174 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 58 



TEXAS 



1164a. CHAUVENET, REGIS. Franklin mountain tin prospects. 



Mines and Min., Vol. 30, 1910, Scranton, pp. 529-531, figs. 3. 



Treats of the locality, extent, and geology of the deposits, also nature of ores in the 

 Franklin Mountains, near El Paso, Texas. 



1165. COMSTOCK, THEO. B. Report on the geology and mineral resources of 



the central region of Texas. 



1st Ann. Rep. Geol. Surv. Texas, 1889 (1890), Austin, p. 345. 



Author was unable, in a critical examination of more than 8000 specimens from 

 various parts of the districts, to detect presence of tin. 



1166. . Tin in Central Texas. 



2d Ann. Rep. Geol. Surv. Texas, 1890 (1891), Austin, pp. 595-602, figs. 68-69. 



Discussion of the situation, with cuts showing the geological conditions in the 

 Llano region where tin ore is said to have been found, character of ore and mode 

 of occurrence. Uncertainty of discovering the mineral in commercial quantities. 



1167. . Tin in central Texas. 



Eng. Mg. Journ., Vol. 51, 1891, New York, pp. 117-118. 



Mr. Comstock, as a member of the Geol. Surv. of Texas, tells of his discovery of 

 tin, the manner of its occurrence, and the localities. Did not find any extensive 

 deposits. 



P. 229. An addition to above article 'made by correspondent [G. A. F.], in which 

 he says two discoveries of tin in the State have been overlooked. 



P. 281. Mr. C. answers correspondent. 



1168. . Occurrence of tin in central Texas. 



Amer. Journ. Sci., Vol. 41, 1891. New Haven, p. 251. 



States that a few crystals of cassiterite have been found in Mason and Llano counties, 

 but not in commercial quantity. 



1168a. DINSMORE, CHAS. A. Development of a Texas tin mine. 



Mg. World, Vol. 31, 1909, Chicago, p. 1120. 



The tin prospect now being developed is on Mount Franklin, 16^ miles from El 

 Paso. The deposit is in a ternary granite, composed of a pink or reddish orthoclase 

 feldspar, quartz and mica; it is intersected in many places by veins of fine-grained 

 granite and pegmatite. This is overlain by rhyolite. The tin-bearing area contains 

 " true fissure veins of quartz carrying cassiterite," and of zones of impregnations in 

 the neighboring granite. The cassiterite occurs disseminated through the quartz and 

 in masses, many of which are pure enough for smelting. Associated minerals are 

 uncommon, and so far consist of hematite, pyrite, pyrrhotite, tourmaline, topaz, 

 fluorite, garnet and hornblende. Tungsten, gold, silver and copper have also been 

 found in small quantities on the property. The cassiterite is often found in very 

 beautiful twin crystals, varying in color from white to dark brown. 



1169. DUMBLE, E. T. Tin. 



2d Ann. Rep. Geol. Surv. Texas, 1890 (1891), Austin, p. LXIX. 



Found in connection with lead ores in Trans-Pecos, Texas. Dr. Comstock and party 

 found pieces of cassiterite in Burnet and Mason counties. 



1169a. LAKES, ARTHUR. A tin mine in the United States. 



Mg. Sci., Vol. 61, 1910, Denver, pp. 346-348. 



Description of tin prospect in Franklin Mountains, 10 miles north of El Paso, Texas. 

 Regis Chauvenet's article "Franklin Mountain tin prospects" in Mines and Min., 

 Vol. 30, No. 9, 1910, Scranton, pp. 529-531 is quoted in full. 



