CoachA reef is a carbonate build-up whose framework of organisms, corals, algae or others, grown in place and bound and cemented together, stands above the surrounding sea floor and resists the waves. A carbonate platform is a thick body of shallow-water carbonate whose flat top lies close to sea level and which is bounded by a slope down to deeper water. An ooid is a round grain of sand size made of concentric layers of calcium carbonate grown around a nucleus as it rolled in agitated water; a rock made of ooids is an oolite.
