- Created by: Woden
- Created on: 17-02-19 18:42
Metamorphic Rocks are the most resistant, and the least resistant are Sedimentary Rocks (excluding unconsolidated material), with Igneous Rocks in the middle.
Hard rocks are resistant to weathering & erosion so a coastline made of granite (e.g., Land’s End) will change slowly. Soft rocks are more susceptible to weathering & erosion so a coastline made of chalk (e.g., Dorset) will change relatively quickly.
If a Cliff face were to have layers of strata alternating between metamorphic and sedimentary rock, the sedimentary rock would erode quicker. This would form a wave cut notch, which in turn would result in an overhang which would eventually collapse and contribute to a wave cut platform. Over time this wave cut platform will become so big that the waves no longer reach the cliff with sufficient energy to cause erosion, thus putting and end to he erosion of the cliff.
A large amount of vegetaion on a cliff can increase its resistance to erosion, most greatly for unconsolidated material (boulder clay), this is because the roots of the vegetation binds the material together, adding more consistency to it.
However, it could also increase the susceptibility to erosion by creating fracture in the rock (mostly in harder rock) leaving it vulnerable to freeze-thaw weathering, recrystallisation of salt and Hydraulic Action.