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(Security classification o/ title, body ol abstract and indexing annotation must be entered when the 



1 ORIGINATIN G ACTIU|-^Y (Corporate author) 



U.S. Naval Oceanographic Office 

 Oceanographic Surveys Department 

 Ocean Surveys Divisic 



ion 



REPORT SECUPI TY CLASSIFICATION 



Unclassified 



26 GROUP 



3 REPORT TITLE 



SUBMARINE GEOMORPHOLOGY OF EASTERN ROSS SEA AND SULZBERGER BAY, 

 ANTARCTICA 



4 DESCRIPTIVE NOTES (Type ol report and inclusive dates) 



Final December 1960 - March 1961 



5 AUTHORCSJ (Last nar. 



Lepley, Larry K. 



(First name not Lawrence) 



6 REPO RT DATE 



January 1966 



7a. TOTAL NO. OF PAGES 7 b. NO. OF R E FS 



^4. 



.5Z. 



CONTRACT OR GRANT NO. 



b. PROJEC T NO 



D71 



01 



AFJ02 



9a. ORIGINATOR'S REPORT NUMBERfS^ 



TR-172 



none 



10 AVAILABILITY/LIMITATION NOTICES 



Qualified requesters may obtain copies of this report from DCD. 



11. SUPPLEMENTARY NOTES 



12. SPONSORING MILITARY ACTIVITY 



NAVY 



13. ABSTRACT 



This report graphically describes the submarine topography of the eastern Ross Sea and 

 Sulzberger Bay areas of Antarctica, and explains the origins of the bathymetric features. 



The principal bathymetric data used were collected from the U.S. Navy's icebreaker 

 STATEN ISLAND during the DEEP FREEZE 61 reconnaissance survey conducted in December 1960 



Recent marine sediments of the Antarctic continental shelf have been rafted from land by 

 ice . A low rate of recent sedimentation on the continental shelf is especially evident at the 

 inner shelf. The prevailing marine sediment of the area is glacial marine till . Hard sand surface 

 occur where strong currents pass over transverse ridges near shore . 



The outer shelf break averages about 255 fathoms in depth; the great depth of the outer 

 shelf is attributed to remnant isostatic depression by the continental ice sheet of glacial maxima 

 when the ice extended to the shelf break. 



The great (600 fathoms) transverse depression of Sulzberger Bay may be the product of erosior 

 during glacial maxima by a locally accelerated "ice stream" whose position was controlled by be< 

 rock structure . The origin of the longitudinal depressions can be attributed to erosion by conti- 

 nental Ice along zones of weakness due to llthologic changes or faulting parallel to the shoreline 



The longitudinal ridges are Interpreted as end moraines formed during pauses in the retreat of 

 the continental ice sheet . The transverse ridges are interpreted as lateral and end moraines of a 



DD 



1473 



former extension of the Ross Ice Sheet . 



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