AND THEIR MEETING WITH GRANljTE. 93 



which the extent of such a triangle may be limited. It seems 

 clear, however, that the greater the superincunrbent mass, and 

 the deeper the bed of ductile strata, provided that the force 

 from below were sufticiently powerful, tlie more extensive 

 would be this influence. And the influence of such a force 

 upon a mass which had, by previous actions, ac([uired a 

 simple curvature, will account for any deviation from that 

 simplicity. By acting upon a set of beds previously rendeied 

 vertical in part, it might thus produce convolutions having a 

 vertical axis, as at Gun's Green. 



Let us now suppose, that, after the strata had cooled to such 

 a pitch as to lose their pliability, a fresh quantity of matter in 

 liquid fusion was impelled against them; the whole penetra- 

 tion would now be effected, by rents traversing the convolu- 

 tions in all directions, and the liquid stone would flow into 

 them, the temperature of the strata not having yet fallen so 

 much as to occasion its immediate consolidation. Some of 

 these rents might penetrate the mass in directions horizontal 

 or nearly so ; and these, swelling by the infusion of liquid from 

 below, would form great unstratified masses, and contribute 

 powerfully to the general elevation. 



All the junctions of stratified with unstratified matter, 

 which took place during this second stage, would possess a dif- 

 ferent character from that in the first. In the first, the axes 

 of convolution would of course be parallel to the neighbouring 

 boundary, between the two substances ; whereas, in the second 

 case, no such parallelism need be looked for, since the liquid 

 stone would flow in rents, and along surfaces which were pro- 

 duced by the laceration of a frangible mass, in which the axes 

 of convolution would act no part. 



According to this view, as all the substances concerned 

 must have lain very deep at the time of the first operation, 

 and as the mass by which this powerful horizontal thrust was 



performed, 



