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This post connects with Chapter 5 in Schooled by Rock, Geology: Petrified: The Death of a Geologist. A deep and early love of rock led me to study geology at Sheffield University in the 80s. It’s where it was all happening. I fell out of love with geology back then, I just wanted to climb the stuff, not classify it. But now I know that learning and classifying does in fact allow you to see and feel more. Before I met Jeannie, apart from dandelions and daisies, flowers were just flowers. But now, she’s bought all this beauty into my life: I see more for knowing what each one is, all their names and varieties.

As climbers, we often marvel at the beauty of the rock formations we encounter. But have you ever wondered about the science behind these rocks, and how understanding their geology can enhance your climbing experience? In this post, we will explore the world of geology and its implications for climbers. The formation and characteristics of different rock types, the details you might see within it can inform your climbing techniques and route choices and add richness to the experience.

The science bit. Apologies to my old geology lecturers. Rocks are formed through various geological processes, including sedimentation, volcanic or igenous activity, and metamorphism. These processes give rise to different rock types, each with its own unique properties and characteristics that influence climbing:

  • Sedimentary Rocks: Formed from the accumulation and compaction of sediments, sedimentary rocks like sandstone and limestone offer diverse climbing experiences. These rocks can vary in texture, from smooth and slippery to gritty and rough, requiring climbers to adapt their techniques accordingly. Here in the UK we have the wonderful gritstone in the north of England, and a variety of sandstones across England, Wales and Scotland. A special shout out to the Torridonian sandstone! 

Limestone is everywhere and is so varied, from a climbing point of view it is another world in itself, a world largely made up of dead things in a frozen soup.

  • Igneous Rocks: Born from volcanic activity, igneous rocks such as granite, gabbro, basalt and dolerite provide solid, stable climbing surfaces. Their crystalline structure often offers excellent friction, but can also be sharp and abrasive on climbing gear and skin. Crack gloves are for pussies! Though I used to think that about clip-sticks. The climbing wonders of Cornish granite and the rhyolite of North Wales are stand-out destinations here at home in the UK.
  • Metamorphic Rocks: Created through heat and pressure, metamorphic rocks – later iterations of previous sedimentary and igneous rocks – like gneiss and schist feature varied textures and orientations, presenting unique challenges for climbers seeking to navigate their complex structures. This stuff looks amazing and it’s what Scotland’s made of essentially.

Geological features such as faults, dikes, cracks and bedding planes show the way and play a crucial role in shaping our movement up the route. Understanding these features can help climbers predict where they might encounter difficulties, and plan their ascent accordingly. Crack width and the likely slope of a gritstone break inform the techniques needed. On some routes, there’s simply no escaping the geology. Mousetrap at Gogarth in North Wales weaves amongst twisted bedding planes that have eroded due to differential weakness into fins and chimneys.

Different rock types call for different climbing techniques, and a deep understanding of the science of rock can help climbers refine their skills and tackle new challenges. For instance, sandstone often requires delicate footwork and precise balance, while granite demands powerful movements and a strong grip. Learning by doing is more important than studying the processes of formation however. But knowing granite as granite or grit as grit helps to connect you back to previous lessons learned on the same rock.

Think about the coloured holds indoors: each colour suggests a small variety of moulds and shapes, and the holds and textures they offer become known. It’s the same when outdoors. Knowing what to expect when you lunge for a possible hold can make all the difference. Hidden holds hide in different places depending on the rock you’re on. Recognising grit smears from how they look: subtle changes in colour, a slight smoothening of the grains and crystals from previous feet. Knowing your positive crimps from your slopers is all important, and if recognised from below, will aid your success.

Rock formations are constantly evolving, shaped by the forces of weathering and erosion. Climbers must be aware of these processes, as they can impact the stability and safety of climbing routes.

Limestone cliffs are often subject to dissolution and may feature loose rock, while sandstone can become brittle and prone to breakage when exposed to moisture and is best avoided at these times. On one day trip to Portland we found the cliff we were aiming for was now scattered as boulders by the waves. The whole thing had fallen down; luckily no-one was climbing on it at the time. 

Some rock types, particularly sedimentary rocks like sandstone and limestone, are more susceptible to damage from climbing activities. Climbers should be mindful of the impact their actions can have on fragile rock, and strive to minimize their environmental footprint. The wonderful flake on Right Unconquerable at Stanage has changed forever. It was better before, although still wonderful.

Climbing offers a unique opportunity to experience and appreciate the world’s geological wonders up close. From the sandstone cliffs of Meteora in Greece to the granite domes of Yosemite National Park, climbing provides a first-hand look at the incredible diversity and beauty of our planet’s geology, on both macro and micro scales.

As you climb Shakin’ Like a Leaf, a 7a at Cheddar, look out for the bands of crinoid fossils embedded within the Carboniferous limestone the cliffs are made from. Crinoids were sea-creatures, distant relatives of star fish, and appear, in fossil form, as small segments and threaded columns that look like screws. They add texture to the smeary footholds you need to use, relevant again now in spite of their geological antiquity; they’re living their best lives. The more you know, the more you look, the more you see.