The Coral Reefs ClipArt gallery offers 14 examples these underwater ecosystems held together by calcium carbonate structures secreted by corals.
"Atoll, a coral reef surrounding a pool of shallow water, usually called a lagoon. The atoll is formed…
"Diagram illustrating Darwin's theory of the formation of Atolls." -Geikie, 1893
"Atolls. A coral island commonly consists of a narrow rim of reef, surrounding a lagoon." -Dana, 1880
Section of a barrier reef.
Formation of Coral Reeds, according to Darwin.
The reef forming the island is of limestone, derived form countless skeletons of minute polyps that…
This is an illustration of a relatively flat island, surrounded by coral-reefs.
The typical representation of coral reef on a topographical map.
A section of an actual coral reef, showing the formation: two sides tall, above sea level with the middle…
"Diagram suggesting the development of a barrier reef and an atoll, successively, from a fringing reef,…
A barrier reef is a coral reef that is far from land.
Diagram illustrating the conversion of a fringing into a barrier reef by subsidence.
Diagram illustrating the conversion of a barrier reef into an atoll.
A fringing reef is a coral reef that is close to land.