44 TIN DEPOSITS OF THE YORK REGION, ALASKA. [no. 229. 
OCCURRENCES OF TIN ORE IN THE UNITED STATES. 
The total amount of metallic tin produced from ore mined in the 
United States has not exceeded 200 tons, though small amounts have 
been found in no less than 17 States and Territories: Alabama, Alaska, 
California, Colorado, Connecticut, Georgia, Idaho, Maine, Massachu- 
setts, Missouri, Montana, New Hampshire, North Carolina, South 
Dakota, Texas, Virginia, Wyoming. 
In Alabama, cassiterite occurs in quartz veins in graphitic schists a 
near granite, and as disseminated grains in gneiss. 
In California/' small amounts of float cassiterite have been found in 
the gold placers at a number of widely separated localities. The ore 
is found in places at the Temescal mine, 5 miles southeast of Riverside. 
At this place there is an area of hornblendic biotite-granite over 2 
miles in diameter which is cut near its borders by dikes of highly 
quartzose and feldspathic fine-grained granite. The ore occurs in 
veinlets of tourmaline and quartz aggregates which run northeast and 
southwest through the granite. A great body of such vein matter, 
covering an area 300 by 250 feet, and 25 to 30 feet high, crops out in 
the Cajalco Hill. What is known as the Cajalco vein courses north-j 
east from this outcrop, and the workings extend for 1,100 feet along it. 
The vein is sinuous, and varies from a minimum of a clay seam to a 
maximum of 8 feet. There 1 is always a clay gouge on one and often 
on both walls. Two hundred and ninety-one and fourteen one-hun- 
dredths pounds of metallic tin were produced from ore mined at 
Temescal previous to 1892, when tin 1 mines were abandoned. 
In the Carolinas a tin belt' extends in a northeast-southwest direc- 
tion for about :-U miles, and lies partly in North Carolina and partly 
in South Carolina. Tin ore is not evenly distributed through this dis- 
tance, though the tin-bearing formation, which consists of crystalline 
schists or gneisses containing pegmatitic dikes, is continuous. The 
rocks of the tin belt are very much decomposed, and the pegmatite 
dikes are very thoroughly kaolinized. The tin ore has been found 
loose in the soil, in the gravels, in bowlders of quartz and mica, and 
occasionally in the pegmatite dikes. The most promising deposit in the 
belt is at the Ross mine, near Gaffney, S. C, from which 3S,4T1 
pounds of the ore were shipped in 1903. 
In Colorado tin ore has been reported near Golden, but little is 
known of its occurrence. 
a Phillips, Wm. B., Geol. Survey of Alabama, Bull. No. 3, 1892. 
bSixth Ann. Rept. California State Min. Bureau, Sacramento, 1886. Eleventh Ann. Rept. California 
State Min. Bureau, Sacramento, 1893. Fairbanks, Harold W., Tin deposits at Temescal: Am. .lour. 
Sci., 4th ser., vol. 4. 1897, pp. 39-42. Rolker, C M., Production of tin in various parts of the world: 
Sixteenth Ann. Rept. U. S. Geol. Survey, pt. 3, 1895, p. 536. 
cThis note is furnished by Joseph Hyde Pratt in advance of Economic Paper No. 8 of the North 
Carolina Geological Survey on " Carolina tin deposits." 
