in Norway and in Canada, 163 



5. Quartz slate and Quartzite, appear as transitions from mica 

 schist, in the manner above referred to. 



6. Gneiss, more or less characteristic, occurs in the group, es- 

 pecially towards the junction with the Primitive Gneiss Forma- 

 tion. 



7. Hornblende schist, occurs in the Trondhjem region, and 

 also in more northern districts. In both, it is connected with, and 

 forms transitions into diorite. 



8. Diorite and other Greenstones. Diorite is " a crystalline, 

 granular mixture of hornblende and albite, sometimes also slaty 

 or porphyritic."* Most of the greenstones in this group 

 seem to be diorites. They are, however, often of very variable 

 characters, and by the substitution of diallage for hornblende, 

 graduate into a species of diabase. 



9. Granite and Syenite, are also eruptive rocks occurring in 

 the group, sometimes intimately associated with the diorites. 

 Hornhlendic granite, a connecting link between granite and syen- 

 ite, and granulite are also mentioned. 



10. Serpentine sometimes occurs in considerable masses. It 

 is confined to the schistose districts south of Trondhjem, and con- 

 sists of the common dark-coloured variety, differing altogether 

 from the light coloured serpentines of the Primitive Gneiss For- 

 mation. Chromic iron ore invariably accompanies it. 



11. Euphotide; a rock thus named is described by Keilhau, 

 as containing large grained diallage or hypersthene. This is 

 however a feldspathic rock, and by reference in a note in a for- 

 mer portion of this paper, p. 17, it will be seen that it is to be 

 regarded as a kind of diabase, and distinct from the true eupho- 

 tides of the Alps. 



12. Talc schist. 



13. Steatite or Soapstone. This, together with the rocks yet 

 to be enumerated, is of comparatively rare occurrence. 



14. Dolomite. 



15. Conglomerates and breccias, somewhat resembling in char- 

 acter those already described in the quarztose division of the 

 schistose formation. 



The rocks above enumerated form, as already mentioned, two 

 distinct geographical regions, which differ also in petrographical 

 characters. The first is the one already mentioned, of Tromsen 



* Cotta : Gesteinlehre, p. 57. 



