UNITED STATES OF AMERICA 



5955 



UNITED STATES OF AMERICA 



sea, is worked in a zone extending from New 

 York through Michigan and Iowa to Kansas. 

 See FERTILIZER. 



Metals. Next to stone the metals were doubt- 

 less the earliest minerals used by man. Stone, 

 copper and iron have successively formed the 

 mechanical basis of civilization, and have given 

 their names to the ages of Stone, Bronze and 

 Iron. Gold and silver, which early attracted 

 ntion by their color and luster, have long 

 been called the precious metals, but in their 

 importance to mankind these are insignificant 

 compared to the great industrial metals, iron, 

 copper, zinc, tin and aluminum. Some gold has 

 been produced in the Appalachian highlands, 

 especially in North Carolina and in Georgia, 

 where the gold fields had their day of excite- 

 ment before the great rush to California in 

 1849, but these are deposits of slight impor- 

 tance. The gold-bearing gravels, forming a 

 belt twenty to sixty miles wide along the west- 

 ern foothills of the Sierra Nevada Mountains, 

 were originally panned by hand. Later came 

 hydraulic mining, which was finally checked by 

 law because it filled up rivers and damaged 

 agricultural lands in the lower valleys by wash- 

 ing huge amounts of sand down the rivers, 

 gold dredges run by electricity are work- 

 ing over these gravels again for a third time. 

 For many years, however, the largest output of 

 gold has been from the vein mines. 



Most of the states in the Cordilleran high- 

 land have now become producers of gold, espe- 

 cially Colorado, Nevada and the Black Hills 

 district in South Dakota. Mercury is indispen- 

 sable in the process of separating gold from its 

 ores, as well as in scientific instruments. The 

 principal mines in the United States are in Cali- 

 fornia. Silver is produced more than ten times 

 as abundantly as gold, but the total value of 

 the annual output is less than that of gold, be- 

 cause of the lower price per ounce, the ratio 

 being at current prices from 1 to 25 to 1 to 30, 

 or thereabouts. The principal Mlvor producing 

 states are Nevada, Montana and Utah. 



Of the industrial materials, iron is vastly the 

 most important, since no other material is 

 adapted to use in fine tools and power machin- 

 ery for cither manufacturing or transportation. 

 Iron ore is widely distributed in the Un 

 States, though the districts where it is found in 

 sufficient quantities for mining are not very nu- 

 merous. During colonial days some ores were 

 worked in the Northern Appalachian highlands, 

 and during the early part of t i --nth cen- 



tury the iron ores around Lake Champlain 



were used. Later the principal sources of sup- 

 ply were found in Pennsylvania and Ohio, while 

 at the present time by far the largest output 

 of iron is in the Lake Superior highland, espe- 

 cially in Minnesota. Next to this Lake Supe- 

 rior district comes the southern district, the 

 most productive mines being around Birming- 

 ham, Alabama. In the Cordilleran highland 

 there are said to be many deposits of iron ore, 

 of which only a few are worked, owing in part 

 to the lack of coal in the vicinity. 



Next to iron, the most important industrial 

 material is copper, largely because it is so 

 tensively used in electrical machinery. Among 

 all the nations of the world the United States 

 has the largest output of copper, as it has of 

 iron. One important production district is the 

 point jutting out from the south into Lake Su- 

 perior. For many years this held first place in 

 the production of copper, but recently the larg- 

 est output has been in the Cordilleran highlands, 

 especially in Arizona and Montana. Michigan 

 now follows these two states in production. 

 Zinc and lead frequently occur in the same de- 

 posits and are used to some extent for the 

 same purposes, as in the preparation of paints, 

 although each has separate uses as well. 



Zinc is produced to some extent in the Ap- 

 palachian highlands, especially in New Jersey 

 and in portions of Virginia and Tennessee. A 

 second zinc district comprises portions of Wis- 

 consin, Illinois and Iowa, where the three states 

 meet, while a third is found in the Ozark re- 

 gion of Missouri and Kansas, which in 1912 had 

 the largest output of zinc. In the Cordilleran 

 highland, the principal output of line is in 

 Colorado, which produces somewhat leas than 

 New Jersey. 



Lead is mined in nearly the same regions, 

 though the output in the Appalachian high- 

 land is less important. Missouri holds first 

 rank in the output of both lead and line, with 

 Idaho, and Utah next in had In the Cordil- 

 leran region lead is in part a by-product of 

 M!VIT, being obtained from the same ore. 



Tin is the one great industrial metal not 

 obtained in the United States in large quant i- 

 al though small deposits have been lo- 

 cated in North Carolina, Texas, California, 

 ill.- !; . H and in Alaska. The 



world's largest producer of tin for many years 

 was Wales, but the southwestern tip of Eng- 

 land (Cornwall) now leads. 



-a\ Fuel*. Next to the great industrial 

 metals the most important to mankind of all 

 mineral resources are the mineral fuels, in- 



