红岩
The shelly sand, clay and gravel deposits known locally as 'crag' cover the eastern part of the county. The western 'feather edge' of the crag is mapped south from the coast west of Sheringham through Cawston and Norwich to the Suffolk border east of Diss. The sequence is divided into the Red Crag, Norwich Crag and Wroxham Crag formations. Some of the youngest rocks in Britain, these are of Pliocene to Pleistocene age.