The Rock Factor
Every canyon on Canyon Log has the most dominant bedrock stated. The rock type directly influences the formation of the canyon. Canyons with the same rock type usually have similar characteristics.
How to interpret this information.
Knowing the type of rock is useful for the following reasons,
- Commitment – Canyons formed in particular metamorphic and sedimentary rock can create deep inescapable sections.
- Anchors – Poor quality, soft rock causes issues for building anchors in the rock.
- Hydrology – The type of rock in the catchment area influences the vegetation and ground permeability.
Sedimentary
Formed in layers on the earths surface under lakes and oceans.
Large waterfalls
High walls
Deep pools
Average strength
An example of a sandstone canyon. Photo – Aaron Murray
Metamorphic
Formed under heat and pressure with both igneous and sedimentary rocks
Large waterfalls
High walls
Deep pools
Average strength
An example of a psammite canyon. Photo – Sol Armer.
Igneous
Formed by the crystallisation of magma
Large waterfalls
High walls
Deep pools
Average strength
An example of a rhyolite canyon.
Elevation Profiles
Igneous
Very steep – Open – Deep pools
The typical elevation profile of a canyon formed in Igneous rock. Large drops and a mix of shallow / deep pools.
Examples
- Dungeon Ghyll
- Fisher place (Raise canyon)
- Swath Beck Gill
- Cym Dyli
Metamorphic
Quite steep – Inclosed – Deep pools
The typical elevation profile of a canyon formed in Metamorphic rock. Mostly medium height drops and some deep pools.
Examples
- Inchree Falls
- End of the World
- Laggan
Sedimentary
Not steep – Inclosed – Mixed pools
The typical elevation profile of a canyon formed in Sedentary rock. Usually small / medium height drops and majority shallow pools.
Examples
- Dundonnall
- Black Rock Gorge
- Prysor
- Butterfly Burn
Exceptions
Some canyons don’t always fit into these categories for example, an igneous canyon may have deep walls or a sedimentary canyon may have deep pools or large drops. The reason for indescrepencies are usually local factors such as terrain and location as well as geological factors such as fault lines and dykes.