300 



ILLUSTRATIONS OF THEl 



6 



but of one 



The preceding fads being fufceptible 



on, are on that account 



pretat 



mely valuable. The phenomena of Salif. 



bury Craig, near the fame 

 equally free from ambiguity 

 rock which forms that precipii 



are 



moft 



Th^ 

 reft 



b a fait 



ic 



on are- 



naceous or marly ftrata 



d thefe, in their 



immed 



d 



ih the for 



fford 



an 



ft 



f 



h 



th 



fi 



f th 



mentioned § Gy^ namely, 

 I ftrata in fuch fitua- 

 tions into a kind of petrofilex, or even jafper. 

 The line which feparates the one rock from the 

 other, is, at the fame time, fo well defined, as, 

 in the eyes even of the moft determined Neptu- 

 nift, to exclude all idea of infenfible grada- 



tion. 



«« 



263. The fame rock affords fome remarkable 

 inftances of the difturbance of the ftrata conti- 

 guous to the whinftone. The beds of the for- 

 mer are bent upwards in feveral places ; and, 

 at one in particular, form an arch, with its con- 

 vexity downward, fo as to make it evident, that 

 the force which produced this bending was di- 

 recled from below upwards. 



264. It is, however, where whinftone takes 



the form of veins, interfering the ftrata, that 



the induration of the latter is moft confpicuous. 



The coaft of Ayrfliire, and the oppofite coaft of 



Arran, 



