GREAT PIEDMONT GLACIER 293 



One of the most interesting features is the evolution of the 

 cwm which is indicated on all sides in the steep facetted slopes. 

 On Discovery Bluff are the couloirs or chimneys; on Mt. Eng- 

 land these become somewhat funnel-shaped; on the face of the 

 Kar Plateau they deepen to a definite if shallow bowl. They 

 obviously only originate on steep slopes where the icy covering is 

 shallow. Avalanche Bay and the Devil's Punch Bowl are respec- 

 tively filled and empty cwms, both at sea level. Along the south- 

 ern crest of the valley are giant cwms each with its own glacier. 

 Here the Miller Glacier has cut through the divide and links the 

 Mackay presumably to the upper Debenham Glacier. The walls 

 are facetted, but not much facetting is visible for the Mackay 

 would seem to be filling its bed to a greater extent than the Ferrar 

 or Taylor glaciers. Traces of a high level plateau at 3000 feet 

 are evident all around Mt. Tryggve Gran, and the ice sheet 

 drains thence into large tributary glaciers such as the Cleveland. 



The upland topography is of three types. There are moun- 

 tains, such as Tryggve Gran, whose shape is due to their strati- 

 graphy. This peak is flat-topped owing to the presence of a dole- 

 rite capping. Others exhibit the typical cusps of the Matterhorn 

 type, due to cwms encroaching on three sides. Others again, 

 such as Mt. Forde, the Whale Back and Whitefinger, are now 

 like giant nunakoller* for the cusps have yielded to the smooth- 

 ing action of frost erosion. 



Scattered over the glacier are the nunatakker * (such as 

 Mount Suess) and nunakoller* (Gondola Ridge and Redcliffs) 

 which have been described in the. narrative. 



(d) Space does not permit of any adequate account of the 

 Great Piedmont Glacier. It has a seaward edge some 200 feet 

 thick over the land, and for a considerable portion its front would 

 appear to be floating, for here the edge is but 30 feet above the 

 sea ice (and presumably 200 feet below water level). It rises 

 to some 2000 feet above the sea about 3 or 4 miles from the 

 coast, and is beautifully moulded over hidden nunakoller. One 

 or two of these project above the ice about a thousand feet, and 

 the mountains behind exhibit beautifully the relation of lower 

 glaciated slopes to cuspate peaks. The plane separating these 



* The two types of islands projecting through the ice sheet need to be distinguished. 

 Nuna-tak is ' lonely pfak,' and I suggest nuna-kol (fide Gran) for the rounded ridges 

 which have been covered by the ice-flood. 



