THE DEPTH AND MARINE DEPOSITS OF THE PACIFIC OCEAN. 47 



Minerals (2.30 per cent) ; the mineral particles here may be roughly 

 divided into two groups according to size, — one has a mean diameter of 

 0.12 mm., the other about 1 mm. There are two fragments of rock, 2 and 

 3 mm. in diameter, irregular, with blunted edges, brown and soft, repre- 

 senting a decomposed volcanic rock, and consisting essentially of limonite 

 and a glassy base, in which augite and a tabular isotropic mineral are ob- 

 served. To these fragments are firmly attached Sponge spicules forming 

 on their surface a reticulated design: The minerals proper consist of quartz, 

 in fragments sometimes 1 mm. in diameter, with blunted edges, augite, a 

 little plagioclase, a few flakes of a chloritic mineral, and a good many man- 

 ganese grains. Many splinters of colorless volcanic glass were also ob- 

 served, in addition to flakes of hematite. 



Fine Washings (96.70 per cent), yellowish-gray clayey matter, with a 

 few small mineral particles. 



No. 10. Station 4671, 20th November, 1904. 

 Lat. 12° 6.9' S. ; long. 78° 28.2' W. ; depth, 1490 fathoms. 



BLUE MUD : dark green when wet, very soft to the touch, and plastic, 

 but not sticky ; when dried, slightly coherent and light gray in color with a 

 faint green tinge. 



Calcium carbonate : per cent. 

 Residue : 100 per cent : — 



Siliceous Organisms (0.5 per cent), only Diatoms were observed. 



Minerals (0.5 per cent), very few, angular and varying in size, mostly 

 quartz and glauconite, with a little felspar, magnetite, and hematite. 



Fine Washings (99 per cent), fine greenish-colored clay, containing 

 many very minute mineral particles, 0.01 mm. in diameter, and Diatoms. 



No. 11. Station 4672, 21st November, 1904. 

 Lat. 13° 11.6' S. ; long. 78° 18.3' W. ; depth, 2845 fathoms. 



RED CLAY (might be called Blue Mud) : gray, plastic, sticky, smooth 

 to the touch ; dries into light-gray lumps difficult to break. The deposit has 

 undergone a kind of decomposition in the bottle, as parts of it have turned 

 nearly black. 



Calcium carbonate : per cent. 



Residue : 100 per cent : — 



