48 THE DEPTH AND MARINE DEPOSITS OF THE PACIFIC OCEAN. 



Siliceous Organisms (small traces), a very few thin Sponge spicules and 

 one or two Diatoms. 



Minerals (traces), angnlar quartz grains, 0.08 mm. in diameter, shapeless 

 flakes of a green chlorite, one or two fragments of decomposed felspar, and 

 a particle of manganese are all that could be detected. 



Fine Washings (100 per cent), gray, flocculent clay, containing a large 

 proportion of minute mineral particles as mentioned above, with augite, 

 hematite, and perhaps hornblende, and a few fragments of siliceous organ- 

 isms. The mineral particles represent nearly one-half the bulk of the 

 deposit, but they are very small, averaging 0.01 mm. in diameter. 



No. 12. Station 4509, 22nd November, 1904. 

 Lat. 12° 26.6' S. ; long. 78° 34.5' W. ; depth, 1949 fathoms. 



BLUE MUD : very dark gray, almost black, plastic, but not sticky, finely 

 granular; much lighter in color when dry. 



Calcium carbonate : 5.07 per cent, well preserved shells of Foraminifera 

 belonging to many genera, Textularidse being the most abundant. 



Residue: 94.9-3 per cent, contains a brown matter apparently of vege- 

 table origin. The material appears to have undergone a certain amount of 

 sifting, either during collection or during transit, for mineral particles are 

 more abundant in some parts than in others, so that the figures given for 

 the percentages of siliceous organisms and minerals are only approximate : — 



Siliceous Organisms (0.5 per cent). Sponge spicules and Diatoms. 



Minerals (3.5 per cent), angular; mean diameter 0.08 mm., principally 

 quartz and plagioclase, with a chloritic mineral and other ferruginous, de- 

 composed minerals that could not be identified. 



Fine Washings (90.93 per cent), brown, amorphous, flocculent matter, 

 with many fragments of minerals and siliceous organisms. 



No. 13. Station 4674, 22nd November, 1904. 

 Lat. 12° 14.4' S ; long. 78° 43.4' W.; depth, 2338 fathoms. 



The material obtained at this station is extremely interesting, consisting 

 of (1) a bottle of ooze, (2) cakes of consolidated sediment, apparently the 

 same as No. 1, and (3) large angular fragments of rocks, some of them over 

 a foot in diameter. 

 (1) DIATOM OOZE: dark grayish green, mottled with lighter colored 



