MINERAL AND :\ IINING. The cipal mineral deposits of Missouri are zinc and lead. These minerals, usually occurring together, are confined to the area south 'of the Missouri River and the zinc is (ginlined to the Galena-Jop lin District, covering about a dozen counties in the southwestern corner of the State. and extend ing into Kansas. Lead is also found in a large area about Jefferson City, and in an other about old lands of the Pilot Knob re gion. The lead ores are galena and lead carbo nate; the zinc ores are calamine and smithsonite. They all occur in the joint; of limestone rocks, chiefly of the Cambrian system. and in cavities where the limestone has been dissolved out. The origin of the metals is in doubt, with some evi dence, however, suggesting a decp•seated source in volcanic rocks.
The output of zinc rose from 2500 short tons in 1882 to 19,533 short tons in 189s, but it 13sei3 in IDOL the third zine.producing State, being exceeded by Kansas and Illinris. The zinc is largely smelted in the gas belt of Kansas, and from there transported to the Gulf ports. The output of lead ore in
1901 was over 29.000 short tons, and the total valne of the zinc and lead output of the State for that year was nearly 87.00.090. Missouri is believed to have considerable eonl deposits, lint its output is kept within narrow limits by the competition of neighboring coal fields. The coal output shows an increase from 784.01I11 short tons in 1873 to 3.802,08.8 in 1901. The product is used principally for local consumption. The output of iron, gold, and manganese is insig nificant, but during the third quarter of the nine teenth century the deposits of Iron :\lountain 1(1.v.) were famous for their large output of hematitic ore, which has up to the present amounted to 5.000,000 tons. Limestone was ob tained in 1901 to the value of $1,302.272. and the products of clay (chiefly brick and tiles) in the same year were worth