THE 



AMERICAN JOURNAL OF SCIENCE 



[FO DRTH SERIES.] 



Art. XX. — A Shaler Memorial Study of Coral Reefs ; by 

 W. M. Davis. 



Contents: 



Page 



A Journey across the Pacific 223 



Theories of Coral Reefs 224 



Evidence derived from Barrier Reefs _ 225 



Coral Reefs on still-standing Islands 226 



Contrast of Cuban and Pacific Reefs . . . _. 227 



Value of Physiographic Evidence 228 



Dana's Principle of Shoreline Development 229 



Out-growing Reefs on still -standing Islands 230 



Reefs as Veneers on Wave-cut Platforms 232 



The Continental Shelf of Australia and the Great Barrier Reef 233 



Reefs and Reef Platforms 234 



Coral Reefs and the Glacial Period 236 



Lagoon Floors are not Wave-cut Platforms 239 



The Valleys of Barrier- reef Islands 240 



Depth of Valleys in Barrier-reef Islands.. 242 



Age of Valleys in Barrier-reef Islands 243 



The Borders of the Coral Zone 246 



The Elevated Reef of Oahu 247 



Elevated Reefs in the Fiji Group 249 



Elevated Fringing Reefs in the New Hebrides 253 



The Elevated Loyalty Atolls 255 



Testimony of Elevated Reefs _ 256 



Submergence and Subsidence 257 



Possible Causes of Submergence 259 



Darwin's Theory of Subsidence 261 



The Problem of Atolls... 263 



The Merits of Darwin's Theory.. 266 



Dana's Confirmation of Darwin's Theory 266 



Subsidence Modified by Glacial Changes of Sea level 267 



Summary of Results.. ^ 269 



A Journey across the Pacific. — A liberal grant from the 

 Shaler Memorial Fund of Harvard University, supplemented 

 by a generous subsidy from the British Association for the 

 Advancement of Science with an invitation to attend its meet- 



Am. Jour. Sci. — Fourth Series, Vol. XL, No. 237. — September, 1915. 

 15 



