Highlight: Lulworth Cove and Durdle Door

The unmistakable limestone arch of Durdle Door
The unmistakable limestone arch of Durdle Door. Photo: Visit Dorset

A famous natural arch and a beautiful secluded cove; their existence owed to the collision of continents and the birth of the Alps. If you visit Durdle Door and Lulworth Cove, look carefully and you will notice that the layers exposed in the cliffs are tilting steeply to the north. This is most notable with Durdle Door itself as it is formed from a layer of hard limestone standing almost vertically out of the sea. Normally layers of limestone would be horizontal. Only the most fundamental force in geology could have altered these rocks in this way – plate tectonics.

Geological processes that created Durdle Door and Lulworth Cove

Around 25 million years ago the African tectonic plate collided with the European plate. The huge pressures generated heaved and folded rocks to create the mountain chain we know as the Alps. Ripples from that collision spread north through the Earth’s crust and gently folded the rocks here, in what would become south Dorset and Purbeck.

Durdle Door and Lulworth Cove lie in the heart of one of these folds, where the rock layers have been tilted steeply. As the sea broke through the hard limestone it washed away the softer rocks behind creating the arch, the cove and the beautiful coastline where Durdle Door and Lulworth Cove are both found. To find out more visit the Lulworth Cove Heritage Centre.