Coralline algal reef frameworks

Published and unpublished accounts of coralline algal reef frameworks are reviewed. The descriptions are divided into frameworks constructed from crustose coralline algae and those constructed from branching corallines. Crustose frameworks are briefly described and illustrated from the Miocene of Malta, Recent ‘coralligène’ from the Mediterranean, Eocene reefs from Spain, Recent algal reefs, of St Croix, U.S. Virgin Is. and algal reefs from Bermuda. Branching frameworks are briefly described and illustrated from the Recent maerl of the NE Atlantic, Recent mud mounds from Florida, Recent algal reefs from St Croix and Recent algal ridges on Pacific reefs. Crustose and branching frameworks show an increase in strength of construction, early submarine cements and macro-borers and a decrease in erodibility from low to high energy environments. The occurrence of genera in coralline frameworks is primarily controlled by their geographic and water-depth ranges. The construction of coralline frameworks is seen as the result of competition for living space on shallow marine hard substrates.