No detailed analysis of the core samples of the glacial marine veneer of the 

 eastern Ross Sea - Sulzberger Bay area was undertaken to test the validity of the 

 writer's proposed division of that area into wet-base and dry-base glacial provinces, 

 Morphological characteristics of the area, however, suggest such a division . 



The sharpness of the submarine topography of the inner shelf and the adjacent 

 and transecting troughs and canyons suggest that only a thin blanket of Quaternary 

 marine sediment exists in the nearshore parts of Sulzberger Bay, indicating that the 

 overriding ice was too cold to drop sediment in this zone. 



Seismic measurements show a several-hundred-feet-thick, apparently uncon- 

 solidated basal sediment layer under the floating Ross Ice Shelf. These measure- 

 ments show that the deeper continental shelf surface extends continuously under 

 this basal layer (Poulter, 1947; Crary, et al ., 1962). 



The transverse ridge extending north from Cape Colbeck has the expected 

 orientation for a lateral moraine of a grounded ice sheet filling the Ross embayment 

 to the shelf edge. If this ridge Is indeed a lateral (or medial) moraine, the ice 

 sheet of the Ross embayment must have moved at a different velocity and as a sep- 

 arate unit from the ice sheet occupying the eastern side of the ridge. Since the 

 grounded portion of the Ross ice sheet must have traveled some hundreds of miles 

 farther than its eastern neighbor to reach the shelf edge. It had a greater opportu- 

 nity to be warmed to the point of becoming a wet-base glacier, thus changing its 

 mechanical parameters. The drumlin-like surface of the basal sediment under the 

 present Ross Ice Shelf (Crary, et al ., 1962; Zumberge and Swithinbank, 1962) 

 suggests that the basal sediment has been overridden by grounded ice. 



The submarine troughs are found exclusively along the shores of the land mass 

 of the proposed dry-base glacial province. According to the concepts advanced 

 by Carey and Ahmad, these could only have been carved by dry-base glaciers. 



2 . East-West Transverse Ridge . The orientation of the transverse ridge which 

 extends west from Edward VII Peninsula and parallel to the present Ross Barrier, 

 and the pebbly material found on its back (SI-3, Fig. 2), suggest that this trans- 

 verse ridge might be the remnant of an end moraine formed by the grounded Ross 

 Ice sheet during a pause In one of its advances or retreats . The coarseness of the 

 GLP-6 sediment (Fig. 2) and the disturbed bottom topography in the vicinity 

 (Profile C-D, Figs. 2 and 3) may Indicate a deposit of turbidlte fronting the 

 basol till of the floating Ross Ice Shelf. 



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