Lake Louise, Alberta, Canada. 383 



Sample Xo. 1 is from the subaqueous part of the delta 

 at the upper end of the lake. In the upper and lower 

 portions of the sample exceedingly tine lamination is 

 faintly shown. In parts of the sample there is little or 

 no trace of lamination. The very fine laminae are ap- 

 parently due to short interrupted periods of sedimenta- 

 tion — in part probably daily — which are the result of the 

 conditions of sedimentation as outlined above. The 

 samples from the delta show no definite evidence of 

 seasonal banding, except possibly that the parts which 

 are finely laminated are summer layers and parts which 

 are not laminated are winter layers, but the lack of lami- 

 nation may also be due to continuous sedimentation in 

 certain parts of the delta during the summer. 



Sample Xo. 2 is from nearly the deepest part of the 

 lake at about mid-length. It shows a faint but definite 

 banding. The material is all very fine except for a few 

 coarse grains of sand which occur occasionally at the base 

 of the individual bands. Each band consists of a coarser, 

 lighter-colored, lower part which passes upward into a 

 finer, darker-colored upper part, the two portions con- 

 stituting a band. The bands vary in thickness and aver- 

 age between 5 and 6 to the inch. The thickness corre- 

 sponds to the approximate estimate of the thickness of 

 the annual layer and the character of the banding is that 

 which is demanded by the conditions of sedimentation. 

 The banding is, therefore, seasonal in character. It is re- 

 markably thin but is probably considerably thicker than 

 the seasonal layer formed in many of our rock bound 

 lakes, whose waters are nearly clear throughout the year. 

 It is also thinner than the average banding of many of the 

 glacial lake clays of Pleistocene age, but closely resembles 

 the banding of the glacial Lake Agassiz clays in the deep 

 part of the basin at Winnipeg, Manitoba. 



Sample Xo. 3 is from the base of the Pleistocene marine 

 clays in the Ottawa valley and shows a definite banding, 

 the darker layers being clay and light colored parts silt 

 with some clay and sand. It differs from sample Xo. 2 

 in that the clayey layers are more sharply defined and the 

 silt layers are much thicker. The material is also 

 coarser. The banding is probably seasonal and the 

 sharply defined character of the layers may be due to the 



