Matt Fratson in conversation with Roger Osborne, author, teacher and Curator of Geology at Whitby Museum, 16th May 2023.

R

The Zechstein formation is quite intriguing for geologists because of how it covers this quite large area - into north Holland, north Germany. It's full of what we call evaporites, and so it’s essentially like a sort of salt pan. And so what is left is what you need for salt. But these are really deep, deep, deep layers. It was around for several million years… full of these sorts of minerals - part potash – and it is particularly mined. But they're beginning a new mine now near Whitby, Anglo-American, to get at more potash. It's used as fertilizer. So essentially the kind of geology of that area has been joined up since before the last ice age.

So that's older stuff, and then there is the Jurassic on top of that - here we have our small collection of Kirkdale Cave stuff. So do you know about the Kirkdale Cave at all?

M

I don’t know very much except that it created quite a stir when it was discovered?

R

Yes - so in 1821 it was discovered by William Buckland and... well, two things. One is it is very much older than your period. We’re talking about the interglacial before the last ice age which is called the Ipswichian. The really big thing about the Kirkdale cave was that it's a very small cave entrance, but containing bones of very large animals.

Buckland figured out hyenas were dragging these bones into the cave. But the really interesting thing is that in order to figure out what was going on, he had to figure out how these animals were actually behaving. Whereas up to then, if somebody found a pile of bones like this, what they would do is basically try and build an animal, you know - they try and fit those bones together and make it work.

So that's how the early dinosaur hunters did things quite wrong occasionally. But nobody had really thought of working out an ecology of the place where all these were found. But he was kind of forced to do that in order to solve the problem. And so that was the it was really the first time anybody had done what we call palaeontology, as opposed to the anatomy of fossils. That’s why it is such an important episode.

M

That's a huge leap, isn't it, from kind of finding a pile of bones, and imagining – okay - this must have been some sort of monster, this is kind of how it looks stitched together - to a point where it’s accepted that there's a nuanced system at work around those bones.

R

Yes. George Cuvier’s thing was being able to build animals from bones that have been recovered and of course it was fantastic and exciting. They built the Brontosaurus from the remains. But yeah, this is a totally different thing.

Back to the Mesolithic, we also have some objects here from Star Carr, though I know less about archaeology. I went to a dig at Lake Flixton about five years ago - they do occasionally revisit these sites and they made this amazing discovery that there was a layer of sort of hardened mud which was just covered in horse hoof marks - just loads of them. And what they figured out was that the people who lived there, of course, they didn't have any sophisticated tools for killing animals. So what they were doing, they thought, was that they were building stockades in the lake, and they were pulling the horses into the lake in order to drown them, so they could then butcher them to eat them. But I mean, this is into the Neolithic.

I do know that we there's a huge amount of material around it because of, you know, the way it works it’s way into the chalk cliffs at Bempton…it’s full of flint. And I think a lot of that would have got washed down to Holderness as well.

There's stuff coming out of the mud and there's stuff being washed down. I know I've been at Spurn and found Whitby ammonites there.

And where you have the cliff - I think it's more or less at Sewerby… If you go from Brid and you sort of walk north, then you get to the point where the chalk cliff appears and the mud cliff is in front of it. But the chalk cliff doesn't actually disappear. It carries on, you just can't see it anymore because now this is filled with glacial mud. They call that the hidden cliff, and it goes inland for quite a long way. It forms the outhern edge of the Wolds, which is why the Wolds is kind of curved like that.

We went on a field trip to that area with the Hull Quaternary Research Group. They do much more work now on Ice Age stuff because they they can date it better with quartz dating, where you where you can tell now from analyzing quartz grains when they were last exposed to sunlight, because the isotopes change. So that tells you when they were buried in these really deep positions. It’s really interesting. You find different material to mine because there’s also pollen sampling which is subtly different.

But one place that you, if you get a chance to go is worth the visit is Skipsea. If you park up at Mr. Moo’s and then you walk down to the beach from there, when you get to the beach, the cliffs are, you know, about three times our height and you walk along - not very far actually, going north. And there's an area of the cliffs which is just full of huge pieces of wood. Tree trunks. Really massive. And about ten years ago some students from Hull were looking at all this. And one of them found some hair in a chunk of this wood. So they took it back and discovered that it was beaver fur. So this apparently random pile of tree trunks in the cliff was actually a beaver dam. So that's like late ice age... possibly around 12,000 years old.

And of course, at that time there were those vast ice sheets - vast amounts of water just flowing around the basin, which is why Lake Pickering was there - and yet it's trying to find ways out and getting blocked by mud and gravel and silt and all that sort of thing. Then, of course, seasonally freezing again and then melting again. They call these periglacial environments and they are real puzzles to work out.

M

I think for me what I kind of love about kind of this stretch of coastline is that it's like a microcosm of really rapid, constant change. And it's a microcosm of wider climate concerns, that sometimes kind of feel like really far away.
 

But actually there are lots of smaller stories wrapped up in this stretch of coastline that tell us about the way that, you know, we either adapted to or didn’t manage to adapt to those changing environments.

R

I mean one of the things I think about a lot is Star Carr, and I'm no expert on this, but I kind of got the sense was that when, in the immediate sort of warming after the last ice age, so we talk about 11,000 years ago, then we started to get seasonal visitors to this part of the country - humans I mean, and then okay settlements as it got warmer… and being around near a lake seemed to me like a really good thing.

There was a really nice book by Barry Cunliffe called Facing the Ocean, which is about how the Atlantic coast was very much populated by people because they were good places to live, lots of food available but then as the temperature became warmer yet, actually that area possibly became not so good to live in, because it became really densely forested. Which we seem to think would be lovely – but actually not maybe so good if you're a hunter you know ... It’s just really difficult to make your way through really dense vegetation. So I think there's a bit of a theory about that – that a lot of places had human habitation in that sweet spot, as the climate was warming. And then when it got too warm, they disappeared. They came back when they could start felling trees and clearing the way once more.