REMMEL BATHOLITH 349 



free spaces of the shear zones. The biotite was similarly segregated, hut 

 its mobility was found to be considerably less than that of the hornblende. 

 If the metamorphism had been yet more energetic in the Osoyoos body, 

 the more soluble compounds would have been carried away completely 

 and the whole would have crystallized in the form of acid biotitic gneiss 

 banded with especially micaceous schists in the zones of maximum shear. 

 Such appears to the writer to be the best explanation of the Eastern phase 

 of the Eemmel batholith. 



2. The composition of the rock and the fact that, as above mentioned, 

 it seems to have been thoroughly recrystallized into a strong, well knit, 

 banded gneiss without cataclastic structure agree with this view. 



3. The conclusion is substantiated in the study of more moderate shear- 

 ing in the Western phase itself. There the strongly granulated and not 

 recrystallized granodiorite shows impoverishment in the more mobile 

 hornblende and accessories, which are segregated into intercalated, re- 

 crystallized bands. Thus hornblende-free, crushed rock indistinguish- 

 able in composition from the rock of the Eastern phase occurs sporadic- 

 ally in many local areas within the normal crushed granodiorite of the 

 Western phase. 



In summary, then, the Eemmel granodiorite, gneissic biotite granite, 

 biotite gneiss, biotite quartz diorite, and hornblende gneiss appear to be- 

 long to a single batholithic intrusion. This mass was originally a t}^pical 

 granodiorite. It has been dynamically and hydrothermally metamorphosed 

 with intense shearing in zones trending north 20 to 25 degrees west. 

 Over most of the batholith so far investigated these zones of physical and 

 chemical alteration are not so well developed as to obscure the essential 

 nature of the primary magma (Western phase). The shearing and trans- 

 formation are much more profound in a wide belt elongated in the general 

 structural direction north 25 degrees west. Here the rocks are well 

 banded biotite gneisses, the material of which is residual after the deep 

 seated, wholesale leaching of the more basic mineral matter from the 

 crushed granodiorite (Eastern phase). 



ERUGER ALKALINE BODY 



Characteristics. — All the way from the Great plains to the Pacific 

 waters nepheline rocks are extremely rare on the 49th parallel of latitude. 

 The boundary section is now so far completed that it can be stated that in 

 the entire section the Kruger body is the only plutonic mass bearing essen- 

 tial nepheline; it is likewise the most alkaline plutonic mass. 



One of its principal characteristics is great lithological variability. It 

 varies signally in grain, in structure, and above all in composition. All 



