&2 Lamination of Tr achy tic Rocks. past i. 



sent high inclination. Facts of this nature are mani- 

 festly of importance, with relation to the structural 

 origin of that grand series of plutonic rocks, which like 

 the volcanic have undergone the action of heat, and 

 which consist of alternate layers of quartz, feldspar, 

 mica, and other materials. 



