122 
PACIFIC SCIENCE, Vol. Ill, April, 1949 
TABLE 1 
The Chemical Composition of some Manganiferous Soils and Pyrolusite Concretions Separate 
from Same Soils 
SAMPLE 
SiO a 
aitt 
FeTT 
TiCL 
MnO,> 
per cent 
per cent 
per cent 
per cent 
per cent 
MANGANIFEROUS SOILS 
Soil No. 1 
31.32' 
32.00 
16.10 
2.90 
. 2.58 
2 
31.72 
36.60 
16.55 
2.85 
5.22 
3- 
31.28 
36.90 
16.20 
2.90 
1.79 
CONCRETIONS FROM 
SOILS 
Concretion 1 
19.87 
33.78 
10.74 ‘ 
1.56 
28.04 
2 
17.54 
26,23 
11.15 
2.02 
30.03 
3 
17.38 
25.70 
13.70 
2.34 
30.78 
4 
18.91 
27.07 
10.88 
1.55 
30.18 
5 
16.83 
29.36 
9.85 
2.29 
29.88 
6 
15.80 
31.34 
12.69 
1.33 
27.93 
7 
16.86 
28.37 
13.25 
1.33 
28.63 
TABLE 2 
The Chemical Analyses of Different Types of Pyrolusite Concretions Found in Hawaiian Soils 
TYPE OF 
CONCRETION 
SiCT 
A ITT 
FeoOa 
TiOo 
MnCT 
per cent 
per cent 
per cent 
per cent 
per cent 
Spherical 1 
15.88 
33.12 
14.20 
2.65 
31.13 
2 
16.67 
32.26 
14.26 
2.61 
29.45 
3- 
17.27 
32.73 
4.47 
1.65 
33.96 
4 
21.24 
28.92 
9.16 
2.26 
29.39 
5 
19.94 
29.92 
7.47 
1.91 
34.16 
6 
11.21 
31.89 
9.46 
2.18 
34.02 
7 
14.38 
39.7 6 
0.66 
2.63 
39.7 6 
Average 
16.66 
32.66 
8.53 
2.27 
33.12 
Tubular 1 
11.64 
25.60 
18.66 
2.74 
23.83 
2 
14.53 
24.86 
16.73 
2.39 
28.73 
3 
9.50 
33.10 
17.77 
3.22 
23.13 
4 
10.82 
30.59 
16.05 
2.61 
24.78 
5 
15.93 
26.25 
11.54 
2.71 
31.09 
6 
17.14 
31.94 
11.37 
2.79 
26.30 
7 
15.68 
27.81 
10.57 
2.22 
31.37 
Average 
13.61 
28.59 
14.67 
2.79 
27.03 
Irregular 1 
10.95 
34.13 
4.76 
2.38 
25.11 
2 
14.33 
29.08 
6.24 
2.27 
28.06 
3 
13.06 
15.29 
8.12 
1.88 
44.19 
4 
17.54 
24.97 
15.15 
3.37 
28.90 
5 
17.96 
25.82 
13.44 
3.31 
30.82 
6 
19.79 
26.67 
10.06 
2.24 
32.70 
Average 
15.60 
26.00 
9.63 
2.57 
31.63 
