xxiv DEPARTMENT OF THE INTERIOR 



2 GEORGE V, A. 1912 



62. A. — Photograph showing relatively rapid erosive effects of glacierlets with 



very small accixmulators (snow-fields). 

 B. — Small glacier deepening cirque, about seven thousand feet above sea. 



63. Lower Okanagan valley and Osoyoos lake. 



64. Looking southeast across Starvation creek canyon. 



65. Compound alluvial cone at Midway. 



66. Accordant summit levels in the Selkirk range. 



67. Plateau-like surface of Remmel batholith. 



68. Plateau-like surface of unroofed Similkameen batholith. 



69. Meadow and park near tree-line about six thousand feet above sea-level, 



Bonnington range. 



70. A. — Coarse felsenmeer in massive grit of the Wolf formation. 

 B. — Coarse felsenmeer in quartzite of the Ripple formation. 



71. A. — Looking south along ridge between Middle and Slesse creeks, Skagit 



range. 

 B. — Southern slope of Mount Ripple, Selkirk range. 



72. (Sheet No. 18), in Part III (with maps). 

 A. — Typical view in Clarke range. 



B. — Summit of the Nelson range (Selkirk system). 



C. — Nelson range, looking west from summit ridge north of Dewdney trail. 



73. (Sheet No. 19), in Part III (with maps'. 



A. — Columbia River terrace and the Pend d'Oreille mountains (Selkirk 



system). 

 B'. — Typical view in the Midway mountains. 

 C. — Typical view in the Skagit range. 



FIGURES. 



1. Diagrammatic map showing subdivision of the Rocky Mountain system at 



the Forty-ninth Parallel. 



2. Diagrammatic map showing subdivision of the Purcell mountain system 



at the Forty-ninth Parallel. 



3. Diagrammatic map showing subdivision of the Selkirk mountain system 



at the Forty-ninth Parallel. 



4. Diagrammatic map showing subdivision of the Columbia mountain system 



at the Forty-ninth Parallel. 



5. Diagrammatic map showing position of the structure-section east of the 



Rocky Mountain summit. 



6. Structure section across the strike, along the ridge southeast of Oil creek, 



eastern slope of the Clarke range. 



7. Diagrammatic drawing from thin section of Waterton dolomite. 



8. Diagrammatic drawing from thin section of typical sandy dolomite of the 



Altyn formation. 



9. Section showing common phase of the molar-tooth structure in the Siyeh 



formation. 

 10. Diagrammatic drawing to scale, from thin section of amygdaloidal basalt 

 in the Sheppard formation, Clarke range. 



