CHAPTER II. 

 THE PHYSIOGRAPHY OF CAPE DENISON. 



The rocky promontory of Cape Denison covers approximately half a square mile. 

 It forms a roughly triangular area with a base of three-quarters of a mile on which the 

 rocks rise to a height of 140ft. above sea level, when they disappear beneath the glacier 

 ice. On the east and the west the uniform ice cliffs of Commonwealth Bay give way 

 to rocky cliffs, which are first of similar height but which descend to sea level as they 

 continue north (Plate XIV., fig. 1). The shore line is indented, and one small bay 

 is 400yds. deep and 100yds. broad at the mouth, and, as it broadens towards the head, 

 it forms an excellent boat harbour. This boat harbour is actually an extension of the 

 valley depression in which the hut is situated a miniature drowned valley. 



The rocks remain uncovered throughout the whole year. A little more than the 

 average area is exposed by the summer thaw, and the winter snow drifts do not bury 

 much on account of the incessant wind. 



AGENTS OP DENUDATION. 



The promontory may be described as a miniature mountain area. It is rugged, 

 and possesses steep rock faces and sharp ledges (Plate XVI., fig. 2). It is carved by 

 four parallel valleys, and the intervening ridges are crowned by numerous small peaks 

 (Plate XV., fig. 1). The sculpturing is the combined effect of different factors which 

 we tabulate and discuss in order, as follows : 



1. Glacier Action. 



2. Frost Action. 



3. Water Action. 



4. Wind Action aud Atmospheric Weathering. 



5. Shore Ice Action. 



6. Nature and Structure of the Rock Mass. 



1. Glacier Action. The area reveals abundant evidence of glaciation. Glacial 

 erratics are promiscuously scattered everywhere. Apart from the well-defined moraines 

 the distribution is as abundant on the higher ridges as in the lower valleys, and the 

 erratics are frequently seen perched in curious positions on the highest crags. Some 

 of the erratics have polished faces and rounded edges, and some show glacial striae, while 

 others are quite subangular. Some weigh several tons, and many consist of foreign 

 rock types. Polished, striated, and grooved surfaces of the " in situ " rock are to be 

 seen. Very highly polished surfaces (Plate XVIII., fig. 1, Plate XXII., fig. 2) are quite 

 characteristic of the peripheral area below the 40ft. contour level. Above this belt 



