GNEISSES IN THE HIGHLANDS OF NEW JERSEY 



60 1 



finer details of the relations between the granite and the basic 

 streaks more plainly than do natural surfaces. Figs. 7-1 1 repre- 

 sent such exposures. In the vicinity of the quarries the coarsely 

 granitic material is far in excess of the banded rock, but occasionally 

 the latter is very plentiful, especially in the older opening. In places 

 there is probably as much of the finely foliated rock as of the mas- 

 sive material; in other places there are great masses of granite 



Ftg. 6 



almost free from inclusions (Fig. 12). Between these two extremes 

 there are all degrees of transition in relative proportions of the two. 

 Quite frequently the contact between granite and inclusions is 

 sharp, although the minerals at the border always interlock; 

 elsewhere the minerals characteristic of the inclusion become more 

 and more infrequent at the sides until only faint parallel lines can 

 be seen in the granite. The manner of transition shows several 

 interesting features. It appears in some cases that the basic miner- 

 als at the immediate contact have become involved in the granitic 

 magma without losing their identity or parallelism, so that a perfect 



