How Hunstanton Cliffs Were Formed

A coastline written in layers

The cliffs between Hunstanton and Old Hunstanton are among the most recognisable geological features on the Norfolk coast.

Seen from the beach, their distinctive bands of brown, red and pale rock appear almost stacked on top of one another. Each belongs to a different geological formation, preserving evidence of environments that existed here during the Cretaceous Period.

At the bottom is the brown Carstone Formation. Above it lies the much thinner red layer known as the Hunstanton Formation, historically called the Red Chalk. Higher still are the pale chalks that form the upper part of the cliff.

Together they create the striped appearance for which Hunstanton Cliffs are known.

The Carstone beneath the cliffs

The lowest major layer visible at Hunstanton is the Carstone Formation, a ferruginous sandstone deposited during the Early Cretaceous.

Its rusty brown appearance comes from its iron-rich composition. The formation contains sand, pebbles and iron-rich grains, with evidence of burrowing and other activity preserved within the sediment.

Carstone is not confined to the cliffs. It occurs across western Norfolk and has also played a part in the appearance of the area's villages and buildings, where the locally available stone has been used as a building material.

At Hunstanton, however, it forms the dark lower part of the geological sequence exposed beside the sea.

Why is the chalk red?

Immediately above the Carstone is the layer that gives Hunstanton Cliffs their most unusual feature.

The Hunstanton Formation, traditionally known as the Red Chalk, is a relatively thin sequence of chalky limestone and marl. At Hunstanton it is only around a metre thick, but its colour makes it particularly conspicuous between the brown Carstone below and the much paler chalk above.

The red and pink colouring comes from finely distributed iron minerals, particularly haematite, within the rock.

The formation also contains evidence of marine life. Fossils recorded from it include ammonites, bivalves, brachiopods and echinoderms, reflecting the marine environment in which the sediments accumulated.

Hunstanton is so closely associated with this rock that the geological unit itself takes the town's name.

From red chalk to pale chalk

Above the red layer, the character of the cliff changes again.

The pale chalk above the Hunstanton Formation belongs to younger deposits of the Cretaceous Chalk Group. The sharp colour change makes the boundary particularly easy to see from the beach and helps create the impression of three strongly defined bands running through the cliff face.

What now appears as a vertical sequence of coloured rock began as sediments accumulating over immense periods of geological time.

The present cliffs allow that sequence to be seen because the coastline has cut through the rocks and exposed them.

The sea continues to shape the cliffs

Hunstanton Cliffs are not a fixed landscape.

Waves, weather and erosion continue to act on the cliff face. Material falls onto the beach, rock surfaces become exposed and the edge of the coastline gradually changes.

At low tide, the beach below the cliffs reveals fallen blocks, rock platforms and further exposures of the formations visible in the cliff itself.

This continuing erosion is part of the reason the geology can be seen so clearly. The sea that is reshaping the coastline is also continually exposing the rocks from which it is made.

A landscape shaped by geology and people

The geology has influenced more than the appearance of the cliffs.

Above them stands Old Hunstanton Lighthouse, overlooking The Wash from one of the most recognisable points on this stretch of coast. Nearby, Hunstanton developed as a seaside town, while locally available stone, including Carstone, became part of the built character of western Norfolk.

The cliffs therefore sit at the meeting point of geological and human history: ancient rocks exposed by a changing coastline, with settlements, paths and landmarks developing around them much later.

Walking through the landscape

Today, Hunstanton Cliffs form one of the first major natural landmarks encountered when following the Norfolk Coast Path east from Hunstanton.

The route passes from the seafront towards the cliffs and Old Hunstanton, before the character of the coast begins to change again.

Beyond the cliffs lie beaches, dunes and saltmarshes leading towards Holme-next-the-Sea and Holme Dunes National Nature Reserve. The Peddars Way reaches the coast in this area, connecting the inland landscapes of Norfolk with the coastal trail.

For walkers, this means the beginning of the Norfolk Coast Path also provides an introduction to the geological history beneath the landscape.

The coloured bands at Hunstanton are not simply a distinctive backdrop to the walk. They are exposed layers of the landscape itself, preserving evidence of environments that existed millions of years before the modern Norfolk coast took shape.