6o6 



CLARENCE N. FENNER 



drag out the crushed fragments into a band, as has occurred in some 

 augen-gneisses. 



Inasmuch as quarrying operations have exposed the rock masses 

 in three dimensions, it is possible to arrive at a very clear concep- 

 tion of the form of the gneissic inclusions. It is seen that they dip 

 very steeply and have an extension in depth comparable to their 

 prolongation along the strike. Their form is therefore that of 

 thinly tabular sheets. 



Fig. II 



In general the strike of the bands is almost straight and conforms 

 to the general northeast-southwest strike of the region, but in 

 places the layers are more or less curved and occasionally so much 

 contorted as to suggest a ''kneading" of the material. In Fig. lo 

 one of the abrupt bends which are often visible is depicted. The 

 movements in the magma by which such features were produced 

 may perhaps be ascribed to the antagonism of forces brought into 

 play by the up-welling of liquid magma into strata subjected to a 

 tangential compression due to the weight of overlying rock. In all 



