The geological history of Tennessee like that of all other 'land areas, is one of many changed conditions. At times possibly all of it was land. At others most or all of it was be neath the sea. At still others some parts were above and some beneath the sea. When above, the land was being worn away; when below, the material that forms the rocks was put down in the ocean bed, -in layers. There are long periods which are not represented by rocks anywhere in the State and others represented only in part, depending upon whether the State was all land or part land and part water. In Lower Cambrian times, the area probably was all land excepting the part covered by the val ley of East Tennessee; in Upper Cambrian, it probably was all sea; in the very long period covered by Ordovician, Silunan,. Devonian, Mississippian and Pennsylvanian times, there were many changes that brought more or less of the area, now above the sea, now beneath it. During Triassic and Jurassic and Lower Cretaceous times, the area probably was land. In Upper Cretaceous times, the western third of the State, possibly more, was beneath the sea, as was West Tennessee in Eocene times. Since Eocene times, none of the State has been submerged, excepting possibly the western part for only a relatively short time.
Mineral Resources.— Tennessee is rich in mineral resources. In the order of their im portance the 10 leading minerals are coal, cop per, zinc, iron, cement, clay, marble, phosphate, limestone and barytes. Coal is mined in the Cumberland Plateau; pig iron is produced in East Tennessee and on the western Highland Rim, in Middle Tennessee; copper, at Duck town in the southeastern corner of the State; cement, at Richard City and Kingsport; phos phate, in Middle Tennessee; sulphuric acid at Ducktown ; brick and tile, in all parts of the State; marble in East Tennessee; gas, coke and the in East Tennessee; zinc in East Tennessee. Besides these, there are at least 12 others of importance and 20 that are known to occur, though not in commercial amount. There is a large reserve of coal, iron, copper, marble, phosphate rock and zinc. Clay, cement material and many other products of lesser importance, are inexhaustible. Seven million tons of coal are mined yearly. The State produces more copper than all States east of the Rocky Mountains except Michigan. The best ball clay in America is found in inexhaustible quantities in the western portion. One million dollars worth of iron is mined yearly, with one-half billion tons in reserve. Tennessee produces more marble than any State except Vermont or Georgia. One Tennessee plant makes more lime than either North Caro lina, South Carolina, Georgia, Florida, Missis sippi, Louisiana or Kentucicy. There is more phosphate rock in Tennessee than in all States east of the Rocky Mountains together.
Forestry, Fish and Game. Forestry, The forests of Tennessee contain untold wealth in various hardwoods. Prior to 1907 but little at tention had been given to this valuable asset. The fifty-fifth general assembly enacted the first general Forestry Law (chap. 397, Acts 1907). This measure received the highest com mendation of the Forestry Department at Wash ington and has proved of inestimable benefit in checking and suppressing forest fires in the State. Under its requirernents railroad rights of way were cleaned up and thus ceased to be a constant menace to private property. Prior to 1907 a majority of the forest fires were traceable directly to these railroad rights of way which had grown up in grass and brush liable to be ignited by any passing train. Ten nessee is divided into three grand divisions: the western division largely bottom lands, the middle division uplands and the eastern division moun tain lands. The rich alluvial lands of the western division produce a heavy timber growth differing from the forests of other sections and consist mainly of oak, cottonwood, hicicory and gum. Along some of the water courses in the overflow region are found cypress trees of great value. The upland forest of the middle division consists of mixed hardwoods, largely oak. The best timber has been culled during the process of cultivation of the soil. The tree growth of value is largely to be found in woodlots, the remainder of the land being devoted to agri culture. Large bodies of timber are rare. Great diversity of tree species is found in the eastern division — the mountain region of Tennessee — due largely to differences in elevation, abundant rainfall and different exposures. Three types may be noted: ridge, slope and cove. In the first type is found chesmut, white oalc, black oak, black gum short leaf pine and black locust.
On some of the high ridges are found balsam and spruce and at lesser elevations black, red and post oak. The slope type consists largely of chestnut, oak, white, black, post oak and hickory. There is also to be found some short leaf pine, sour wood and black gum. The cove type represents the heaviest growth and great est variety. Topography and soil both favoring. Here is. found yellow poplar, basswood, mag nolias and black walnut. In addition chestnut, white oak, beech, sugar maple, hemlock, red oak and hicicory, together with a sprinkling of black birch, bitternut, locust, ash, buckeye, sour wood, elm, cherry, sassafras and sycamore. Cer tain coves contain many of the above species and others few. Forest fires prior to 1907 were very destructive but are not to be com pared to those of the Northwest. The neces sary brevity of this article leaves much of in terest unsaid.