4: Macfarlane on the Primitive Formations 



Other rock« allied to this, have been discovered in a good many 

 localities, and described as gabbro. 



10. Sfrjyentine, sometimes occurs in such considerable masses a& 

 almost to entitle it to be regarded as a member of the formation. 

 It is generally of a light yellow colour. The well known de- 

 posit of noble serpentine, occurring in the parisii of Snarum, comes 

 under this head. 



11. Granular limestone, as marble, in layers and irregular 

 masses. 



12. Conglomerates ^Ti^ breccia, mostly the latter. One is de- 

 scribed as " a granite-like combination of gneiss and granite," 

 another " angular pieces of gneiss united by a gneissoid cement ; " 

 a third consists of " a gneissoid or granitic matrix, enclosing 

 small fragments of other gneissoid rocks." 



Besides the rocks above enumerated, there occur numberless 

 varieti^^s, forming transitions between these types of rock, some of 

 which have been already adverted to. Sometimes, as Naumann 

 remarks, '* within small spaces, one and the same specific com- 

 position shews characters so quickly and so frequently changing, 

 than we soon- get accustomed to seek what is similar, only in the 

 specific identity of the constituents, and not at all in the way or 

 quantity in which they are combined." Beitriige zur Kentniss 

 Norwpgens, I. 188. 



As the name Primitive Gneiss formation implies, the most 

 widely distributed rock is the gneiss, either in its characteristic 

 form or its varieties. The next most frequently recurring rocks 

 are granite, mica schist and hornblende schist, or rocks related 

 to these types. Some other rocks which I have enumerated, such 

 as chlorite and talc schists, gTanular limestone and quartzitc, 

 occur in comparatively small quantity, while the remainder of 

 those mentioned must be looked upon as uncommon occurrences. 



As to the mode in which these rocks are associated with each 

 other, the whole of them are arranged in parallel layers or zones, 

 side by side, underlying or overlying each other. Hitherto no 

 regular succession of rocks has been marked ; they appear to be 

 interstratified with each other without rule. The aTanitic masses 

 are partly conformable with the parallel masses of the schistose 

 rocks, and partly occur irregularly. It has been remarked that 

 when the granite becomes more or less gneissoid, its masses are 

 regularly interstratified with the other schistose rocks; but where 

 the granite is totally free from all traces of gneissoid texture, the 



