CHANGES IN THE STRATIFIED ROCKS 289 
ends may be seen to change into actual faults; and 
the same kind of strains, applied to different classes 
of rocks, will cause the brittle to break while others 
bend. 
It is not to be understood that faulting is confined 
to the surface, for there are some great faults that 
Fic. 170. 
Photograph of a fault slip which caused the Japanese earthquake of 1891. 
appear to extend far down into the earth. Sometimes 
the total displacement amounts to only a fraction of 
an inch, while again it may be measured by thousands 
of feet. In the great faults, the breaking and move- 
ment have probably been accomplished very slowly, 
just as in the case of rock-folding. Even now in Japan 
(Figs. 170 and 219), and in various other parts of the 
U 
