MALASPINA GLACIER. 235 



south end of the Hitchcock range, and again about the base of 

 the Chaix hills. 



When a stream flows along the side of a glacier a move- 

 ment in the ice or the sliding of ston6 and dirt from its surface 

 sometimes obstructs the drainage and causes the formation 

 of another variety of marginal lakes. In such instances the 

 imprisoned waters usually rise until they can find an outlet 

 across the barrier and then cut a channel through it. 



A glacier in flowing past the base of a mountain frequently 

 obstructs the drainage of lateral valleys and causes lakes to 

 form. These usually find outlets, as in the case of lakes at the 

 end of mountain spurs, through a subglacial or englacial tunnel, 

 and are filled or emptied according as the tunnel through which 

 the waters escape affords free drainage or is obstructed. Several 

 examples of this variety of marginal lakes occur on the west and 

 north sides of the Chaix hills. They correspond in the mode of 

 their formation with the well - known Merjelen See of Switzer- 

 land. 



Other variations in the manner in which glaciers obstruct 

 drainage might be enumerated, but those mentioned cover all of 

 the examples thus far observed about Malaspina glacier. The 

 conditions which lead to the formation of the marginal lakes are 

 unstable, and the records which the lakes leave in the form of 

 terraces, deltas, etc., are consequently irregular. When streams 

 empty into one of these lakes, deltas and horizontally stratified 

 lake beds are formed, as in ordinary water bodies, but as the 

 lakes are subject to many fluctuations, the elevations at which 

 the records are made are continually changing, and in instances 

 like those about Malaspina glacier, where the retaining ice body 

 is constantly diminishing, may occupy a wide vertical interval. 



Drainage begins on the southeast side of Chaix hills at 

 Moore's Nunatak, where during the time of our visit there were 

 two small lakes, walled in on nearly all sides by the moraine 

 covered ice of Malaspina glacier. The water filling these basins 

 comes principally from the high ice fall at the north, where the 

 glacier descends over a projecting spur running east from 



