Rock Types and Geology for Climbers

Climbers and Rocks
Rocks and Climbrocks
- Characteristics of Climbrocks
- Rock, when is it fit for climbing?
14 – The “expanded range of climbrocks“
43 – The number of Climbrocks
- Search Climbing Areas by Rock Type
Further reading
Rate and share this article

The following article gives an overview about the many rock types that are out there for climbing. In doing so it tries to bridge the gap between the scientific view of a geologist and the information needs of an interested climber. Where else but on theCrag you can search for climbing areas by your preferred rock type?

The information presented here was compiled by Dipl.-Geologist Harald Rost and adapted for theCrag by Ulfi

Climbers and RocksBack to contents

Rock, this is what climbers are looking for. Outdoor climbing in a natural setting - if it is not ice climbing - requires rock. And luckily for us climbers, there is plenty of it all over the world. As climbers we also know that there are different types of rock and that - depending on the rock type - the climbing might be quite different. The rock type not only influences the general feel or even style of climbing, it tells you something about rock quality, if you can (should) climb a rock after rain, or it helps explain why certain types of bolts age differently under different conditions. It also impacts how a crag “ages” (e.g. becomes more and more polished) or why other stakeholders might suddenly be interested in the rock - typically quite detrimental to the interest of climbers.

Most climbers know the basic rock types like limestone, granite, gneiss, sandstone or basalt. Those who watched James Bond climbing in For Your Eyes Only might know about conglomerate. But if you talk to a geologist about rock types this just scratches the surface. So how do we classify rocks, how many climbable rocks are out there and where are they?

Rocks and ClimbrocksBack to contents

How many climbable rock types (climbrocks) are there? It is quite hard to find an answer to this question in literature. There is a tremendous number of rock types and unfortunately many more names for all of them (for example, check the list on Wikipedia)! Nomenclature might be related to occurrence, genesis, geological age, minerals, size of grains, colour, technical use and much more. Aggravating there are transitions and peculiarities of rocks which result in diverging names. Additionally there sometimes are misleading trivial names, trade names and so on. There also are diverging meanings of English and German names or names in other languages. Don’t be surprised if you do not know them all.

This article tries to simplify this complex topic. Using the common genetic structuring theCrag lists only rock types which are somehow in broader use by climbers due to occurrence, accessibility and characteristics or might be interesting due to other special reasons. A helpful criterium is the presence of sport climbing routes on a specific rock type. Thus claystones, rock salt and gypsum for example are not included here even though they might be climbed in individual cases or under special conditions.

Characteristics of ClimbrocksBack to contents

Rocks and their respective characteristics are essential to the forming of landscape. The landscape itself surely often influences your choice on where to go for climbing. However which climbrock characteristics are relevant for climbing? Is it possible to describe every type of rock you climb on by its individual climbing characteristics?

For sure it is. However, as more as you simplify it, somehow it becomes harder and as soon as you only present the basic range of rock types, those 7 or 8 types mentioned at the beginning of this article, it is nearly impossible in a really meaningful way. Unfortunately it is very common to characterise and describe an individual rock type for climbing in four sentences and with a single picture. This simply is not enough and is one of the main reasons for false impressions, hear-say and surprises once at the cliff.

For climbing not only the rock type and its material is essential, but additional features, too, which partly even are independent of the rock itself. Texture and structures (history of sedimentation or intrusion and/or tectonics as well), exposition, weathering and individual site features (e.g. is the site manmade or natural) might be even more important.

Within quarries even the art of excavation influences rock and climbing. Possibly blasting which intentionally could be used for best smashing of rock already might have smashed wall faces so much that even very solid rock is completely unreliable and not suitable for climbing any longer.

Sandstone can be fine-grained and coarse-grained, same as granites, but additionally the later can even occur with porphyritic structure (e.g. Falkenberger Granite). Sandstone may be more rigid as granite. Limestone may be rougher than sandstone. Sandstone might have more holes in its surface than dolomite… Moreover, all of that might not even have a great effect on climbing because the rock anyway is polished by water or ice – or animals like… e.g. climbers – or the climbing actually uses younger tectonic structures as e.g. fissures and cracks.

As you can see, it is not really simple and describing rock requires much more than just a good handful of rock types!

Look at granite for example. It is not even necessary to look at the broader range of granitoids and their differences. Sometimes there are no ‘typical‘ granites within one single pluton. Moreover not even one individual granite site and climbing crag really is homogeneous. You may get an impression by looking at the picture above and reading more about it within this awesome work about El Capitan: Geological Mapping Project. Now, did you really imagine something like this only having heard and read that granite typically is rough, there often are fissures and rounded structures are predominant? In analogy, this applies to nearly all rock types. They simply cannot be described with just four sentences and one picture.

Rock, when is it fit for climbing?Back to contents

The criteria that make rock a climbrock are somewhat easier to grasp. For this in general a rock has to have a minimal thickness and areal occurrence. (E.g. a dike, possibly consisting of special rock type, may be quickly crossed over but only therefore is no climbrock itself). A minimum of strength and durability against weathering and surface disintegration, regarding the specific climate, ensures reliability of holds and trustworthiness of bolts and anchors. Evaporite rocks, e.g. rock salt and gypsum, as well as claystones are not suited and only are climbable temporarily or under special circumstances. You will hardly find sport climbing routes in those rocks, especially using standard gear.

However, there are exceptions everywhere: despite not fitting the general requirements of reliability, ‘chalk‘, which is a very special limestone, is used as a climbrock using drytooling equipment (read and see more).

14 – The “expanded range of climbrocks“Back to contents

Using the criteria for climbrocks and trying to aggregate wherever possible still results in about 14 types of rock. Twice as many as the basic number listed at the beginning of the article

sedimentary: sandstones, conglomerates, carbonates, chert
metamorphic: gneiss, marble, quartzite, some “greenstones“
plutonic: some “granitoids“
volcanic: phonolite, rhyolite, “basalts“, “some other volcanites“
hydrothermal and metasomatic: quartz

However, for example the thuringian slate (Spiegelwand) isn’t included yet. The same is true for tufa, chalk, calcareous sinter (all three just special limestones) and other things rock climbers may enjoy, but make a simple typification obviously impossible. Therefore, theCrag uses the following list of 43 climbrocks. Of course it is still a simplification but currently probably the best and most complete listing and grouping of climbrocks out there. Thanks to Harald Rost for sorting that out and insisting to get theCrag to use it!

43 – The number of ClimbrocksBack to contents

According to this table there are 43 climbrocks. The table supplies some point-like info and the links lead to additional external information. The information presented here is not based on Wikipedia info, however most of the linked Wikipedia-articles about rock and geology are in general fine and accurate. Additionally you may click on links to climbing areas and routes on theCrag to find out where you can experience the respective climbrocks in real life.

In order to keep the systematics correct and to present the info in context some rocks are included, which are not climbrocks as per the definition above. Ice is completely ignored as water by definition is not a rock even when frozen. Not even in the polar region you will find any permanent climbing routes, especially none with really long lasting bolts and anchors. However, in permafrost regions water ice may change general unsuitable rocks and even loose rock to climbable aggregates by the additional binding of the ice.

Simply try and feel it!

In case this article has invited you to learn more about rocks and on occasion to climb different rocks: Good luck and Glückauf! Have a close look and you will realize that everything is changing as soon as the rock type changes: landscape, vegetation, wine, people, climbing… Have fun and climb safe!

Rock Types and Geology for Climbers

Contents

Climbers and RocksBack to contents

Rocks and ClimbrocksBack to contents

Characteristics of ClimbrocksBack to contents

Rock, when is it fit for climbing?Back to contents

14 – The “expanded range of climbrocks“Back to contents

43 – The number of ClimbrocksBack to contents

Search Climbing Areas by Rock TypeBack to contents

Sedimentary Back to contents

Igneous Plutonic Back to contents

Metamorphic Back to contents

Hydrothermal and Metasomatic Back to contents

Igneous Volcanic Back to contents

Further readingBack to contents

Rate and share this articleBack to contents

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