A look back at Ynys Môn’s history with Dr. John Conway from GeoMôn 

John Conway is an author of GeoMôn Trails, The Coastal Footpath Guidebook, and the GeoMôn website. GeoMôn is a Global Geopark on Ynys Môn, home to one of the world’s top 100 geosites. 

Hi John, can you tell us a little about yourself? 

Hello, I’m a geologist. Yes, one of those strange people who loves rocks, but actually what I really love is the scenery they make up. Not just the beautiful views, but the soil they create which grows our food and supports all the trees, woodland grass, and even our gardens.  

What do geologists do and what do you love about it? 

We are really historians studying the history of our planet, investigating the origins of the landscapes you see around you. For example, have you ever gone down to the beach and wondered: Where did all these different pebbles come from? Where does the sand come from? 

As geologists, it’s our job to answer those seemingly simple questions. We can look at the cliffs and see they’re made of solid rock, but when there is a really big storm and we see huge waves bashing against the cliffs, they don’t look so permanent. Each wave is like a gigantic sledgehammer hitting the cliff with the force of hundreds of tons, all while picking up huge boulders and hurling them against the cliffs.  

Gradually these boulders break down into the smaller rocks and pebbles we see on the beaches. So, to go back to my question: Where does the sand come from? It comes from cliffs nearby, which storms gradually smash into finer and finer particles until all that’s left is sand. 

This process has been going on for over 4,000,000,000 years. As geologists, we look at the processes which are happening in the present day and then looks to the rocks to see what happened to form them, questioning whether we can find their origin. 

That’s an interesting thought, what interests you most when it comes to history? 

I find archaeology fascinating – going right back to the earliest humans on this planet in the Stone Age. They were geologists in their own right, using different rocks for different things. 

For example, flint was a particular favourite because when you break it, it breaks with a very sharp edge, as sharp as any metal knife. They also used rocks that didn’t splinter or shatter in place of hammers and tools.  

But my favourite thing that our ancestors used rocks for are ‘pot boilers’. At Stone Age sites we often find mounds of stones that were used to raise temperature in a vessel, a pot of water for example, hence the name pot boilers. I did an experiment once to test their ideas, taking different types of rock and putting them into a bonfire to see what happened. Ingenius really!  

All this happened thousands of years ago before any modern theories about geology, but I just find it interesting that from the very beginning our ancestors were recognising different types of rock for different uses.    

Tell us about the landscape on Anglesey and why it’s interesting 

Anglesey is famous for having lots of different types of rock. Right on our doorstep, we can walk on the beach and see pebbles of all shapes, colours and sizes. 

Anglesey has a footpath running all round the coast, so it’s quite easy to go on the various headlands or beaches and see all the different rocks that make up our island. If we walk up the west and north coasts, the rocks are generally greenish in colour and full of zigzag lines. If we walk on the East Coast from Lligwy southwards, rocks are generally greyish in colour and made of big thick slabs, totally different to the other two coasts.  

Looking at these rocks in detail, we can start to work out what they are made of and how they’ve formed. There’s actually a Stone Age site on Holyhead Mountain where pot boilers were found, but that’s a story for another time. 

Do you think more people should take an interest in learning about rocks? 

Absolutely! Rocks of different types contribute massively to our environment. They form different types of soil which support different types of plants, so the whole of our biodiversity and food production is, in some way, affected by different types of rock.  

We also use an awful lot of different types of rock to support our civilisation – things like building stone, coal for oil, the different metals we use and materials to build our roads. 

You can learn more about North Wales’s geological history on GeoMôn’s website. And for budding, young geologists check out Rock Tales by Chris Fletcher.