nian of the Lake Superior region, though they may represent an erosion period between Upper Huronian and Keweenawan (Van Hise). Around this old island the Cambrian seas made their deposits, and in wider circles the later Ordovician and Silurian beds were laid down, until the Devonian shore line lay roughly from Saint Louis along the Missouri River to Jefferson and on to Sedalia, and thence south into Arkansas. There are scant deposits of the Devonian age, and the Carboniferous seas and later marshes had about the same margin, leaving the area to the north and west of the line described as an outcrop of the coal measures. From a period late in the Carboniferous time, the whole State seems to have remained above the sea continuously to the present time.
Soil. Over all of the glaciated area and for some miles south of the Missouri River, the surface is covered with loess, which caps the bluffs and the country adjacent with a coating many feet in thickness, furnishing a soil of great fertility. The soils of the State outside of the glaciated area are largely residual, their quality determined by the character of the country rock and its slopes. The hard ridges have a thin soil, unsuitable for agriculture; but the inner low lands, on the softer limestone, and the flood plains of the rivers, have a soil of great fertility.
Forests. The State north of the Missouri River is essentially a rolling prairie with timber lands mostly restricted to the river valleys. The woodland of the State, including stump land, in 1899 occupied 41,000 square miles, or 60 per cent. of the entire area. The State south of the Missouri River is normally a forest area, thinning out westward, being occupied most largely by mixed hard woods, cypress dominating in the Mississippi bottom lands at the southeast.
For Fauna, see paragraph under United States.
Mineral Resources and Mining. The principal 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 confined to the Galena-Joplin District, covering about a dozen counties in the southwestern corner of the State, and extending westward into Kansas. Lead is also found in a large area about Jefferson City, and in another about the old lands of the Pilot Knob region. The lead ores are galena and lead carbonate; the zinc ores are calamine and smithsonite. They all occur in the joints 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 evidence, however, suggesting a deep-seated source in volcanic rocks.
The output of zinc rose from 2500 short tons in 1882 to 19,533 short tons in 1898, but it fell to 13,083 in 1901. Missouri is the third zinc-producing State, being exceeded by Kansas and Illinois. 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 20,000 short tons, and the total value of the zinc and lead output of the State for that year was nearly $7,000,000. Missouri is believed to have considerable coal deposits, but its output is kept within narrow limits by the competition of neighboring coal fields. The coal output shows an increase from 784,000 short tons in 1873 to 3,802,088 in 1901. The product is used principally for local consumption. The output of iron, gold, and manganese is insignificant, but during the third quarter of the nineteenth century the deposits of Iron Mountain (q.v.) were famous for their large output of hematitic ore, which has up to the present amounted to 5,000,000 tons. Limestone was obtained in 1901 to the value of $1,362,272, and the products of clay (chiefly brick and tiles) in the same year were worth $4,474,553.
Agriculture. Agriculture is the leading industry. In 1900, 33,997,873 acres, or 77.3 per cent. of the total area, was included in farms. In every decade from 1850 to 1900 there was a decided gain in the farm acreage, the increase since 1860 being wholly in the acreage of improved land, which in 1900 amounted to 67.4 per cent. of the total farm area. The average size of farms decreased from 215.4 acres in 1860 to 119.3 in 1900. In the latter year 31.1 per cent. of the farm acreage was included in farms ranging in size from 100 to 174 acres. The per cent. of farms rented was slightly greater in 1900 than in the preceding census years, the farms leased on the share system being 19.5 per cent. of all farms, and those rented for cash 11 per cent. The crop production is characterized by the great attention given to corn, which constitutes over 71 per cent. of the total cereal crop, and places Missouri among the leading corn States. The area devoted to corn increased continuously from 1870, the increase in the acreage during the decade 1890-1900 being 22.3 per cent. Wheat is the next most important of the cereals. Its production had increased steadily until about 1880, but since then the acreage has remained almost stationary. The acreage of oats continued to gain until 1890, but in the following decade it decreased 45.4 per cent. The production of rye decreased over one-half between 1880 and 1900, while barley and buckwheat have become quite unimportant. A largely increasing acreage is devoted to hay and forage, which together rank next to corn in area. A great deal of flax is raised near the western border of the State south of the Missouri River, and the acreage devoted to this crop increased 78.9 per cent. between 1890 and 1900. In the lowlands in the southeast corner of the State cotton is the leading crop. Potatoes and sorghum cane are grown throughout Missouri. The State ranks third in the production of watermelons, and is prominent also in the production of tomatoes, cabbages, and other vegetables. The tobacco crop has decreased every decade since 1860, and between 1890 and 1900 it decreased 61.6 per cent. Broom corn and castor beans receive some attention. Both small fruits and orchard fruits are grown in abundance. In 1900, 7494 acres were devoted to strawberries alone. In the same year there were over 20,000,000 apple trees, these constituting 75.2 per cent. of the total number of fruit trees and exceeding the number in every other State. Between 1890 and 1900 the number of apple trees increased 145.0 per cent., peach trees 127.9 per cent., and most other varieties a still greater per cent. The gain in apple and peach culture was greatest in the southwestern corner of the State. The following table of acreages is self-explanatory:
