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Tuesday 13 September 2011

Did the Irish Sea Glacier reach the English Channel?



 




Long, long ago, BMPPTDGW (before MPP, TD and GW) our old friend Geoffrey Kellaway suggested that glacier ice had reached the English Channel.  He was, of course, laughed out of court ... although I hope I gave his ideas some degree of respect in my discussions on this blog concerning the "giant erratics" on the coasts of Southern England.

Well now, time to think again.  Thanks to Henry for drawing this to my attention -- a presentation by Daniel Praeg which has recently been made at specialist conferences.  No doubt there is a considerable stir, because what these guys are showing from their work in the Celtic Sea is an extraordinary series of parallel or "fanning out" ridges which run right out to the edge of the shelf, at c -200m.   That is far beyond the maximum ice limit as assumed by Chris Clark, myself, and everybody else.

These ridges are not of any great amplitude, and on top of them are smaller transverse ridges, but the authors are quite convinced that they are not marine bedforms or anything to do with currents, tidal streams or sea bed slumps etc.  They appear to me made of glacial or glacio-marine sediments, but it remains to be seen whether these sediments run right through the ridges, or whether we are looking at a surface veneer that might have been dropped from floating ice.  No doubt this will all be published in due course, and we will then be able to examine the detailed evidence.

The "accepted limit of glacial till" (the white line on the map) is wrong anyway, as we know from our discussions on the Bristol Channel, but if we reconstruct an ice margin based on the existence of these submarine ridges -- either in the Devensian or in some earlier glaciation, we have the intriguing possibility that glacier ice did indeed push well into the English Channel, maybe even to the east of a line drawn between Land's End and Finisterre.

See this earlier post:
http://brian-mountainman.blogspot.com/2010/06/sea-ice-and-giant-erratics.html 

Reference:  GLAMARous RIDGES : exploring glacial landscapes in the Celtic Sea
Daniel Praeg1, Stephen McCarron2, Paul Goldsberry2, Martyn Stoker3
(Powerpoint presentation -- available as a PDF)

34 comments:

Constantinos Ragazas said...

Brian,

Hmm! … we have ice in your “ice free” area, now we have ice in the English Channel!

It's getting warmer and warmer! Soon you will be once again making a public acknowledgment that I was right!

This brings us closer to my claim that Salisbury Plain was covered by ice during the Devensian.

Of course, all scientific evidence is welcomed. But we can reach the same conclusion (as I have) if we consider that the stone alignments, circles and earthworks ARE evidence that ice covered the area. In my article I describe the natural mechanisms that explain these 'facts on the ground'.

Kostas

Tony Hinchliffe said...

Broadening the subject out to that of glacial Britain/ Europe in general, I have just heard BBC Coast's Neil Oliver talking about his 2011 book,"A History of Ancient Britain", on Radio 5. He seems well informed about glaciation, at least in general terms, and for a qualified archaeologist. Perhaps you should contact Neil. As the Presenter of the "Coast" Series as well, he ought to be receptive to all points of view on Pembrokeshire, Salisbury Plain & the bluestones.

Constantinos Ragazas said...

Brian,

Is the photo of these ridges (in buff) found submerged in the English Channel, a Google Earth photo? Can these ridges be seen by satellite photography, or using submarine photography? Or perhaps a totally different technology like radar or sonar.

Can you tell me how the geographical orientation of these submerged ridges relate to the orientation of the stone alignments at Carnac, France?

I have always been impressed and puzzled why the stone alignments in Brittany all had the same geographic orientation. If men made these, why not use a variety of different orientations? Why just rows and rows of stones orientated the same and with no sense and reason?

It seems to me these submerged ridges are geographically close to Brittany. I remember reading that some stone alignments at Carnac actually lead into the sea along the coast.

Could these ridges be in fact submerged stone alignments? Like the submerged stone circle found in the bottom of Lake Michigan. Now that would be most revealing!

How DID Neolithic men erect stones alignments and circles at the bottom of the sea? They had to be aliens …

Kostas

BRIAN JOHN said...

Definitely not Googlr Earth! A range of very sophisticated techniques involved -- after all, these are now covered by up to 200m of sea water!

All the stone alignments in Brittany have the same orientation? i don't think that's true -- perhaps Geo will know?

Geo Cur said...

Kostas ,the general direction of the stone rows are similar but they vary even within each ro . Average is 65 -71 degrees . They are however considered to be above faults and one bloke Mereaux believed them to be earthquake indicators .I think the fault line aspect is true but not sure .

Constantinos Ragazas said...

Geo Cur,

Thanks for the info! I had read years ago that the stone alignments in Brittany had more or less the same orientation, but couldn't find the reference where I read that. And I also knew that these were above faults.

All this, of course, raise serious questions about these stone alignments being the work of men!

In my article I argue that such rows of stones were formed when men and even boys dropped these stones 'from above' over the ice edge. Or possibly, these stones just naturally fell over the edge, as the photo suggests.

They form a record of where the ice edge was over time. I think, looked at this way, these rows of stone alignments may provide geological records that can have scientific value to someone that can pursue this line of reasoning.

If it turns out (as I suspect) that the ridges discovered submerged in the English Channel are also similar stone alignments, that would really be BIG NEWS and capable of turning our whole thinking around and closer to my theory! Nature had more to do with all these than prehistoric men, as we currently think.

Let's keep an open mind and the truth will surely be revealed to us sooner or later!

Kostas

BRIAN JOHN said...

Kostas -- take it from me that the ridges in the Celtic Sea are nothing like what you want them to be. I have seen the evidence from the presentations. They are either eskers of submarine bedforms created by currents etc.
And as for the ice edge at Carnac -- you have the same old problem as ever: not a scrap of evidence. Please do not delude yourself that the evidence is moving towards a verification of your theory. It is not.

Constantinos Ragazas said...

Brian,

You may be right!

If you are right, I'll go to the nearest taverna and have some ouzo!

But if I am right, I'll go to the nearest taverna and have some ouzo!

Kostas

Geo Cur said...

Kostas ,the orientation of the stone rows are on average 50 degrees further south than the orientation of the ridges . Three rows Lagatjar , Leure and Raguenes have the stones set perpendicular rather than parallel to one another . At St Just some of the stones were erected into cairn material which in turn overlay a hearths dated 5580 BP . Part of the Kermario alignment overlies a Long mound . Does that not pose a problem for your theory ?

Constantinos Ragazas said...

Geo Cur,

Thanks! I really do appreciate the input. Seems that you know many details about prehistoric archeology and I find that valuable. Are you an archeologist?

Let me just say that often I may overreach with my claims. Brian knows that better than anybody! But let me also add that my commitment is only to Truth and Reason.

I am in the enviable position to question everything and embrace nothing that does not make sense to me. Though I may have some (many?) details wrong (or right), I do believe that I have the larger picture in this correct.

Nature played a far greater role in the making of these prehistoric monuments (all over the world and not just in the UK) than we currently think. I also do not believe that prehistoric men had the capabilities that too often we romantically prescribe to them.

My theory falls somewhere between these two extremes of Nature and Humans. I have specific mechanisms that in my mind provide sensible explanations to all the 'facts on the ground' that I am aware.

But I should (and do) reserve judgment on these latest 'facts on the ground' in this post by Brian. They are certainly very puzzling, even to me! It seems that the nature and composition of these submarine ridges can be established with a couple of scuba divers taking pictures and samples! Brian, are there obstacles to that?

So to your question, “Does that not pose a problem for your theory ?” I would argue not!

Certainly natural features can overlay and run into one another. And there can be special circumstances which result in what appears to be a contradiction on first sight. But I need to know more specifically what these references that you make look. Can you post some links to these for me to look at?

Kostas

Geo Cur said...

Kostas ,LOL, no not an archaeo . The Lagatjar etc perpendicular rows are mentioned with plans in Burl "Megalithic Brittany" 1985 and Mark Patton "Statements in Stone " 1993 .
The Kermario row overlying a long mound can be found on the web by searching "kermario long mound " failing that the main book is Giot , L'Helgouach & Monnier "Prehistoire de la Bretagne" .The St Just hearth etc is from Charles Le Roux who wrote a series of papers in Gallia Prehistoire from 1979-1983 .he has had plenty translated but sadly not these .

Constantinos Ragazas said...

Brian,

In your post, you write,

“These ridges are not of any great amplitude, and on top of them are smaller transverse ridges, but the authors are quite convinced that they are not marine bedforms or anything to do with currents, tidal streams or sea bed slumps etc.”


In your comment to me you write,

“take it from me that the ridges in the Celtic Sea are nothing like what you want them to be. I have seen the evidence from the presentations. They are either eskers or submarine bedforms created by currents etc.”

Do I sense here a contradiction and/or a stubborn refusal to consider anything I suggest? Interesting on all counts!

And please don't block my responses to Geo! It skews the discussion by leaving one side blank and blinking!

Kostas

BRIAN JOHN said...

No contradictions -- since I put up the post I have seen two further papers -- one of which says they are submarine bedforms caused by marine processes, and the other that says they are eskers. So there is a scientific controversy going on!!

Constantinos Ragazas said...

Brian,

Why can't scuba divers investigate these ridges and solve this mystery? Just 200 m deep does not seem all that deep.

Kostas

Constantinos Ragazas said...

Geo Cur,

Picking up on an earlier post … it is true, then, that all the stone alignments in Brittany are oriented NE to SW, generally speaking. Of course there are some fluctuations and exceptions in the direction of the ice edge due to other more local factors.

If my hypothesis is true, however, that these stone alignments mark (more or less) the retreating ice edge, then the direction of such retreat would be from SE to NW.

Of course, NW from Brittany we have Salisbury Plain and further west Wales and Ireland and beyond that Iceland and Greenland. I ask. Isn't this in fact the direction of the retreat of glaciers? Is this just another coincidence out of many coincidences?

We could, of course, claim that the intention of Neolithic men over several thousands of years was to erect these stone alignments in the way these alignments are!

That doesn't make sense to me! Does it make sense to you?

Kostas

Geo Cur said...

Kosta , can you tell me the the bearing of the leading ice edge ? Whatever it is I will then point out stone rows that are perpendicular to that bearing .

Alex Gee said...

Kostas
Although a reasonable idea, 200m is far too deep for conventional Scuba diving.
An investigation by diving; would most probably require a commercial outfit/set-up.
The costs would be prohibitive.

The conditions and dificulties involved (location,tides etc) in obtaining acceptable samples, would also be extremely challenging.

Constantinos Ragazas said...

Geo Cur,

I am working on a 'working hypothesis'. No claims as to hard geological evidence. That much I've learned from Brian!

But sometimes, looking at the facts 'from afar' enables us to see more of 'what is' than looking at the facts under a microscope and through the lens of conventional theory. Lenses (whether real or theory) have 'focal points' beyond which we cannot 'see'.

Before I get into more trouble with Brian and you, let me quickly add that I believe in both: the microscope and the telescope!

When it comes to looking at the evidence with 'fresh eyes', however, nothing is better than having a 'non-expert' seek to 'make sense' of the facts. This is so because his/her sensible mind is more connected with Nature. And of course the truths we seek, I believe, are truths of Nature (and not men!). On this we may disagree, but that is OK.

I look at the stone alignments at Carnac, Brittany as marking the edge of an ice sheet. So take their bearings as those of this ice sheet. The fact that most all of these (with rare exceptions that may have other sensible explanations) are rows and rows of near-parallel and near linear arrangements in my view agrees with my 'working hypothesis': that these stone alignments mark the edge of a retreating ice sheet. Certainly you wont expect the edge of a retreating ice sheet to 'cross itself', perpendicular or not!

The submarine ridges in Brian's post reminded me of these rows of stone alignments. That some of the stone alignments recede submerged into the sea along the Brittany coast reinforced in my mind this connection and possibility. The orientation of these stone alignments also perfectly agrees with the NW direction that you would expect of such retreating ice glaciers. This also adds 'fuil to my intellectual fire'.

But I acknowledge that this is 'wild speculation'. Brian cannot make it! You probably cannot make it. And Alex Gee I am certain cannot make such 'leap of logic'. But I can and I should for all of us!

Kostas

Geo Cur said...

kostas , whhre do the stone rows that are aligned NW-SE .i.e. perpendicular to the edge of the retreating ice fit into your theory?

Constantinos Ragazas said...

Geo Cur,

According to you (and the article I recall reading), these stone alignments are in the direction 65 to 71 degrees on the average. That would make these alignments generally in the NE to SW direction.

If you are asking about some exceptional alignments NW/SE, these I believe can be sensibly explained by local factors. After all, an ice edge is never perfectly straight for miles on end. You can have an ice edge (and a coastline and even a road) running generally in the NE/SW direction, yet in some places locally the same edge to be in a different direction, even the opposite direction! Have you ever following a road marked N but traveling S, yet be on the right road?

Kostas

Constantinos Ragazas said...

Alex Gee,

Thank you for making my 'puzzlement' astonishing! Here we have a 'myth-shattering-mystery' submerged just 200 meters in the English Channel, yet can't find the funding to find the answers.

It's time to call Cameron to bring the Titanic crew to location!

Kostas

Geo Cur said...

Kostas , roads are man made and avoid local topographical problems like bogs ,rocks and constant inclines that glaciers have little concern for .
There are a lot more stone rows in the UK than those mentioned in Brittany and they are aligned in all directions .

Constantinos Ragazas said...

Brian,

Having read some on eskers, I am now completely confused!

Eskers form as stratified deposits of sand and gravel left behind by meltwater channels under and through glaciers. How could these ridges submerged some 200 meters in the English Channel be eskers? And why such strange fan pattern with all of these ridges linear and parallel -- reminiscent of stone alignments?

I am assuming that glaciers are above ground and sea surface, and not under water. And I assume water channels through glaciers could take any direction. But more than that! What can we make of the 'small traverse ridges on top of the long linear ridges? How does that fit the 'esker view'?

Brian, in previous posts we debated the transport mechanism of the many large boulders found along the coast and specifically at Medmerry Beach -- where a storm in the 1800s revealed huge boulders in the seabed along with 'empty pits'.

You argued that these stones were dumped on the beach by a 'flotilla of icebergs', while I thought it was more sensible that these boulders came overland on the surface of an ice sheet and dropped over the ice edge along the coast.

That would explain the embedded boulders as well as the 'empty pits' – as these would have formed when blocks of ice (carried the same as boulders) would in a similar manner embed into the seabed; but when the ice melted 'empty pits' would be left behind.

Brian, I speculate that the ridges found submerged in the English Channel may be related to the many boulders found along the coast; as well as the stone alignments found along the coast of Brittany just on the other side of the Channel.

Certainly, if a 'flotilla of ice rafts' dumped boulders on the coast, many of these boulders would also be dumped into the sea.

But here is the problem with you 'flotilla transport theory'! The stones dumped into the sea would then be randomly spread on the Channel floor, and not in alignments.

If these ridges are found to be stone alignments, then only my theory would explain them! As for the 'small transverse ridges on top'? No problem! These are the outlines of the stone boulders!

Kostas

BRIAN JOHN said...

Sea level was low at the time, Kostas. That's the whole point. So the eskers (if that's what they are) were formed under the edge of the ice sheet as it stagnated on an area that was subsequently submerged.

Constantinos Ragazas said...

Geo Cur,

When glaciers advance they “have little concern” for what's in their way! But it's only when glaciers retreat that they dump their booty!

The edge of a retreating glacier can be as varied as a coastline or a country road avoiding bogs! Man-made roads often follow Nature-made landscapes. That's why the analogy holds!

Kostas

Constantinos Ragazas said...

Brian,

From the photo and from your post, these ridges go up to the edge of a 1000 meter drop in the seabed. What kind of glacier meltwater would “stagnate” at the edge of a 1000 meter drop?

Kostas

Geo Cur said...

Kostas , even if the ice did reach Brittany your theory suggests the the people who were throwing the rocks of the edge were doing so for their descendents to pick up millenia later . Cue for Occam's razor , but it's worse ,the ice didn't reach Brittany .

Constantinos Ragazas said...

Geo Cur,

Just to make one point clear … my view is that prehistoric people DID NOT pick up stones to erect in rows and rows of near parallel near linear arrangements!

Occam's Razor? Nothing can be simpler than what I theorize! No advanced prehistoric lost civilizations, no alien visitations, no magic! Just Nature creating conditions that men then exploit!

I must be doing something wrong to have confused you over this simple point!

Kostas

Geo Cur said...

Kostas ,how do you explain the stone rows of brittany if the ice didn't reach there ?

Constantinos Ragazas said...

Geo Cur,

It is my 'working hypothesis' that some sort of ice at some contemporaneous period with human habitation either 'reached there' or 'formed there'.

The recent discovery of the submarine ridges Brian posted on seems to indicate that glaciers reached much further into the English Channel than previously thought. So it is not a 'fact' that 'ice didn't reach there', but just an accepted belief! I question all beliefs and interpretations of raw evidence!

As a 'working hypothesis', its power to explain the 'facts on the ground' in a simple sensible and consistent way 'proves' it.

This of course is 'falsifiable'. If, for example, rock samples taken from stone alignments at Carnac trace to some quarry in Paris and records are discovered for their transport to Carnac, then I retract my hypothesis and make no further mention of it. But if such samples trace to, say the southern coast of the UK or Ireland, then the evidence would built up in favor of my hypothesis. And if the submarine ridges turn out to be more stone alignments (as I believe they are!) that would definitely boost my hypothesis as it is the only one that would explain that evidence. So much still awaits for future findings.

But the alternative to my 'working hypothesis' – that prehistoric men could and would erect these rows of stone alignments – just does not make sense to me. If it makes sense to you, then you have lots more to answer to – besides a blanket claim of 'human quirky intentions'.

Kostas

Geo Cur said...

Kostas , it is certainly not a fact that the glaciers did extend to Brittany . Good to see that you you have a "point " where you will accept that your hypothesis fails i.e. if the stones are local to the area and therefore no suggestion of human or glacial transport .If the stone had come from say , the Paris basin then I imagine we would have heard about it .I can't find anything on the petrology/lithology apart from a possible Lukis paper from the 19th c maybe someone from Erceldoune might know .

Constantinos Ragazas said...

Geo Cur

A 'hypothesis' by definition can never be a 'fact'. But it is a self-organizing principle around which the facts can coalesce and find simple, sensible and consistent explanations.

I believe my 'working hypothesis' that these parallel rows of stone alignments mark the ice edge of a retreating ice sheet does that.

Using your alternative explanation that these rows of stones were built by prehistoric people, can you answer what was the purpose to them?

If prehistoric people had the time, resources and inclination to built such stone alignments, why didn't they use such energy and skill to mark the boundaries of farm fields, or even to fortify their towns and villages?

It doesn't make sense to me! But I am willing to entertain your thoughts on these sensible questions! But please, no more 'quirky intentions' non-explanations!

Kostas

Geo Cur said...

Kostas ,the use of "fact" wasn't in relation to your hypothesis but in opposition to the 'facts on the ground' .
Where did I say the"quirky intentions " you keep quoting .
I havn't a clue either for the function or reason of stone rows or the other major monuments built in prehistory .

Constantinos Ragazas said...

Geo Cur,

To quote from your earlier post, you wrote

“ … it is certainly not a fact that the glaciers did extend to Brittany”

That is what I am hypothesizing. And there are now new evidence that Brian has posted which seems to support this assumption. We'll see. In the least, it is a disputed fact which I hypothesize as being true!

As for the “quirky intentions”, this ties in to the thread of comments you posted under the post “Bluestone Quarries and Occam's Razor”. But if that is not your position explaining these stone alignments as man-made, then I will not bring it up again.

You write, “I havn't a clue either for the function or reason of stone rows or the other major monuments built in prehistory .”

Neither does anyone else that believes these prehistoric monuments were made by prehistoric people.

My theory on these, however, CAN explain their purpose and method of construction in a simple, sensible and consistent way. Let me suggest that between two competing theories, the theory that can explain more of the evidence and can answer more of our questions in a consistent way has more claim to being true.

On a different note, let me just say that I agree with you in your disputes with Robert! I don't see how he could argue that because the found piece of wood is 8000 years old, that it is a plank in a Mesolithic wooden boat. In a photo Robert has posted in his blog on this, there can clearly be seen a cut or notch into this wood that can only be made by metal hand saw. I suspect this was the reason why the archeologists that found the wood did not think it was significant.

I have argued with Robert this wood, though old, could have been used at any time. We must separate the date of the wood from the date when it was used; possibly a multiple of times.

I did not know that amber can be found along the eastern coast of England! There goes another of Robert's arguments for his Mesolithic boat people!

Kostas