

tl 



e 



111! 



fo 



■al 



^1 



31 



■ 



"Oil: 

 tilt 



fi 



i ^ 





.f 



'\ I 



\: 



it 





t 



/ 



HUTTONIAN THEORY. 



165 



t, 



of the bivalve kind : it was ftruck off from the 

 folid rock, and cannot poffibly be confidered as 

 an adventitious foffil. 



Now, no rocks can be 



decidedly pr 



ry than thofe about Plymouth. They confift of 



calcareous ftrata, in 

 or micaceous limefto 



form either of marble 



L 



alternating with varie- 



of the fame fchiltus, which prevails through 



Cornwall to the weft, and extends 



ft 



d into 



D 



d oh the fea-coaft, as far as th 



Berry- head. Thefe all interfed the horizontal 



plan 



a 



from eaft to weft nearly 



; they 



are very ered, thofe at Plymouth being elevated 

 to the north. 



Though, therefore, the remains of marine 

 animals are not frequent among the primary 

 i'ocks, they are not excluded from them ; and 

 hence the exiftence of fhell-fifti and zoophytes, 

 is clearly proved to be anterior to the formation 

 even of thofe parts of the prefent land which are 

 juftiy accounted the moft ancient. 



152. The rocks which contain fand or gravel. 



or which are of a granulated texture, muft alfo be 

 confidered as carrying in themfelves ateftimony 

 of the moft unequivocal kind, of their being 

 derived from the detritus and wafte of former 

 rocks. Now, the fad ftated in the text, con- 

 cerning fand found in fchiftus, moft juftiy ac- 

 counted primary, might be exemplified by adual 



L3 



reference 



t 



