EARTHQUAKES 



213 



Fit,'. 213. Map showing the principal earthquake regions of the New World. 

 (Montessus de Ballore.) 



was formed averaging 18 inches in width, and traceable for a dis- 

 tance of 60 miles, parallel to the axis of the adjacent mountain 

 chain." ' The development of fractures or the opening of joints 

 is in some cases accompanied by faulting. This was the case in 

 Japan during the earthquakes of October 28, 1891, when the surface 

 on one side of a fissure, which could be traced for 40 miles, sank 2 to 

 20 feet (Fig. 215). There was also notable horizontal displacement, 

 the east wall of the fissure being thrust locally as much as 13 feet 

 to the north. 



Circular surface openings or basins are developed in some cases 



1 Geikie, Textbook of Geology, 4th ed., p. 372. 



