The Voyage of the Beagle Chapter 20 - Keeling Island: Coral Formations Part 3

In which an intricate theory is presented to explain the formation and varying structures of coral-reefs, including fringing reefs, barrier-reefs, and atolls, through the gradual subsidence of land and the upward growth of corals. Observations of reef distribution, land elevation, and volcanic activity combine to reveal the subtle interplay of earth’s movements and the coral-building creatures’ remarkable adaptations, preserving enduring records of geological change beneath the seas.