Take a look at the cliffs here and you'll notice they're made of muds and sands peppered with pebbles. This material is called glacial till, or the more apt name of boulder clay. It's formed as ice picks up and scrapes bits and pieces of rock fragments, dumping them in an uneven mess once the ice sheet stops moving or starts to melt. We can see the same thing happening today with ice sheets in Greenland and smaller glaciers around the world. By looking carefully at some of the pebbles within the bolder clay in Norfolk, it's actually possible to tell where the ice came from.
Some pebbles match exactly with rocks which are unique to Norway.
These Norwegian pebbles hitched a one way ride on the ice sheet and were dropped off at what is now the coast of Norfolk. Rocks and pebbles which are moved from there place of origin by ice are called erratics and are great clues to the geological detective. The Norwegian erratics tell us the ice must have come from Norway. The Norfolk coast was about the furthest south the ice sheet advanced. To the south, rivers such as the Thames, Rhine and Maas were flowing into a basin dammed to the north by the ice.