John Renouf: The contribution of the Société Jersiaise to geology

Hi, hello everybody, it's uh rather nice to be here speaking in this rather.

Welcoming room I always feel here at the socite.

And uh speaking on obviously a subject with which I have had something of a long association, geology. Um, To get straight into what I'm going to cover, uh, I've just sort of almost spun a coin for 33 topics which will embrace other things, but 33 topics for my talk and um these relate to people whom I So for one reason or another, have a special regard for in their geological contributions.

Uh, just one final general point, the relationship between geology and archaeology for most of you here is undoubtedly one which is the geological aspects of archaeology rather than geology per se.

And um the actual things I'm talking about are going to be something of a mixture of the two. But to get straight into it, the latter part of the 19th century, from about 1860 onwards, saw a major confrontation in the geological world concerning the age of the earth and.

There was on one side of this argument, Lord Kelvin. Uh, noted the preeminent scientists virtually of that generation, and his field was thermodynamics, and his work is still sort of up there amongst the greats of thermodynamics.

However, he took it upon himself in the 1860s, it would have been to consider the age of the earth. Attempts have been made to work out what this was. And he used his knowledge of thermodynamics to make a calculation, which first produced an age of about 40 million years, and that reduced over the next 30 years till the early 1890s to to 20 million years. However, the geological establishment The geologists who had had more than a century behind them of detailed studies of the rocks and the processes involved, uh, and also supported more latterly by Charles Darwin and his work on the Origin of Species. They had concluded that there was no way that the age of the earth could be less than than several 100 million years. And this is a very bitter confrontation at times, and it was in the sort of middle of this period that they came, came, came to Jersey, um, well, the Jesuits were established at uh the Maison Saint Louis, that's recent, more recently the Hotel de France, um, and they had a strong scientific element to them and did a lot of teaching in science. And in 1881, they. Jesuit, Charles Newry came, came to Jersey and immediately he'd had some sci uh quite a lot of scientific training. He immediately set about because he loved doing it, he walked the island everywhere and he observed every rock outcrop that he could possibly find all over the whole island. And within 4 to 5 years, an incredibly short time if you think about it, just imagine you doing it now, setting out to do it. In that time, he, he produced a map of the island. This is, this is Charles Newry. And That is the map that he produced in 18 was published in 1886. And it is highly regarded by geologists um ever since, and you could take that map and go out and you could use it today and you wouldn't be so far out in what you were doing. He wasn't actually a member of the So in 1886 or in 1881, when, when he started work, but.

The esteem in which this map was held immediately led to his being elected, believe it or not, a more McDonna of the Sosity in 1887, a very rapid rise in terms of the so, um, and I just want to look at one little aspect of his work, which is quite intriguing, and that is the pinnacle. I don't know how many of you here know it, it distresses me somewhat these days to find out how many young people wouldn't know what the pinnacle was or the pinups I rather prefer calling it.

Um, I mean it's a remarkable piece of geology that, and he wrote an account of the origin of this. And You can see here if I can get the little machine to work. You can see this black line here.

This is the line of a of a dike dipping towards the left as you look at it, up beneath, beneath the pinnacle. And it's strongly eroded on this side and at the bottom of the pinnacle on the western side where it drops into the sea, there's quite a large cave underneath it.

And this little black shot here on this side, this is the eastern side, the land side.

There's There is that, but if you look at the plan, there is the pinnacle, and this, this view here is from across here, so that the black line which you see here, this dike which was eroded, in fact runs here on this side and this is where the vertical cliff is and that's where the deep undercut is. But um just on this side here. There's a deep gully which goes in underneath some head deposits, rubble deposits there, and you can go right through that and out the other side, showing that the pinnacle itself in its fundamental structure is separated from the main heights of Leland.

And the You can read this.

I'm not going to translate it. If you don't know French, you'll have to look it up. Um, he, he predicted that because of the undercutting of the pinnacle, which is a reasonable assumption, I think, that it wouldn't be here, it wouldn't be there 100 years hence.

So this is 1886 that he predicted that, well you know now that I could, he couldn't have produced a photograph in colour like I've just done if it had gone. So it, it did happen in that time, but the The point I really want to make here is that if I pose to you. Two simple questions and you search your soul for this.

How, how would you answer it? How long has the pinnacle been there? In that sort of form. And how long is your estimate of how long it will last there? Will you agree with him that it won't be there at the end of the next century, or do you feel that he's still uh sort of um underestimating or um the time involved. And it would be very easy to say that because of that statement that Noi was making a big mistake here that it wasn't that it wasn't geology anymore when you, you know, he'd lost the plot. But the background of what I said about the arguments about the age of the earth. are very pertinent here because he was a Jesuit priest.

And the church wasn't always in favour of the idea of. And evolution and for the origin of species and so he must have been aware of these undercurrents or overcurrents as it were of in terms of the age of the earth when he made this sort of prediction in the back of his mind, I'm quite sure he's regarded a much shorter time involved. The actual age of the earth is roughly 4.6 billion years, which is quite a bit older than any of the ideas that even existed at that time.

So that was Newry, one of the geological greats as Ralph Nichols, Doctor Ralph Nichols, one of our members calls it geologist, and I think he's right, and Arthur Morrow also praised him extensively, and I do too. His, his little booklet is great reading. What he This map of the whole island, this white arrow shows the outcrop of the Roseal conglomerate, and that's what I want to treat next, um, and this involves, A number of different, quite remarkably widespread threads here.

This, this is a a late friend of mine, Derek Laming, who, who mapped the Torquay red beds around Torquay and I had him over here in Jersey to give a talk in the late 70s, and here we are, or me photographing him um at the little uh bay below the Tael Fort at the Teshu.

Um, and you'll notice the conglomerate here with these big round boulders in it and um.

That is typical Roselle conglomerate, and the Roselle conglomerate, he had a bizarre idea of the origin of it, I won't go into it here. Newry that is. But the actual final sort of assembly of arguments and coming to a definitive conclusion didn't happen until the 1930s. But what I want to do is to. Go back a little bit. Here is a French French group.

Of geologists with me showing them around and this is at Tit de Hoo, and you can see the size of some of the boulders, some of them are very big.

Now I'm going to jump.

I don't know if any of you recognise that picture.

I mean it's in the archives of the Soci. This is, um, I find it quite delightful.

Major yebot, and this is him in about 1913 on military service in India or um as it then was India, but in fact the Punjab, which is. Northern India and in fact the salt range where where where the next photographs I'm going to show come from here is a sort of semi-arid.

Or at times very arid area.

And This is before he was, he could have known that much about, about the geology of Jersey. You might like to read this, that this, this was written by another geologist in Jersey, George Clyman, publishing in 1923, so that's 10 years after the riot was out in, um, out in India and when in fact he'd come back to Jersey and was embarking on the major part of his sausages career.

We've already heard of one of his feats, which was the um drawings of the Maronary horde. But what he noticed was the accumulation of pebbles in the.

Gorgeous that he was looking at in the Punjab.

Uh, see again the mind of the salt range there, and he took these two photographs here which he gave me the full use of ever since, and you can see just gullies without any vegetation, mountainous gullies, and you can see these isolated boulders here, some of them, there's a very big one there, some are huge, um, which They knew out there where they came from and how they got there. They were flash floods from the hills back of this gully, which just um accumulated weathered boulders over periods of anything from 1 to 1 to 50 years depending upon the gully in the particular area. And then a flash flood comes and the whole lot is swept down these valleys and spread out onto the plain in front. And he, he reckoned that this was a a a very good um explanation of the Roselle conglomerate.

However, Pliman writing that article that I just showed you there, didn't agree with him, but He put forward several arguments, extraordinary really when you think about it. He thought they might be volcanic in origin, glacial in origin. Or marine in origin. And the possibility obviously from the Ryebot um example that he been put to him, also river action in the mountains.

And it wasn't actually even after that article was published in 1923, that the um um HW Corns in 1933.

Published his article in the Bulletin. It's a very long article. He got sidetracked by other arguments that had intervened, but he finally came down on the side of this being the origin of the Roselle conglomerate. I mean that is that observation by Rybot is striking in my view.

It's one of the most sort of thinking outside the box sort of thoughts that I could possibly, possibly imagine anybody having.

Even then in 1933, um, following Corns's article, there was still total uncertainty about the age of it, which was being argued about very considerably right until the post-war years, um, and this next um map shows you Jersey here, Alderney up here, this is the French coast, Cutfrail uh Cut somewhere down there.

And um these, these are mountainous. This is a reconstruction from 520 million years ago of our area and at the time there were mountains there which, which were sort of alpine, so Himalayan in size and hence the Roselle conglomerates. Um, there's been very good work done on these red beds, as they're called, by David Wendt, who also did his thesis on these rocks here, and he's published quite recently a guide to the Geology of Aldery which embraces the adjacent coast there, um, and I'm hoping that we'll be able to do something more back on Jersey together. So that's, that's the story of one of one of Major robot's con contributions to uh geology, striking one. And the next one, I'm jumping in terms of time, not 520 million years ago here, these are the head cliffs at Bor. The rubbly orangey head deposits which is uh angular fragments of the local rock which is here has fallen from these cliffs during the last cold stage, last ice age if you will, um, and, um, forming these cliffs in so many of our bays, notably, perhaps one thinks of um Bon Wei. And of course they are relatively unstable, these cliffs, and there's been lots of landslips. In 1934, the um.

Members of the So Shelogique mineralique to Britain, of which Marie Van this morning, she's a member of course and knows a lot about the history also of that society. They had a major trip into Jersey which was led. Amongst other people by Arthur Moran, Doctor Arthur Moran and um.

Oh, AJ Robinson, Rufus Robinson. Um, and A couple of the uh important drawings in that article which was published on this trip in 1936, were drawn up by a lady, Monsieur Monsieur Casimir. Uh, she was notable somewhat later because she did quite a lot of geology outings with Walter Klopfel during the German occupation and got a bit of stick for that, but in fact it was always reckoned that there's just two in fact geologists who were just interested in things.

Anyway, she drew up this very interesting section. And I would also mention of her that she actually taught me when I was at Victoria College prep briefly after the war.

So there's a nice link there. But this, this shows you just the cliffs coming down from the heights of Boon where you can imagine. Imagine the hoar rock um. Uh, uh, building here and the vertical cliff where there's been a recent collapse of course, and at the bottom this head sits on a raised beach of beach cobbles. Undercut right at the bottom here and then it goes down the beach and if you look carefully, this is just one section through, you have to to dogleg it to get the the full feature of it and it drops to the low tide here. But what I want you to notice here is a high tide, that's the present high tide um and and and that was the uh above the level of the high tide of today, this was. Um, and this actual diagram was very advanced for its time.

I mean, I've put on a very modern naming of that interglacial high sea level, Cobble Beach as 5E, that's the marine isotope stages which all these sea levels are worked out, worked and or referred to these days. Um, and these are, this cliff here is one that was eroded or certainly existed in, in the previous, uh, time here and even more previous up here. But How I mean that was also linking the Sos because there are those three people who were involved in the production of this article and also took the people around Jersey, but I want to jump now to the cot here. And um Matt Matt this morning mentioned the, the question of, of, of me talking about this and I just want to cover briefly the contribution of Um, in just a moment, I'll come to him. This is a cross section through, and you can see the resemblance between Monsieur Casimir's drawing with a steep cliff and Um, cobbles at the bottom and head like sediment there and but, but there's a big difference here which I, which I'll, I'm leading towards. Pierre Bordo, who also has been mentioned, he worked at Lacotte slightly prior to the Second World War, but then he took it up again in the early 50s and worked through and he did this work on his own at the cot for 7 or 8 years.

And he was, this is the sort of thing you saw in you, you still see in Lacot, which, which is a rubble deposit here, and he was able to spot in this, you can see beds almost horizontal there, but more steeply dipping there. And there's a line of separation here which he spotted. And that line of separation. Separates The beds Here From the beds here.

This is not a solid cliff. The solid cliff is behind here. And what, what he recognised was a set of observations which had this is the same age as the one you I showed you at Bonu, but The cliff. Under which is undercut here is older than that raised beach, not younger.

In the case of Bonn Wei, it's, it's younger, the, the um. The sediments here are younger.

And this is the basis now that we understand of the of the significance of the last 200,000 years of erosion around Jersey's coast. And That was um Bulldo's major, major contribution.

To, to the um. Evolution of the cot cave.

So both those the the three major people I've mentioned Ni. Uh, Rabot and Budo all made quite exceptional geological observations which had a lot, a lot to contribute and have not in any sense been been sort of denied by further research.

Even, you know, you can understand now, we've had talking about this in, in, in the earlier discussions about how you perceive the past. I knew he was of his time and therefore time in his time was perceptions of it totally different from ours, you know.

I think of 4, 4.5 billion years for the age of the earth. He was thinking perhaps of 20 million, 30 million years, totally different framework within which which he was operating.

So that is always what one has to bear in mind, looking at the past that you interpret things in the understanding of what knowledge was at the time. Thank you.