High Tide Blog

Roger’s blog appears regularly in the Scarborough Review. Read his archive of posts here.

Endless winter?

You won’t need me to tell you that the roads have taken a bit of a battering from the wintry weather. Layers of tarmac stripped off, potholes everywhere and drains bursting with meltwater. All that from just a week of snow, ice and freezing winds.

Now just imagine that week of weather lasting a year, or maybe a decade; or how about 100,000 years. That’s how long the last ice age lasted. In just a week the weather gave us a mini-demonstration of how something as apparently feeble as water and wind can, when it’s cold enough, chew up hard stone and throw it around like matchwood. This gives us just a small taste of what happened in the earth’s recent past.

The evidence of those 100,000 years is all around us. Those piles of gravel scoured off the roads are small versions of the huge gravel pits all across the region – best seen at Burton Riggs nature reserve off the A64. The piles of mud and silt that are blocking drains are miniature versions of the fans of debris washed out of glacial channels like Forge Valley and Newtondale.

This month we’ve been seeing geology in action as solid rock and stone is recycled into gravel, mud, silt and sand before being laid down and solidified all over again. It’s a process that goes on along the coast all the time as the sea wears away at the land, and piles up sand and pebbles on our beaches in return. Now we’ve seen the same powerful forces at work inland.

It’s all been going on for a long, long time. Geology students can all quote James Hutton, the founding father of geology, who said that the earth’s cycle of uplift and erosion had ‘no vestige of a beginning, no prospect of an end’. Thankfully that’s not quite true of the Yorkshire winter – even if it feels like it.

Spring is on the way and we can forget about winter until . . . next year.

Rain and rocks

Everyone knows there are just two kinds of weather in Yorkshire; it’s either ‘a grand day’ or, more likely, ‘a rum day’. The British love to talk about the weather because we’re all in it together, but if you live out in the countryside you’re often in it more than you want to be. This winter seems to be particularly wet – no major floods but the fields are all fairly sodden, with pasture and arable land severely in need of a good dry spell.

When I give talks about local rocks and landscapes, and how they work together, I usually end up talking about water. All that rain has to go somewhere and the presence of becks, rivers and springs has dictated where we put our houses, villages and towns throughout human history. And watercourses depend, to a large degree, on the underlying geology. That’s true along the Yorkshire coast but with an added twist.

Regular readers will know that the last ice age brought massive ice sheets across the North Sea and over the strip of low-lying land along the coast. When the ice melted around 11,500 years ago it left a thick layer of mud stretching from Saltburn down to Filey Bay, and from Bridlington to Spurn Point. This mud effectively blocked the local rivers from draining to the sea, and sent them on new courses inland.

But over the last few thousand years streams have started to carve routes out of the soft glacial mud making new ways to the sea. Because they are so new the gullies they cut tend to be steep and narrow. Villages along the coast were built where there is access to the sea, plus shelter and fresh water, so these steep wet gulleys were ideal. Runswick, Staithes, Robin Hood’s Bay and even Whitby are all tucked into recent river valleys. People flock to experience the atmosphere of these picturesque villages – it’s yet another way in which geology has contributed to the beauty of the Yorkshire coast.

Lumpers and Splitters

You will all remember from Gulliver’s Travels the rival tribes of Big-Enders and Little-Enders, fiercely divided by the way in which they opened their boiled eggs.

In the fossil world we have the equivalent groups, known to us as ‘lumpers’ and ‘splitters’. In this case it’s all to do with how many species a researcher manages to identify. Let me explain.

Say you were given a pile of beautiful ammonite fossils and asked to divide them into groups. You might separate them out by size, whether the coils overlap, the curve or otherwise of the ribs and whether they divide, the presence or absence of a protruding keel, etc, etc. Now comes the tricky part. What if you were then asked how many different species you have in front of you? Bear in mind that members of a species can reproduce with each other but not with individuals from another species, something that’s impossible to check with dead animal groups.

So, are all the differences you’ve identified signs of different species – or are some just variations within a species? If you are a splitter you will say they are all different species, a lumper will declare for as few species as possible. The difference matters crucially because the presence of particular species is used as an indicator of age, environment, ancient geographical position among other things.

The most famous splitter in these parts was SS Buckman whose work on Yorkshire Type Ammonites extended to seven volumes published over a period of 21 years. It is often whispered in fossil circles that the reason for Buckman’s long-windedness was that he was paid a fee for every new species he identified. But that could be just a rumour put about by the lumpers. To split or to lump – the fight goes on!

Lucky Skunks

For those of us who live here the Yorkshire coast is, of course, the centre of the universe. But we are slightly removed from the country’s main arteries of trade and commerce. To me that’s a plus. I look on the coast, the North York Moors, the Vale of Pickering and the Wolds as a distinct part of the world, separated by geography (and of course geology) from the rest. I think of this as my home patch – the place where I feel comfortable. Conversely I feel a bit like a Scarborough Woof out of water once I get anywhere near Thirsk or Hull not to mention the teeming streets of York or the giddy lights of Leeds.

So it comes as a pleasant surprise to find that a lot of other people, from all over the country, similarly hold the Yorkshire coast to be a very special place. I discovered this during a recent trip to Dublin. I was there for a conference of geology museum curators, though my real mission was to seek out some giant reptiles from the Yorkshire coast – more on that another time. Around 60 folk from prestigious places ranging from the national museums of England, Scotland, Wales and Ireland, to Oxford University Museum and the tiny Horniman Museum in south London were all gathered to hear talks, chew the fat and sink some Guinness.

During the two days a string of people came up to me (I was wearing my Whitby Museum badge) to tell me how much they loved the museum and the Yorkshire coast. Everyone there had spent time on this coast and remained in awe of its beauty and its geology. Because, while some people might think we’re a bit off the beaten track, for geologists we are the luckiest skunks on the planet, living in one of the most beautiful and interesting places anywhere.

Of course we all know that, but it’s nice to have your beliefs confirmed. So when you’re looking for a way to shed the seasonal excess, get out into the countryside and appreciate just how lucky you are.