72 F. p. fiULLIVER — PLANATION AND DISSECTION OF URAL MOUNTAINS 



the Urals and to those portions of the great central and Siberian plains 

 which lie next the mountains. 



The Russian field-workers have given much attention to the age of 

 the deposits as determined by their contained fossils, to their superpo- 

 sition, and to their faulting ; but practically no work has been done on 

 the interpretation of the geologic history of the Urals from a study of 



2S° 



Figure 1. — T)raina<jt System of Ural Mountains. 



the forms of the surface as controlled by the underlying structures. An 

 occasional mention of a harder stratum as a ridge-maker is found in the 

 " Guide to the excursions of the Seventh International Geological Con- 

 gress," but no systematic use of form is made. Tlie Russian geologists 

 have not yet introduced the physiographic method of the Americans. 

 This paper is written to point out the problems in the line of physio- 

 graphic work needed in this region and to offer a suggestion as to what 



