1. Tropical Marine Biology

2. Reef - any upthrusting substrate in the ocean
(generally rock or coral)

3. Coral Reef - compacted and cemented assemblage of skeletons
and skeletal sediment of sedentary organisms living in warm
marine water with strong illumination

4. Classification of Reefs

7. Types of Coral Reefs
Atolls - ring or horseshoe shaped

8. Types of Coral Reefs
Atolls -

9. Types of Coral Reefs
2. Fringing Reefs - built on margins of land

10. Types of Coral Reefs
2. Barrier Reefs - Separated from land by lagoons

11. Comparison of the three types of reefs
-form at the edge of land mass
-form around volcanoes
stand offshore separated from land by lagoon -outer edge is upturned

12. Final type of reef - Patch Reef
-isolated coral community - often in lagoon

13. How are reefs formed?
Atolls as an example

14. Lyell - 1832 - Principles of Geology
-Formation of Atolls
-corals grew on submerged volcanoes

15. R.A. Daly- 1910 - Glacial Control Theory

16. Darwin ’s
Theory of Volcanic Subsidence

17. Drilling at Eniwetok Atoll
Why????

18. Drilling at Eniwetok Atoll
Drill core
Coral
skeleton
matrix
(CaCO3)
Ca m
Igneous
(volcanic)
rock

19. In the process of atoll formation, the three kinds of reefs grade into one another