242 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. 
[no. 228. 
I. Amphibole-picrite, near Sequoia P. O., Yosernite National Park. 
Uvaldose. Collected by Turner, but not described. Analysis by 
George Steiger, record No. 1884. 
J. Amphibole-pyroxene rock, perknite, 3 miles northeast of Coul- 
terville. SR. £ of sec. 2 of minnesotase. Described by Turner in 
Journ. Geol., vol. 9, p. 508. Analysis by George Steiger, record 
No. 1860. Contains pyroxene and amphibole, with a little quartz and 
pyrrhotite. 
K. Amphibole separated from quartz -monzonite, Tioga road, south- 
east of Mount Hoffman. Sp. gr., 3.203, 2.15°. 
L. Mica separated from the same rock as I. Sp. gr., 3.05, 21°. 
Analyses K and L by W. F. Hillebrand, record No. 1774. 
Samples K and L are described by Turner in Amer. Journ. Sci., 
4th series, vol. 7, p. 294. 
I. 
J. 
K. 
L. 
Si0 2 
43. 1 7 
11.42 
4.97 
6.36 
16. 97 
11.62 
1.11 
.10 
.22 
2.51 
1.23 
.04 
.06 
48.04 
7.82 
2. 01 
9.32 
13. 33 
13. 01 
.69 
.48 
.17 
2.90 
1.16 
trace 
.90 
.23 
47.49 
7.07 
4.88 
10.69 
13.06 
11.92 
.75 
.49 
1.86 
1.21 
none 
35.75 , 
14.70 
4.65 ' 
14.08 j 
12.37 i 
.17 
.32 
9.1S| \ 
1.03 * 
3.64 
3.1fl | 
.03 
A1 2 3 
Fe 2 3 
FeO 
MgO 
CaO 
Na 2 
K 2 
H 2 at 110° 
H 2 above 110° 
TiO, 
P 2 5 
S 
so 3 
i 
v. 2 o, 
.04 
none 
.51 
.02 
none 
none 
trace 
.05 
trace 
.45 
. 02 
.12 
(?) 
Cr 2 3 
MnO 
.14 
none 
MO, CoO 
BaO 
none 
SrO 
Li.,0 
co 2 
.71 
none 
F 
.06 
1 
.17 
Less O 
100. 63 
.03 
100. 06 
.45 
100. 05 
.02 
99. 90 
.07 
100. 60 
99.61 
100. 03 
99.83 
