K) ECONOMIC GEOLOGY OF SILVERTON QUADRANGLE. prou,. 183. 
COMSTOCK, T. B. The distribution of San Juan County ores: Eng. 
and Min. Jour., Vols. XXXVIII and XXXIX, 1884-85. 
A series of brief papers. 
Hillebrand, W. F. Miscellaneous mineral notes: Bull. II. S. Geol. 
Survey No. 20, 1885, pp. 89-99. 
Describes kaolinite from National Belle mine and zinkenite from Brobdignag 
mine, on Red Mountain Range, near Chattanooga. 
Hillebrand, W. F. New mineral species from Colorado: Bull. 
IT. S. Geol. Survey No. 20, 1885, pp. 100-107. 
Describes zunyite and guitermanite from the Zuiii mine, Anvil Mountain, near 
Silverton. 
Emmons, S. F. Geological sketch of the Rocky Mountain division: 
Tenth Census, Vol. XIII (Precious Metals), 1885, pp. 82-85. 
A general sketch of the San Juan region by counties. A table of mines, giving 
country rock, dip, and strike of vein and ore minerals. 
Emmons, S. F. Notes on some Colorado ore deposits: Proc. Colo. 
Sci. Soc, Vol. II, 1885-1887, pp. 85-105. 
San Juan region an excellent field for the study of f ssure deposits. Points out 
that so-called "geyser mounds" of the Red Mountain district are merely masses 
of country rock bleached and altered by solfataric action. 
Emmons, S. F. On the origin of fissure veins: Proc. Colo. Sci. Soc, 
Vol. II, 1885-1887, p. 207. 
Ascribes shape of Yankee Girl ore body to the formation of a shattered zone at 
intersection of three or more fissure planes. 
Comstock, T. B. The metallurgy of San Juan County ores: Eng. 
and Min. Jour., Vol. XXXIX, 1885, pp. 00-71; also Vols. XLI 
and XLII, 1886. 
A series of brief papers dealing chiefly with causes of failure of various 
smelters. 
Ihlseng, M. C. Review of mining interests of the San Juan 
region: Colo. State School of Mines, annual report of field work 
and analyses, 1886, pp. 19-63. 
General notes on the mines. 
Comstock, T. B. The geology and vein structure of southwestern 
Colorado: Trans. Am. Inst. Min. Eng., Vol. XV, L886-87, pp. 
218-265. 
Advances speculative views as to the origin of the ore deposits and divides th e 
veins into groups. The Red Mountain deposits are supposed to occupy the 
throats of extmct geysers and the bowls of nonsintering hot springs. 
Lakes, A. Geology of the Colorado ore deposits: Ann. Kept. State 
School of Mines, 1887, pp. i-clix. 
Contains scattered and unimportant references to veins of the San Juan Moun- 
tains. 
REUSCH, II. Krystallizirter Kaolin von Denver in Colorado: Neues 
Jahrbuch fiir Mineralogie, etc., 1887, II, pp. 70-72. 
Description and chemical analysis of kaolin from National Belle mine, Red 
Mountain. 
