11. Ferric oxide. Represents the per- 

 centage of hydrochloric acid-solu- 

 ble iron present on a dry weight 

 basis and reported as ferric oxide. 



12. Manganous oxide . This is the per- 

 centage of hydrochloric acid- solu- 

 ble manganese present on a dry 

 weight basis and reported as man- 

 ganous oxide. 



13. Magnesium oxide . This is the per- 

 centage of hydrochloric acid- solu- 

 ble magnesium present on a dry 

 weight basis and reported as mag- 

 nesium oxide. 



14. Calcium oxide . This is the per- 

 centage of hydrochloric acid- solu- 

 ble calcium present on a dry weight 

 basis and reported as calcium 

 oxide . 



15. Potassium oxide. This is the per- 

 centage of hydrochloric acid-solu- 

 ble potassium present on a dry 

 weight basis and reported as po- 

 tassium oxide. 



16. Phosphorus pentoxide. The major 

 portion of phosphorus in marine 

 sediments is believed to be from 

 apatite and the bodies and skeletons 

 of animals. This is the percentage 

 of phosphorus (soluble in hydro- 

 chloric acid) present on a dry 

 weight basis reported as phos- 

 phorus pentoxide. 



17. Strontiunn. This is the percentage 

 of acid-soluble strontium present 

 on a dry weight basis. 



18. Chlorides . These values are the 

 percentages of total soluble halides 

 present on a dry weight basis. 



19. Organic nitrogen . These values are 

 in weight percent of total sample 

 and are an indication of the amount 

 of organic matter present in the 

 sediment. The nitrogen content in 

 these sediments is very much 

 lower than in most shelf sediments 

 and is close to the limits of accu- 



racy of the Kjeldahl method. The 

 high carbon-nitrogen ratios may be 

 an indication of the relatively 

 greater age of some of the sedi- 

 ment. 



20. Organic carbon. The organic car- 

 bon values are good indicators of 

 the organic content. Trask (1932) 

 has stated that an approximation 

 of the total organic content can be 

 calculated by multiplying the or- 

 ganic carbon by 1.8. These values 

 shown are in terms of weight per- 

 cent of total sample. 



21. Calcium carbonate . This is ac- 

 tually total carbonate in weight 

 percent of total sample. Minor 

 amounts of magnesium and stron- 

 tium carbonate are always present 

 in organic carbonates. Variation in 

 carbonate content is probably great 

 because of the relatively small size 

 of the samples. A single shell may 

 fall into any representative split of 

 a small sample and affect the re- 

 sulting carbonate values by several 

 percent. The values are precise 

 for any one sample but variation is 

 high at any individual station. 



22. Gravel . This is the weight percent 

 of total sample of particles having 

 diameters larger than 2 mm. 



23. Sand . This is the weight percent 

 of total sample of particles having 

 diameters between 0.062 rnm. and 

 2.000 mm. 



24. Silt . This is the weight percent of 

 total sample of particles having 

 diameters between 0.004 mm. and 

 0.062 mm. 



25. Clay. This is the weight percent of 

 total sample of particles having 

 diameters less than 0.004 mm. 



26. Median diameter. These are ac- 

 tually mean diameters as computed 

 by the IBM 650 digital computer. 

 The difference between the mean 



26 



