The calcarenite material is often a conglomerate varying from little shell material to nearly all fossil shells with little sand. An example is material from Pleistocene Lake Okeelanta. In the deeper sections of this paleolake the fossil mollusc shell percentage of the matrix can vary from 10% to 60%. Near the eastern shore of this lacustrine system (GKK pit, Palm Beach County, Florida, USA), the matrix can be near 100% shell material.
Calcilutite (finer particles of mud instead of sand substituted with shell material cemented with lime) also can vary greatly as a conglomerate with shell material.