140 ANALYSES OF ROCKS AND MINERALS, 1880-1908. 
F. Dacite, east end of Chaos, northwest base of Lassen Peak. Lassenose. The 
youngest dacite of the region. Contains quartz, feldspar, biotite, and hornblende, 
embedded in a clear pumiceous glass. Analysis by W. F. Hillebrand, record No. 
670. Described by Diller in Bull. 150, p. 218. P. R. C. 1430. 
G. Secretion in F. Hessose. Consists chiefly of plagioclase and hornblende, with 
some olivine and clear glass. Analysis by Hillebrand, No. 671. P. R. C. 1431. 
H. Dacite (?), west side of old crater rim near the Thumb, at the head of Mill Creek, 
Shasta County. Yellowstonose. Shows phenocrysts of hornblende, plagioclase, and 
pyroxene, and apparently of quartz, in a gray, microlitic groundmass. Analysis by 
Hillebrand, No. 674. P.R. C. 1432. 
I. Streaked dacite, falls of south fork of Bear Creek, Shasta County. Lassenose. 
Contains plagioclase with a little sanidine, hornblende, quartz, magnetite, some 
pyroxene inclusions, and glass base. Analysis by R. B. Riggs, record No. 524. 
P.R.C. 80. Described by Diller in Bull. 150, p. 213. ' 
J. Dacite tuff, Rice’s quarry, 6 miles southeast of Paskenta, Tehama County. Clear 
glass, with fragments of quartz, feldspar, and hornblende. Analysis by George Steiger, 
record No. 1427. P. R. C. 1433. 
J 2. Another sample of J. Analysis by E. T. Allen, record No. 2020. See Diller, 
Am. Jour. Sci., 4th ser., vol. 15, p. 360. P. R. C. 1434. 
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K. Pyroxene andesite, west end of Butte Mountain, Plumas County. Hessose. 
Prominent phenocrysts of pyroxene and minute ones of plagioclase, in a dark ground- 
mass containing much globulitic matter. Analysis by W. F. Hillebrand, record 
No. 411. P. R. C. 1435. 
L. Pyroxene andesite, south base of Burney Butte, Shasta County. Tonalose. 
Numerous small phenocrysts of plagioclase and a few of pyroxene, in a gray ground- 
mass containing much amorphous matter. Analysis by R. B. Riggs, record No. 684. 
P. RB. C. 1436. 
M. Hornblende andesite, Tuscan Buttes, 7 miles east of Red Bluff. Tonalose. A few 
small phenocrysts or fragments of hornblende, in a groundmass consisting mainly of 
plagioclaseand gray microlitic matter. Analysis by Hillebrand, No. 412. P.R.C. 1437. 
N. Hornblende andesite, near Buntingville, Lassen County. Lassenose. A few 
phenocrysts of hornblende, in a groundmass consisting mainly of small feldspars. 
Analysis by T. M. Chatard, record No. 413. P. R. C. 1438. 
O. Hornblende andesite, northwest summit, head of Burney Creek, Shasta County. 
Tonalose. Inconspicuous plagioclase and, rarely, olivine, in a groundmass of 
plagioclase and pyroxene. Numerous dark spots are due to altered hornblende. 
Analysis by Riggs, No. 683. P. R. ©. 1439. 
Rocks in this group dried at 105° before analysis. 
