18 GEOLOGICAL FORMATIONS. 



edges have thus been exposed at the surface of the earth, and 

 may be measured with little difficulty. And, although in 

 most, if not all, places, some of the strata are wanting, yet, 

 by observing a number of the associated links in the chain of 

 development in one place, and connecting and matching them 

 with corresponding sections of the chain found in other places, 

 and which extend higher or lower, the whole series may be, 

 and has been, re-constructed with approximate accuracy and 

 certainty. And by comparing the lithological characters of 

 rocks, and especially the fossils which they contain, it is 

 found that the order of development is invariably such as 

 I have described, and is the same in all parts of the 

 world. 



It was said that the Granite, which seems to be the oldest 

 of the rocks, underlying, as it does, all the stratified series, is 

 itself unstratified. This is true, also, of its various modifica- 

 tions in the Porphyry, Basalt, and Greenstone. These rocks, 

 therefore, could not have been formed, as other rocks were, 

 by sedimentary deposits at the bottom of oceans and lakes. 

 On the contrary, they bear unmistakable evidences of having 

 been originally in a molten state from the action of intense 

 heat. That no links may be wanting in the chain of our 

 further inductions, some of these evidences require to be 

 briefly stated, as follows : 



It appears that, in many instances, after thick beds of 

 stratified rooks, including some of the older members of the 

 foseiliferous series, were formed immediately over the granitic 

 rocks, the latter have flown upward, not only in hemispherical 

 and conical, but sometimes in sharply angular forms, displac- 

 ing the superincumbent strata, and producing mountain eleva- 

 tions. In the upheaving effort it has, apparently by injection, 

 filled up the smallest crevices of the contiguous rocks, fre- 



