226 F. B. TAYLOR ORIGIN OF THE EARTh's PLAN 



derthrusting of the deep-seated mass beneath Asia. By this hypothesis 

 the crustal sheet in which the folding, oA^erthrusting, etcetera, are pro- 

 duced is not the part in which the principal movement occurs. The 

 crustal sheet is regarded as a passive element, and the mountains of Asia 

 exist only because some other part of the earth than the crust moved ' 

 horizontally and the crust became involved in that movement. But if 

 the same results in mountain making can be derived from horizontal 

 movements of the crust alone, why postulate a more complicated indirect 

 process ? 



Even Chamberlin^s Planetesimal hypothesis, which has brought so 

 great an advance over the Nebular hypothesis of Laplace with reference 

 to the origin and growth of the earth, meets these same two difficulties, 

 and with no better success.^^ 



It seems certain that no man living has ranged so widely over the 

 fields of geology for the entire earth as Eduard Suess. He appears to 

 have made himself familiar with every official report and every important 

 memoir or scientific contribution that has ever been written on the sub- 

 ject. His earlier studies turned his mind along certain lines of interpre- 

 tation, chiefly depression of oceanic basins and tangential crustal move- 

 ments overthrusting those basins. This was natural, for every one must 

 arrange his thoughts around some central idea as he goes on working 

 year after year, decade after decade. Indeed, one's thoughts will in- 

 evitably crystallize themselves around some uniting principle, whether 

 he will or no. These early principles of interpretation served Suess well 

 throughout the greater part of his life. But is it not deeply significant 

 that after a lifetime of study along the lines of those early principles, 

 Suess at last leans toward a different interpretation, both as to the cause 

 of displaced strand-lines and of deformations of the lithosphere? And 

 is it not still more significant that in both instances his leaning is toward 

 a cause which conforms precisely with increased oblateness of the earth's 

 figure, or with oscillations of the same ? 



The argument presented in this paper rests at last on the truth of 

 Suess' interpretation of the mountain plan of Asia. The principles 

 which he worked out there have been applied without important modifi- 

 cation to the other continents, and the conclusions reached in this way 

 appear to accord very closely with suggestions made by Suess himself in 

 his later writings. For a change in the degree of oblateness, either in 

 oceanic oscillations or in deformations of the lithosphere, one is inclined 

 to reject all internal causes and to look to some form of tidal force as the 

 only possible agency. 



!• Chamberlln and Salisbury : Geology, vol. II, pp. 82-132. 



