'm 



218 THE BEAtrTIES OF NATURE chap, vi 



Hence demidation will act witli more effect 

 on the upper than on the lower portion 

 of the folds, and if continued long enough, 

 so that, as shown in the above diagram, the 

 dotted portion is removed, we find the origi- 

 nal hill tops replaced by valleys, and the origi- 

 nal valleys forming the hill tops. Every 

 visitor to Switzerland must have noticed hills 

 where the strata lie as shown in parts of Fig. 

 18, and where it is obvious that strata corre- 

 sponding to those in dots must have been origi- 

 nally present. 



In the Jura, for instance, a glance at any 

 good map of the district wiU show a succes- 

 sion of ridges running parallel to one another 

 in a slightly curved line from S.W. to N.E. . 

 That these ridges are due to folds of the 

 earth's surface is clear from the following 

 figure in Jaccard's work on the Geology of the 

 Jura, showing a section from Brenets due 

 south to Neuch&tel by Le Locle. These folds 

 are comparatively slight and the hills of no 

 great height. Further south, however, the 

 strata are much more violently dislocated and 

 compressed together. The Mont Saleve is the 

 remnant of one of these ridges. 



