GRANITE-GNEISS IN CONNECTICOT 641 
the same origin as does the general form of the area..° At 
several points, too, along the western border and southern end 
of the granite-gneiss (Map, 2), the line of contact cuts across 
the strike of the foliation of the enclosing schists. This is not 
noticeable at all of the localities at which actual contacts between 
the two rocks can be seen, though it is at one or ‘two, but it 
comes out on mapping the dip and strike of the schist. This 
foliation of the schists seems to be a stratification foliation and 
not a secondary structure, because (1) it is parallel to the alter- 
nating beds of schist and fine-grained micaceous gneiss which 
make up the schist formation, and (2) the dip and strike of the 
foliation is not uniform throughout the area, but varies through 
all possible changes. 
2. Contact Phenomena.— At some of the localities where the 
exact contact of the two rocks is seen there is the clearest proof 
within narrower compass of the eruptive character of the granite- 
gneiss (Map, 3). The line of contact is frequently irregular, the 
granite-gneiss often cuts across the foliation ot the schist or 
sends tongues into the schist; and sheets of schist, partly torn 
from the main schist mass, occur projecting into the granite-gneiss. 
As the granite-gneiss occurs in the midst of completely crys- 
talline schists, any considerable contact metamorphism of the 
surrounding rocks would not be expected. In many granite 
intrusions into crystalline rocks no contact metamorphism is 
seen. In the present case besides quartz, feldspar, biotite and 
occasionally hornblende, the schists carry at times garnet, 
staurolite, cyanite and tourmaline. The latter often seems to be 
connected with the pegmatite dikes which cut the schist. None 
of these less common minerals is more abundant near the con- 
tact or can be considered a result of the metamorphic action of 
the granite-gneiss. 
It is sufficient merely to mention at this point another evi- 
dence of the igneous character of the granite-gneiss, namely, the 
fine-grained granulitic character which it assumes at some points 
about its border. This endomorphic metamorphism of the 
granite-gneiss will be described more fully below. 
