2.3 Flashcards
1
Q
How does varying resistance create complex cliff profiles?
A
- weaker strata below can be eroded faster, creating wave cut notches
- wave cut platforms form when harder overhang is too heavy for weaker strata to support
2
Q
How does varying permeability create complex cliff profiles?
A
- groundwater flow can exploit joint structure and dissolve binding materials
- can create high pore water pressure within cliff, reduces stability
- can also lead to slumping along impermeable/permeable boundary if seaward dip
3
Q
What rocks are permeable?
A
Sandstone
Limestone
4
Q
What rocks are impermeable?
A
Most igneous rocks
Most metamorphic rocks
Mudstone
Clay
5
Q
What factors add to the complexity of a coastal formation ?
A
Age of rock
Variation in permeability of rock
Variation in resistance of rock
6
Q
What are the properties of the entablature?
A
Made of laterite
More permeable than colonnade
Not regularly arranged
7
Q
What are the properties of the colonnade?
A
Basalt columns
Jointed horizontally and vertically
Less permeable than entablature
8
Q
How are entablatures formed?
A
Rapid cooling of basalt columns from top downwards by water
9
Q
How are colonnades formed?
A
- Slow cooling of basalt from bottom upwards
- Creates joints as basalt contracts as it cools
