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(Security claasillcalion ol title, body ol abs 



St be entered when the 



all report ie classified) 



1 ORIGINATIN G ACTIVITY (Corporate author) 



U.S. Naval Oceonographic Office 

 Oceanographic Surveys Department 

 Ocean Surveys Division 



2a. REPORT SECURITY CLASSIFICATION 



Unclassified 



26 GROUP 



3 REPORT TITLE 



SEDIMENTS OF THE NORTHERN ARABIAN SEA 



4. DESCRIPTIVE NOTES (Type of report and inclusive dates) 



Final Report 26 February to 31 March 1961 



S AUTHORCS; (Last name, fir 



Stewart, Richard A, 

 Pilkey, Orrin H. 



6 REPO RT DATE 



January, 1966 



7a. TOTAL NO. OF PAGES 



28 



76. NO. OF REFS 



17 



Sa. CONTRACT OR GRANT NO. 

 6. PROJECT NO. D~/l 



01 

 AFJ02 



9a. ORIGINATOR'S REPORT NUMBERfS; 



TR-186 



nbsrs that may be assiened 



10 AVAILABILITY/LIMITATION NOTICES 



Qualified requesters may obtain copies of this report from DCD . Price $ 1 .00 



11 SUPPLEMENTARY NOTES 



12. SPONSORING MILITARY ACTIVITY 



Navy 



13 ABSTRACT 



Topographically the northern Arabian Sea can be divided into two basins separated by the 

 northeast-southwest trending Murray Submarine Ridge. The northwest Gulf of Oman Basin 

 exhibits a more Irregular topography, particularly along the continental margin, than does the 

 southeast Arabian Sea Basin, which is dominated by the large sediment cone of the Indus River. 

 Sediments with median grain sizes In the sand and silt range are largely restricted to the con- 

 tinental shelves and upper continental slopes. Basin sediments are calcareous (17 to 51 percent 

 calcium carbonate) and become more so to the south . A band of relatively pure carbonate 

 materials is present on the outer Indian shelf. Detrital grains of dolomite and calcite are 

 present in small amounts in most samples, and frosted, pitted quartz grains are common in the 

 coarse fraction of sediments from the northwest basin. The non-carbonate coarse fraction of 

 the sediments contains much feldspar and an unstable heavy mineral suite of both metomorphic 

 and igneous origin . Dust Is an Important source of sediments over the entire area . The dust 

 contribution is relatively more important, and the overall rate of sedimentation is lowest in 

 the Gulf of Oman Basin as compared to the Arabian Sea Basin. 



DD 



1473 



Security Classification 



