294 SCOTT'S LAST EXPEDITION 



topographic types is here about 3000 feet high. Behind many 

 of the rocky capes the piedmont appears to be nearly stagnant, 

 or receding slowly, for the ice either begins to thicken very grad- 

 ually, or is greatly sun-weathered. In no case is there any evi- 

 dence of pressure or ' overhang ' on the capes, though the 

 crevasses opposite the valley glaciers show some movement, no 

 doubt due to the pressure of the latter. 



In conclusion it will be of interest to trace the features accom- 

 panying the growth of an ice age as exhibited in Victoria Land. 

 Near Cape Evans the change of a snow drift into a glacieret, 

 and of the latter into a glacier, can be studied in many places. 

 The later stages depend greatly on the topography. If the land 

 is flat i.e. part of an old peneplain the ice sheet merely spreads 

 out in great lobes, of which examples occur near the Solitary 

 Rocks on the flattened slopes north of the Taylor Glacier. This 

 grows larger and spreads out laterally, and, to my mind, plays a 

 protective part, as in the Great Piedmont. 



If, however, we are dealing with steep contours, the incipi- 

 ent glaciation accompanied by water at this stage cuts out 

 couloirs and shallow cwms. The next stage is probably that rep- 

 resented by the scarp of Lister. Ultimately some cwms encroach 

 on others and dominating ' finger valleys ' are initiated. These 

 ultimately become ' outlet ' glaciers. 



The ' outlet ' glaciers rise to a maximum, overriding the 

 slopes and carving out what later appear as shoulders or benches. 

 At this period there is true glacial erosion. The riegel are over- 

 ridden and planed down, the fiords are cut out, the lakes are 

 deepened. Later the snowfall diminishes and the erosive power 

 decreases, and the glaciers dwindle through all the stages re- 

 corded by Hobbs. The Beardmore Glacier with its tributaries 

 largely entering at grade, the Mackay with a few ' hanging ' 

 glaciers, the Ferrar with a preponderating number of tributaries 

 hanging on the slopes of the main trough, are examples of the 

 earlier stages in this decline. The Koettlitz with its tributaries 

 5 miles back from the main glacier and the Taylor Glacier with 

 its extraordinary ice-free outlet trough 25 miles long are later 

 stages in the retrocession of the ice mantle. 



