32 



MARINE BOTTOM SAMPLES OF LAST CRUISE OF CARNEGIE 



Table 1. Synoptic table of bottom samples collected 



Sam- 

 ple 



Sta- 

 tion 



Date 



Position 



and 

 depth in 

 meters 



Type of sample 



Estimated 

 CaCOa con- 

 tent in per 



cent; basis 

 of estimate 



Color and physical characters 



58 



116 



59 117 



60 



61 



119 



127 



62 128 



25 



63 130 



64 131 



Sep. 



40 37 N 



132 23 W 



3806 m 



37 05N 



123 43 W 



3188 m 



33 49N 



126 20 W 



4418 m 



Red clay 



7; total C02 



Green mud 



Red clay 



<5; inspec- 

 tion 



0.57; acid 

 soluble CaO 



(Dry) olive-brown 173k(0-Y); 

 (moist) silty clay (U.S.B.S. clas^ 

 clay; frustules of diatoms; 

 moderately coherent, crumbly 



(Moist) mummy-brown 17lm(0-y) 

 Silty clay (U.S.B.S. class=clay); 

 frustules of diatoms; moderate- 

 ly coherent, crumbly 



(Dry) between vinaceous-buff 

 and avellaneous 173c(0-Y) 



Clayey silt (U.S.B.S. class=clay); 

 frustules of diatoms; moderate- 

 ly coherent, crumbly 



(Dry) near light grayish-olive 

 2i4-l/2c(OYY); (moist) brown- 

 ish-olive 192m(YO-Y) 



Clay (U.S.B.S. class=clay); co- 

 herent; when moist, somewhat 

 plastic; when dry, brittle 



(Dry) between tilleul-buff and 

 vinaceous-buff 173e(0-Y) 



Clay (U.S.B.S. class=clay); few 

 shells of foraminifera; coher- 

 ent; when moist, slightly 

 plastic, moderately sticky; 

 when dry, brittle 



(Dry) between light grayish-olive 



and grayish-olive 2l4a(0-YY) 

 Clay; coherent, brittle 



(Dry) between light drab and 



dark gray 174c(0-Y) 

 Clay (U.S.B.S. class=clay); 



coherent, brittle 



piece of fresh pumice over 1 cm in diameter and 2 manganese-palagonite nodules of about the same size. 

 One of these, when sectioned (see plate Xm) shows the spherulitic alteration of colorless isotropic vol- 

 canic glass in the center, to reddish-orange palagonite, containing fresh phenocrysts of monoclinic feld- 

 spar and hornblende, near the surface. The palagonite spherulites are often surrounded by manganese; 

 some of them are entirely replaced by manganese, which is distributed in more or less laminar fashion. 

 Nearer the surface there are only isolated fragments of palagonite spherulites in the thick manganese 

 coating. 



Sample 58. Radiolaria are very abundant in this sample, but the principal component is perhaps diatoms 

 at least in the finer grades. Other organic components are sponge spicules and arenaceous foraminifera. 

 Inorganic components of sand grades include: rounded grains of fresh pumice, 3 mm in longest diameter, 

 in which there are porphyritic clusters of magnetite, hypersthene, green hornblende and plagioclase feld- 

 spar (labradorite, Ab45An55); a few semiangular fine-grained volcanic rock particles about 1 mm in 

 diameter which contain small crystals of plagioclase feldspar; together with plagioclase, quartz, basic 

 volcanic glass, and monoclinic feldspar. Subhedral hornblende is the chief heavy mineral, followed by 

 euhedral hypersthene, magnetite crystals, biotite, and colorless augite. Some of the plagioclase parti- 

 cles ate zoned. 



Sample 59. Both diatoms and radiolaria make up a very large proportion of this sample, but diatoms pre- 

 dominate, especially in the finer grades. Other organic remains are arenaceous foraminifera, sponge 

 fragments, and pelagic foraminifera. Semiangular grains of quartzite, limestone, and a fine-grained vol- 

 canic rock are apparently ice-borne. Besides these, there are small amounts of basic volcanic glass 

 (index of refraction greater than 1.56) and pumice (index of refraction 1.515). These are exactly similar 

 in appearance to the glass and pumice from samples 56 on, the glass being packed as usual with mlcro- 

 lites of feldspar. Some of the grains of the pumice are rounded. Very fresh plagioclase feldspar (labra- 

 dorite), quartz, monoclinic feldspar, biotite, hypersthene in euhedral single and twinned crystals, 

 hornblende, magnetite and pyroxene (?) are also present in the sand grades. 



