2. AT THE CHALK FACE

HUNSTANTON CLIFFS

The vivid bands of white, orange and brown rocks that make up the spectacular coloured cliffs of Hunstanton, on the edge of The Wash on the north Norfolk coast, are a cross-section of geological time.

Dating from the Early Cretaceous period, about 100 million years ago, they consist of a dazzling-white layer of Ferriby chalk on top; a layer of fossil-rich orangey-red chalk (including fossil ammonites and belemnites), and finally the deep red-brown carstone forming the base of the cliffs. The three main beds are separated by bands of marl.

All these rocks were laid down under the sea in various conditions, ranging from shallow tropical lagoons to – in the case of the white and red chalk – deeper marine deposits.