.t<-^ 





iiddi 



^lis). 



^ ^^ 5tt| 



" ft 



' \ 



■-occjj 



yotiiRi 



1 ■ ;' 





^ -tuiie It: 

 .. :lietE 



t 



isa 



4' 



h. 



d, bj t 



lore t^"" 

 leiilt:" 



ever 



U' 



'■¥ 



li 



-"''.... 



■:tr 





J 







i- 



) 







r' 



If 



V 



I 



HUTTONIAN THEORY. 



295 



two of them which yet remain to be mention- 

 ed, are even more fo than any of the reft. 



Where a bed or tabular mafs of whinftone is 

 interpofed between ftrata, and wherever an op- 

 portunity offers of feeing its termination, if the 



r 



ftrata under it are not broken, it may be re- 

 marked, that they do not abut themfelves bluff 

 and abrupt againft the whin. On the con- 

 trary, if we mark the courfe of the ftratum 

 which covers the whinftone, and of that 

 which is the bafe of it, we fhall find they 

 converge toward one another, the interpofed 

 mafs growing thinner and thinner, like a wedge. 

 When the latter terminates, the two former 

 come in contact, and have no ftratum interpo- 

 fed between them. Thus the roof and bafe of 



•m 



the whinftone rock are contiguous beds, that 

 appear as if they had been lifted up and bent, and 

 feparated by an interpofed mafs. Had the whole 

 been an efted; of fimultaneous depofition, the re- 

 gular ftrata muft have been abruptly terminated 

 by the whin, like two courfes of different forts 

 of mafonry where they meet with one another. 



259. From this wedge-form of the w^hinftone 

 mafTes, and in general from the irregularity of 

 their furfaces, another conclufion follows, fimilar 

 to the preceding, and one which has been already 



mentioned. Where the furface of the interpo- 



T4 



fed 



# 



