94 ON THE CONVOLUTIONS OF STRATA, 



performed, must have been of great bulk and consequent soli- 

 dity, it seems probable, that the convoluted mass, together 

 with the matter in a liquid state which it had received after 

 its consolidation, would, upon a subsequent application of the 

 elevating cause, be more easily raised than the solid unstrati- 

 fied mass, by whose swellings the convolutions were first ef- 

 fected. 



It is natural, then, to expect, that in the various rents and 

 agitations which these masses have evidently undergone, the 

 original mover of the convolution, and the scenes of its meet- 

 ing with the stratified mass, may very frequently have been 

 left in the deep abyss. In an account which I am now pre- 

 paring to lay before the Society, of circumstances relating to 

 the revolutions of the earth's surface, I shall have occasion 

 to state a fact, which seems to prove, that the particular mass 

 of killas of which we have been speaking, has undergone one 

 palpable revolution of this sort, by which the mass in its im- 

 mediate neighbourhood has been left at a considerable distance 

 below it. I must hope, however, that on some occasions, scenes 

 exhibiting the junction of the prime mover with the strata, and 

 in which the axes of convolution shall be found parallel to 

 that junction, may hereafter be discovered, in situations raised 

 up, and well exposed to view ; and I recommend this as an 

 object of great interest to geological observers. 



Our attention is naturally turned in this case to Granite, as 

 far surpassing in importance every other species of unstrati- 

 fied body ; and I have little doubt that it has in fact been the 

 agent of these convolutions. I have not, however, been able 

 to discover any case in which it has performed this function. 

 All the junctions which I have seen belong decidedly to the se- 

 cond class mentioned, and bear marks of an infusion of the li- 

 quid granite into hard and brittle strata ; and the peculiar 



junction 



