101 ON THE CONVOLUTIONS OF STRATA, 



have been converted into stone. The whole assemblage of 

 granite, killas and sandstone, having been raised into the posi- 

 tion which they now occupy, by revolutions of a still posterior 

 date. 



The present order of things may thus be accounted for, by 

 a set of progressive steps of elevation, without the necessity 

 of supposing, everywhere, an interposed submersion. Not 

 that I am disposed to deny the occasional occurrence of such 

 submersions ; which may naturally be expected to have taken 

 ]ilace, in consequence of the voids, which could not fail to be 

 produced by so many undoubted elevations. 



Tiic circumstances thus stated are different, as may be ob- 

 served, on the Hill of Lauren, from those of the junction on 

 the bed of the AVater of Dee, as described above ; but such 

 differences are perfectly consistent with our view of a liquid 

 forcing its way among a set of beds previously consolidated 

 and indurated. 



The conformable junction at the Water of Dee, is the only 

 one which, being ambiguous, does not contradict the Werne- 

 rian view of the general system ; a view that is completely ex- 

 cluded by the perturbed junction at Lauren. Now, both of 

 these junctions are consistent with the Huttonian theory, ac- 

 cording to which, a diversity of this sort was to be expected 

 in such circumstances. It is very obvious, that the substance of 

 a vein must be of newer formation than the rock through which 

 the vein passes ; and it is no less obvious, that where the angu- 

 lar fragments of one substance are contained in another, the 

 substance tlius contained must be the older of the two. In 

 these observations, we have seen that two veins of granite, 

 which penetrate the killas, do constitute one continuous mass 

 with the great body of granite which lies below, and are of 

 course of contemporaneous formation with it. The conclu- 

 sion. 



