586 T. C. CHAMBERLIN 



find any essential difference between the structure, the debris 

 burden, or the mode of action of the two glaciers. The moraine 

 is very symmetrical and shows no preponderance of action on 

 either side. The right-hand slope is made up of gray crystalline 

 rock contributed by the lobe of the great ice-sheet, and the left- 

 hand slope is made up of red sandstone contributed by the lobe 

 of the little ice-sheet. The work of each is perfectly declared 

 and is singularly balanced. 



If from this point of junction and conflict we turn to the 

 right and follow the border of the Tuktoo glacier, we shall find 

 it holding aloof in a measure from the Sentinel nunatak whose 

 base it skirts. A vertical wall faces the nunatak throughout the 

 entire arc skirted by the glacier. At no point does the ice press 

 hard against the sides of the mountain. On the west angle it 

 rises somewhat on the foot slope but does not close up the 

 fossa between the ice and the mountain. 



Our first illustration (Fig. 6o) is taken from the base of the 

 nunatak looking northeasterly obliquely across the south face of 

 the eastern lobe of the glacier. It will be seen that the vertical 

 wall possesses the same features of interlamination of debris in 

 the basal part, and of freedom from debris in the upper part, 

 which has so generally characterized the glaciers previously 

 described. The face here is the smoothest and most strictly 

 vertical which I observed in Greenland, and the amount of inter- 

 laminated debris is notably fine in grain and small in amount. 

 The absence of a moraine or talus slope at the base (except at 

 the extremity) will be noted. The interlamination of detritus 

 reaches to the height of about seventy-five feet above the base. 

 Although an offshoot of the great ice-cap, it is to be noted that 

 the debris does not rise higher than in the glaciers from the 

 small Redcliff ice-cap. The amount of the included debris 

 happens to be here somewhat less than that in most of them. 



In describing the upper Blase Dale glacier of the island of 

 Disco (p. 785, Vol. II) note was made of numerous fracture 

 lines traversing lateral portions of the glacial surface in a direc- 

 tion at variance with, indeed transverse to, the normal course of 



