MECHANICS OF FORMA TION OF ARCUA TE MOUNTAINS 183 



B 



Fig. 25. — Results of lateral compression of parallel horizontal layers of materials 

 which have varying degrees of rigidity, but are rendered plastic by the loads upon 

 them. The active force is applied at the left (after experiments by Bailey Willis). 



A , relatively less rigid beds deformed by failure beneath a competent (more rigid) 

 stratum. There is also to be observed a slide which passes through aU members alike. 



B, successive anticlines and slides — imbricated structure. 



