CLARKE.] 
CLAYS, SOILS, ETC. 
301 
J to K. Supposed fire clays collected in the area of the Apishapa 
sheet, by G. K. Gilbert. Analyses, partial, by H. N. Stokes, record 
No. 1503. Titanium present, alkalies undetermined. Analyses made 
on ignited material, reckoned as 100. The loss on ignition is separately 
stated below each analysis. 
SiO, 
MgO 
CaO. 
Ignition 
J. 
K. 
L. 
M. 
86. 58 
78.07 
76. 96 
61.98 
12.72 
20.22 
20.77 
37. 51 
.45 
.89 
1.11 
.45 
.11 
.26 
.32 
.09 
.11 
.71 
.19 
99.44 
98.97 
99.87 
100. 22 
4.75 
7.51 
7.98 
12.51 
N. 
93. 11 
5. 56 
1.15 
.10 
.32 
100. 24 
4.45 
SiO, 
MgO. 
CaO. 
Ignition 
0. 
p. 
Q. 
85.98 
85.25 
54.93 
13.67 
11.45 
43.65 
.41 
2.24 
.69 
.21 
.26 
.05 
.64 
.21 
100. 27 
99.41 
99.96 
5.07 
4.81 
16.80 
58. 56 
39. 17 
.55 
.45 
1.08 
99.81 
19.58 
S. Loess-like alluvium, Golden, Jefferson County. 
T. Fire clay, Golden, Jefferson County. 
Analyses S and T made by W. F. Hillebrand in the Denver labora- 
tory. 
Si0 2 
ALA 
Fe 2 3 
MgO 
CaO 
Na 2 
K 2 
H 2 0+ organic matter 
PA 
99.98 
72.31 
50.35 
12.66 
34.44 
4.67 
.75 
.94 
trace 
1.15 
2.47 
.10 
3.75 
.48 
1.80 
13.88 
.23 
100. 00 
