Slowly, over a period of time, the face of the cliff is worn away by continuous wave action. Up to the time that the cliff becomes unstable, the erosion continues to weaken the structure at its base. From the moment when cracks start to appear, large sections of the cliff collapse into the sea.
While something else is happening, such as the erosion of the lower cliff by waves, fossils that were once buried deep within the rock begin to emerge. Over that period, the cliff retreats further inland, exposing more fossils in the process.
Immediately after the cliff face collapses, a danger zone is created where the rock is unstable. In the end, the continuous erosion forms a sloping rocky platform at the base of the cliff, where fossils become fully visible