66 



MARINE BOTTOM SAMPLES OF LAST CRUISE OF CARNEQE 



that of manganese and the relation between manganese 

 and phosphate is shown in figure 2. Particularly in Glo- 

 bigerina ooze there is a fairly close relation between 

 these two substances. From figure 1 it may be seen that 

 in Globigerina oozes the manganese content varies di- 

 rectly with the amount of iron. Crawley (1902) and Heck 

 (1934), among others, have pointed out the close relation 

 between manganese, iron, and phosphate in soils. It is 

 probable that the same conditions with respect to these 

 substances prevail on the sea bottom in areas of pelagic 

 sediments, particularly in the southeast Pacific. 



Analyses of Pelagic Foraminifera 



Partial chemical analyses of foraminifera separat- 

 ed in the process of mechanical analysis and by treat- 

 ment with bromoform from five Globigerina oozes are 

 given in table 15. From these it may be seen at once 

 that shells of pelagic foraminifera, at least after partial 

 recrystallization under deep-sea conditions, consist al- 

 most entirely of calcium carbonate and contain very lit- 

 tle, if any, magnesium carbonate, contrary to the results 

 of Clarke and Wheeler (1922). In four of the five sam- 

 ples analyzed, the amount of calcium found is slightly 

 more than sufficient to balance the amount of CO2, owing 

 to clayey material present inside the shells which could 

 not be washed out. Analyses of two different separates 

 from sample 19, however, gave an excess of CO2 over 

 CaO. It is possible that in this highly ferruginous Glo- 

 bigerina ooze some of the calcium has been replaced by 

 ferrous iron during the process of recrystallization of 

 the foraminifera on the sea bottom. 



Table 16. Analysis of altered volcanic 



material from Carnegie sample 11, 



station 40 



Constituent 



Value in 

 per cent 



Analysis by Sharp-Schurtz Com- 

 pany, Lancaster, Ohio. Abbreviation 

 used as follows: n.f. = none found. 



Spectr ogr aphi c Analysis 



Parts of sixty-seven samples were examined spec- 

 trographically by Mr. George Steiger for the following 

 elements: boron, barium, beryllium, bismuth, germa- 

 nium, tin, and zinc. The results are tabulated in table 

 17, and certain of them are illustrated in charts 8 and 9. 



The tests were made using a Gaertner spectrograph, the 

 samples being placed directly in the arc on Acheson 

 graphite electrodes, without previous chemical separa- 

 tion. Blank tests run with the electrodes alone showed 

 no lines of the metals mentioned above. Quantities be- 

 low a limit between 0.01 and 0.03 per cent cannot be de- 

 tected spectrographically by the method used without 

 previous chemical separation. Besides determinations 

 of these six metals, plates were made including spectra 

 which will make it possible to determine the presence of 

 silver, arsenic, cadmium, lead, antimony, lithium, and 

 strontium. Mr. Steiger's report on the analyses is as 

 follows: 



"Boron is widely distributed in small quantities 

 throughout nature and it might readily be expected in the 

 oceanic muds. Germanium was included in these tests 

 for the reason that this metal although formerly consid- 

 ered very rare has been quite recently shown by several 

 investigators to be widely distributed; this has also been 

 my experience. The present tests have shown that at 

 least in these muds germanium occurs if at all in small- 

 er percentages than it does in many minerals and rocks. 

 There is but little information on the distribution of small 

 percentages of bismuth in rocks and minerals. Berylli- 

 um, from recent work, seems to be more widely distrib- 

 uted throughout nature than was formerly supposed. 



"The distribution of barium as shown by these tests 

 is of interest. My analyses of oceanic clays collected by 

 the Challenger expedition, published in the Data of Geo- 

 chemistry (Clarke 1920), gave in the composite of 51 

 red clays from the deeper parts of the ocean 0.20 per 

 cent BaO, and in the composite of 52 specimens of blue 

 muds from the more shallow parts 0.06 per cent BaO. 

 Most of the samples in the present series, having been 

 taken from under relatively deep water would be expect- 

 ed to run around the 0.20 per cent limit, and the absence 

 or low barium content of some of them cannot be ac- 

 counted for by shallow water conditions. If volcanic dust 

 be the source of these muds, barium salts being relative- 

 ly insoluble, their concentration might be expected in 

 muds from the deeper parts of the ocean, other more 

 soluble salts being dissolved on their way down. On the 

 other hand, if the muds have been derived from rocks on 

 adjacent shores, owing to their high specific gravity the 

 barium salts would sink more rapidly and concentrate 

 close to the shore line. Data from the present tests show 

 barium to be concentrated principally in the southeast 

 Pacific, the samples coming from this section without 

 exception not only contain barium, but the individual 

 tests were much stronger, indicating higher percentages. 

 Those of the northeast Pacific come next, nearly all of 

 them contain barium but the tests as a rule were not so 

 strong, while most of those from the western Pacific and 

 from the Atlantic contain little or no (probably less than 

 0.02 per cent BaO) barium. This segregation is nicely 

 shown by excluding those specimens on which some doubt 

 is placed, reported as "possibly present" and "doubt- 

 ful." In this way a differential may be had between 

 those specimens of "high" and those of "low" barium 

 content, the division line being around 0.05 per cent BaO. 

 Whether the high barium content of the rocks in the west- 

 ern part of the American continents is responsible for 

 the concentration of barium in the samples from the 

 eastern Pacific is doubtful as it seems a long distance 

 for barium to be carried, but it seems significant that 

 both the land rocks and the bottom sediments high in 

 barium are adjacent to each other." 



