GNEISSES IN THE HIGHLANDS OF NEW JERSEY 



605 



apart by the force of injection, elsewhere being transfused into the 

 original layers and crystalHzing these, or digesting and carrying 

 away certain constituents, or entering into reactions with the 

 component minerals. The variations found may be readily ex- 

 plained by the greater predominance of one or the other of these 

 factors. The manner of action will be considered in more detail 

 in Part II of this article. The fluidity of the magma is manifested 



Fig. 10 



by the narrowness and persistence of some of the injected layers. 

 The question of the actual degree of fluidity will also be considered, 

 in the later discussion. 



Certain phenomena suggest that a force of crystallization may 

 at times have been an effective factor in separating the layers. 

 Aggregates of microchne and quartz crystals in the form of augen 

 are seen, inclosed by curving bands of schist as in Fig. 13. Such 

 augen may have suffered a small amount of deformation and 

 granulation of the solid material by shearing movements subse- 

 quent to crystallization, but obviously not to such a degree as to 



