210 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. [bull. 168. 
O. Feldspathic mica-schist, Chowchilla River. See 17th Ann., Part 
I, p. 691. Contains quartz, feldspar, biotite, muscovite, apatite, and 
specular iron. Analysis by W. F. Hillebrand, record No. 1461. P. 
R. C. 744. 
P. Andalusite-hornfels, Yaqui Gulch. Principally quartz, andalu- 
site, brown and white mica, black graphite-like grains, a little iron 
ore, and probably feldspar. Analysis by George Steiger, record No. 
1643. Described by Turner in Bull. 150, p. 342. P. R. C. 135. 
Q. Andalusite-schist, Chowchilla River. See 17th Ann., Part I, p. 
691. Contains quartz, biotite, andalusite, sericite, a little muscovite, 
probably graphite, iron ore, a few garnets, and apparently chlorite. 
Analysis by Hillebrand, No. 1461. P. R. C. 743. 
R. Chiastolite-schist, Yaqui Gulch. Contains chiastolite, sillima- 
nite, brown mica, sericite ( ?), probably graphite, and clear grains which 
appear to be quartz and feldspar. Analysis by Steiger, No. 1643. 
Described by Turner in Bull. 150, p. 342. P. R. C. 135. 
S. Hornf els, Agua Fria Creek. See 17th Ann. , Part I, p. 691. Con- 
tains quartz, brown mica, iron ore, and plagioclase. Analysis by 
Hillebrand, No. 1461. P. R. C. 747. 
Si0 2 .. 
A1A- 
Fe 2 3 
FeO.. 
MgO. 
CaO.. 
Na 2 0. 
K 9 0.. 
H 2 above 110 c 
Ti0 2 
PA 
MnO 
SrO 
BaO 
Li 2 
so 3 
CI 
F 
c 
Less 
70.40 
14.70 
.65 
2.57 
1.47 
1.63 
3.17 
3.46 
.19 
.91 
.51 
.05 
.08 
trace 
.09 
trace 
.15 
100. 03 
65.10 
17.77 
1.95 
3.29 
1.43 
1.38 
2.25 
2.45 
.47 
2.49 
.72 
.14 
none 
none 
none 
none 
.03 
trace 
.12 
1.21 
100. 80 
.06 
100. 74 
64.28 
17.28 
1.10 
5.34 
2.57 
1.19 
.91 
2.93 
.20 
2.72 
.65 
.27 
.09 
trace 
.10 
trace 
.43 
100. 06 
62.15 
19.34 
4.23 
2.25 
1.88 
1.50 
1.60 
3.07 
.19 
1.79 
.80 
.15 
trace 
none 
.04 
none 
.13 
none 
.22 
1.12 
100. 55 
.10 
100. 45 
14.03 
.46 
4.68 
2. 23 
3.89 
2. 29 
3.35 
.08 
.98 
.57 
.21 
.04 
trace 
.08 
trace 
100. 16 
