Surficlal sediments of the Antarctic continental shelf are composed primarily 

 of ice-rafted material (U.S. Navy, 1957); these iceberg sediments form a belt 

 200 to 600 miles wide (LIsltzyn, 1962) as compared to an average shelf width of 

 only 105 miles (Voronov, 1960). 



These separate lines of evidence indicate that Pleistocene sedimentation of -■ 

 the Antarctic continental shelf has been rather slow . 



The outer limit of the zone of glacial marine sediment is correlated with the 

 maximum extent of pack ice, i .e., frozen sea water. Seaward of this zone is 

 a circumferal 600- to 1,000-mile-wlde zone of diatom ooze (U.S. Navy, 1957; 

 LIsltzyn, 1962). For the most part, diatoms are restricted to the cold, less saline 

 surface waters which extend from the Antarctic coast to the Antarctic Convergence, 

 where they meet the warmer, more saline waters farther north . 



"Clay" (glacial rock flour?) and diatomaceous clay oozes are spread on the 

 Antarctic continental rise. These consist of fine glacial sediments and diatom 

 debris discharged in large amounts from the continental shelf (Zhivago and Lisitzyn, 

 1957) . Long cores from this peripheral area show alternations of green-brown clay 

 and diatomaceous clay ooze with typical diatomaceous sediments . According to 

 Lisitzyn (1962), these repeated changes in sediment types prove that climatic 

 changes have taken place during Quaternary time. As a result of these changes, 

 the boundaries of the main sediment types have shifted northward and southward 

 more than 500 miles. At the present time, a substantially warmer period exists 

 in the Antarctic zone. Hough (1950) interprets in a similar manner the alternations 

 of coarser glacial marine sediment with fine-grained "nonglacial" sediments of a 

 core from the continental rise bordering the Ross Sea . AAany of the core samples 

 of the eastern Ross Sea - Sulzberger Bay area also showed similar fine and coarse 

 alternations (Goodell, unpublished analysis; Goodell et al., 1961). 



In brief, the surficial sediments of the continental shelf are composed primar- 

 ily of mechanically disintegrated material, i.e., rock flour, fragments, and 

 larger erratics, all of which have been ice-rafted from land. The sediments are 

 unsorted, unaltered, and low In organic matter (U.S. Navy, 1956). Diatoms 

 make up a large part of the organic matter (Lisitzyn, 1962). 



C . Present Glaciation 



From his field work in the area. Wade (1937) found that the Edsel Ford Range 

 acts as a 150-mlle-long barrier to the continental ice cap of the Rockefeller 

 Plateau to the east . The rock outcrops occur in NW-trendIng mountain chains 

 (Fig . 5) . Their present configuration is the result of folding, Ihtrmions, and 

 glaciation . The sub-ice topography of the northeast shoreline of Sulzberger Bay 

 would be a series of fjords if the ice was removed. 



T3 



