CLARKE.] 
IGNEOUS AND CRYSTALLINE ROCKS. 
201 
G. Diorite, north fork of Mokelumne River. Contains quartz, feld- 
spar, biotite, sphene, epidote, and secondary chlorite. P. R. C. 771. 
H. Diorite, north fork of Mokelumne River. Contains plagioclase. 
quartz, hornblende, biotite, apatite, iron ore, epidote, and chlorite, 
P. R. C. 772. 
I. Plagioclase-gneiss, north fork of Mokelumne River. Contains 
plagioclase, hornblende, biotite, and apatite. P. R. C. 768. 
J. Plagioclase-gneiss, north fork of Mokelumne River. Contains 
plagioclase, hornblende, brown mica, apatite, epidote, and grains of 
iron ore. P. R. C. 767. 
G. 
H. 
i. 
j. 
Si0 2 
69.66 
17.57 
.21 
1.04 
.58 
4.54 
4.91 
.71 
.05 
.50 
.21 
.03 
55. 86 
19.30 
.91 
4.78 
2.94 
7.31 
3. 52 
1.52 
.19 
1.23 
1.20 
.38 
52. 21 
18.79 
2.71 
5. 30 
5.11 
8.01 
3. 31 
1.60 
.12 
1.35 
1 . 16 
. 36 
46. (53 
19.47 
3.. 26 
(i. 6:; 
5. 37 
9.15 
3.19 
1.55 
.10 
1.61 
1.82 
.66 
.02 
.02 
.21 
.06 
.14 
trace 
none 
.19 
A1 2 3 
Fe 2 3 
FeO 
MgO 
CaO 
Na 2 
K 2 
H 2 0at 110° 
H 2 above 110° 
Ti0 2 
P 2 (X 
V 9 0o 
NiO 
none 
trace 
.05 
.03 
none 
none 
trace? 
trace 
.16 
.04 
.13 
trace 
none 
.39 
trace 
.06 
MnO 
SrO 
BaO 
.08 
trace 
none 
.06 
Li 2 
C0 2 
FeS 2 
1 
100. 09 
99.86 
100. 23 
100. 08 
