227 



Kilometres a batholith extending southward and westward 



for many kilometres and northward a short 



71 m. distance beyond Tappen station. The central 



114-2 km. and greater part of the batholithic mass is com- 

 posed of biotite granite. Like the syenitic phase, 

 it is massive, relatively little crushed, and lacking 

 the multitude of pegmatitic injections so charac- 

 teristic of the Shuswap orthogneisses. This 

 batholith thus seems to be of post-Shuswap 

 date and it is tentatively referred to the late 

 Jurassic period of granitic intrusion. 



The bold bluff of Bastion mountain north of 

 the Arm is composed of the Sicamous lime- 

 stone dipping 28 to the N.W. The limestone 

 forms a continuous band along the southern 

 face of the mountain to the shore of the main 

 lake north of Canoe point, and 15 kilometres 

 from the bluff overlooking Tappen. 



Looking southward from Salmon Arm, a 

 thick cap of Tertiary lava (basalt and augite 

 andesite of the Kamloops groups), unconform- 

 ably overlying the granite, is seen in Mt. Ida. 

 This is the first of many similar remnants of 

 these Oligocene (?) volcanics to be encountered 

 in the railway belt. (See page 148.) 



As the train leaves Tappen and climbs the 

 grade to Notch Hill station, the dark Bastion 

 schists overlying the Sicamous limestone may 

 be observed occasionally across the valley. 



8o-i m. Notch Hill Station— Alt. 1,685 ft. (513 m.). 



128-9 km. At this point the line is crossing greenstones 

 and chloritic schists, representing the volcanic 

 Adams Lake member of the Shuswap series 

 (page 124) or else much metamorphosed ntrus- 

 ives of the same general epoch. The Blind Bay 

 valley is floored with the Sicamous limestone 

 presumably repeated here by a strike-fault. 

 The ridge southwest of Notch Hill is com- 

 posed of a second outlier of the Oligocene (?) 

 87-8 m. lava-field. Near Squilax station the railway 



144-5 km. touches the unconformity between this volcanic 

 cap and the Shuswap green schist formation. 

 Here the growing delta of Adams river draining 



