2:^0 
THE VOYAGE OF H.M.S. CHALLENGEE. 
The remains of siliceous organisms in these samples range from 1 per cent, in 6 cases 
to 20 per cent, in 1525 fathoms, and the average is 2’89 per cent. They consist of 
Sponge spicules, Radiolaria, Diatoms, casts of Foraminifera, and arenaceous Foraminifera. 
The mineral particles are all angular, and range from less than 1 to 10 per cent., the 
average being 2'85 per cent. In size they vary from 0‘06 to OTO mm. in diameter, 
the average being 0'08 mm. These mineral particles consist of magnetite and augite in 
11 instances, felspar and hornblende (8), sanidine, volcanic glass, and lapilli (6), 
])lagioclase and mica (5), pumice (4), manganese (3), quartz (2), and olivine, altered 
mineral particles, and cliloritic scales (l). 
The fine washings range from a trace in 1240 fathoms to 4178 per cent, in 900 
fathoms, the average being 15’01 per cent. 
The average composition of the ChaUeiiger samples of Pteropod Ooze is as follows : — 
Pelagic Foraminifera, 
47-15 
Carbonate of lime, . 
< 
Bottom-living Foraminifera, 
3-15 
Other organisms. 
28-95 
Siliceous organisms, . 
2-89 
Residue, . 
- 
Minerals, . . . . 
2-85 
Fine Washings, 
15-01 
2075 
10000 
By comparing this with the table showing the average composition of Globigerina 
Ooze on page 218, it will be observed that Pteropod Ooze differs from Globigerina Ooze 
in the residue being less abundant and, chiefly, in the relatively large percentage of 
calcareous organisms other than Foraminifera. 
The Challenger dredges and trawls brought up pieces of pumice in 4 instances from 
these deposits, and manganese nodules and organisms coated with manganese in 3 cases, 
jis well as a large number of deep-sea animals. 
The following three analyses of samples of Pteropod Ooze are from Station 22, 1420 
fathoms. Station 23, 450 fathoms, and Station 24, 390 fathoms. 
! 
Portion 
SOLUBLK IN IICl. 
Portion insoluble in HCl. 
station. 
= ■! 
•- a 
A O 
tA 
No. 
Loss on 
Ignition. 
SiO, 
1 
AI 3 O 3 
FcjOs 
MnOj 
CaCOs 
CaSOi 
Caa 2 P 04 
MgCO, 
Total. 
22 
1420 
60 
3-80 
' 414 
4-42 
... 
80-69 
0-41 
2-41 
0-68 
92-76 
1 AL203,Fc203,Si02> 
. . . 3-45 
23 
4C0 
61 
4-00 
2-60 
1-80 
300 
... 
84-27 
1-00 
g.tr. 
1-28 
93-95 
I Al 303 ,Fc 303 i SiOj) 
. . . 2-05 
24 
800 
62 
2-00 
3-65 
0-80 
3 06 
... 
82-66 
0-73 
2-44 
0-76 
94-10 
1 AlgOa^Fe-jOs^SiOa, . 
1 
. 3-90 
In No. 62 the flner ]mrU hod been washed away. 
