DROWNED ANCIENT ISLANDS — HESS 297 



of guyots, and might, if the hypothesis here presented is correct, show 

 features exactly comparable to guyots but at depths shallower than 

 500 fathoms. At the latitude of the Gulf of Alaska the water may 

 have been too cold for reefs to gTOW on the platforms. 



ACKNOWLEDGMENTS 



The writer wishes to thank Dr. J. Brookes Knight, Prof. F. A. 

 Vening Meinesz, Prof. A. F. Buddington, Prof. Charles Steel, and 

 Dr. J. C. Maxwell for reading the manuscript and offering numerous 

 valuable criticisms. The writer also wishes to express his appreciation 

 to his quartermasters on the U. S. S. Cafe Johnston for the care with 

 which they took soundings while at sea, in particular QMl/c Kobert 

 Kiefer, QMl/c R. K. Pritchard, QM2/c H. Jensen, and Q^I3/c Frank 

 Grumblatt. W. Miner Buell, Jr., of the Hydrographic Office, United 

 States Navy, was very helpful in collecting data on ocean-bottom fea- 

 tures from documents in the Hydrographic Office, and many of the 

 data were plotted by Ensign William Roche and Miss D. Trussell of 

 that office. 



FURTHER COMMENT ON GUYOTS AND ATOLLS IN THE LIGHT OF 

 RECENT INFORMATION 



Since the above paper was first written investigations of Bikini Atoll 

 have yielded important information, in particular the seismic profiles 

 reported on by Dobrin, Suavely, White, Beresford, and Perkins (1946) . 

 Further comment seems desirable on the problems suggested by this 

 information. 



The seismic profiles indicate the presence of a rock comparable 

 to basalt below the atoll. This high-velocity material reaches a maxi- 

 mum depth of 11,000 feet on the eastern side of the atoll, but rises 

 to a[ depth of 5,500 to 6,000 feet not far from the southern rim, at a 

 point slightly to the west of the north-south center line of the atoll. 

 The western third of the atoll was not investigated during this survey. 

 Since the highest point on the "basalt" surface lies on the western 

 margin of the area investigated, it is possible that this "basalt" rises to 

 a level nearer the surface somewhere in the vicinity of the western 

 or southwestern rim of the atoll. 



It is evident from the survey that the volcanic core of the atoll 

 forms a peak located eccentrically with respect to the present atoll 

 structure. Textbook diagrams have led most of us to expect that the 

 volcano would be nicely centered beneath the lagoon. A logical con- 

 sideration of the proposition would have indicated that the peak of 

 the volcanic core should lie not under the center of the atoll, but more 

 or less displaced toward the lee side with respect to the prevailing 

 winds, for reef growth is more rapid and vigorous on the windward 

 side. The same conclusion was implicit in the results of the Royal 



