90 K W. Skeats- The Coral-reef Problem. 



view is correct, the massive reef of a large atoll must lie uncon- 

 formably upon talus of indefinite depth. Hence the Funafuti 

 borings could not, in any case, have penetrated massive reef 

 material in situ to a depth greater than about 45 meters." 

 Again, at p. 218, he states: "the boring at Funafuti showed 

 massive coral to persist to a depth of about 46 meters. Below 

 that depth the log of the boring suggests that it passed 

 through talus material all the way to the bottom at a depth of 

 340 meters. This conclusion was reached by the writer after 

 a careful study of the Funafuti report, issued by the Royal 

 Society of London; a subsequent inspection of a duplicate set 

 of the core material has tended to confirm the opinion." 

 These statements of Agassiz and Daly require some comment. 

 The underlying mass of Tertiary limestone beneath a shallow 

 reef, pictured by Agassiz, and the reef platform required by 

 Daly's hypothesis cannot be recognized in the Funafuti boring. 

 Prof. Daly's opinion, after an examination of the report and 

 of a duplicate set of core material, that below 46 meters the 

 bore continued in talus material to the bottom, appears to the 

 writer to be in conflict with the published facts and with the 

 views of the experts who examined the material. It would 

 involve a sharp, unconformable break at 46 meters below 

 the surface between the coral reef rock and the underlying 

 talus. The evidence on the contrary shows similar organisms 

 and texture above and below this depth, and the only change 

 noticeable near this depth is a gradual mineralogical change 

 from aragonite to calcite between 100-180 ft. 



Conclusions 



The conclusion is reached, based on the examination of the 

 organisms and textures from the bore and the submarine con- 

 tours of the island of Funafuti, that the only hypothesis of ori- 

 gin capable of correlating and accounting for all these facts is 

 the subsidence theory of Darwin. Supporting evidence of the 

 shallow-water origin of all the material and therefore subsi- 

 dence of the land will be brought forward in a succeeding 

 paper dealing with the formation of dolomite and its distri- 

 bution among coral and other limestones. 



The conclusions to be drawn from this summarized statement 

 of observations, both positive and negative, seem to the writer 

 to be clear, namely, that the whole material of the atoll from 

 the surface down to the bottom of the core at 1114 ft. 6 inches 

 is essentially homogeneous in origin and organisms, and all of 

 it was formed in shallow water. This necessarily involves 

 either a subsidence of the land to the extent of 1114 ft. or 

 possibly while the bulk of the material was formed during 

 subsidence, a small portion may be due to growth during a 

 post-glacial rise in sea level. 



