6 Canadian Record of Science. 



square inches to hundreds of yards, and have an appear- 

 ance very similar to the rocks of the bands at the border, 

 looking, however, still a little harder. Farther and farther 

 away from the contact they lose much of their angular 

 form and appear simply as dark, elongated streaks in the 

 granite, which seems to be dissolving or absorbing them. 



The granite of these intrusions, in its typical develop- 

 ment, is red or pinkish, and somewhat foliated. Occurring 

 all through it, however, are patches of a rock distinguished 

 by a prevailing gray color. It cannot be stated with 

 certainty that these gray gneisses are especially developed 

 in the neighbourhood of the inclusions nor about the 

 contact, though they certainly occur in those places as 

 frequently as elsewhere. 



That this contact is one of intrusion seems certain. 1 

 There is also evidence to show that practically all the 

 rocks of this series have been subjected to pressure, motion, 

 and deformation. The absence of any distinctly cataclastic 

 structure in the rocks about the contact indicates that 

 such deformation has not taken place to any extent since 

 the rocks have recrystallized ; but the prevalent foliation, 

 the presence of muscovite and microcline, as well as of 

 numerous cracks and strain shadows in the various 

 minerals, and the absence of any fine-grained zone in the 

 igneous rock near the contact, all point to the conclusion 

 that the intrusion took place deep in the earth's crust 

 when movements were in progress, and when, in conse- 

 quence, the limestones were at a high temperature. 



In the case of more brittle rocks, even under the con- 

 ditions just mentioned, this invasion and movement would 

 doubtless have caused a shattering and fracturing, which 

 would now be evidenced by numerous faults and by a 

 more or less cataclastic structure in the rocks about the 

 contact of: the intrusion. But these limestones, softened, 



1. cf. Adams, F. 1J., and Barlow, A. E., "On the Origin and Relations of the Gren- 

 ville and Hastings series in the Canadian Laurentian," Am. Jour. Sci., 1897, Vol. Ill 

 p. 176. 



