Ch. IX.] VEINS IN PRIMARY ROCKS. 183 



the containing rock, that no one has disputed their contem- 

 poraneous nature ; but it has been supposed, that the appear- 

 ances of motion are deceptive, and to be explained on other 

 principles. " In a multitude of contemporaneous veins," ob- 

 serves Mr. Carne, " some may appear to be heaved ; but the 

 apparent heave seldom affects more than one vein : and it is, in 

 general, easy to perceive, that what appear to be separate 

 parts of the same vein, are different veins, which terminate 

 at or near the cross-vein." * This description equally applies 

 to what are called true veins or lodes ; the intersected parts 

 appear to have been moved, but such a displacement is only 

 apparent, not absolute : and it might, therefore, be a safer 

 course to doubt whether the large veins have experienced any 

 movements, since the small ones display similar appearances, 

 which cannot be referred to a mechanical cause. We must 

 not, however, farther anticipate the discussion on this subject, 

 but proceed to offer some examples of this phenomenon on a 

 large scale, for which we are indebted to Mr. Kenwood : 

 premising that he uses the mining terms, in reference to 

 heaves and throws, in the same sense as Mr. Carne. f 



1. One vein intersects another with or without producing an 

 apparent heave. This proposition is so simple, that it needs 

 no illustration, when a vein is only examined at a given 

 point ; but if the vein be followed in its downward course, it 

 will be found, that " the extent of the heave is not always, or 

 indeed usually, the same at all depths. Thus, the main lode 

 of Ting Tang mine (near St. Day, intersecting granite and 



* Gcol. Trans, of Cornwall, vol ii. p. 52. 



f Idem, p. 86. " 1 use the term heaved," says Mr. Carne, " as applicable 

 only to a longitudinal shift of the vein ; and, thrown up or thrown down, to 

 those shifts which take place on the meeting of two veins, underlying in different 

 directions, in their downward course. In describing the heave of lodes as to 

 the right or left, I mean, that when lodes are heaved by other veins, they may be 

 found on the other side of the traversing veins, by turning either to the right or 

 left hand. I use these terms in preference to the points of the compass, because, 

 in whatever direction a miner may pursue a lode, a right or a left hand heave is 

 precisely the same on both sides." 



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