10 PROCEEDINGS OF THE INDIANAPOLIS MEETING. 



A recess was then takeu until 2.30. p. m., after which the following paper 

 was read : 



THE CONTINENTS AND THE DEEP SEAS. 

 BY E. W. CLAYPOLE. 



[Abstract.) 



An opinion has become current of late among geologists that the main features of 

 the relief of the earth's surface — the ocean abysses and the continental masses — are 

 aboriginal. Those who have adopted this doctrine hold that all the variations that 

 have occurred in the outlines of land and water have been caused by oscillation in what 

 they call " the border of the ocean " where the water is comparatively shallow. The 

 conversion of a deep ocean into land or of land into deep ocean has never, they main- 

 tain, taken place. 



It is the purpose of this paper to examine the bases on which this opinion rests in 

 order to discover whether or not they are trustworthy. 



The doctrine itself may be a reaction from the opposite extreme advocated about 

 forty years ago by Edward Forbes. This able but perhaps too zoological geologist 

 ordered the continents about in a fashion that is rather surprising. "With the highest 

 respect for one who did so much for science, I may yet be allowed to insist that he 

 carried too far the doctrine of instability, as some in the present are tending too far in 

 the reaction. 



The original suggestion came apparently from Darwin, who writes in his " Origin 

 of Species " (edition of 1860, p. 357): 



" I do not believe that it will ever be proved that within the recent period continents which are 

 now quite separate have been continuously or almost continuously united. Several facts in dis- 

 tribution seem to me opposed to the admission of such prodigious geographical revolutions within 

 the recent period as are necessitated on the view advanced by Forbes." 



Following him came Professor Dana, who inculcated the same doctrine in stronger 

 terms in his " Manual " (edition of 1874, p. 738) : 



" The earth's crust rises over large areas into plateaus or continents, leaving a depressed area of 

 much larger extent occupied by the ocean. These plateaus show by their position that they were 

 the parts of the crust that first stiffened, and that the oceanic basins are due to a subsequent con- 

 solidation of the areas which they occupy, the attending contraction carrying them below the level 

 of the previously solidified continental areas." 



The new doctrine has been strongly defended and as strongly opposed ; but in order 

 to examine its merits it will be best to consider in order the chief arguments advanced 

 in its support. 



There will be no advantage in discussing the fundamental hypothesis of Professor 

 Dana, because it is purely an hypothesis and has nothing to support it. It may be 

 true or false, but neither can be proved. 



The condition of the problem is this: A land-area equalling about one-fourth part 

 of the surface of the globe rises above the water-level to the average height of one-fifth 

 of a mile. The remaining three-fourths of the surface is sunk below that level to the 

 average depth of two miles. The depression of the ocean-bed therefore below the sea- 

 surface is in capacity thirty times as great as the elevation of the land above it. The 

 continents are comparatively insignificant masses lying but little above the water and 

 capable of being submerged (excepting a few peaks) by a slight submergence. Were 



