Most atolls began as ________ around volcanic islands which later subsided beneath the sea.
A) fringing reefs
B) dolines
C) polyps
D) tombolos
E) none of the above

Question

Quizplus · Accepted Answer

Fringing reefs form along the shoreline of a landmass and when the landmass subsides, a shallow lagoon forms between the reef and the coastline. Over time, the island may completely disappear below the surface of the water, leaving only the fringing reef and lagoon behind. This process can eventually form an atoll.

Most Atolls Began as ________ Around Volcanic Islands Which Later