GNEISSES IN THE HIGHLANDS OF NEW JERSEY 



603 



suggested by the fact that frequently even the coarser micaceous 

 blades or aggregates of dark minerals show evidence of parallelism, 

 and this would be difhcult to account for under the supposition that 

 solution was so perfect that the original structure was completely 

 wiped out. In Fig. 9 some of these features may be seen. The 

 band of dark inclusions appearing in the middle of the quarry- 

 face has a boundary with the granite on the left-hand side which is 



Fig. 8 



quite sharply defined and persistent. On the right there is more 

 scattering of the dark minerals and an irregular, ill-defined marginal 

 portion. Still farther to the right the original bands have been 

 pretty well replaced by coarse granite and show only as scarcely 

 traceable lines of coarse mica or chlorite. The block shown in 

 Fig. II would by itself be considered a fairly normal massive 

 granite, but even here a suggestion of parallel arrangement of the 

 dark minerals may be perceived, surviving as a slight evidence of 

 the process by which it has been produced. Frequently, however, 

 in the largest masses of granite all indications of a parallel structure 

 are absent. 



