ReefDiary

coral facts

World's first coral reefs occurred about five hundred years ago,their first close relative developed in Europe 230 million years ago.The Great Barrier Reef is relatively young at just 500,000 years old. The current reef's structure is much younger at less than around 8,000 years old.most reefs have formed on hard surface ,like a base of an old reef that died when the sea level is low,or on the edge of a rocky island. It depends on how the reefs start out, several types of reefs can form. Coral reefs form in the deep ocean and are called atolls. The theories on how coral reefs form were first put forward by Charles Darwin (of The Origin of Species fame) who proposed that atolls form around the edges of high volcanic islands that gradually submerge beneath the sea with changes in sea level or subsidence of the land. Hence,an atoll starts life as a fringing reef, then it becomes more of a ring growing on the shrinking land-mass, until the land disappears and just the coral circle remains. In some cases, the coral growth is unable to keep pace with the sinking island, and sunken dead reefs have been found.

posted by TheReefsLife's @ 6:37 AM