196 

 Miles and j s cut through Lower and Middle Cambrian 



Kilometres. ° 



strata. At Takakkaw falls, 1,248 feet (380 m.) 

 high, the water cascades over Middle Cambrian 

 limestone. The same formation causes the 

 Twin falls, farther north in the valley, but the 

 fall is not as great. 

 129 m. Upper end of No. 1 Tunnel. Between the 



206-4 km. Pass and 



131 • 1 m. Lower end of No. 2 tunnel. Field, a dis- 

 209-7 km. tance of about 



eight miles (12-9 km.), there is a difference 

 in elevation of 1,160 feet (353-5 m.), of which 

 900 feet (274 m.) occurs within four miles 

 (6-4 km.). To overcome this steep grade 

 the Canadian Pacific railway has constructed 

 two spiral tunnels. The upper one (No. 1), 

 3,200 feet (982-4 m.) long, is in Lower Cambrian 

 quartzites in the base of Cathedral mountain. 

 The lower one (No. 2), 2,900 feet (884 m.) 

 long, is in Middle Cambrian limestones in 

 the base of Mt. Ogden. There is a difference 

 of 60 feet (18-3 m.) between the rails at the 

 ends of the tunnel, in both No. 1 and No. 2. 

 The average grade is now 2-2 per cent, whereas 

 the grade of the old road, now used as a wagon 

 road, is 4-4 per cent. 



Before entering No. 2 tunnel, the glacier- 

 shaped Kicking horse valley is seen, with its 

 broad aggraded valley floor. On the left 

 of the valley is Mt. Stephen (10,485 ft. — ■ 

 3,196 m.), and on the right is Mt. Field 

 (8,645 ft.— 2,636 m.). 

 132-5 m. About one mile (i-6 km.) west of Cathedral 

 211 -2 km. station the railway passes through a short 

 tunnel in Lower Cambrian quartzites. Be- 

 tween this tunnel and the wagon road there 

 is a normal fault with about 3,000 feet (921 m.) 

 displacement. Mt. Stephen is on the down- 

 throw side, so that the Lower Cambrian 

 quartzites in the Cathedral mountain come 

 against the Eldon formation, at the top of 

 the Middle Cambrian, in Mt. Stephen. This 

 break has been called the Stephen-Cathedral 

 fault. 



