352 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 75 



Glaciers. — The great glacier (Hunga) is best illustrated by plate 

 96, where it is shown from its origin in the great cirque on the slope 

 of Robson and the northern slopes of Resplendent down to its termi- 

 nation at Robson Pass, a distance of 4 miles (6.4 km.). It is a fine 

 illustration of a glacier passing over a high cliff, as seen between lya- 

 tunga Mountain and Billings Butte. The glacier is about three- 

 quarters of a mile (1.2 km.) in width between lyatunga Mountain 

 and Titkana Peak, and above the ice fall the cirque is nearly 4 miles 

 (6.4 km.) across. The snow slopes and ice cliffs of Resplendent 

 glacier are beautifully shown by plates 94 and 108. On the north- 

 western side of Robson, plate 98, Tumbling glacier descends from 

 beneath the Helmet (11,160 feet, 3,401.6 m.) to Berg Take, where 

 it breaks off to form small bergs. This glacier is most appropriately 

 named, for it virtually tumbles down the cliffs in a descent of over 

 5,500 feet (1,676.4 m.). 



The southwestern face of the mountain is too steep for the accumu- 

 lation of any considerable amount of snow. An incijMcnt glacier is 

 formed by the snow field clinging to the southern slope, and the debris 

 from this accumulates to form a somewhat similar glacier beneath 

 the great southern cliff. Most of the snow that falls on the upper 

 western and southwestern face of the mountain is blown over by the 

 prevailing westerly winds into the cirque on the eastern side. 



NOTE ON THE STRATIGRAPHIC SECTION 



During the summer of 1911, a Smithsonian Institution expedition, 

 in cooperation with Mr. Arthur (). Wheeler of the Alpine Club of 

 Canada, visited the Robson Peak District. My son Charles, who ac- 

 companied the party, brought back a few Middle Cambrian fossils 

 picked up while hunting, and told me that ridge after ridge encircled 

 the great Robson Peak with strata that sloped inward towards the 

 peak. This suggested that there was an opportunity to study another 

 great section in the Rocky Mountains 200 miles (321.8 km.) north 

 of that along the line of the Canadian Pacific Railway. In the summer 

 of 191 2, I left my work on the Kicking Horse section near Field, 

 British Columbia, and spent 23 days in a reconnaissance of the Mount 

 Robson District from Moose Pass on the northeast to Mount Robson 

 on the southwest. There was only time to locate a promising line for 

 the great section of quartzites, sandstones, shales, and limestones, to 

 take a series of photographs to indicate clearly the location of. the 

 section, to collect fossils from a few critical horizons, and to measure, 

 estimate, and^more or less arbitrarily locate and tentatively name ten 



