OF UNSTRATIFIED ROCKS AND VEINS. 135 



is really continuous ; however deep that connexion 

 may be situated. But, with respect to trap, no such 

 inference can be made. Separate portions may ori- 

 ginally have been separate deposits ; as similarity of 

 character is insufficient to establish their original 

 identity, and as they do not admit of being compared 

 by positions or inclinations ; tests which, from their 

 origin and forms, are inapplicable to them. 



Of the Antiquity of the umtratified Rocks. 



The relative antiquity of the members in any con- 

 tinuous series of strata, is readily known from their 

 order of succession. In these, geology even teaches 

 us to distinguish certain revolutions, marking very 

 different and distinct periods or portions of time 

 during which they were formed. But we have no 

 similar criterion by which to judge of the relative an- 

 tiquity of unstratified rocks that occur together; 

 though possessing one, sometimes, when a vein from 

 one traverses the mass of another ; while, in our 

 judgments respecting the relative antiquity of any of 

 them to the stratified, we must be guided by rules 

 which can only determine that question within certain 

 limits. 



With regard to granite, it would be imagined, on a 

 superficial view, as it actually has been maintained, that 

 because it is the lowest it is therefore the most antient 

 rock. This is an error arising, partly from unduly 

 extending the law of succession as it relates to the 

 stratified rocks, and partly from overlooking the ob- 

 vious phenomena which attend that substance. It is 

 unnecessary to add the moral reasons, arising from 

 habit, authority, hypothesis, or unwillingness to ac- 

 knowledge error. The detailed arguments on this 



