REPORT OF THE CHIEF ASTRONOMER 



235 



SESSIONAL PAPER No. 25a 



The calculated norm is : 



Quartz 840 



Orthoclase 2-78 



Albite 12-05 



Anorthite 30-86 



Hypersthene 21-18 



Diopside 18-40 



Magnetite 3-02 



Ilmenite , 1-36 



Apatite -31 



Water 1-68 



100-04 



This rock belongs to the presodic subrang of the as yet unnamed docalcic 

 rang of the salfemane order, vaalare. 



RESUME OF PETROGRAPHY. 



As a convenient summary, the mineralogical and chemical analyses of the 

 different phases have been assembled in Tables XI and XII. 



Table XL — Weight percentages of minerals as determined by the Bosiwal method. 





o 

 o 



u 



■§.s 



g o 



Gabbro, 30 feet above 

 lower contact in sill E. 



Intermediate rock, 200 

 feet below upper 

 contact in sill C. 



Intermediate rock, 200 

 feet above lower 

 contact in sill E. 



Hornblende - biotite 

 granite, 100 feet be- 

 low upper contact in 

 sill C. 



Biotite granite, 50 feet 

 below upper contact 

 in sill C. 



Biotite granite, 40 feet 

 below upper contact 

 in sill C. 







Biotite gi*ar 

 below up] 

 in sill C. 





58-7 



•9 



348 



54-8 

 "25 : 6" 



49-4 

 220 



42-9 

 66 



160 

 173 









8-9 



22-0 



15" 2 





165 



18-5 











Oligoclase 









1-5 

 249 



1-5 



29-1 



10 



Soda-bearing orthoclase. . . . 









5"5 



27-8 



325 











39 





40 



63 



117 



22'8 



37-2 



57' 1 



3'2 



460 



" "V 



41 '6 



Muscovite 



46 





•2 

 14 



"id" 



•3 

 11 



•3 

 ■ .[■■ 





•2 



Titanite 



37 



•5 

 1-2 







Magnetite or ilmenite 



19 



•5 



l'O 

















25 



■4 



















The total is 100 in each case. 



Specific gravity 2990 2"980 2"954 2942 2754 2728 2733 



