LARKE.] 
IGNEOUS AND CRYSTALLINE ROCKS. 
175 
2. ROCKS FROM EUREKA. 
Described by Hague and Iddings, Mori. XX. 
A. Basalt, summit of Richmond Mountain. Red, porous. Contains 
Aigite, less hypersthene, feldspars, and magnetite, in a glassy base, 
nth accessoiy olivine and quartz. Analysis by J. E. Whitfield, record 
jfo. 424. 
B. Andesitic perlite, south of Carbon Ridge. Contains plagioclase, 
Lornblende, biotite, quartz, hypersthene, augite, magnetite, apatite, 
,nd zircon, with a glassy base. Analysis by W. H. Melville, record 
to. 1240. 
2^3- 
Si0 2 
A1 ? 
Fe 2 . 
FeO. 
MgO 
CaO.. 
Na^O 
K,0. 
H 2 Oatl05°... 
H 2 above 105 c 
TiO a 
PA 
NiO 
MnO 
Li 2 
so, 
50. 38 
19.83 
6.05 
2.00 
5.36 
10.03 
2.15 
1.76 
1.37 
none 
none 
.38 
trace 
.83 
100. 14 
65.13 
15. 73 
2.24 
1.86 
1.49 
3.62 
2.93 
3.96 
.52 
1.91 
.58 
.23 
.07 
trace 
100. 2/ 
