10 Canadian Record of Science. 



as the '■ plagioclase phase " of granite, is not of unusual 

 occurrence in this class of rocks. 1 



It has been found a matter of convenience, sustained 

 by the nature of the rocks themselves, to class the rocks 

 of which specimens have been examined into four groups, 

 and these have been named conditionally : (1) Gneissic 

 Granites, (2) Gray Gneisses, (3) Altered Limestones, and 

 (4) Inclusions in the Gneissic Granites. In the following 

 descriptions, however, each rock has been named accord- 

 ing to the generally accepted nomenclature depending on 

 mineralogical composition and structure, and thus there 

 are Quartz Diorite gneisses, Scapolite Amphibolites, etc. 

 Since all the specimens are exceptionally typical of the 

 rocks they represent, and as each represents a somewhat 

 different rock, it has been thought advisable to give a 

 rather detailed description of each specimen, in order to 

 bring out more clearly the relations of the several rocks 

 to one another. The order followed has been made to 

 correspond as nearly as possible to the degree of the 

 metamorphism which the rocks have undergone, since it 

 was thought that this would give a better idea of the 

 gradations from one specimen to the next, and as it has 

 the advantage of being briefer than any other arrange- 

 ment could be. 



GNEISSIC GRANITES. 



These rocks, which are generally of a reddish color, 

 make up the great bulk of, and characterize the batholitic 

 intrusions. It is they, supposedly, which during the 

 activity of the igneous forces, have metamorphosed the 

 limestones about their contact. 



1. Mclnnes, H. , "Geology of Seine River, etc.," Geol. Surv. Can., Ann. Rep't., 1S97, 

 Vol. X , Part H, p. 16. 



Smyth, C H., jr., "Crystalline Limestones and Associated Rocks of the North- 

 Western Adirondack Region," Bull. Geol. Soc. Am., 1894, Vol. VI., pp. 260-267. 



Kemp, J. F. and Uollick, A., "The Granite at Mount Adam and Eve, Warwick, 

 Orange Co., N. Y., and its Contact Phenomena," Annals N. Y. Acad. Sci., 1894, 

 Vol. VII., p. 641. 



