Except Bird and Denis islands, which are of coralline limestone, the Seychelles are of granite, with in places fringing reefs of coral based on granite foundations.
These atolls are of coralline formation and of irregular shape.
The phosphatic nodules occurring throughout the Red Crag of Suffolk are regarded as derived from the Coralline Crag.
Suakin stands on a coralline islet connected with the suburb of El-Kef on the mainland by a causeway and a viaduct.
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.
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 peninsula is almost wholly composed of a bed of coralline and porous limestone rocks, forming a low tableland, which rises gradually toward the S.
Araucarites Hudlestoni, described by Mr Carruthers from the Coralline Oolite rocks of Malton in Yorkshire; Araucarites sphaerocarpa from the Inferior Oolite of Somerset; also another cone found in the Northampton Sands, which is probably specifically identical with A.
The Blue Clay forms, at the higher levels, a stratum impervious to water, and holds up the rainfall, which soaks through the spongy mass of the superimposed coralline formations.
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.