472 



DEPARTMENT OF TEE INTERIOR 



2 GEORGE V., A. 1912 



of decreasing age for trie corresponding rocks. It should be noted that analysis 

 No. 3 refers to a crushed and otherwise metamorphosed phase of the Osoyoos 

 batholith; through the leaching out of hornblende, iron oxides, etc., this analysis 

 probably shows higher silica than the original average rock would show. The 

 latter rock would have a silica percentage not far from that shown in the 

 Kemmel batholith, Col. 2. 



Excepting the Kruger alkaline body" there is a pretty definite law governing 

 the series, whereby it shows an increase of silica with decreasing age. This 

 law is yet more clearly appreciated when one considers, first, that the older phase 

 of the Similkameen batholith with 66-55 per cent of silica is immediately suc- 

 ceeded by the younger phase which must have from 67 to 70 per cent of silica; 

 and, secondly, that the Older phase of the Cathedral batholith with 71-21 per 

 cent of silica is succeeded by the Younger phase with about 76 per cent of silica. 



Table XXX. — Analyses of members of Olcanagan composite Itatholith. 



- 



1 



2 



3 





^ 



5 



6 



Si0 2 



47-76 



63 30 



68 43 



52-71 



66-55 



7121 



Ti0 2 



220 



■50 



•20 





49 



•40 



16 



A1 B 3 



18-58 



1764 



. 1580 



18 



72 



16-21 



15 3S 



Fe 2 3 



2.19 



1-58 



106 



4 



31 



1-98 



•25 



FeO 



939 



308 



1-85 



2 



14 



1-80 



147 



MnO 



•29 



•47 



10 





11 



■12 



•06 



MgO 



415 



123 



1-46 



1 



99 



132 



•33 



CaO 



9-39 

 03 

 •02 

 361 

 •47 

 12 

 •53 



503 



None. 



05 



4'56 



116 



14 



•51 



408 

 •02 

 •09 

 3' 47 

 251 

 05 

 •53 



5 



52 



386 



01 



•03 



4 07 



2-84 

 01 

 •24 



T37 



SrO 





J3aO 







•09 



Na.,0 



4 



7 



1 



46 

 42 

 18 

 09 



4'28 



K 2 



4-85 



H 2 0- 



02 



H 2 04-: 



•43 



P 2 6 



•78 



•27 



•07 





3? 



15 



■05 - 



oo„ 











14 























99-51 



99 52 



99 72 



99-60 



99 59 



99-95 



1. Ashnola gabbro. 



2. Remmel batholith, Western phase. 



3. Osoyoos batholith, somewhat metamorphosed. 



4. Average of three analyses of Kruger alkalines. 



5. Similkameen batholith. 



6. Cathedral batholith. 



We have seen that the Kruger alkaline body is of small dimensions and 

 that it may be an injected, chonolithic mass rather than a true subjacent body. 

 The fact that this body forms an interruption in the regular basic-to-acid series 

 of the plutonics is, therefore, no objection to regarding the law of increasing 

 silica with decreasing age as strictly applying to the recognized batholiths of 

 the region. The succession of undoubted batholithic magmas gave rocks with 



