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ATOLL (native name atollon in the Mal...

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Originally appearing in Volume V02, Page 870 of the 1911 Encyclopedia Britannica.
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ATOLL (native name atollon in the Maldive Islands)  , a See also:horse-See also:shoe or See also:ring shaped See also:coral See also:reef enclosing a See also:lagoon . The usual shape is that of a partly submerged dish with a broken edge, forming the ring of islands, See also:standing upon a conical See also:pedestal: The dish is formed of coral See also:rock and the shells of various reef-dwelling See also:mollusca, covered, especially at the seaward edges, with a film of living coral polyps that continually extend the fringe, and enlarge the See also:diameter of the See also:atoll . The lagoon tends to deepen when the See also:land is stationary by the See also:death of the coral animals in the still See also:water, and the patchy disintegration of the " hard " coral, while waves and storms See also:tear off blocks of rock and See also:pile them up at the margin, increasing the height of the islands, which become covered by vegetation . The lagoon entrance in the open See also:part of the horse-shoe is always to leeward of prevailing winds, since the coral growth is there slower than where the waves constantly renew the polyps' See also:food See also:supply . The conical pedestal rising from the depths is frequently a submarine volcanic See also:cone or See also:island, though any submerged See also:peak may be crowned by See also:art atoll .

End of Article: ATOLL (native name atollon in the Maldive Islands)
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