Coccolith

Coccoliths are microscopic (maximum 0.01 mm ) disc-shaped platelets of lime, forming the shell of calcareous algae of the order Coccolithophorida. Born out mass deposits of these shells chalk rock is the namesake for the geological period of the Cretaceous.

Under Coccolithenschlamm is understood in geology a lime mud, which consists of coccoliths. These were alive on the spherical gelatinous bodies planktonic flagellates ( coccolithophores ). The white chalk cliffs of Calais, Dover and the islands of Rügen and Møn consist to a large extent from fossil coccoliths. Chalk earlier consisted of coccoliths, today made ​​of plaster.