302 ^- i^OTÖ : CAUSE OF THE GREAT 



crust is the productiou of u series oi' folds with alternating <reosynclinals 

 and geanticlinals ; the crests of such wa\^e-like f(jlds corres])ond to 

 longitudinal uK^untain-raiiges, the intei'vening troughs being longitu- 

 dinal valleys. The direction in which the force acts is at right-angles 

 to;the strike <jf the saddles, or to the axis of a intjuntain-chain. Fold- 

 ing such as we have mentioned of course inv(jlves tilting, and all the 

 different forms (jf inclination haN^e l^een described as occurring' in 

 nature. We may cite, as an example of such, a, chain of the Samba- 

 gawan schistose rocks that stretches from the city of Tokushima to 

 Cape Sadano-misaki in the Island of Shikoku; while the valley of the 

 Yoshinogawa, which runs |)arallel with that range and discharges its 

 waters into Linschoten Strait, may Ije taken as the model of a 

 longitudinal valley. 



When the stowing (jf mountains ^and the puckering of beds are 

 carried to a certain degree, the limit of elasticity of rocks will be over- 

 stepped, and one effect of this may be that the beds of the upcast side 

 are l)odily shoved over those of the downcast side. A set of such 

 " cree])s " (IIVc'^.sc/) will produce what is termed the overlaj) tault or 

 Schupjx'nstriiciiir. At the same time part of a mountain may be dis- 

 lodo-ed alono- a fissure runnini»' i)arallel to the axis and strike of a rido-e. 

 The movement of a complex of strata in such a case along the line of 

 loii(fitmli}ial or periplicnil fault will cause a lotnjiimliiial ('artlKjiiah'. 



If the liorizontal force do not act with equal intensity over the 

 area affected l)v it, one part will be more strongly compressed by it 

 than another, and will consequently he pushed forward along a fissure 

 that is directed at right-angles to the axis of a mountain. In this 

 way, parts of a> mountain-chain may be thrust forward along sets of 

 transccrxe fissures. At the same time the strata will suffer downward 

 displacement, and such a dislocation be accompanied by what is called 

 a transverse eartlupiake. That the great earthquake of October last, 



