292 ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. [no. 228. 
SANDSTONES FROM CALIFORNIA. 
1. SANDSTONES FROM MOUNT DIABLO. 
Described by Turner and Melville in Bull. Geol. Soc. Amer.,vol. 2, 
pp. 383—H4:. Analyses made by W. H. Melville in the San Francisco 
laboratory. 
A. Upper Cretaceous, Chico sandstone. Light brown, finely gran- 
ular, carrying grains of mica and feldspar. 
B. Lower Cretaceous, Neocomian sandstone. Hard, granular, green- j 
ish. From headwaters of Bagley Creek. 
C. Miocene sandstone. Granular, particles light brown and black, 
friable. From near Wall Point. 
D. Chico sandstone. Greenish gray, compact, crystalline. 
A. 
B. 
c. 
D. 
Si0 2 
73.71 
10.40 
3.89 
1.88 
1.62 
.96 
3.48 
.99 
1.06 
2.60 
none 
.17 
none 
56.84 
11.37 
1.46 
4.95 
3.10 
7.62 
3.26 
.86 
1.45 
3.34 
.10 
. 22 
5.10 
44.54 
12.63 
2.50 
3.08 
5. 55 
14.65 
3.35 
1.37 
1.43 
2.25 
.29 
.44 
7.76 
36.93 
A1 2 3 
7.22 
Fe 2 3 
1.59 
FeO 
2.95 
MgO 
2.34 
CaO 
29.34^ 
Na 2 
2.94 
K 2 
.64 
H 2 at 100° 
.57 
H 2 above 100° 
3.45 
P 2 5 
.16 
MnO 
C0 2 
.57 
«11.30 
100. 76 
99.67 
99.84 
100. 00 
«C0 2 determined by difference. 
Traces of organic matter are found in all four sandstones, but were not determined. 
