Mr HOPKINS, ON RESEARCHES IN PHYSICAL GEOLOGY. 61 



the mass to be removed by denudation, the general surface will coincide 



(2) 



WWWF 



with M'N', and the broken plane of the vein will no longer intersect 

 it in a continuous line, but as represented in (Fig. 3), along the broken 



/D' 



A 



(3) 



line EC CD'; thus producing the appearance of a horizontal movement 

 of the mass on one side of the vein AB, relatively to that on the other. 



63. That these phenomena cannot, in some cases, have been pi-o- 



D> 



(4) 



duced by actual horizontal movements, appears to admit of the most 

 demonstrative proof; for it is sometimes found that when two veins 



