CLARKE.] 
SLATES AND SHALES. 
287 
CALIFORNIA. 
Cretaceous shales from Mount Diablo. Described by Turner and 
Melville, Bull. Geol, Soc. Amer., vol. 3, pp. 383-414. Anlayses by 
W. H. Melville, made in the laboratory at San Francisco, except F 
(record No. 1166), which was done in the Washington laboratory. 
A. Brownish black, resinous. From Bagley Canyon. 
B. Slate colored, soft, friable, little altered. From near Bagley 
Creek. 
C. Same locality as B, less friable, but considerably altered. 
D. Slate colored, friable. From Arroyo del Cerro. 
E. Very friable. Same locality as D. 
A. 
B. 
c. 
D. 
E. 
Si0 2 . 
56. 66 
17.64 
.49 
5.22 
3. 50 
1.67 
2.17 
2.27 
3.01 
5.92 
.15 
53.65 
17.64 
4.06 
3.72 
5.15 
2.27 
2.53 
2.22 
3.95 
4.57 
.23 
trace 
.01 
49.14 
16.91 
4.39 
3.82 
5.43 
3.28 
4.67 
1.53 
3.39 
6.97 
.24 
trace 
.22 
25. 05 
8.28 
.27 
2.41 
2.61 
27.87 
undet. 
undet. 
1.44 
2.86 
.08 
trace 
4.11 
24.20 
40.17 
12.76 
2.10 
3.56 
15. 42 
4.24 
.57 
1.36 
9.19 
6.73 
.08 
trace 
.16 
3.48 
ALO, 
Fe 2 3 
FeO 
MgO 
CaO 
Na 2 
K 2 
H 2 at 100° 
H 2 above 100° 
PA 
NiO 
MnO 
.19 
C0 2 
so 3 
.93 
99.82 
100. 00 
99.99 
99.18 
99.82 
