1 . Transverse Depression . As will be pointed out in succeeding paragraphs, 

 it is probable that the large broad-based trough which extends from under the 

 floating ice shelf of Sulzberger Boy seaward to a point near the outer shelf break 

 (Fig . 2) is on ice-carved feature. 



Odell (1937) concurred with Wright and Priestly (1922) that the ice covering 

 of the continent has a predominantly conservative effect; it is only where the out- 

 flow glaciers (e .g ., "ice stream" where outward movement of continental ice is 

 accelerated) acquire a certain critical velocity that they can be considered eroding 

 agents comparable with other geologic forces . Flint (1957) gives many examples 

 (Northern Hemisphere) of deep glacial troughs carved by an ice cap with little or 

 no erosion in adjacent areas covered by It. Flint concludes that the effective- 

 ness of glacial erosion varies greatly, both from place to place and from time to 

 time, with rate of flow, thickness of ice, basal load, and erodability of the ground. 



Mel lor (1959) estimates that ice streams, which occupy a small fraction of the 

 total length of the Antarctic coast, are responsible for the removal of more tee 

 from the continent than the "sheet flow" (the general outward movement of the 

 continental ice) over the remaining length of the coast. 



Shepard (1931, 1948) points out that glacial troughs differ from typical sub- 

 marine canyons in their: 



a . great width; , 



b . trough shape, I .e ., steep walls and broad base; 

 c . straight or smoothly curving sides; 



d. undulating longitudinal profile; 



e. depths in the Inner (landward) portions of the valleys comparable with 

 or greater than the depths in the outer (seaward) portions of the valleys; 

 basin depressions . 



Shepard's description of glacial troughs fits the transverse depression of Sulzberger 

 Bay. 



From the foregoing glaclologlcal and topographic considerations, it appears to 

 this writer that the transverse depression of Sulzberger Bay was carved or deepened 

 by a former ice stream . 



Fairbrldge (1952) suggests that the Edsel Ford Range Is separated from Edward 

 VII Peninsula by block faulting. Thiel and Ostenso (1961, Fig. 1) show a deep, 

 3,000-foot trench or depression In the bedrock below the Ice cap about 100 miles 

 southeast of the southern Edsel Ford Range, In line with the transverse depression 

 of Sulzberger Bay. The bathymetric contours of Figure 5 show a major concavity 

 off the edge of the continental shelf block adjacent to the seaward end of the trans- 

 verse depression. A NW-SE line can be drown through these three features. The 



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