DISLOCATIONS OF STRATA. 103 



mote origin than slides. This opinion must however 

 be qualified ; as it is shown in the succeeding chap- 

 ter, not only that curvatures and fractures may be 

 simultaneous, but that strata are actually bent by the 

 same forces by which they have been broken and 

 separated from their connexions. 



All the appearances which belong to fractures and 

 shifts, are to be seen on a small scale, in perfection ; 

 occurring in innumerable rocks, so as to form cabi~ 

 net specimens which are perfect natural models of the 

 great events that have produced so many important 

 changes in the surface of the globe. The varieties 

 thus occurring, are often singularly interesting, from 

 their peculiarities ; and, among those that have been 

 described, there is none more remarkable than one of 

 which I have given an account in the Geological 

 Transactions. In this, a succession of equal slides has 

 taken place, in such a manner as to separate an inter- 

 secting vein of the original rock into numerous parts ; 

 marshalling these in a new line which forms a consi- 

 siderable angle with the original position of the vein. 

 While the fact is in itself remarkable, it serves as 

 an indication of the changes which must take place in 

 the form of the surface, when slides of an analogous 

 nature have occurred on the large scale. 



The phenomena of rock veins having already been 

 described, and those of mineral veins forming the 

 object of a separate chapter, it can only be necessary 

 to remark in this place, that all the displacements 

 which occur in strata, and all the reasonings which 

 apply to their disturbances and motions, equally occur 

 in veins, and are equally applicable to them, of what- 

 ever description they may be. As such veins often 

 exist in the rocks, before displacement, it is evident 

 that they must be implicated in all the consequences 



