Discovering Lulworth Cove along the Jurassic Coast of Dorset
- Wayne Munday
- Jul 11, 2022
- 2 min read
Updated: Jan 2
Lulworth Cove is one of the most iconic natural landmarks along Dorset’s Jurassic Coast, attracting visitors eager to experience its striking scenery and exceptional geological significance. Managed as part of the Lulworth Estate, this near-circular bay is a classic example of a concordant coastline, where parallel bands of rock control coastal erosion. Around 10,000 years ago, Ice Age meltwater and wave action breached the resistant Portland limestone, eroding softer clays and sands behind it to form the cove seen today. Beneath its beauty lies a deeper story of continental collision, as distant Alpine mountain building folded Jurassic rocks into the Purbeck Monocline, dramatically exposed at Stair Hole in the Lulworth Crumple.
The coastline of the Lulworth Estate between Lulworth Cove and Durdle Door has been influenced by its geology. This coastline is defined as a concordant coastline where bands of differing rock types run parallel to the coast and in this case the harder outer rock is Portland limestone facing the sea.
Lulworth Cove is a near-circular bay created by coastal erosion. Around 10,000 years ago a river of glacial meltwater from the ice age flooded and removed the softer clay and sand rocks behind the Portland limestone until the sea eventually broke through and created the Cove.
Between 65 and 7 million years ago when the Alpine orogeny, or Alpine Mountain building event occurred creating the Alps, Pyrenees and Carpathian Mountains in Europe. The Alpine orogeny led to intense metamorphism, warping and crumpling of stacked-up layers of sedimentary limestone rock that was previously deposited in a shallow warm sea 145 – 150 million years ago during the Jurassic Period.
This sedimentary rock became vertically uplifted creating geological features such as the Weald-Artois Anticline stretching across Southern England into Northern France.
As modern-day Dorset was over 1,000 km from the collision zone of the Alpine orogeny it did not create any mountains but instead uplifted and folded rocks into what is now known as the Purbeck Monocline or the northernmost 'ripple'.. This ripple continues under the sea towards The Needles of the Isle of Wight as the "Purbeck-Isle of Wight Disturbance".
This geological fold in the southern part of England is best seen at Lulworth Cove with most dramatic example is at Stair Hole in the ‘Lulworth Crumple’. Within the folds there are ring-shaped imprints of fossilised ancient trees.
