Ch. IX.] VEINS IN PRIMARY ROCKS. 191 



but it traverses the elvan without producing a like effect; 

 showing that, if the veins have experienced motion, the con- 

 taining rock has not participated therein." 



6. Veins are sometimes dislocated and heaved without the inter- 

 vention of veins of any description. " For example, in Bal- 

 noon mine (near St. Ives), the lode is entirely in granite, and 

 is separated, both in length and depth, into regular detached 

 portions, exhibiting all the phenomena of heaves and throws, 

 without the usual accompaniments of intersecting veins, some- 

 what after the manner of the subjoined figure. 



Fig. 24, 



Bcdnoon Mine. (Transverse Section.) 



An instance of this kind has also been mentioned by Mr. 

 Hawkins. " It is very remarkable," he says, " that at Ding 

 Dong mine, in Madron, the tin lode is both heaved and 

 started (thrown) by the cutters and clifts (seams or joints) of 

 the granite through which it passes." * 



In concluding this brief sketch of the Cornish veins, which 

 has been divested as much as possible from all theoretical 

 considerations, we would ask whether enough has not been 

 advanced to show that the general idea of these veins is incor- 

 rect : and when we hereafter discuss the nature of their origin, 

 it will be seen that our knowledge on this subject is as un- 

 satisfactory as the descriptive details. From the leading facts 

 which have been now brought together, we learn that veins, 

 whether large or small, possess precisely the same characters : 

 they are intimately connected with the containing rock by 

 mineral transitions, and vary in composition as the nature of 



* Geol. Trans, of Cornwall, vol. ii. p. 241. 



