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