66 GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. 



the cliff, well seen in plate xxr, the entire upper surface of the glacier is 

 veneered with angular rock debris, effectually preventing surface melting, as 

 already shown. This material is derived from the Wenkchemna group of peaks, 

 through the agency of avalanches and the ordinary processes of weathering. 

 With the entire breadth of the glacier spread out along the base of the cliff 

 all portions receive their quota, leaving no portion of the ice exposed to the 

 sun. The de'bris, at first, is covered with the snow, but it is concentrated by 

 melting until the amount is sufficient to prevent further loss of ice at the surface 

 when the action ceases. No ground-morainic material was observed" upon the 

 surface, in contrast with the Victoria, and this is -accounted for by the absence 

 of hanging glaciers; What might be mistaken for such upon the northern face 

 of Mt. Deltaform, and upon either side of peaks 4 and 5 (plate xxi), are simply 

 the continuous neVe" fields of the commensal streams. This method of acquiring 

 its load leads to a somewhat irregular distribution of the rock de'bris, resulting in 

 hummocks and depressions, especially towards the northeastern corner (plates xxi 

 and xxv). These irregularities of surface are also shown in plate xxin, figure 2. 

 It was from this portion of the glacier that the view for plate xix, figure i, was 

 taken. This irregularity of surface renders travelling across the glacier laborious 

 and somewhat dangerous, except near the neVe line. The almost complete 

 concealment of the ice by de'bris renders this glacier a poor one for the study 

 of ice structure and the usual surface features. The third ice stream, coming 

 from between peaks 5 and 6, in the vicinity of the neVe" shows stratification 

 and dirt zones to advantage, the strata ranging from five to ten feet in thickness. 

 Low glacial tables occur here and the phenomenon described upon page 58 of 

 this report, as possibly due to reflection of heat from the surface boulders. 



The line of junction between neighboring ice streams is roughly indicated 

 upon the surface by ridges of rock de'bris, somewhat low and poorly defined 

 near the neVe", but gaining in height and distinctness in their course across 

 the glacier. These ridges are the lateral moraines of the individual ice streams 

 and they are especially well defined over the eastern third of the glacier. Upon 

 either side of the third stream these ridges are double for a considerable dis- 

 tance. Toward the western end of the glacier these moraines are neither so 

 well defined nor so continuous and, owing to the deflection of the streams to 

 the eastward, by the ancient moraine, swing around into a position almost 

 parallel with the frontal. By the blending of these lateral moraines upon 

 adjacent streams the single ridges resulting become the medial moraines of 

 the piedmont glacier, and the outermost laterals of the two marginal streams 

 become the laterals of the unified glacier. At the eastern end of the glacier the 

 first stream is so short that the right lateral of the second ice stream constitutes 

 the right lateral of the glacier as a whole. If the first stream ever extended to the 

 front then this lateral moraine was originally a medial. A deep depression, snow- 

 filled in 1904, separates it from the double de'bris cone and from the mountain 

 spur shown upon the map. At the western side of the glacier, owing to the 

 deflection eastward of the ice streams, there is no distinction to be made between 



