CLARKE.] 
SANDSTONES. 
245 
SANDSTONES FROM CALIFORNIA. 
1. SANDSTONES FKOM MOUNT DIABLO. 
Described by Turner and Melville in Bull. Geol. Soc. Amer., vol. 2, 
pp. 383-414. Analyses made by W. H. Melville in the San Francisco 
laboratory. 
A. Upper Cretaceous, Chico sandstone. Light brown, lincly gran- 
ular, carrying grains of mica and feldspar. 
B. Lower Cretaceous, Neocomian sandstone. Hard, granular, green- 
ish. From head waters of Bagley Creek. 
C. Miocene sandstone. Granular, particles light brown and black, 
friable. From near Wall Point. 
D. Chico sandstone. Greenish gray, compact, crystalline. 
Si0 2 ... 
A1 2 3 
Fe 2 3 
FeO 
MgO 
CaO 
Na 2 
K 2 
H 2 0at 100° 
H 2 above 100° 
PA 
MnO 
C0 2 
A. 
73.71 
10.40 
3.89 
1.88 
1.62 
.96 
3.48 
.99 
1.06 
2.60 
none 
.17 
none 
100. 76 
B. 
56.84 
11.37 
1.46 
4.95 
3.10 
7.62 
3.26 
.86 
1.45 
3.34 
.10 
. 22 
5.10 
99. 6/ 
C. 
44.54 
12.63 
2.50 
3.08 
5.55 
14.65 
3.35 
1.37 
1.43 
2.25 
.29 
.44 
7.76 
99. 84 
36.93 
7.22 
1.59 
2.95 
2.34 
29.34 
2.94 
.64 
.57 
3.45 
.16 
.57 
a 11. 30 
100. 00 
aC0 2 determined by difference. 
Traces of organic matter are found in all four sandstones, but were not determined. 
