[DOC] [TLE] J! Archive - Show #1907, aired 1992-12-15 [PAR] This animal used in bathtubs doesn't have a nervous system .... An atoll is a 
circular one of these that has grown around a sunken volcanic island... [DOC] [TLE] Coral Reef: Formation - MarineBio.net [PAR] 4.1.1 ... ocean water in the tropics enough so that it has a lower density than the 
subsurface water. ... These plants are called phytoplankton and photosynthesize 
to grow. ... Aerial view of the stages of coral reefs (fringing, barrier, atoll). ... in 
warm, clear ocean waters (such as would be common around a new oceanic 
island). [DOC] [TLE] Atoll - Wikipedia [PAR] An atoll sometimes called a coral atoll, is a ring-shaped coral reef including a 
coral rim that encircles a lagoon partially or completely. There may be coral 
islands/cays on the rim. (p60) The coral of the atoll often sits atop the rim of an 
extinct seamount or volcano which has ... The distribution of atolls around the 
globe is instructive: most of the world's... [DOC] [TLE] Difference Between Atolls And Coral Reefs - KnowledgeNuts [PAR] Jan 11, 2014 ... An atoll is a very specific kind of coral reef; it is a circular reef that forms around 
the mouth of an underwater volcano. ... if not thousands of years, coral will begin 
to grow on these underwater structures. ... They may also have an island or a 
handful of small islands in the center. .... John Connor  1 year ago. [DOC] [TLE] 1. Darwin's 'big coral atoll idea' - Earth Learning Idea [PAR] 1. Darwin's 'big coral atoll idea'. Try thinking like Darwin did to solve the coral 
atoll mystery ... If these islands are circular or nearly circular at the surface, 
Darwin ... reef to grow in a circular shape in the first ... When they have made their 
cone-shaped 'sunken ... sink steadily, over a very long time, so that volcanic 
islands sank... [DOC] [TLE] Microdocs: Darwin's Volcano - Stanford University [PAR] Darwin thought coral atolls grew up from sinking volcanic islands; Agassiz ... 
Atolls  how these remote, circular coral reefs could form puzzled many 19th ... 
atoll formation  atolls begin as a fringing reef growing around a volcanic island. 
... One year later, a second Royal Society expedition drilled down to 698 ft (210 m
). [DOC] [TLE] atoll | coral reef | Britannica.com [PAR] Atolls consist of ribbons of reef that may not always be circular but whose broad 
configuration ... Some of these islands have been settled by oceanic peoples like 
the ... stage of a continuing upgrowth of reef around a sinking extinct volcanic 
island that ... Reefs tend to grow outward from a fringing-reef stage toward the 
better... [DOC] [TLE] The Origin of Certain Fiji Atolls - JStor [PAR] coral reefs; and the recognition of these significant features has in recent ... of 
these now-dissected limestones, around which a new barrier reef ... islands and 
Darwin's theory of the formation of atolls by upgrowth on ... on denuded volcanic 
hills, rises 600 fee b a. FIG. 1 and is enclosed with the eight other Isles of the 
cluster... [DOC] [TLE] What are the three main types of coral reefs? [PAR] When a fringing reef continues to grow upward from a volcanic island that has 
sunk entirely below sea level, an atoll is formed. Atolls are usually circular or oval
... [DOC] [TLE] The Pacific Islands 487 [PAR] Atolls begin as coral reefs grow around a volcanic island. Over ... The area above 
the sunken volcano becomes a lagoon ringed by coral reefs. Over time, ocean ... 
One group of winds, called trade winds, blows toward the ... in circular patterns. ... 
Once these warm ocean currents hit land, they have to change direction. In the. [DOC] [TLE] Darwin Online: Introduction to Coral reefs [PAR] The maturation of his brilliant explanation for the formation of atolls is ... they were 
coral reefs growing up from the crater rims of sunken volcanoes. ... If the coast is 
sinking, as

Question: An atoll is a circular one of these that has grown around a sunken volcanic island
Answer: a coral reef