"Atoll, a coral reef surrounding a pool of shallow water, usually called a lagoon. The atoll is formed by the building of a coral reef on a circular or nearly circular foundation. It is usually broken in one or more places so that the lagoon is connected with the surrounding waters." -Foster, 1921

Atoll

"Atoll, a coral reef surrounding a pool of shallow water, usually called a lagoon. The atoll is formed…

Formation of atoll.

Atoll

Formation of atoll.

Completion of atoll.

Atoll

Completion of atoll.

"Atolls. A coral island commonly consists of a narrow rim of reef, surrounding a lagoon." -Dana, 1880

Coral Island of Atoll

"Atolls. A coral island commonly consists of a narrow rim of reef, surrounding a lagoon." -Dana, 1880

"represents a section of an island, from the ocean (o) to the lagoon (l). On the ocean side, from o to a, there is shallow water for some distance out; and where not too deep, the bottom is covered here and there with growing corals. Between a and b there is a platform of coral rock, mostly bare at low tide, but covered at high ... b to d is the wooded portion of the island. The whole width (is) from the beach (b) to the lagoon (c)." -Dana, 1880

Section of Coral Island of an Atoll

"represents a section of an island, from the ocean (o) to the lagoon (l). On the ocean side, from o…

Magna Carta Island is an island in the River Thames in England, on the reach above Bell Weir Lock. It is in Berkshire (formerly Buckinghamshire) across the river from the water-meadows at Runnymede. The island is one of several contenders for being the place where, in 1215, King John sealed the Magna Carta. Whilst the charter itself indicates Runnymede by name, it is possible the island may have been considered part of Runnymede at the time. It is known that in 1217 the island was the meeting-place of Henry III and Louis (afterwards Louis VIII) of France.

Magna Charta Island

Magna Carta Island is an island in the River Thames in England, on the reach above Bell Weir Lock. It…

"Diagram suggesting the development of a barrier reef and an atoll, successively, from a fringing reef, by sinking. 1, Fringing reef, formed in shallow water; 2, barrier reef, developed from fringing reef after subsidence; 3, the atoll which succeeds the barrier reef." -Salisbury, 1919

Barrier Reef Development

"Diagram suggesting the development of a barrier reef and an atoll, successively, from a fringing reef,…

Diagram illustrating the conversion of a barrier reef into an atoll.

Barrier Reef

Diagram illustrating the conversion of a barrier reef into an atoll.