NOZ DE SMITHSONIAN EXPEDITIONS, IQIO-IQII 43 
had not been favorable for the presence and preservation of examples 
of much of the life which, from what was known of older faunas and 
the advanced stage of development of the Upper Cambrian fauna, 
must have existed in the Middle Cambrian seas. During the season of 
1909, the finding of a block of fossiliferous siliceous shale which had 
been brought down by a snowslide on the slope between Mount Field 
and \ount Wapta, led the secretary to make a thorough examination 
of the section above it in 1910. Every layer of limestone and shale 
was examined, until the fossil-bearing band was finally located. After 
Fic. 47.—View looking out of a glacial cirque in the Van Horne Range, 
British Columbia. These abandoned cirques are very common in the Canadian 
Rockies where they are frequently occupied by shallow lakes and snow banks, 
like those in the immediate foreground. Photograph by Burling. 
that, for 30 days the shale was quarried, slid down the mountain side 
in blocks to a trail, whence it was transported to camp on pack horses, 
where the shale was split, trimmed, and packed and then taken down 
to the railway station at Field, 3,000 feet below. 
A number of sections of the Cambrian rocks were studied and 
measured in the mountains north and south of Laggan, Alberta, and 
many beautiful panoramic photographs secured. 
