activity? Parker Pearson believes Stonehenge was erected as a monument to the ancestors of all Britons. The aim was to unify the different peoples of the British Isles by honouring all their dead. Stones were taken from west and east and erected together to solidify alliances that had been struck up between these different people. "Stone is eternal and was used to represent the dead," said Parker Pearson. "That is the purpose of Stonehenge.
Darvill does not agree. "I think that very early on Stonehenge was a burial ground but after 2600BC these burials stop. So how can this be a place of the dead?" By contrast, Darvill points to the quarries in the Preseli Hills in Wales, the source of Stonehenge's bluestones. "These are all associated with sacred springs today," he said.  "That association is a very ancient one. These stones were brought to Stonehenge because they were thought to have healing properties. That is why all that effort went into its construction. It was a place where people thought their illnesses might be cured and their lives saved."

AND THE OTHER THEORIES ARE...
According to the 12th-century cleric Geoffrey of Monmouth, Stonehenge was built by Merlin to mark the place where knights, slain in the fight against Saxons, were buried.
Other historians have argued that the Romans or Danes built it.
In more recent times, scientists have argued that Stonehenge's alignment suggests it could have been used to calculate astronomical movements and to predict lunar eclipses. However, the feasibility of performing such measurements in prehistoric times has been questioned.
In 2003, writing in the Journal of the Royal Society of Medicine, University of British Columbia researcher Anthony Perks claimed the great stone circles were erected as a giant fertility symbol, constructed in the shape of the female sexual organ.
In 2008 the Telegraph columnist Oliver Pritchett argued, tongue-in-cheek, that Stonehenge was really built to house Britain's first public inquiry.

Link source: Robin McKie, The Observer,

Strontium isotope ratios


The standard BGS geological map of Great Britain and Ireland. Strontium isotopes in the environment (and in cattle teeth) are related above all else to bedrock geology -- but might the pattern also be distorted in areas where there is, for example, thick till in the areas where cattle are grazing?


The simplified strontium ratio map -- five categories only


The more detailed strontium ratio map -- eight categories.

Thanks for various contributions on this -- including those from Geo and Myris.  Even given the difference in the groupings involved in the two strontium isotope maps, there are discrepancies that are difficult to interpret.  However, it does seem clear that there is no way you could differentiate the teeth from cattle raised in the Orkneys from those which were raised in many parts of Southern England within twenty or thirty miles of Stonehenge.  Even in areas with higher ratios, I cannot see how you could claim that ANY of the cattle tested could have come from Scotland, given that there are many areas of Palaeozoic rocks much closer to Stonehenge, for example in South Wales and in Devon and Cornwall.

It appears that Prof MPP has now acknowledged (in Leicester the other day) that the "Orkney connection" with Durrington Walls and Stonehenge had better be abandoned.






Wednesday, 13 March 2013

Erratics from the Newport area



Many thanks to Rob Ixer for making sections of these rocks and identifying them in the cause of science.  This helps to build up the database of local and erratic rocks in North Pembrokeshire.  As Rob indicates, some of the rocks are difficult to give locations for, except to say that some of them might have come from SE Ireland.  This would make sense, since we know that the Irish Sea Glacier also affected that area -- and in a number of posts I have suggested a gradient on the Devensian ice surface across St Georges Channel.

Caution required here -- much work still to be done, and many more erratics to be examined and identified!  See the two links below to previous relevant posts.

1.  Bedrock from near the summit of Carningli – dolerite or microtonalite. An even-grained fine-grained igneous rock with dark mafics and feldspar. Not a typical spotted dolerite.

Erratics

2. Very coarse volcanic agglomerate / ignimbrite (??) from the southern flank of Carningli. Not sure whether the outcrop is bedrock or a very large erratic. Not certain. It is a siliceous rock with simply twinned feldspar megacrysts but also black fine-grained areas (single quartz crystals??)/?slate clasts.  (NB. This cannot be an ignimbrite as there are no fiamme.)

3. The strange rock found on the shore of the estuary, across the river from the Parrog, Newport. Felsite, maybe from North Wales?  Not certain. Siliceous igneous rock with feldspar megacrysts and a sub-spheroidal fabric. Crystal tuff??

http://brian-mountainman.blogspot.co.uk/2012/02/mystery-erratics-on-newport-beach.html  

4 - 8. Erratics exposed during land clearance off the Cilgwyn Road, about a mile from Newport.

4. Fine-grained grey igneous rock (NOT a sandstone) -- knocked off a nice rounded boulder. Most interesting Feldspar megacrysts in siliceous matrix with a sub-spheroidal fabric. Quartz-chlorite mainly.   This is definitely a felsite erratic. I suspect that this may be a granophyre; it has plagioclase megacrysts in a sub-spherulitic matrix all within a chlorite ‘matrix’.  Granophyre.

5. Dark reddish marl -- from the Cambrian sandstone series? Flaky -- almost a shale... from a rough sub-angular boulder.    Foliated fine-grained indurated laminated ?metamudstone with pink-orange and grey alternating laminae. Not Permo-Trias but Palaeozoic.  Could be SE Irish.

6. Medium-grained purple sandstone. Cambrian? From a nice rounded boulder. Origin -- SE Ireland? Very indurated red-purple fine-grained sandstone/meta-sandstone. Certainly at least Palaeozoic Exotic!

http://brian-mountainman.blogspot.co.uk/2012/04/cambrian-sandstone-erratics-on.html

7. Fine-grained red sandstone. Cambrian? From a bigger rounded boulder. Origin -- SE Ireland? Fine-grained indurated micaceous sandstone with quartz veining along joint plane. Devonian/Lower Palaeozoic? Not Permo-Trias.

8. Rough greyish volcanic ash //agglomerate? Has vesicles -- highly variable crystal structure. From a large sub-angular boulder. Don't think this is local..... Very silicified coarse-grained sandstone (litharenite) with shale/slate clasts and voids after lost shale/fossils?. Trace muscovite and weathered feldspar. Meta-sandstone polylithic with igneous and meta-sedimentary rocks and trace ??bone.  Lower Palaeozoic in age.

Tuesday, 12 March 2013

The Stonehenge Neolithic mace head


Many thanks to Anon for sending me this photo of the REAL Stonehenge Neolithic mace head -- made of gneiss.  This must be the one found by Hawley in association with a cremation burial.  The pit was NOT one of the Aubrey Holes, so it was not associated with any ritual burial which involved placing a bluestone on top of the cremation debris.  This one is in the museum in Salisbury, and is shown on its web site:

http://www.salisburymuseum.org.uk/collections/stonehenge-prehistory/stone-macehead

It's really rather a splendid mace head -- so why didn't MPP choose to examine this one in front of the camera?  It would at least then have been of the right age, and from approximately the right context...... and that would have made that section of the film a great deal more trustworthy.

More on the Durrington Walls cattle


A still from the TV documentary, showing the frequency of occurrence of the sampled teeth from Durrington Walls. The size of the sample wasn't stated -- but note that the great majority of teeth were from the blue, green, orange and yellow zones, implying that most of the cattle came from within a hundred miles of the sampling site.  Note also that very few animals came from far away.


 The "strontium isotope map" which purports to show the "signatures" in strontium isotope measurements affected by local geological and water supply contexts.  This map is different in some respects to that used by Sarah Viner in her podcast.


Another byproduct of that Channel 4 Documentary on Sunday night is a fresh look at the published data on the teeth of those cattle from Durrington Walls.  I was encouraged to do this by the extravagant claims made by Prof MPP about all those midwinter solstice barbeques at Durrington, attended by most of the British population.  It sounds as if those parties were quite something, with 4,000 people there every time, celebrating, worshipping and building Stonehenge.  All the visitors apparently brought their own meat supplies on the hoof........  as MPP says on the new documentary, it was not so much a matter of "bring a bottle" as "bring a cow."


When MPP first announced these gigantic events to the world, the media loved it, and there was saturation coverage.

But how strong is the evidence?  I have searches as best I can, and unless there is a lot of unpublished material in the pipeline, the conclusions about gigantic feasts attended by ancient clans from the Orkneys (and everybody else of note) appear to be based on 13 animal teeth.  I give the key references and abstracts below.  In Sarah Viner's podcast, she mentions that 2 of the sampled teeth are from animals that spent all their lives on Salisbury Plain,  7 came from animals born in Central England, South Wales or Devon and Cornwall,  2 probably came from Cornwall or Wales -- or maybe further north, and 2 had higher values, showing that they probably came from the Grampians of Scotland or from restricted areas in South Wales or Cornwall where certain types of igneous rocks are prominent.  They might also have come from the continent.



There was nothing in the research to suggest any link with the Orkneys -- so goodness knows why MPP went trundling off there for the film and pretended that people had travelled all the way from Orkney to Durrington walls for one or more of the gigantic winter solstice feasts.


The conclusions of the "strontium signature" research - based on a statistically very small sample -- are that most of the animals killed and eaten were relatively local, and that two of them were from a greater distance.  As far as I can see, there is nothing in the research to suggest that these animals were not moving about all over the country in the process of normal trading (or cattle stealing) activities -- and nothing to suggest that they were brought to Durrington Walls specifically for the purpose of feasting at the solstice.  Why, in any case, would people want to travel all the way from Scotland in the depths of winter, with animals on the hoof, all the way to Stonehenge....?

As far as the "winter killings" goes, I would like to see the evidence on that.  In all farming communities you kill animals in the winter because that's when you need extra protein and because you can avoid the cost of feeding them during the cold snowy spells of weather which come along after the turn of the year.



So there we are then.  We seem to have yet another gigantic MPP fantasy, based upon remarkably little evidence.  I know that the evidence for feasts comes from pig bones and other sources as well, but when we look at the idea of these great gatherings of revellers converging from all quarters of Great Britain, it would be helpful if we could have a bit more evidence please, and a few more teeth to look at.......


Here are the key publications: 
 
Cattle on the hoof: Strontium isotope analysis of cattle teeth from Late Neolithic Durrington Walls 
(Sarah Viner, Jane Evans, Umberto Albarella, Mike Parker Pearson) (2009?)
http://alexandriaarchive.org/bonecommons/items/show/862

Description
Cattle are a common component in zooarchaeological assemblages from the Late Neolithic in Britain and were undoubtedly important in both the economic and ritual spheres of Neolithic life. At present relatively little is known about the role of mobility in the husbandry regimes that characterised the time, as the movement of animals can be difficult to detect in the archaeological record. The application of strontium isotope analysis can provide insights into the movement of animals and humans in the past. In the case of cattle, tooth enamel provides 87Sr/86Sr values that are set during the period of tooth development and that will reflect the geology of the grazing area. By comparing these early grazing signatures with values from archaeological sites it can be established whether individuals were of autochthonous or allochthonous origin. This paper will present the results of Sr isotope analysis of 12 cattle teeth from Late Neolithic contexts at Durrington Walls, Wiltshire, a site located on chalkland. The findings suggest that while some animals were raised under conditions similar to those that are found at Durrington Walls, a number could not have been raised on chalkland. Not only were a large proportion of the cattle analysed raised in non-chalk areas, but a number of possible areas of origin could be identified for the allochthonous specimens. These results have implications for the long distance movement of cattle, and for the interaction between people in different parts of the British Isles during the Late Neolithic.

Sarah Viner, University of Sheffield
Jane Evans, NIGL, Keyworth
Umberto Albarella, University of Sheffield
Mike Parker Pearson, University of Sheffield

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

Cattle mobility in prehistoric Britain : strontium isotope analysis of cattle teeth from Durrington Walls (Wiltshire, Britain)

Viner, Sarah; Evans, Jane; Albarella, Umberto; Pearson, Mike Parker. 2010.  Cattle mobility in prehistoric Britain : strontium isotope analysis of cattle teeth from Durrington Walls (Wiltshire, Britain). Journal of Archaeological Science, 37 (11). 2812-2820. 10.1016/j.jas.2010.06.017

http://www.sciencedirect.com/science/journal/03054

Abstract/Summary

An important role has been envisaged for cattle during the Neolithic period in Britain based on their prominence within the faunal assemblages of the period as a whole. The relative ease with which cattle can be moved over long distances and the requirement to provide ample pastureland leads almost inescapably to the consideration of prehistoric cattle movement. This paper presents the results of an investigation into the mobility of Late Neolithic cattle at the well-known site of Durrington Walls, Wiltshire. 87Sr/86Sr values from cattle (Bos taurus) teeth were compared to local vegetation samples, well established values from archaeological material and to known geological conditions in order to determine whether individual animals were raised in areas with similar geological conditions as those found at the site (i.e. chalkland), and therefore whether the animals were of allochthonous or autochthonous origin. In total, 13 mandibular molars from Durrington Walls were analysed. Two of the animals included in the study were certainly raised under conditions similar to those found in the vicinity of Durrington Walls, but the other 11 provided signatures so distinct from that found locally that they could not have been raised on chalkland. From the results it is suggested that cattle were brought to the site from a variety of grazing areas in different parts of Britain. The implication of these findings is that the movement of cattle was undertaken during the Late Neolithic, and that in a number of cases substantial distances must have been traversed in order for animals to reach the site. In addition, the study provided valuable information for the interpretation of the site, which attracted people from a variety of regions, probably for ceremonial reasons. 

Monday, 11 March 2013

Stonehenge laser scan


Isn't this wonderful?  thanks to Dave Maynard for drawing it to my attention -- it is an EH laser scan creation, as reproduced in the Newsletter of the Graphic Archaeology Group.   It's probably very scientific, and shows something significant -- but I prefer to look on it as a work of art.  
Click to enlarge.

Skeletons, Secrets, Stonehenge and Skulduggery



I have been taking another look at the Channel 4 programme called "Secrets of the Stonehenge Skeletons" and have paused it in the middle because I am now seriously confused.

MPP says that the bluestones were in position around 5,000 years ago, set into the 56 holes which we call the Aubrey Holes.  His thesis is that the stones were put into position to "seal in" the cremated bones of men, women and children who belonged to high-status families or aristocracy.  The bones confirm this, having come apparently from 63 different individuals, C14 dated to 3000 BC to 2800 BC.  So far so good.

Then it gets confusing.  The commentary of the film says "amongst the cremated bones of the bodies at Stonehenge, his team has unearthed two ancient clues."  One of them was a beautiful mace head, and the other was a pottery incense burner with traces of burning on its rim.  MPP is shown examining them, together with a highly ornamented mace staff or shaft with zig-zag bone features affixed.  These are all referred to as "Stonehenge grave goods".  MPP then says to camera:  "The presence of a mace head in one of the burials at Stonehenge indicates that that man was a person of authority."





But hang on a bit -- don't we have a problem here?  I thought that all these items were supposed to be Bronze Age?   So I did a bit of googling, and found that the mace head and bits and pieces of the staff did indeed come from Bush Barrow, where they were discovered by Cunnington and his colleagues in 1808.  They were not unearthed by MPP and his team at all.   These items were indeed Bronze Age, and are normally associated with the Beaker culture on Salisbury Plain, which did not make an impact until about 2,500 BC -- about 500 years later than the placing of the cremated bones in the Aubrey Holes.

I am not sure where the pottery incense burner came from, but I'm pretty sure I have never seen a mention of such a thing in connection with either the cremated bones or the Aubrey Holes.  Does anybody recognize it?

So in arguing for his hypothesis of aristocratic families being cremated and being buried beneath bluestones in the Aubrey holes, MPP has apparently used artifacts that are at least 500 years too young to have any bearing on the cremations; and he has also used artifacts that have not even come from the Stonehenge site.  Very naughty indeed -- and as far as I am concerned, this illustrates that (like various other professors who shall be nameless) he is not averse to inventing evidence or misrepresenting evidence in order to support a favourite hypothesis.  Academic fraud?  I leave it to others to decide........

And if there is serious misrepresentation here, MPP cannot blame the producers of the programme.  Some of the misleading statements have come from the spoken commentary (which he must have seen and approved) and some of them come from his own mouth, on film.


More on Neolithic boats


This looks like an interesting book -- relevant to some of our earlier discussions about Doggerland and about Neolithic seafaring.  I have glanced at a few pages (on the Amazon web site!) and I get the impression that around 5,000 years ago (when lots of bluestones were supposedly being moved about by our heroic ancestors) there was no real capacity for heavy-duty long-distance stone transport by sea.

It appears that the early voyagers used very simple log boats rather like those found at Carpow and Must Farm.  Some had rounded bows and sterns but more seem to have had transoms or "end-plates" slotted into a groove at the stern end, making steering easier and making it easier to protect boats from theft. (The idea is then when you leave your boat on the shore for hours, days or weeks, you take the transom with you, making it impossible for anybody to use the boat in your absence......)


The Bronze Age Carpow Boat following its recovery from the mud and silt of the Tay Estuary.  Part of it is missing, but the overall shape is apparent.


One of the six Bronze Age boats recovered at Must Farm, Cambridgeshire.  One can see the hollowed out cross profile.


The transom in position at the stern of the Bronze Age Carpow Boat.

Although boats like these were sometimes over 9m long, and could accommodate maybe eight paddlers, they must have been seriously unstable in rough water or out in the open sea -- and were clearly best suited for use on lakes or within sheltered estuaries.  Robert van der Noort speculates on whether they were utilitarian items, used for fishing and rough duties along the coast -- or whether they were high-status items.  Probably they did have a lot of status attached to them, since they must have required many hundreds of hours of hard work to make them in the first place -- even in the Bronze Age, with metal tools available.  In the Neolithic, with only stone tools available, the status or value of such a boat must have been even higher.  On that basis the author of the book suggests that they were used primarily for carrying high-value trade goods -- necklaces, maces, ornamental axes, amber and other precious stones, and maybe high-value pottery or fabrics or skins.

Even with outriggers in place, and with the use of sail, I cannot see that boats such as these can have carried 4-tonne bluestones across the Bristol Channel in pre-Bronze age times.  This leaves us with rafts and skin boats or curraghs as the only contenders -- and there is likewise no evidence at all that the required technology was available to Neolithic seafarers at the time we are talking about.

The only slight consolation for those who want to believe in the sea transport of the bluestones is that domestic animals must have been transported between Great Britain and the continent, and between Britain and Ireland.  How would a sheep, or a cow, or a goat, be carried in a dugout canoe?  Animals are notoriously difficult to move about in boats.  Maybe they were trussed up and forced to lie on the floor of the dugout for the duration of the voyage?  Seriously uncomfortable, for both the paddlers and the animals concerned........  But to transport a bluestone is to move up another notch on the difficulty scale.

By the way, there is more on the dugout canoes here:

http://www.pkht.org.uk/carpow-logboat.php

http://www.mcdonald.cam.ac.uk/news/120120/Current_Archaeology_Must_Farm_Feb_2012.pdf