Calcification of exposed filaments of endolithic algae, micrite envelope formation and sediment production

Iceland spar (calcite) crystals, placed in the shallow subtidal marine environment at Discovery Bay, Jamaica, are infested by the filamentous endolithic (boring) alga Ostreobium sp. Within 25 days after the crystals are placed in the sea, filaments project from the substrate into the sea; between 65 and 95 days the exposed filaments become completely calcified by low Mg calcium carbonate, both internally and externally. The submarine …