Slide 2:
150 metres (500 feet) The layer of chalk forming these cliffs is very thick (there is more hidden underground)
Slide 3:
Under a microscope you can see that chalk is made from the shells of microscopic sea creatures. Chalk is made of calcium carbonate Sometimes, larger fossils are found – these prove that the chalk was formed under the sea!
Slide 4:
Even away from the coast, you can see the chalk just underneath the thin soil.
Artists often carve images on the chalk hills.
Slide 5:
The sea dissolves the chalk, particularly along any cracks to form deep caves.
Slide 6:
Sometimes, whole sections of the cliff collapse very suddenly
Slide 7:
Checking on the chalk cliff – an interesting job!
Slide 8:
Is chalk useful? What is it being used for in these photos?