IGNEOUS AND CRYSTALLINE ROCKS. 157 
12. MARIPOSA COUNTY. 
Rocks collected by H. W. Turner, and partly described in his papers in 14th and 
17th Ann. Additional data supplied by Turner. 
A. Soda granulite or aplite, about 4 miles west of Mariposa. Mariposose. See 
17th Ann., pt. 1, p. 721. Contains plagioclase (albite?) and micropegmatite, with 
less epidote, quartz, sphene, and apatite. Analyses by W. F. Hillebrand, record 
No. 1461. P.R. C. 748. 
B. Micropegmatite, Agua Fria Creek. Lassenose. See 17th Ann., pt. 1, p. 691. 
Contains quartz, plagioclase, brown mica, epidote, and a little iron ore. Analysis by 
Hillebrand, No. 1461. P.R. C. 746. 
C. Soda granite porphyry, Merced River, below the mouth of the north fork. Las- 
senose. Published in 17th Ann. Contains feldspar, largely albite, hornblende, 
muscovite, abundant epidote, apatite, and a little iron ore. Analysis by George 
Steiger, record No. 1573. P. R. C. 774. 
D. Granite porphyry, about one-fourth of a mile north of Lake Tenaya, Yosemite 
National Park. Toscanose. See 14th and 17th Ann. Contains orthoclase, quartz, 
plagioclase, and biotite, with a little iron ore and sphene: Analysis by Hillebrand, 
record No. 1432. P. R. C. 726. 
E. Granite, west of Lake Tenaya, Yosemite National Park. Lassenose. See 14th 
and 17th Ann. Contains quartz, orthoclase, plagioclase, and biotite, with some 
hornblende, iron ore, sphene, and apatite. Analysis by Hillebrand, No. 1432. 
P.R. C. 725. 
A B C. D E 
SiO pie Saree adgee ih steelededne: centre oe es oer deat aeccceee 74.21 | 73.18] 71.88 | 72.48! 66.28 
AMO sh ece acmeccenans aca a cee eke eee eee eene eae 14.27 | 13.66| 15.57} 14.06] 16.03 
Fe,03 21 | 1.07 89} 1.80 
FeO. 2.24] 130] 105] 1/88 
MgO 293 | .68 62} 1.12 
CaO. 210! 203] 217) 3.75 
Na,O 3.70] 5.81] 3.30} 4.10 
K : 3.49 
2 
20 at 110° 
F. Amphibole-biotite granite, Nevada Falls trail, Yosemite Valley. Toscanose. 
Contains alkali feldspar, plagioclase, quartz, amphibole, biotite, magnetite, and 
apatite. 
G. Biotite granite, base of El Capitan, Yosemite Valley. Toscanose. Contains 
alkali feldspar, plagioclase, quartz, biotite, titanite, apatite, and iron oxides. 
H. Brown mica separated from G. 
Analyses F, G, and H by William Valentine, record Nos. 1732, 1733. 
Samples G and H are described by Turner in Am. Jour. Sci., 4th ser., vol. 7, p. 294. 
