366 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. [no. 228. 
J to K. Supposed lire clays collected in the area of the Apishapa i 
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. 
J. 
K. 
L. 
M. 
N. 
Si0 2 - - 
86.58 
12.72 
.45 
.11 
.11 
78.07 
20.22 
.89 
.26 
76. 96 
20.77 
1.11 
.32 
.71 
61.98 
37.51 
.45 
.09 
.19 
93.11 
Al.,0, 
5.56 
Fe 9 Oo - 
1.15 
MtrO 
.10 
CaO - 
.32 
Ignition 
98.97 
4.75 
99.44 
7.51 
99.87 
7. 98 
100. 22 
12.51 
100. 24 
4.45 
Sio, . 
Al,( ), 
Fe 2 3 
MgO. 
CaO . 
Ignition 
O. 
85.98 
L3.67 
.41 
21 
100. 27 
5.07 
85.25 
11.45 
2. 24 
.21 
.26 
99.41 
4.81 
Q. 
54.93 
43. 65 
.69 
.'05 
.64 
99.96 
16.80 
R. 
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 laboratory. 
s. 
T. 
Sio 
72. 31 
12.66 
4.67 
.94 
1.15 
2.47 
3.75 
1.80 
.23 
50. 35 
Al.,0, 
34.44 
Fe.,0, 
. 75 
MgO 
trace 
Ca( ) . 
Na.O 
.10 
K,()_ 
48 
ELO+ 
organic matter 
i:;. 88 
P.O. 
99.98 
100. 00 
