The term coprolites has been made to include all kinds of phosphatic nodules employed as manures, such, for example, as those obtained from the Coralline and the Red Crag of Suffolk.
The phosphatic nodules occurring throughout the Red Crag of Suffolk are regarded as derived from the Coralline Crag.
It comprises a large number of low coralline islands and atolls, which are disposed in nine clusters extending over a distance of about 400 m.
There is an endless amount of stone, very little of which is hard enough to be good for building material, the greatest part being a soft coralline limestone.
They are entirely marine, and are not uncommon in the coralline zone of the sea-coast.