Hard rock, such as basalt, resists wave erosion creating a headland and sea stacks.
3 . Softer rock & glacial material
weathered more quickly & mass
movement result in less steep slope
4 . Joint & bedding planes
determine cliff formation & amount of
material movement to cliff foot
Rock type & structure influence nature sub-aerial processes deliver material to cliff foot sub-aerial erosion Cliff profile & cliff evolve depend on the effectiveness of sub-aerial processes on cliff face & strength of cliff material.
Hard rock & soft rock evolution are : Episodic & Cyclical: Material accumulates at the cliff foot, separated by longer periods of slower erosion, attrition and sediment transport as accumulated material is made smaller by attrition, then removed by marine action is itself episodic. As the toe armour is removed the cliff base is exposed to wave action and the erosion Cycle is repeated.