GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. 87 



inward towards the center, this portion of the ice possibly having received less 

 severe treatment than that nearer the center of the channel. In the case of the 

 Yoho the question arose (page 76) as to whether the stratification was obscure 

 because of its destruction by a similar cascade, or because of its original weak 

 development. In the case of the Illecillewaet there is sufficient bare peak and 

 rocky crest exposed to supply the broad ne"ve" field with successive layers of wind- 

 transported dust and a very perfect stratification results from the concentration of 

 this dirt at the surface of successive deposits (plate xxxv, figure 2). The almost 

 complete lack of stratification about the nose, where it should be well displayed, 

 along with the dirt zones, must in this case be ascribed to the cascade. The dust, 

 originally concentrated between the strata, is brought to the lower margin of the 

 ice, where it collects and drips as black mud (plate xxxiv, figure i) over the val- 

 ley floor. The color is due to the presence of organic matter, of which there is 

 enough present to render the material offensive, when set away damp in a warm 

 room. Four determinations of the organic matter present in material collected 

 in 1903 gave 16.75, IJ - 2 5> r o.68, and 17.23 percent., or an average of 13.98 per 

 cent. 



It seems impossible that the coarse stratification of the ice could be so com- 

 pletely destroyed and the finer lamination preserved so perfectly and continuously 

 as we should have to suppose if we referred the blue bands to the original lami- 

 nation of the neVe". As pointed out upon page 44 and as shown in plate xm, figure 

 i , the blue bands, with the superficial dirt stripes, are very clearly shown about the 

 nose of this glacier, from 15 to 36 being counted within the distance of a foot. 

 They are approximately parallel with the valley floor and would probably con- 

 form with the strata, providing the latter were present. They dip inward, in 

 general, about the nose at angles of 3 to 8, but in places are inclined outward 

 by this amount. As soon as the ice begins to experience pressure from the 

 moraines, or the valley walls, the blue bands become more and more steeply 

 inclined, beginning with angles of 8 to 16 and increasing up the valley to 70 

 to 75. The relation of bands in the ice to the stones which are fluting the 

 under surface (plate xxxiv,) has been discussed upon page 44. 



The glacial granules, with the melting phenomenon described in connection 

 with the Victoria Glacier, are well shown about the nose. In size they stand 

 next to those of the Yoho and range from the size of hickory nuts to that of hen's 

 eggs. They are limited largely to the blue bands, or the white seams that 

 intervene, but in cases are seen to cut across from one to the other. As the 

 granules assume distinctness the blue bands become more and more obscured. 

 Between the granules there is developed, under suitable melting conditions, 

 a very perfect and beautiful network of capillaries described upon page 41. 



6. DRAINAGE. 



a. Surface and marginal drainage. Upon the nights of September 7-8 and 

 8-9, 1904, the minimum temperature of the ice was measured by inserting a ther- 

 mometer to the depth of twelve inches in the face of a crevasse near the nose. 



