9. AMADOR COUNTY.

Rocks collected by H. W. Turner, and analyses published in 14th Ann., p. 441, and 17th Ann., Part I, p. 521. Additional data supplied by Turner. Analyses by W. F. Hillebrand, record Nos. 1432, 1456, and 1597.

A. Rhyolite, south point of Buena Vista Peak. Contains sanidine, quartz, and biotite in a glassy groundmass. P. R. C. 729.

B. Quartz-monzonitę, north fork of Mokelumne River. Contains plagioclase, microcline, quartz, abundant biotite, iron ore, sphene, apatite, and perhaps rutile. P. R. C. 770.

C. Quartz-monzonite, north fork of the Mokelumne River. Like B. P. R. C. 765.

D. Quartz-porphyrite-schist, 24 miles southeast of Buena Vista Peak. Contains porphyritic quartz and hornblende, also calcite and other carbonates. See 14th Ann. P. R. C. 723.

E. Quartz-diorite-gneiss, north fork of Mokelumne River. Contains plagioclase, hornblende, quartz, brown mica, accessory biotite, and iron oxide. P. R. C. 764.

F. Diorite-porphyry, north fork of Mokelumne River. Contains plagioclase, brown hornblende, epidote, and a little sulphide of iron and chlorite. P. R. C. 769.

G. Diorite, north fork of Mokelumne River. Contains quartz, feldspar, 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.

K. Wollastonite-gneiss, north fork of Mokelumne River. Mainly wollastonite, but garnet, quartz, and sphene are also present. P. R. C. 766.

L. Melaphyr-tuff, altered basalt, west of Jackson. Contains augite and plagioclase, with secondary quartz, chlorite, and chrysotile. Originally glassy in part, but devitrified. See 14th Ann. P. R. C. 722.

M. Reddish-brown mica separated from pyroxenic-gneiss, north fork of Mokelumne River, about 1 kilometer above mouth of Bear River. Described by Turner in Amer. Journ. Sci., 4th series, vol. 7, p. 294. Analysis by William Valentine, record No. 1736.

10. CALAVERAS COUNTY.

Rocks collected by H. W. Turner, and described in 14th Ann., p. 441. Additional data supplied by Turner relative to analysis B. Analyses by W. F. Hillebrand, record No. 1432.

A. Meta-dacite, 14 miles southeast of Milton. Contains quartz, feldspar, and hornblende. P. R. C. 777.

B. Meta-dacite, 1 miles northeast of Milton. Contains feldspar, quartz, epidote, chlorite, and iron ore, in a groundmass made up probably of feldspar and quartz. P. R. C. 752.

C. Meta-andesite, 14 miles northward from Jenny Lind. Contains quartz, plagioclase, epidote, and chlorite derived from augite.

Rocks collected by H. W. Turner, and partly described in his papers in the 14th and 17th Annuals. The latites were named and described by Ransome in Bull. 89. Some additional data have been furnished by Turner.

A. Soda-syenite-porphyry, dike east of Moccasin Creek. Consists mainly of albite, with a greenish mineral which is probably ægirite. Analysis by H. N. Stokes, record No. 1563. P. R. C. 773.

B. Augite-syenite, dike on Turnback Creek, about 1 mile north of Carter post-office. Hitherto unpublished. Contains orthoclase and augite, with less plagioclase and quartz. Analysis by Stokes, No. 1642.

C. Diorite, dike 14 miles southeasterly from Sonora. Contains feldspar largely altered to hornblende. A few black grains are probably iron ore. Analysis by W. F. Hillebrand, record No. 1548. P. R. C. 759.

D. Quartz-pyroxene-diorite, large area east of Sonora. Contains plagioclase, quartz, biotite, augite, rhombic pyroxene, and a trace of iron ore. Analysis by Hillebrand, No. 1548. P. R. C. 760.

E. Diorite, dike about 1 miles southeasterly from Sonora. Contains altered plagioclase and hornblende, with epidote, chlorite, and iron disulphide as secondary products. Analysis by Hillebrand, No. 1548. P. R. C. 761.