The cove has formed because there are bands of rock of alternating resistance running parallel to the shore (a concordant coastline). On the seaward side the clays and sands have been eroded away. A narrow (less than 30 metre) band of Portland limestone rocks forms the shoreline. Behind this is a narrow (less than 50 metre) band of slightly less resistant Purbeck limestone. Behind this are 300-350 metres of much less resistant clays and greensands (Wealden clays, Gault and Upper Greensand).
Forming the back of the cove is a 250 metre wide band of chalk, which is considerably more resistant than the clays and sands, but less resistant than the limestones. The entrance to the cove is a narrow gap in the limestone bands. This was formed by a combination of erosional processes by wave action , glacial melt waters and the processes of weathering. The wide part of the cove is where the weak clays and greensands have been eroded. The back of the cove is the chalk, which the sea has been unable to erode as fast.
The unique shape of the cove is a result of wave diffraction. The narrow entrance to the cove ensures that as waves enter they bend into an arced shape.
Not sure about this shot, taken in the context of a single photo. It was taken as one shot of a 7 or 8 shot panorama which worked reasonably well. But thought I’d have a play with some processing that’s a bit different to the usual crop/sharpen and save to try and emphasise the layers in the exposed face of the cliff. Perhaps a different crop would work better, what do you think??