Tourmaline Contact Zones.—Smyth. 383 
must be the old mineral localities, and such proves to be the 
fact. The writer had no time to make a careful search for 
these, but three or four openings were found and examined. 
The minerals occur in clearly marked veins, cutting sharply 
across the foliation of the schists. All of the openings found 
were in a part of the ridge where intrusive phenomena were 
less‘-marked than usual, and this, together with the fact that 
the minerals occur in what are essentially quariz veins, which, 
moreover, carry some calcite, might lead to the conclusion 
that they are not to be connected with the igneous activity. 
But such a conclusion is negatived by the fact that it is 
possible to find every gradation from these mineral veins, 
through pegmatytes, to dikes of normal granite and there 
seems no question that the veins owe their existence to the 
granitic intrusion. The character of the veins and their dis- 
tance from the mest intense igneous. activity point to the con- 
clusion that they are in reality mineral veins, and not dikes. 
In other words, they result from the filling of fissures not by 
a normal igneous magma but by hot concentrated solutions 
charged with gases and vapors derived from the neighboring 
magma. 
As in the case of pegmatytes, to which these veins are 
closely related, it is impossible to draw a sharp line between 
fusion and solution, indeed it is clearly recognized that no 
sharp distinction exists. But since much smaller’ fissures 
occurring in the region of greater intrusive activity are filled 
with normal granite, the conclusion seems obvious that the 
veins were filled by solution. The lack of tourmaline as a 
conspicuous mineral of the veins, and the absence of change 
in the walls are in harmony with this view. The character 
of the phenomena presented here may have resulted from the 
greater distance of the veins from the main intrusions or from 
their being of later date, forming during the cooling of the 
magma. 
Hamulton College, Clinton, N.Y. 
