This rock is probably from the western raised beach which is about 240,000 years old. It dates back to the Ice Age, which was a series of both warm and cold spells. The raised beach is from one of the warmer periods and it shows us that sea levels can rise several metres without the burning of any fossil fuels.
Look closely and you’ll see lots of small shells, such as those on the close-up photos.
Find out more on the rocks and pseudofossils page.