The diagram depicts the natural process in which coastal erosion led to exposure of fossils beneath a cliff.
The cliff face once stood further out and the waves cannot reach it at low tide. But waves at high tide, in contrast, can reach halfway up the cliff and hit it continuously. The force coming from waves creates some cracking on the cliff face. Gradually, the waves wore out the base of the cliff. Some stones or rocks from the cliff fell into the sea and stayed just below the sea surface.
The upper part, with no supporting base, can collapse easily into the sea. Therefore, the area beneath the remaining cliff is considered a danger zone. As waves keep attacking the cliff, it will retreat more and soon expose the fossils inside. In addition, a sloping rocky platform will be formed.
In summary, the diagram shows how coastal erosion damages the natural landscape but also discovers the valuable fossils hidden inside.