REPORT OF THE CHIEF ASTRONOMER 431 



SESSIONAL PAPER No. 25a 



A long slab of gabbro, ranging with the Cathedral fork of Ashnola river, is 

 similarly a roof -pendant of the Eemmel batholith; it may be called the Ashnola 

 gabbro (see Figure 32). A still larger pendant, composed of gabbros and peri- 

 dotites, lies in the Eemmel batholith just west of the main valley of the Ashnola. 

 On account of the extraordinary diversity of rocks and of rock structures in 

 this pendant, it may be called the 'Basic Complex' (see Figure 33). 



Northeast of the complex is an elliptical stock of biotite granite, intrusive 

 into both the Eemmel granodiorite and the Basic Complex. The white, massive 

 outcrops of the granite are very conspicuous on the northern spurs of Park 

 mountain; the rock may be referred to as the Park granite (see Figure 33). 



Within the five-mile belt these various rock bodies occupy areas shown in 

 the following table. The bodies are noted in order from east to west, beginning 

 on the east: — 



Square miles. 



Osoyoos batholith 50 



Anarchist 6eries in Kruger mountain 15 



Kruger alkaline body 9 



Similkameen batholith 75 



Chopaka schist (Anarchist series) 2 



Chopaka basic intrusives \\ 



Horseshoe schist (pendant; Anarchist series) 1 



Snowy schist (pendant ; Anarchist series) I 



Cathedral batholith 61 



Remmel batholith .. 64 



Ashnola gabbro (pendant) 1| 



Basic Complex (pendant) 6£ 



Park granite stock 9 



Total 296 



The batholiths and the rocks of the Anarchist series extend far to the north 

 and to the south of the belt, so that the total area of each is much greater than 

 is shown in the table. The figures given for all the other bodies represent nearly 

 their respective total areas. Less than 7 per cent of the belt is underlaid by 

 rocks not clearly plutonic in origin, and of that 7 per cent perhaps half is green- 

 stone or other igneous rock. The 3 or 4 per cent of non-igneous rock is chiefly 

 quartzite and phyllite of the Anarchist series. The sedimentaries have been 

 completely cut asunder by the plutonics; it is now possible to walk from one 

 end of the belt to the other, the whole distance of 60 miles, and not once set foo^ 

 on bed-rock which is other than of deep-seated 1 , igneous origin (see Figure 27).- 



UNITY OF THE COMPOSITE BATHOLITH. 



Barring a few patches, the enormously thick pre-Paleozoic, Paleozoic, Meso- 

 zoic, and Tertiary sediments and schists represented in the Cordillera elsewhere 

 are wanting in this part of the Cascade system. With thicknesses running into 

 tens of thousands of feet, they once unquestionably composed the Okanagan 

 range, and of them the ancestors of these Boundary mountains were built. 

 Erosion has removed some of the formations, attacking the earth's sedimentary 

 crust from above. There is every reason to believe that perhaps even more of 



