During Pleistocene time, the Bermuda Islands repeatedly underwent partial inundation and re-emergence. The land areas were continuously attacked and reduced by rain and ground water but repeatedly renewed, during times of submergence, by deposition of marine limestone and by contemporaneous additions of shore-born and wind-transported carbonate sand, now eolianite. Soils formed under subaerial conditions are now buried beneath later deposits and constitute important stratigraphic markers. The igneous foundation rock appears to have been exposed during some low marine stands, and the former shore lines seem to be recorded by submerged terraces. The major karst features are largely below sea level, and they must date from times of continental glaciations.
Previous writers have assigned eolian accumulation to times of Pleistocene low sea level and soil-making to times of interglacial high sea. Both conclusions are held to be erroneous.