376 W. A. Johnston — Sedimentation in 



Art. XXXII. — Sedimentation in Lake Louise, Alberta, 

 Canada;* by W. A. Johnston. 



Introduction. 



Lake Louise is a small but well-known lake along the 

 line of the Canadian Pacific railway in the Canadian 

 Rockies. The sediments being formed in the lake are 

 glacial silts derived from Victoria glacier near the head 

 of the lake. The character of the sediments and condi- 

 tions of sedimentation are somewhat similar to those of 

 the glacial lakes which existed in northeastern America 

 and in other regions at the close of the Ice Age. A 

 question of interest therefore arises as to whether sea- 

 sonal banding occurs in the sediments and if so, whether 

 it is similar to the supposed seasonal banding of the 

 glacial lake deposits. Many geologists hold that the 

 banding of the glacial lake clays is seasonal in character 

 and estimates of post-glacial time have been made by 

 counting the annual layers of the post-glacial clays. One 

 of the most notable of these estimates is that of Baron 

 Gerard de Geer who determined by this method that it is 

 about 12,000 years since the ice-sheet disappeared from 

 the vicinity of Stockholm, Sweden. 1 There has been, 

 however, so far as known, no direct proof of the annual 

 character of the layers or bands. In order, if possible, 

 to determine this question core samples from the bottom 

 of Lake Louise were obtained in June, 1921, by means of 

 a bottom sampler and sounding machine, and an estimate 

 was made of the average thickness of the annual layer of 

 sediment being formed in the lake. 



The character and origin of the lake basin was investi- 

 gated and soundings of the lake were made by W. D. 

 Wilcox 2 in 1899, and an excellent description of the 

 characteristic features of Victoria glacier is given by 

 William H. Sherzer in a paper published in the Smith- 

 sonian Contributions to Knowledge, vol. 24, 1907. 



* Published by permission of the Director, Geological Survey, Canada. 



1 A geochronology of the last 12,000 years. Extrait du Compte Bendu du 

 XI :e Congres Geologique International, 1910. 



2 A Certain Type of Lake Formation in the Canadian Eocky Mountains; 

 Jour, of Geology, vol. 7, pp. 247-260, 1899. 



