CLARKE.] 
IGNEOUS AND CRYSTALLINE ROCKS. 
199 
2. BRADSHAW MOUNTAINS QUADRANGLE. 
Analyses by George Steiger, record No. 1996, hitherto unpublished. 
Petrographic data furnished by C. Palache. 
A. Quartz-monzonite porphyry, Battle Flat. TonaJo.se. Contains 
quartz, orthoclase, oligoclase, green hornblende, and a little apatite 
and magnetite, with much secondary chlorite and calcite. 
B. Camptonite, Crazy Basin, 2 miles east of Alexandra. Shoshonose. 
Contains brown hornblende, augite, biotite, feldspar, magnetite, and 
apatite. The feldspar is apparently about equally orthoclase and 
andesine, but largely altered to sericite and calcite. 
C. Basalt, facies of tract^dolerite, headwaters of Little Ash Creek. 
Auvergnose. Contains labradorite, violet augite, olivine, magnetite, 
and abundant apatite, with secondary serpentine. 
D. Trachydolerite, headwaters of Little Ash Creek. Akerose. 
Contains oligoclase, augite, a little orthoclase and nephelite, aegirite, 
olivine, and abundant magnetite and apatite. 
E. Zoisite-hornblende-diorite, head of Yava Wash. Kedabekast . 
Contains zoisite, about 17 per cent; actinolite, 17 per cent; quartz, 
orthoclase, albite, chlorite, kaolin, and magnetite. 
Si0 2 
A1 2 3 
Fe,() : , 
FeO 
MgO 
CaO 
Na 2 
K 2 
H 2 0at 105°... 
H 2 above 105 
Ti0 2 
C0 2 
PA 
Mn( > 
A. 
B. 
c. 
D. 
60. 39 
43. 68 
46. 74 
52. 06 
13.94 
16. 91 
16. 96 
15.52 
4.07 
5. 06 
6.44 
5. 49 
2.91 
4.01 
4.13 
7.06 
2.39 
4.76 
6.18 
2.23 
5.17 
8.07 
11. 90 
5.46 
2.68 
2.37 
3.13 
5. 24 
1.88 
4.44 
.50 
2.24 
1.11 
1.95 
1.24 
1.00 
2.76 
3. 39 
.89 
.59 
.41 
1.24 
1.04 
2.41 
2.10 
3. 13 
.58 
none 
.07 
.72 
.56 
.32 
.08 
.07 
.23 
.12 
99.96 
99.80 
100. 52 
99. 74 
E. 
45. 73 
19. 45 
5. 28 
3. 18 
6. 24 
13.86 
.64 
.32 
1.57 
3. 56 
.23 
.28 
trace 
none 
100. 34 
