STRATIGRAPH1CAL ELEMENTS: CRYSTALLINES, ETC. 59 



sions, a characteristic which the felspar always possesses when 

 present in these schists. 



There is no suggestion, in spite of the occasional felspars, that the 

 rock is an ultimate stage of the pressure metamorphism of a granitic 

 rock. On the contrary it seems very much more probable that the 

 felspars have been produced in the schist by the proximity to it of a band 

 of gneissose-granite. Further examples will abundantly illustrate this. 

 Dr. A. Lawson (Rainy Lake Geology, Annual Report, Canadian Survey, 

 1887, p. 33 F) describes a similar case in reference to the schists in 

 contact with the Laurentian gneiss which has acted as a granite in 

 places. He writes : " Within the hornblende-schists, distinctly recog- 

 nisable as such, there may occasionally be detected large crystals of 

 felspar which are quite foreign to these rocks ; as if the felspathic 

 magmas had penetrated within the schists and crystallised there in 

 the same large crystals in which they are wont to appear in the coarse 

 gneiss/' 



This feature is only noticeable here on a small scale ; but in the 

 neighbourhood of Kedarnath in British Garhwal I have seen very 

 much more pronounced effects of the same kind. 



In a similar rock from the same locality, No. ¥ f 5 , the presence 

 of felspars is distinctly visible to the eye. 



sat n e1ocllit°y Ckfr0mtbe Under the microscope they come out more 

 prominently in generally irregularly elongated 

 grains shewing binary twins. The minerals composing the rock are the 

 same as in the last specimen. The inclusions in the felspar are also 

 the same as in that rock, though there are also included fragmentary 

 rounded little beads of garnet. The larger garnets which enter 

 into the composition of the rock are in sub-angular idiomorphic grains, 

 much cut through by irregular dark cracks, and almost colourless or 

 of a very pale port-wine colour. The minute beads of garnets included 

 in the felspars seem to be in some way connected with the large 

 grains which are always near to them, as if the one had given up its 

 material to form inclusions of a secondary nature in the felspars. 

 The brown mica of the rock bends round the felspar grains. 



( 59 ) 



