Explain the role of geology in the formation of contrasting cliff profiles. Flashcards
(14 cards)
Cliffs consisting of resistant igneous or metamorphic rock often have…
steeper and higher profiles than cliffs made up of sedimentary rocks and unconsolidated material.
What are the cliffs on the Holderness coast made up of?
Clay meaning they are low cliffs
Give examples of geological structure?
Jointing, dip, faulting, folding
What type of cliff profile does jointing of metamorphic rock form?
Very distinctive vertical cliff profiles
What is folding?
where the bedding planes of ductile or plastic rock can be folded.
What does folding lead to in cliff profiles?
Creates cliff profiles at an angle of 90 degrees to the angle of the fold
What is faulting?
Where the rock is fractured
What happens to the cliff profile as a result of faulting?
Creates a steep cliff profile at the fault such as the cliffs in Cornwall
Why may there be differential erosion of alternating strata?
Due to impermeable and permeable surfaces. This produces complex cliff profiles.
How are folds formed?
Pressure during tectonic activity
What is the dip of strata?
The angle at which rock strata is alligned
Why are faults formed?
When the pressure on rocks exceeds rocks strength. The fault then slips and moves along fault planes
What is the cliff profile like in seaward dipping strata?
Mass movement is more likely, more landslides and debris
What is the cliff profile like in lanward dipping strata?
A steeper and overhanging cliff profile. More rockfall
