Topic– Salient features of world’s physical geography.
1) Discuss the different theories explaining the formation of Coral Islands.(250 words)
Certificate Physical and Human Geography by Goh Cheng Leong; Islands and Coral Reefs
Discuss- this is an all-encompassing directive which mandates us to write in detail about the key demand of the question. we also have to discuss about the related and important aspects of the question in order to bring out a complete picture of the issue in hand.
Key demand of the question.
The question wants us to simply write in detail about the theories trying to explain the formation of Coral Islands across the world.
Structure of the answer
Introduction-Mention that the subject of the origin of coral reefs has been debated for our one and a half centuries and several theories have been put forward but none has been universally accepted.
- Discuss the theory put forward by Charles Darwin- subsidence theory. E.g
- This theory assumes that all coral reefs began as fringing reefs around and Island are the topmost portions of extinct volcanoes that stood above ocean bed. Due to the general down-wrapping of the earth’s crust, the islands gradually subsided but the corals continue to grow upwards to keep pace with the subsidence etc.
- Discuss the theory put forward by R.A Dally- Glacial control theory. E.g
- This theory believes that during the height of Ice Age the water was too cold for any Coral growth take place but with the return of warmer climate water locked Up in ice sheets melted. Consequently, there was a rise in sea levels and columns begin to grow @ around 1 foot in a decade to keep pace with the rising water level etc.
Conclusion– based on your discussion, form a fair and a balanced conclusion on the given issue.