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On approaching large masses of granite, the schistose series 

 becomes more highly altered, sillimanite and other contact minerals 

 making their appearance, but the invaded rocks often take upon them- 

 selves a character so closely resembling that of the invading granite as 

 to "amalgamate the two rocks into one great gneissose complex." 

 Thus the foliation of the invading granite, which can often be seen to 

 be parallel to that of the invaded gneisses, is in many cases certainly 

 due to the biotite folise of the latter, having retained their original 

 position, while the associated "quartzo-feldspathic elements have been 

 incorporated with those of the granite," as every gradation can be 

 traced from inclusions retaining their natural orientation to the merest 

 trains of mica fiakes in a granitic rock. In other cases, however, the 

 foliation of the invading granite does not coincide with that of the 

 invaded gneiss but cuts it. Powerful movements were the "initial 



cause of the whole series of phenomena With regard to the 



granites, it is difficult to believe that they are wholly foreign matter; 

 though here it is necessary to observe the utmost caution, the chemical 

 difficulties being so great." Although Messrs. Home and Greenly are 

 guarded in their statements, their studies being rather general in char- 

 acter, it is clear that they believe the processes at work to be very 

 similar, if not identical with, those described by Michel-Levy and 

 Duparc. 



The views put forward in these papers lead us back to the time of 

 Hutton, who, in his Theory of the Earth states that the kind of gran- 

 ite which shows banding and foliation is probably an altered sediment, 

 the foliation being a survival of the bedding of the original rock. This 

 fact, however, does not by any means discredit the view as manv of 

 Hutton's opinions after long neglect have finally proved to be correct. 

 The views also have certain features in common with the crenitic 

 hypothesis of Hunt. The whole process is, however, very recondite 

 and mysterious in character. 



One of the great difficulties in the way of the acceptance of these 

 views is the absence of chemical proof. In those contact zones on 

 which accurate chemical work has been done, it has been shown that 

 no considerable transference of material has taken place. In these 

 other cases where this enormous transference of material is assumed^ 

 no accurate chemical work seems to have been carried out to support 

 the contentions. In Duparc's work, as has been mentioned, a number 

 of analyses of various normal and "granitized" rocks are given, but 



