CLARKE.] 
IGNEOUS AND CKYSTALLINE ROCKS. 
123 
Q. Mica-dacite-porphyry, Bunsen Peak. Lassenose. Analysis by 
Whitfield, No. 419, hitherto unpublished. Reported by Iddings as 
containing- olig-oclase-andesine, quartz, biotite, little magnetite, apatite, 
and zircon. 
R, Mica-dacite-porphyry, Birch Hills. Lassenose. Like Q in com- 
position. Analysis by Whitfield, No. 718, hitherto unpublished. 
S. Hornblende-mica-andesite-porphyry, Fan Creek. Yellow stonose. 
Analysis by Whitefield, No. 713, hitherto unpublished. Reported by 
Iddings as containing- andesine-olig-oclase, hornblende, and biotite in a 
groundmass of feldspar (probably oligoclase and orthoclase), with a 
little magnetite, biotite, and hornblende. 
T. Hornblende-mica-andesite-porphyry, Gray Peak. Lassenose. 
Analysis by Whitfield, No. 715, hitherto unpublished. Composition 
similar to that of S. 
Si0 2 . 
ALA 
Fe 2 3 
FeO. 
MgO 
CaO. 
Na 2 
KA 
HA 
Ti0 2 . 
PA- 
MnO 
Li 2 0. 
so 3 . 
CL.. 
co 2 . 
70.52 
15.85 
2.28 
.36 
.09 
2.59 
3.93 
3.43 
.35 
trace 
.17 
.09 
trace 
.29 
99. 95 
70.24 
17. 36 
1.38 
.79 
.53 
2.74 
3.69 
2.65 
.71 
trace 
trace 
none 
none 
trace 
none 
none 
100. 09 
65. 63 
17.00 
2.55 
1.19 
2.03 
3.48 
4.42 
1.64 
2.00 
trace 
.07 
none 
.04 
trace 
trace 
97 
65. 64 
17.29 
3.07 
1.29 
1.78 
1.98 
5.77 
2.44 
1.03 
none 
.23 
trace 
.04 
trace 
trace 
.17 
100. 32 
100. 73 
