SCENERY AND TOPOGRAPHY 



The subsequent phenomena are described in terms of 

 the PaHmpsest theory. 



Palimpsest Theory. — If now we turn to the great 

 outlet valleys, such as those occupied by the Taylor or 

 Ferrar glaciers, we find evidence of a similar cirque- 

 cut topography drowned by the overflow of plateau-ice 

 from the hinterland. This is made clear in the dia- 

 grams annexed. In the upper figure (see Figure 17) 

 we see several cirque (or cwm) glaciers burrowing into 

 the sloping land surface. One lies below Solitary 

 Rocks and one below Nussbaum Riegel (see Figure 

 16). Later the Taylor Glacier overflows from the 

 Plateau and pours down over the cirques, cutting away 

 part of the Solitary Rocks and Nussbaum Riegel. 

 These barriers on recession are still visible. The con- 

 strictions in the valley and occasional steeper falls in 

 the Ferrar Glacier are probably due to the same cause. 

 Thus on recession we see somewhat faintly preserved 

 the relics of the cirque-erosion cycle in the shape of 

 bars across the floor of the valley, which on the whole 

 is due to normal glacier planation. This combination 

 of topographies is expressed in the term palimpsest, 

 which means that older writing can be observed on a 

 parchment below the present scrip. The pre-glacial 

 stage, the stage of cirque-erosion, and the ice-flood 

 stage are all indicated in Figure 17. 



Niinatak and Niinakol. — These are rock ''islands" 

 surrounded by a sea of glacier ice. The term nunatak 

 means "like a land" and it expresses an irregular 

 rocky residual, too hard to be eroded completely, and 

 still towering above the glacier. But in Antarctica and 



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