56 



MARINE BOTTOM SAMPLES OF LAST CRUISE OF CARNEGIE 



CHEMICAL ANALYSES 



General 



Partial chemical analyses were carried out on forty- 

 six samples, of which forty-three are from the Pacific, 

 including twenty south Pacific Globigerina oozes, nine 

 northeast Pacific red clays, four siliceous oozes collect- 

 ed northeast of Japan, two south Pacific red clays, four 

 terrigenous deposits, two radiolarian oozes from the 

 central Pacific, and two shallow-water deposits, one 

 from the harbor of Callao and the other a calcareous 

 beach sand from Easter Island. Determinations of Si02, 

 Ti02, AI2O3, total iron (as Fe203), Mn02, MgO, CaO, 

 Na20, K2O, P2O5, Zr02, and acid-soluble CaO and 

 MgO were made by the Sharp-Schurtz Company of Lan- 

 caster, Ohio, who also determined the amounts of chlo- 

 ride (CI) in twelve of the samples. Dr. Parker D. Trask 

 determined the amounts of organic nitrogen (N) in the 

 samples, and Miss Esther C. Allen and the writer deter- 

 mined the percentage of carbon dioxide in certain of them 

 (see table 8). Spectrographic analyses (for boron, bari- 

 um, and other elements) of all the samples mentioned 

 above, together with about thirty others, were made by 

 Mr. George Steiger. Dr. C. S. Piggot made determina- 

 tions of the content of radioactive substances in twenty - 

 eight samples. The results obtained by Dr. Piggott and 

 Dr. Trask have been published already (see Trask [1932] 

 and Piggott [1933]). 



The results of the chemical analyses are shown in 

 table 9 which gives, in addition to the analytical values 

 for the substances above mentioned, calculated values 

 .for organic carbon, water, chloride, sulfate, and carbon 

 dioxide. 



When the samples were received in Washington from 

 the Carnegie, they were divided and the separate parts 

 were sent to Drs. Trask and Piggott for analysis. Most of 



the remaining samples were sent to the Scripps Institu- 

 tion in 1930. After arrangements had been made between 

 Dr. Fleming and Dr. Vaughan for the carrying out of 

 chemical analyses, the samples of sufficient size for 

 analysis were again roughly quartered by Mr. Alfred 

 Barker and parts sent to the Sharp-Schurtz Company. 

 During these processes of division of the samples, some 

 washing apparently took place, as the amounts of chlo- 

 ride found in them are usually much less than might be 

 expected from Gebbing's (1909) analyses of deep-sea 

 clays. 



The parts received by the Sharp-Schurtz Company 

 in 1931 were quite moist or were suspended in water. 

 Their report on the procedure of analysis is as follows: 



"These samples individually were completely trans- 

 ferred to platinum dishes, evaporated to dryness on a 

 steam bath and finally dried completely in an air bath at 

 110° C. They then were transferred individually to an 

 agate mortar, powdered, thoroughly mixed, and returned 

 to the original containers. Before analysis all samples 

 were dried at 110° C to constant weight. For the sepa- 

 ration and determination of silicon dioxide, aluminium 

 oxide, titanium dioxide, zirconium dioxide, calcium oxide, 

 and magnesium oxide, the methods described by Hille- 

 brand and Lundell (1929, pp. 862-868) were followed 

 closely, with the exception that the filtrate from the 

 R2O3 group was given a preliminary treatment with am- 

 monium persulphate to remove the manganese that other- 

 wise would be carried down by both the calcium and 

 magnesia. 



"The alkalies, (Na20) and (K2O), were determined 

 by the J. Lawrence Smith method on a separate portion. 

 Manganese was determined on a separate portion by the 

 bismuthate method. Phosphorus pentoxide was precipi- 

 tated on a separate portion as ammonium phosphomolyb- 



Table 8. Comparison of CaC03 determinations made by direct measurement of CO2 

 and by determination of acid-soluble CaO 



Average 

 Average deviation 



0.43 



-0.18 

 1.09 



■ 1.28 

 1.28 



A large part of the deviations in columns 8 and 10 may be owing to errors of sampling, since 

 different parts of the original unground, undried samples were taken for the CO2 determinations 

 (made in La JoUa) and the CaO determinations (made by Sharp-Schurtz Co.) 



