120 



PROCEEDINGS OF THE CANADIAN INSTITUTE. 



general axis of the dyke have a coincident strike of N. 55° W., while 

 the schists which abut sharply on the dyke have a strike of N. 80° E. 

 The intrusion is, I believe, identical with the gneiss of the Lauren- 

 tian to the south, and is a striking proof of the plastic or viscid 

 condition in which these rocks must have once been, either as an 

 original state or as induced at the time of folding. The belief that 

 this intrusion of gneiss is the same as the Laurentian gneiss of the 

 region to the south, and that it is simply a portion of the latter that 

 has been injected in a molten state within the rocks in which it is 

 now found, is^based not only on the similarity of the rocks, but also 

 on the nature of the line of contact at this point, which in the con- 

 ditions represented in Fig. 5 gives us another proof of the once viscid 

 condition of the rocks. 



The gneiss and the schists hei'e are the 

 same in every way as those described in the 

 preceding figure which occur onl}^ a few yai'ds 

 to the north. The wedging of the two rocks 

 one within each other in the way represented 

 finds its readiest explanation in ascribing a 

 plastic or viscid condition to the rocks at the 

 time of this folding under enormous pressure. 

 This condition of things along the line of 

 contact is, it may l>e mentioned, somewhat 

 abnormal, the rule being that the hornblende 

 schist presents an even line of junction with 

 the gneiss, strictly confoi'mable, so far, at least, as parallelism of the 



planes of foliation of the gneiss, cleavage 

 and bedding (not necessarily sedimentary ) 

 of the schists, together with transitional 

 alternations of beds of gneiss and schist 

 may be taken as indicative of conform- 

 ability. 



Another instance of intrusive gneiss 

 breaking through schists is seen on the 

 extx'emity of Rendezvous Pt. in Long 

 Bay. Here, as seen in Fig. 6, an ir' 

 regular wedge of distinctly foliated gneiss 

 juts in from the shore line within the schists, presenting all the 

 characters in its contact with the adjoining rock of an intrusive mass. 



Fig. 



