The exposure of Nothe Grit, to the south of Weymouth, suggests a return to shallower water conditions and a more turbulent environment. In the following 4.5 million years a cycle of lagoonal, tidal and deep water environments caused by a world-wide fluctuations in sea levels, deposited beds of sand, clay and limestone across the entire county. The Corallian strata can be seen on the Weymouth anticline, between Abbotsbury and Osmington. It then disappears to emerge as a low escarpment between Mappowder and Cucklington on the Somerset border. Near the top of this formation is the Ringstead Waxy Clay in which large delta shaped oysters are found and at the top of the Corallian is the Ringstead Coral Bed.