红岩
The Red Crag Formation at depth in eastern Suffolk clearly has one member, the "Sizewell Member", a coarse shelly sand with thin beds of clay and silt. It was interpreted as having been deposited in large scale sand waves where the sea bed was deeper. The overlying "Thorpeness Member", was provisionally assigned to the Red Crag based on its lithology but there is more evidence to suggest that it is part of the Norwich Crag Formation.