THE GLACIAL-CONTROL THEORY OF CORAL REEFS. 

 By Reginald A. Daly. 



CONTENTS 



Page. 



Outline of theory 158 



Earlier statements of elements of the theory 162 



Pleistocene temperatures of the tropical ocean 166 



Lowering of sea-level by Pleistocene glaciation 171 



Diminished volume of ocean water 171 



Gravitative influence of ice-caps 173 



Conclusion 174 



Islands and continental shores during the Glacial period 174 



Character of the shore rocks 174 



Heights of the Pleistocene islands 177 



Conclusions ; 177 



Origin of the coral-reef platforms 178 



Size of the actual platforms 178 



Pre-Glacial history of volcanic islands 178 



Duration of Pleistocene abrasion 179 



Rate of Pleistocene wave-benching 180 



Depth of the Pleistocene benches below present sea-level . . . . 182 



Depths of lagoons and of coastal shelves in stable areas .... 183 



Testimony of islands uplifted in post-Pliocene time 199 



Origin of the existing reefs 209 



Colonization of the platforms 209 



Upward growth of the reefs 210 



Special development of reefs at the edges of platforms 21 1 



" Drowned " atolls and other banks 212 



Volumes of the existing reefs 218 



Objections to the Glacial-control theory 220 



Glacial lowering of sea-level within the tropics 220 



Restriction of reef corals by Pleistocene cold 221 



General crustal stability in the coral-sea areas 221 



Sea-cut platforms and drowned valleys outside the coral seas . . . 223 



Drowned valleys of the coral islands 224 



Pleistocene cliffing of oceanic islands 229 



Biology of oceanic islands 231 



Difficulties of the subsidence theory 231 



Its alternative statements 232 



Uniformity of the assumed subsidence 233 



Alleged proofs of current subsidence 234 



Permanence of the Pacific basin . 234 



Small maximum depth of lagoons . 235 



Flatness of lagoon floors; comparison of depths in lagoons and on 



banks 240 



Psychological influence of classic diagrams 245 



The test by boring through reefs 247 



General conclusion 248 



