The shape of atolls; an inheritance from subaerial erosion forms

Abstract

Reviews various theories of atoll formation and summarizes observations in the northern Marshall islands which lead to the conclusion that the annular reef and lagoon structure of some oceanic atolls reflects marginal rims and central depressions developed by subaerial weathering processes on emerged limestone platforms, modified by subsequent organic growth following resubmergence of the platform. Alternation of organic growth and erosion was related to eustatic changes of sea level during the Pleistocene.