REPORT OF THE CHIEF ASTRONOMER 



427 



SESSIONAL PAPER No. 25a 



underlies all of the belt as far as Horseshoe mountain, on the divide between the 

 Ashnola and main Similkameen rivers. This may be called the Cathedral batho- 

 lith — named after the fine monolithic mountain occurring within the limits of 

 the granite. The fourth principal unit lies between the Cathedral and Osoyoos 

 batholiths ; it is composed of a basic hornblende-biotite granite which is trenched 

 by the deep valley of the Similkameen river, and an appropriate name for it is 

 Similkameen batholith. These four principal units make up five-sixths of the 

 whole area here described. 



Complex of Palaeozoic schists 

 asid basic intrusives 



■+ + -h + + 4 -4 ■/-: 



Y + + *■ + 4- + + +j ..<">.._ 

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 • • - \ f + t- + + + 4- -p 4- 4- + '4 + + + +'*■ + 



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" '.' •"'. 4. + + ++ + + 4- + 4-4-+I-4-4-4-4- 



4 KRUGER A L K A L I N E + 



\+4-+ + 4-r-444-444h444 hi 

 ' •.".' "■■.„_+ 4 4 4 4 4 4 4 4 4 4 4 4 .4 4 / ~ ' \ 



"■•---.+ 414444 + 4441 i/ Palaeozoic series cf 



\" ' ' " -£. 4 4~ 4 4 4 4 4 4 4 : . 



■ • ■ ■ -ry -., f + + + + + + + +•. Kruger Mountain 



44, 44-4-444/ 



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A T H L I T H •; + 4- /■ 4 



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'. '. . S I M I L K A M E E N 



International Boundary 



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f 2 + 4 L + + ., U J- 4 4 4 -•. 

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Figure 28. — Map showing relations of the Osoyoos, Similkameen, and Kruger igneous 

 bodies and the invaded Paleozoic formations. Scale 1 : 110,000. 



The subordinate geological members (excluding dikes) within the batho- 

 lithic area are eight in number. 



The largest of these consists of apparently-Paleozoic schists, quartzites, 

 greenstones, and other rocks forming the ends of two tongues that enter the belt 

 respectively from north and south (see Figure 28). These rocks occur on the 

 roughly tabular Kruger mountain. The two schist tongues adjoin the Osoyoos 

 batholith and nearly cut it off completely from direct contact with other plutonic 

 units in the belt. 



Between the schists and the Similkameen batholith is a comparatively small 

 area of highly composite intrusives belonging to the malignite and nephelite- 



