I think this is an important topic -- and Kostas is quite justified in asking the question "Is the Stonehenge Layer confined to Stonehenge, or is it found across a wider area of Salisbury Plain?" If it is found just in tight proximity to the stones, then I suppose we have a justification of the view that the layer is strictly man-made, being associated in some way with stone working or stone destruction. If it is found (with bluestone or foreign fragments in it) miles or tens of miles from Stonehenge, then we are in interesting territory!
The above pics show the pitted and broken surface of the chalk (showing the multiplicity of stone sockets), packing stones and the brownish layer of superficial materials nicely labelled up during the 2008 Darvill and Wainwright dig. This is what the two professors say about the layer:
The ‘Stonehenge Layer’
Our excavations within Stonehenge in 2008 (see CA 219) confirmed what earlier excavations had hinted at: namely that the Bluestones started to be broken up and chipped away more or less from the time they were set up in each successive arrangement. The great spread of flakes and debris usually referred to in the archaeological literature as the ‘Stonehenge Layer’ is not, as once thought, the debris from a one-off act of dressing the stones prior to their erection. Instead, these flakes have accumulated over millennia and include evidence for the use of Bluestone to fashion axes. Furthermore, detailed analysis of the finds from our excavations, now well under way, has highlighted two other important points. First, that some kinds of stone that we found as flakes and blocks in the excavated sample are not represented amongst the existing range of pillars standing at the site. Detailed petrological work by Rob Ixer and Richard Bevins has racked the source of one such rock type – a kind of rhyolite – to probable source outcrops near Pont Saeson, on the north side of the Preseli Hills (despite a speculative note in British Archaeology Nov/Dec 2009, page 7, suggesting a source elsewhere in Wales). Second, that interest in the Stonehenge Bluestones did not cease in prehistoric times. In the 4th century AD a shaft was dug adjacent to Bluestone Stone 35a that was refilled with rich dark soil. It was then ritually sealed by the placeme up, would have marked the position of the shaft. Coins, pottery, brooches, surgical instruments, and possibly also a curse-tablet from earlier excavations show that Stonehenge was just as much a sacred spot in Roman times as it had been earlier.
From
T Darvill and G Wainwright
The Stones of Stonehenge
http://www.archaeology.co.uk/news-features/the-stones-of-stonehenge.htm
Issue 252 of Current Archaeology
---------------------------
We have seen references to bits of bluestone at the Cursus and at Woodhenge, and then we also have other bluestone flakes and chips turning up elsewhere -- not to mention the MPP theory of bluestones being used at "Bluestonehenge" -- and perhaps I could ask a question of you guys who know some of the other excavations: is the soil sequence the same as that shown in the top picture above, away from Stonehenge? And what's the "dark layer" which is sometimes mentioned? Is that in a consistent stratigraphic position?
35 comments:
Sorry folks -- my caption is confusing. the top pic is from the 2001 dig -- the lower one is of course from the Atkinson era -- 1958. They don't do cranes like that any longer.........
I put that one up to show the incredible complexity of the intersecting sockets etc -- Profs D and W found the same thing in their dig.
oops -- I meant 2008 dig....
Atkinson and others seemed to accept that the layer may have extended beyond the Ditch but not I believe to any great extent .
Mike Pitts found dolerite and tuffs among flint and sarsen in a pit near the Heelstone , Hawley also found a pit with “large clump of sarsen chips “ outwith the monument , neither compared them to the “ layer “ .None of the numerous excavations around various points of the Avenue describe anything resembling the “layer “ either .
Thanks Geo -- very helpful. What do the soils look like at Durrington Walls etc? Typical reddish soil with lots of bits of chalk and flints, grading down to broken chalk bedrock below, and with a humus-rich layer at the surface? I remember reading a big tome about the Salisbury Plain soils a while back -- must try to find it again.....
Ah yes -- 24 April 2011 -- seems like years ago!!
Link here:
http://brian-mountainman.blogspot.com/2011/04/soils-of-stonehenge-area-no-trace-of.html
I think the soil was quite a bit deeper at Durrington Walls than at Stonehenge. GW used JCB 's to do the initial clearing down to the chalk .
Brian
The 'dark layer' is an organic deposit made when water lodged in the ditch after it was abandoned - the common name of 'peat' would have been the best description - but archaeologists don't like to link water with the ditch for some misplaced reason.
The layer is concave to the contours of the ditch and found halfway between the top and bottom of the ditch on top of a backfilled or natural subsided bottom layer - so this is not a 'stonehenge layer' and would not extend beyond the ditch.
As for the broken bluestones stones - they are 3725 'logged' samples found although only half the site was excavated so we are looking at 7500 pieces minimum if not more as the ones laying on the surface would have been no doubt taken as souvenirs over the last 5,000 years making the original stone scattering nearer the 10,000 mark.
Large numbers of these flints were found in the backfill of stone holes holes such as the Aubrey Holes which show that they were scattered widely over the surface prior to the removal of the bluestones from the Aubury Holes - as they naturally fell in afterwards.
This then indicates that the ditch was 'cleaned out' regulary as it does not have these stones in the base or the 'dark matter' that established itself after the ditch was neglected.
This lack of understanding of how the ditch came to being and why it was used has caused archaeologists to incorrectly date Stonehenge at 2500-3000BC based the remains of antler picks used to clean out the ditch (and not create) have been found.
In conclusion, the extreme numbers of broken stone pieces would allow the 'layer' to naturally spread beyond the ditch into the top soil only, but NOT as a 'natural' feature.
RJL
From just a photo,its impossible to say for certain, but in my opinion. The Atkinson photo does not appear to show any evidence of man made stone sockets. The Deeply pitted appearance of the Chalk bedrock surface, has all the Morphological hall marks, diagnostic of chemical dissolution of the chalk in the epikarstic zone.
I'd be interested in and welcome anyone elses opinion or alternative interpretation.
I've only had a brief look, and it requires a proper on site investigation to establish the presence of the Stonehenge layer or fragments of bluestone. But the borehole records on the BGS website, show a widespread distribution of reddish brown to dark brown top soils, with chalk and flint fragments grading down to blocky chalk bedrock, to at least 15km away to the north west. .
Brian,
Interesting photos! The tortured face of the chalk under the Layer does not appear to me to be the work of Man, but the work of Nature.
I have some inconvenient questions. If we were to dig anywhere in the inner Stonehenge area, will we see the same surface texture? Are the 'pits' which are said to have contained stones in a circle? Or here, there and everywhere! Randomly, as only Nature (but not Man) intent.
As you know from previous posts, I believe the empty pits were formed by blocks of ice dropping in a jumble from above over the ice edge and leaving the empty pits once they melted away.
Finally, I don't believe these pits are deep enough to have contained megaliths. Aren't the megaliths in fact 'implanted' into the chalk bedrock, rather than raised and held erect by packing stones? From the photo, many of the packing stones seem to be rather rounded.
What do you think!
Kostas
If we are talking about solution processes and the interface between solid chalk and the regolith above, it is quite relevant, I think, to ask what this interface might look like in three dimensions. There is also the tendency, in archaeological digs, to scratch away at everything loose until you come to something solid -- so I do wonder sometimes whether a layer, a boundary or a surface might be an "artifice" created by the excavation process. I dare say that archaeology textbooks and manuals have chapters devoted to this sort of thing.......
That having been said, I have seen quite a few sections where chalk soils have been revealed, and I don't recall seeing such jagged or irregular boundaries between the solid rock beneath and the regolith above.
Brian,
Your site is becoming a 'think tank' on matters of Stonehenge! Many thoughtful comments and useful information.
Concerning the Stonehenge Layer and its confines to Stonehenge. (I realize the Layer may have a more restrictive definition, but I simply mean the layer of debitage to be found at Stonehenge proper. I think you use the term in this sense too.)
From Alex Gee, we have:
“borehole records on the BGS website, show a widespread distribution of reddish brown to dark brown top soils, with chalk and flint fragments grading down to blocky chalk bedrock, to at least 15km away to the north west.”
From Geo Cur, we have:
“Atkinson and others seemed to accept that the layer may have extended beyond the Ditch but not I believe to any great extent .
Mike Pitts found dolerite and tuffs among flint and sarsen in a pit near the Heelstone , Hawley also found a pit with “large clump of sarsen chips “ outwith the monument ...”
From Rob Ixer, commenting on the 'debitage' found at Stonehenge and at other sites, we have:
“I can detect NO 'regional' differences no sites of especial knocking.”
This is what I come to understand from all this. Correct me if I am wrong.
1)The stone fragments in the debitage at Stonehenge are no different than the stone fragments found in the debitage in other prehistoric sites.
2)The debitage layer at Stonehenge is generally confined to the Stonehenge area, extending not much beyond the Avenue and around the Heel stone.
3)In the surrounding countryside (beyond these contained areas where stone fragments debitage exist) boreholes show no evidence of stone fragments found in the debitage at Stonehenge and other sites.
Conclusion: Stone fragments debitage layers are well confined to monument sites but do not extend and cover the surrounding countryside much beyond the sites proper.
I know more study is needed. But do you accept this conclusion as a good starting point thinking about this?
Kostas
Kostas ,in relation to 1),some sites eg cursus are relatively "clean " . Megalithic sites tend not to have anything like the Stonehenge layer , most stones tend not to be dressed or have a tradtion of souvenir chipping .
Sockets for standing stones vary .It depends on the stone shape and monument . Tall thin stones have the deepest sockets, others are keeled , squat stones often are just set in minimal pits relying on mass and gravity , others are set in a beds of small stones . Recumbents need only a little digging to ensure they are level .Timbers being narrower and generally much taller had post holes estimated at one third of their height above ground .
Geo,
I appreciate the info you are providing. But I also see much interpretation in what you report of the 'raw facts'. Based on an 'understanding' that underlies your observations of the facts. This is not atypical and I see it as 'being human'. And is reflected in all other 'human endeavors' as well. Its what makes 'honest discussion' difficult but also very necessary. I value this dialectic for that reason.
Each of us brings to these discussions different perspectives necessary in arriving at the truth. Though we can question our views we mustn't question our integrity holding these views. It is fair to say my views are very different from all others in this blog. I am, as you once said, an 'exception of one' in believing that Nature had more to do in the construction of these monuments than prehistoric men. There are many reasons why I believe this. Some I have already mentioned in previous comments. Others I hope to bring up in the proper context.
As difficult as it may be sometimes, we must separate 'facts' from 'interpretations'. For example.
Fact: stone debitage can be found in other megalithic sites, but not as profusely as in Stonehenge.
Interpretation: the megaliths in other sites are not as dressed as those at Stonehenge and therefore there will be less waste debitage at these sites.
Flaw: Waste chippings from polishing an orthostat would fall at the base of the standing stone and near the vicinity, and not be evenly and deeply mixed-in with the soil. Such stone fragments will form a distinct layer with high frequency of chippings that trace to the orthostat. What we have, instead, are great variety of stone fragments evenly spread throughout the Stonehenge circle and not trace to any currently standing stones (though, it is argued, they may trace to some buried stones or stones that have been destroyed down to small waste debris and spread all over the area).
From the information reported in this blog we have the following geomorphology:
Debitage layers found (to a larger or smaller extend) at prehistoric sites cannot be differentiated as to site. These layers do not extend more widely into the surrounding countrywide. Beyond the sites proper, the surrounding terrain is covered by expected layers of soil, but no debitage.
This I take as a 'preliminary view' which needs to be confirmed by proper scientific field study.
Using this view as 'plausible', I ask:
What natural or human agency can account for these 'facts on the ground'?
Human agency cannot account for this. Glacier deposits cannot account for this. Only my 'local ice cover' theory can fully account for this! This is my humble conclusion!
Kostas
Kostas ,how many times have I to ask , could you please refrain from making up statements that I didn’t make eg when did I say “stone debitage can be found in other megalithic sites, but not as profusely as in Stonehenge. “
Read what I actually said ie “, most stones tend not to be dressed or have a tradtion of souvenir chipping .” it was a statement of fact , not interpretation , if you disagree with that provide the evidence in a counter argument . I tend to stick to facts ,boring as that may be ,if I do roam into interpretation as in the rare case of BA iconoclasm there are warning signs , don’t take this too seriously this is merely my imagination at play but at least there was some supporting evidence , unlike your imaginative ideas which still remain evidence free .
Geo,
In my 24 October 2011 15:27 comment on this thread I summarized information presented by others in this blog and the understanding I have based on this. I asked for corrections to that understanding. And I am perfectly willing to adjust my understanding of the facts.
So, what exactly in not correct? I am not interested in having a 'food fight' with you. I am only interested in knowing the 'raw facts on the ground', as distinct from interpretations of these facts.
Your statement “...some sites eg cursus are relatively "clean " “ to me implies that other sites have more debitage.
Your statement “...most stones tend not to be dressed or have a tradtion of souvenir chipping .” to me reflects your views of human agency in the forming of the debitage. Do stones 'dress' by themselves or have a tradition of 'souvenir chipping'?
Your observations of the facts carry with them your underlying understanding of the facts! This is plain human! No less so in Physics than in prehistoric archeology!
There is no need to argue the facts. We can objectively and scientifically determine the facts. Are there stone debitage in other prehistoric sites? Are the stones in the debitage at these sites indistinguishable as to site? (Dr Ixer thinks so!). And do the debitage layers found at Stonehenge and other sites extend beyond the site proper into the surrounding landscape? (Alex Gee says borehole evidence of that landscape only show soil and flint and chalk).
If I am wrong in any of the facts, I'd be delighted to correct my knowledge of the facts. I simply cannot accept 'interpretations of facts' as 'facts', however. And I am objective enough to know the difference.
Kostas
I think we are going round in circles here, folks. Can we now forget about this and move on to something else?
You’re the boss Brian so feel free to delete but there are some simple points that might help clarify some things for Kostas .
Debitage like the Stonehenge “layer “ is almost unknown . Many sites have finds like burials , signs of feasting or habitation , deposits including cremations and artefacts ,paved areas etc . Megalithic sites like stone circles tend not to have their stones dressed or have traditions where the stones are chipped for souvenirs .
Cursus (plural ) are relatively “clean “ meaning they have little of the above .
Thanks Geo. You are a very patient fellow -- enough now, please, Kostas.
"What we have, instead, are great variety of stone fragments evenly spread throughout the Stonehenge circle and not trace to any currently standing stones (though, it is argued, they may trace to some buried stones or stones that have been destroyed down to small waste debris and spread all over the area).
NO NO No No No No No No No I am not certain a single statement is correct -aside from the repetition.
(Von Daneken all is forgiven.-bring on the Chariots of Fire, sorry different but related blog!!)
B.....y read what is written-this is why you should read the PRIMARY literature and not etc etc etc.
Much, perhaps most, of the debitage is spotted dolerite; most of the standing orthostats are spotted dolerite.
So I shall spell this out in mono- ah small short words
the rhyolitic debitage, a major, but not sole, component of the debitage and SH layer cannot be matched to the standing rhyolitic orthostats. No more no less.
Mr Ragazas go away and read at least 5 primary sources and then take their salient point and work from there-this is part of the research method more satisfying than idle speculation.
Jean-Robert Sabot
Jean-Robert Sabot you write,
“the rhyolitic debitage, a major, but not sole, component of the debitage and SH layer cannot be matched to the standing rhyolitic orthostats. No more no less.”
Is this PRIMARY? If so, thank you! I have no problem accepting facts.
Please explain how this 'rhyolitic debitage' got to Stonehenge!
Kostas
Brian
Returning to dissolution processes.
Thats a good point. The Chalk/Regolith Contacts I've seen have been much more regular and far less jagged, if at all.
The much greater irregularity, of the surface in the photo, seems more typical of a Carboniferous Limestone/Regolith Contact;as seen in karst areas like the Mendip Hills.
GCU, Given your expertise in the subject,I am genuinely interested in your opinion on this. Would you mind commenting on the following?
By my understanding, the much greater irregularity, of the carb limestone surfaces; when compared to the (normally) much smoother and more regular surface of the Chalk. Is mainly due to the much faster dissolution rate of the Carb Limestone(although other variables have an influence).
The question that needs answering. Is why does the chalk bedrock surface at the site in the photo, appear to have been subjected to much greater/faster dissolution, than that observed at most other Chalk/regolith contacts?
Could the reason be, that the chalk was exposed at some time to water with a much lower than normal Ph.
Such as Glacial meltwater?
Resulting in much higher than normal rates of solutional denudation?
Although that's a silly idea, Glaciers never reached anywhere near Stonehenge?:)
If the idea is plausible,it could well be possible, to map the extent of any ice cover (and the route of any outflow channels)by quantifying the degree of dissolution of the chalk surface at different locations.
***No RJL this is not evidence for an inundation***
Alex Gee,
I am very interested in what you are saying! I too have been very puzzled by the surface texture of the exposed chalk bedrock in the Atkinson photos. It just does not seem likely these pits were made by men for the purpose of erecting stones. The pits are much too irregular and there are pits within pits and all other forms of random features.
I have argued before for a 'local ice cover' of Salisbury Plain (perhaps what remained of the great glacier melting, but preserved in time caught within the Deventian freezing episode). A meltwater retaining basin may have formed at Stonehenge, with the Avenue being the eventual draining channel.
As I have tried to argue in my many posts in the past, this hypothesis can explain many (all!) of the 'facts on the ground' as I know them. I have a long list of even minute details of these facts that can be so explained!
I am very interested in what Brian has to say to your comments.
Kostas
Sorry Kostas
As I said in my post, even if there was proof(nasty word) to support the idea, It doesn't support RJL's theory, or your theory either.
With regard to my post: My suggestion is only based on a photograph, so at the moment Its not even a proper hypothesis just a suggestion on a blog site. I have no evidence whatsoever that dissolution of the chalk surface at the site,has occured at more than normal rates. If it has, there are other equally plausible explanations.
Alex Gee,
In your post you write,
“Could the reason be, that the chalk was exposed at some time to water with a much lower than normal Ph.
Such as Glacial meltwater? “
This comes closer to my position than anything posted in the past. But I understand your reservations!
And I agree with you. Detailed scientific study is needed. But we do agree human agency cannot account for such surface in the bedrock.
In the spirit of an open and honest exchange of ideas, I ask:
1)Is the chalk bedrock at Stonehenge the same everywhere at Stonehenge as is shown in the photo?
2)Is the chalk bedrock beyond Stonehenge in the surrounding countryside different from that shown in the photo?
3)Does the Avenue show characteristics of a meltwater drain channel?
4)How does the Stonehenge bedrock compare with the chalk bedrock at other sites?
Kostas
Kostas ,Anthony Johnson described the underlying chalk in the centre of the monument as “resembling a very badly mauled Swiss cheese “ , none of which is due to natural causes but all human agency . As has been advised by others it might be an idea to read some primary source material and the all important “Cleal , Walker & Montague “ Stonehenge in it’s landscape “ which will cover many of your questions and go some way to explain the Swiss cheese . http://www.amazon.co.uk/Stonehenge-Its-Landscape-Excavations-Archaeological/dp/1850746052/ref=sr_1_sc_1?ie=UTF8&qid=1319750086&sr=8-1-spell
Geo,
I like “very badly mauled Swiss cheese”. Fits perfectly. Or you are suggesting that the holes in Swiss cheese are 'man made'!
Of course, why rely on Johnson to describe what we can plainly see in the photos? Don't you trust your own eyes and mind to see what is there and think what is sensible?
My question is whether the entire Stonehenge area proper looks like that. And if the bedrock surface of some other sites are similar. Know of any “raw evidence” of that? Photos will be fine!
No need to be academic over this! They have no more common sense than the 'man on the street'.
I am very patient and persistent. Have no trouble letting the “raw evidence” lead us to the truth.
Will you be there to 'see it' and celebrate with me?
Kostas
OK -- I was going to abandon this one -- but it seems to have taken on a life of its own.
This all relates to the multiplicity of pits and sockets (some intersecting) which seems to be revealed in the 1958 excavations and in later digs conducted on the bluestone horseshoe and circle perimeter. This heavily pitted chalk surface might be:
(a) a natural feature caused by aggressive solution processes at the regolith / chalk interface;
(b) an "artifice" caused by the tendency of archaeologists to scrape away at anything soft during these excavations;
(c) a result of the builders of Stonehenge changing their minds all the time, and moving stones about from one setting to another.
Kostas (he will correct me if I am wrong) wants another theory in there, namely that these pits are "compression pits" caused by heavy stones sliding down an ice face and thumping into the soft chalk bedrock. I am dismissing that one, since Kostas is always strong on theory and deficient in fact -- and has failed to show us a single example from the natural world which might lead us to say "Yes, this happens there -- and therefore it could have happened here." Occam's Razor, Principle of Uniformitarianism and all that......
Much as I like the idea of "aggressive solution processes", this doesn't look to me like something attributable to solution of the chalk -- and from excavations elsewhere at Stonehenge the regolith - chalk interface seems to be much smoother and more regular. Mind you, there haven't been a lot of digs away from these "hot spots" simply because the archaeologists always head for the zones where they will get greatest "added value." Fair enough.
On balance, I'm very happy to accept that these pitted areas are indeed excavated stone sockets, with the chaos simply down to the changing priorities and/or indecision of the builders.
Brian,
Since you commented on my theory I like to comment on your misunderstanding of my theory!
My view is that the chalk bedrock surface is natural and not man-made.
I don't believe, however, that “these pits are "compression pits" caused by heavy stones sliding down an ice face and thumping into the soft chalk bedrock.” as you claim I claim.
But I do believe such 'empty pits' found at Stonehenge and also discovered in 1890s at Medmerry Beach (as you posted last year) may have formed when blocks of ice in a jumble dropped over the ice rim to embed into the soft chalk bedrock. When latter the ice melted and the meltwater basin drained and dried the 'empty pits' and the 'jumble of ice imprint' in the soft chalk bedrock were left behind.
This explanation also explains the mysterious 'empty pits' at Medmerry Beach! Remember?
Please ask for clarification of my explanations rather than persist in your misunderstanding of them. I am a mathematician! I deeply believe in 'evidence and proof'! So you can appreciate my sensitivity to this issue!
Kostas
OK Kostas -- sorry for misunderstanding you!
However, your new scenario is just as unlikely. Why should the chalk be softer than it is today? Where is the evidence for this meltwater basin and for the "melting ice pits"? Nowhere to be found. Where are the parallels from the modern world? Nowhere to be found. Where is the evidence for your geothermal hot spot? Nowhere to be found.
Your problem, as I have said many times before, is that you have conjured up a hypothesis on the basis of a quite inadequate understanding of geomorphology -- and thus have to spend all your time trying to find "evidence" to fit the hypothesis.
Since you keep on protesting your vast respect for truth and the scientific method, will you just do us all a favour by abandoning your hypothesis, going back to the beginning, and collecting up some field evidence? Then, when you have done that, you can come up with a new hypothesis that best explains the things that you have found?
In other words, please try to work to the same principles as the rest of us?
Kostas -- I am blocking your latest post. I am not going over all of this again -- life's too short. End of discussion.
Kostas , you said “” I like “very badly mauled Swiss cheese”. Fits perfectly .””
Careful you’ll be reading poetry next .
And also said “Of course, why rely on Johnson to describe what we can plainly see in the photos? Don't you trust your own eyes and mind to see what is there and think what is sensible? “
They are a perfect example of not trusting your eyes . Apart from being mirrors of our souls they are also mirrors of our beliefs in this case your beliefs , quoted below .
“Interesting photos! The tortured face of the chalk under the Layer does not appear to me to be the work of Man, but the work of Nature.”
“It just does not seem likely these pits were made by men for the purpose of erecting stones. The pits are much too irregular and there are pits within pits and all other forms of random features.”
Show how belief can make us “plainly see” things mistakenly .
Geo -- stopping this one now, to save all of us from apoplexy.....
In the second picture of Stonehenge being excavated, could the holes within holes phenomena be the result of the previous digs that had happened at Stonehenge and also can anybody tell me which stone that is at Stonehenge in the picture... Great blogs by the way :)
Thanks Anon -- I'm not sure that any of the earlier excavators at Stonehenge would have knowingly dug down into the chalky debris or bedrock. I suppose it's possible in some of the early and unrecorded digs. I'm most convinced by the interpretation which says there were genuinely many different stone settings, with stones moved about and with new sockets established -- some of which intersected with earlier sockets.
Which stone is that? Can't remember offhand -- but if you go to the English Heritage site and look at the library of Atkinson / Stonehenge photos, there are many which can be examined. And I think they are well labelled too -- and noting which stones are portrayed in each photo.
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