'Grain-diminution' of algal colonies to micrite

Abstract

Studies of Recent and Paleozoic calcareous algal deposits indicate that early diagenetic alteration can result in a change of calcareous algal filaments and cells to cryptocrystalline calcium carbonate. The apparent absence of reef framework builders of some of the enigmatic micritic to fine-grained bioherms or knoll-reefs of North America, Europe, and Australia, may be explained by 9grain diminution9 of calcareous algal colonies.