"What glaciation?" I hear you cry. "There wasn't one! There could not possibly have been one......"
Well, maybe it's time to bring Geoffrey Kellaway in from the cold. We have spoken on this blog many times about Kellaway's famous article in "Nature" -- in which he talked about the glacial ransport of the bluestones from Pembrokeshire to Stonehenge. He was vilified for that, particularly by the archaeological establishment. But he was also vilified for another paper, published in 1975, in which he and fellow authors Redding, Shephard-Thorn and Destombes argued that ice from the west may well have pushed into the English Channel during at least one of the pre-Devensian glaciations. The paper was published in the "Philosophical Transactions of the Royal Society" -- it was difficult to get at, and was not widely read. But now, thanks to the efforts to digitise classic papers and to make them widely available, it is on line, here:
http://rsta.royalsocietypublishing.org/content/roypta/279/1288/189.full.pdf
Phil. Trans. R. Soc. Lond. A. 279, 189-218 (1975)
The Quaternary history of the English Channel
By G. A. Kellaway, J. H. Redding, E. R. Shephard-Thorn and J.-P. Destombes
Several lines of evidence for former glaciation of the English Channel are considered. These include the following major geomorphical features: (1) extensive areas of flat featureless sea bed bounded by cliffs with residual steep-sided rock masses rising about 60-150 m above them, (2) terrace forms bounded by breaks in slope or low cliffs, (3) palaeovalley systems related to the present land drainage, (4) enclosed deeps (fosses); all except (3) may be attributed to a glacial origin. The distribution of erratics on the Channel floor and in the modern and raised beaches of its coasts are attributed to widespread Saalian glaciation. This glaciation was responsible for the deposition of morainic material at Selsey and the damming-up of glacial Lake Solent. The so-called ‘100 foot raised beach’ of west Sussex is now re-interpreted as a fluvioglacial deposit laid down at the northern margin of the English Channel ice. It is thought that at the height of the Saalian glaciation mean sea-level fell to between 90 and 180 m below o.d. and that for a time the ice was grounded near the western margin of the continental shelf. Possible reconstructions of the limits and main movements of the Weichselian and Saalian ice sheets covering the British Isles and English Channel are included.
In the article, there are a few strange things, and some of the information and contexts are very dated, having been overtaken by 45 years of subsequent research -- but the article is meticulous, cautiously stated, and full of fascinating observations and deductions. One of the things that struck me, after all these years of forgetting about it, was the conclusion drawn with regard to glaciation traces and directions of Saalian (Anglian) ice movement. Kellaway et al suggest two Saalian glacial episodes -- one which might be equivalent to the Anglian and the other to the Wolstonian. Leaving that little matter on one side, this map is really quite fascinating:
It's a pity the map is so faint. But note that what Kellaway and his friends were suggesting in 1975 was dismissed out of hand by almost all of those working in the Celtic Sea arena, and continued to be dismissed until within the last five years -- during which we have seen the maximum extent of glacier ice in the south-west approaches pushed further out, year by year, until it is now being positioned at the Celtic shelf edge -- just where Kellaway et al placed it in 1975. The submarine evidence for that appears to be very strong.
What is more, the directions of ice movement across Pembrokeshire and the Isles of Scilly are much more accurate than those shown in most recent research papers by the BRITICE team, and by placing an elongated ice shed over south-western Ireland and southwards across the Celtic Sea, Kellaway et al propose ice crossing much of the Celtic Sea and travelling NW towards SE -- as distinct from NE towards SW. I have done a number of posts suggesting just such a situation, since that is the only way I can explain an ice edge at more or less the same altitude in Pembrokeshire and the Isles of Scilly, at least during the Devensian.
Variations of this map have been published many times by researchers associated with the BRITICE project. The ice streams do not appear to accord with the evidence on the ground in Pembrokeshire and the Isles of Scilly.
One of the maps in which I have proposed a more realistic reconstruction of ice streams. This accords much more closely with the map published in 1975 by Kellaway et al.
And another interesting thing is the ice lobe flowing into the English Channel from the west. That makes perfect sense, if the ice was grounded close to the shelf edge 250 km SW of the Isles of Scilly and if the islands were completely inundated by ice, as suggested in my QN paper just published.
As some old Biblical fellow said once, a prophet is not without honour, save in his own country.........
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And here is another interesting item:
2 comments:
"No prophet is accepted in his home town", said Jesus at Nazareth when the natives were turning decidedly unfriendly and cynical.
LUKE CHAPTER 4 VERSE 24.
What those present - day cynics of the glaciation of South Western England need to take on board is that the study of glaciation is an on - going, dynamic science. Just as archaeology has been utilising state - of - the - art science in its attempts to explain the distant past, so too have Glaciologists working within the sphere of Glacial Studies.
If only Geoffrey Kellaway RIP HADN'T worn THOSE glasses, I reckon he'd have been a rival to and a match for the likes of Richard Atkinson [who you've lately told us became a supporter of the Glacial Hypothesis towards the end of his life].
Something more in the style of Ronnie Barker, sadly also RIP, might have provided the necessary gravitas on the Early Goggle Boxes.
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