332 



taken place without velocity-differences and normal to the geantiolinal 

 axis, gaping fractures will nevertheless be lacking in the portion CI)', 

 and in the case of a row of islands a strait will correspond with a 

 minimnin of the vertical projection of the geanticlinal axis. 



2. Horizontal movement at the surface, corresponding loith the 

 movement at greater depth. In the portion CD' gaping fractures 

 will be formed which — in so far as they occur near the surface 

 of the sea — may be visible as straits between the islands. 



In the positions A' C and B' D' the old strikes will not differ 

 from the direction of the new geanticlinal axis; to what extent they 

 will do so in the portion CD', will depend on the movements near 

 the surface. If these movements are non-rotational, differences up 

 to 45° will occur; with rotation of the portions of the fractured 

 surface the differences may be approximately zero. 



Curving older strikes with a bending -point, and curving geanticlinal 

 axis loith displaced bending-point in the final stage. 



One of the numerous variations of this more general case is 

 represented in Fig. 5. 



Fig. 5. 



= Older strike. 



AC DB and A' G' D' B' = horizontal projection of the 

 geanticlinal axis, resp. in the initial-, and the terminal stage 

 of the period under consideration. 



1. No horizontal movement at the surface. In the final stage the 

 old strikes are nearly all oblique to the geanticlinal axis, near the 

 bending-point even approximately normal to it. Straits will correspond 

 with depressions of the geanticlinal axis. If the geological structure 

 changes chiefly in the direction vertical to the old strike, islands of 

 highly different structure will in some places be located side by side. 



2. Horizontal movement at the surface corresponding ivith that at 

 greater depth. When, in the terminal stage of the considered period 

 of movement, the points A, B, C and D have reached respectively 



