CRUSTAL MOVEMENTS 



189 



ing of the ocean basins has been greater than the rise of the sea- 

 level because of sedimentation from the land. This is perhaps 

 the reason why wind and water and ice have not been able to 

 destroy the continents, though this is their constant aim. 



Fig. 184. Closed anticline, near Levis Station, Quebec. 



Types of Crustal Deformation 



Changes of level imply deformation (bending, breaking, etc.) of 

 the outside of the solid part of the earth. This deformation takes 

 the form of (1) gentle warping, (2) folding, and (3) faulting. 



Fig. 185. Section of the western part of the Jura Mountains. 



Warping and folding. Sedimentary rocks were originally laid 

 down in nearly horizontal beds, just as sediments are being laid 

 down at the present time. But the rock strata of most parts of 



