DISLOCATIONS OF STRATA. 107 



cutnstance proves to have been introduced in a fluid 

 state. Thus we, at any rate, establish one evident im- 

 mediate cause for the displacement of rocks, and may 

 with equal security conclude, that the remote one lies 

 in the power of heat. Could there be any doubt 

 respecting the existence of this power, and of its effi- 

 cacy in producing the effect of elevating the strata, 

 the state of the Coral islands of the Pacific Ocean, 

 which is fully detailed in a subsequent place, (chapter 

 xvii.) would put it beyond dispute. In these, the 

 elevation of masses of coral by the agency of volcanoes, 

 is proved in a manner that cannot for a moment be 

 questioned. 



It remains next to inquire into the causes of the 

 elevations or dislocations of strata, in those cases 

 where no immediate evidence of force is present ; and 

 to see, lastly, whether any train of analogy can be 

 established throughout this chain of facts, capable of 

 leading us a little further, namely, to the general 

 causes of dislocation and elevation ; a question form- 

 ing one of the most important of those which are 

 included in a theory of the earth. 



Although, in many instances, neither the presence 

 of trap nor granite can be traced in the vicinity of 

 elevated and displaced strata, it does not thence follow 

 that they are not present. It is well known that trap 

 rocks have entirely disappeared from the surface in 

 many places; leaving, as indications of their former 

 presence, scattered masses, deep collections of basaltic 

 soil, or veins. Of these facts, Scotland aifords in- 

 numerable examples which cannot be misconceived. 

 Here, it is plain, we might attribute the displacements 

 of strata which occur in such situations, to unknown 

 or hypothetical causes, when they are in fact the re- 

 sult of well-known actions, and of the former presence 



