largely on their ferromanganese content and 

 demonstrated that sediment color and benthic 

 biomass were closely related. 



Gorshkova (1966) suggested that the large 

 accumulations of mangancjc in Kara Sea sedi- 

 ments were attributable to the semiclosed con- 

 figuration of the coastal zone of the Kara Sea 

 which, coupled with the great quantity of man- 

 ganese brought in by the inflowing rivers fa- 

 vored the vital activities of microorganisms 

 and the biochemical settling of manganese. 



Nesterova (1960) investiagted the chemical 

 composition of the suspended and dissolved 

 loads of the Ob River which enters the Kara 

 Sea from the south and found that Fe, Mn, P 

 and other minor elements are transported 

 largely in mechanical suspension and only 

 partly in solution. 



Strakhov ( 1966, using the data of Nerterova 

 (1960) for the chemical composition of Ob 

 River water and the data of Gorshkova (1957) 

 for the composition of Kara Sea sediments, 

 found more iron and manganese in the surface 

 sediments of the Kara Sea than could be ac- 

 counted for by river input alone. He attributed 

 the excess to the migration of iron and manga- 

 nese from the reducing zone of gray and gray- 

 green sediment layers to the oxidizing zone of 

 the brown upper layers. 



Kulikov (1961) observed that the highest 



iron and manganese concentrations were in 

 clayey sediments and in areas of the Kara Sea 

 where Ob and Yenisey river water is found. He 

 also noted a tendency for iron and manganese 

 to concentrate in trough and depression sedi- 

 ments. 



Kulikov (1961) reported that in the Kara 

 Sea the mineralogical composition varies rela- 

 tively little with depth in sediment cores. 

 Heavy minerals may constitute as much as 10 

 percent of the 50 to 100 micron fraction (Gor- 

 shkova, 1957; Kulikov, 1961). According to 

 Kulikov, amphibole, pyroxene, epidote and 

 dark ore minerals in varying proportions make 

 up the bulk of the heavy fractions. The light 

 fractions contain predominantly quartz (60 to 

 80 percent), orthoclase (20 to 30 percent, 

 sometimes 40 to 60 percent), and plagioclase 

 (5 to 20 percent). The clay fractions contain 

 up to 70 percent hydromica. 



Estimates of rates of sedimentation for the 

 deeper areas of the Kara Sea based on both 

 radium concentrations and clastic inputs to the 

 Kara Sea (Yermolayev, 1948a,b; Saks, 1953, 

 cited in Kulikov, 1961 ) range from 4 to 6 cm. 

 per thousand years. The rate of sedimentation 

 within the boundaries of the Ob- Yenisey shal- 

 lows (<50 m.) varies from 30 to 100 cm. per 

 thousand years (Saks, 1953, cited in Kulikov, 

 1961). 



Procedures 



Field 



The cores from the CGC Northwind survey 

 from which surface samples were cut for this 

 study were obtained with a Kullenberg gravity 

 corer. The cores from the CGC Edisto-CGC 

 Eastwind survey (fig. 3) were obtained with a 

 Phleger corer. Cores from both surveys were 

 retained in plastic liners and were stored at 

 low temperature (above freezing) to reduce 

 bacterial activity. Sediment samples remaining 

 after the analyses described below are availa- 

 ble on request from the author at the Depart- 

 ment of Oceanography, Florida State Uni- 

 versity, Tallahassee, Fla. 32306, and after 

 August, 1971, from the Smithsonian Oceano- 

 graphic Sorting Center, Washington, 

 D.C. 20390. 



Laboratory 



In the laboratory the cores were split longi- 

 tudinally, described (table 7) and sampled. 

 Surface samples from 42 Northwind cores and 

 5 grab samples were obtained from the Univer- 

 sity of Wisconsin, Geophysical and Polar 

 Research Center, and were used for the geo- 

 chemical analyses. In addition core N-148 was 

 sampled at 1-cm. intervals for the geochemical 

 sampled at 10-cm., 5-cm., or shorter intervals 

 for grain size analyses and at 1-cm intervals 

 for the geochemical analyses. With the excep- 

 tion of core E-26 which was studied in detail, 

 only the top centimeter of each core was used 

 for the geochemical studies. 



The samples cut from the CGC Edisto-CGC 

 Eastwind survey cores for grain size analyses 



