136 UNIVERSITY OF MISSOURI BULLETIN 



been produced, the crust has broken and blocks have collapsed, 

 been elevated, or tilted. These likewise have had their effect 

 in producing the variations of land surface that exist. Many 

 attempts were made in the last century to work out general- 

 izations from the study of the facts of deformation and sev- 

 eral schemes were proposed. None of them, however, has 

 stood the test of criticism and time. They were all more 

 or less local. No one of them essayed to connect all the 

 deformations of the whole crust into one general scheme. 

 There were separate schemes for each continent. 



It was not until the very last years of the nineteenth 

 century that the local crustal deformations of the whole earth 

 were woven into one comprehensive scheme of earth-form 

 development by the constructive work of the great German 

 geologist Suess. He worked out not only a scheme of earth 

 deformation, but included a scheme of continental develop- 

 ment throughout geological history. His studies finally led 

 him to the generalization that all crustal deformation is, ex- 

 cept locally, a downward deformation ; that the many mani- 

 festations of deformation are but various phases of a short- 

 ening radius, and that all crustal movements have been down- 

 ward movements, except where these downward movements 

 and the radial shortening have produced local intense com- 

 pression, resulting in local upbowing of the rock beds. 



The ocean basins, therefore, are great areas of the earth 

 that have collapsed in response to the adjustment to the de- 

 creasing radius. The continents are the blocks that have been 

 left standing at higher positions, whether the initial one or 

 not, while mountain ranges are the crumplings of the conti- 

 nental blocks at weak places due to compression. He not 

 only works out the development of the existing relation of 

 continents and ocean basins as they exist at present, but he 

 traces the outlines of preexisting continents that have col- 

 lapsed wholly or in part, parts of which now lie at the bot- 

 toms of ocean basins, while other parts form constituents of 



