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GEOGRAPHY. and perfectly flat, but it is oftener much divided into three districts, each having quite distinct sur­ of the Morristown atlas sheet are of sedimentary by streams into large or small areas with flat tops. face features. These divisions are the ridge dis­ origin that is, they were deposited by water. General relations. The area represented on In West Virginia and portions of Pennsylvania trict, the Lick Valley, and the knob belt. Beside They consist of sandstone, shale, and limestone, the Morristown atlas sheet lies entirely in Ten­ the plateau is sharply cut by streams, leaving in these, Bays Mountain, in Greene County, is the all presenting great variety in composition and nessee, and includes portions of Hancock, relief irregularly rounded knobs and ridges which southwestern end of a group of high ridges lying appearance. The materials of which they are Grainger, Hawkins, Hamblen, Jefferson, Cocke, bear but little resemblance to the original surface. chiefly in the Greeneville region. The valley composed were originally gravel, sand, and mud, and Greene counties. It is bounded by- the par­ The western portion of the plateau has been com­ south of Parrottsville and Salem, also, is part of derived from the waste of older rocks, and the allels 36° and 36° 30' and the meridians 83° and pletely removed by erosion, and the surface is the Nolichucky basin of the Greeneville area, but remains of plants and animals which lived while 83° 30', and it contains 990 square miles. now comparatively low and level, or rolling. is too small for distinction here. the strata were being laid down. Thus some of In its geographic and geologic relations this Altitude of the Appalachian province. The The ridge district, the most extensive of the the great beds of limestone were formed largely area forms a part of the Appalachian province, Appalachian province as a whole is broadly three, lies northwest of the line of the two Bays from the shells of various sea animals, and the which extends from the Atlantic coastal plain on dome-shaped, its surface rising from an altitude mountains, and consists of a series of long, par­ beds of coal are the remains of a luxuriant vegeta­ the east to the Mississippi lowlands on the west of about 500 feet along the eastern margin to the allel ridges and lines of hills separated by narrow tion, which probably covered low, swampy shores. and from central Alabama to southern New York. crest of the Appalachian Mountains, and thence valleys. Two of the valleys, passing through The rocks afford a record of sedimentation All parts of the region thus defined have a com­ descending westward to about the same altitude Mooresburg and Morristown, are broad and level, from early Cambrian through Carboniferous time. mon history, recorded in its rocks, its geologic on the Ohio and Mississippi rivers. but few of the others contain much level land. Their composition and appearance indicate at structure, and its topographic features. Only a Each division of the province shows one or The mountain ridges are long and straight, and what distance from shore and in what depth of part of this history can be read from an area so more culminating points. Thus the Appalachian vary in height from 2,000 to 2,300 feet, with a water they were deposited. Sandstones marked small as that covered by a single atlas sheet; Mountains rise gradually from less than 1,000 feet few summits attaining 2,500 and 2,700 feet; the by ripples and cross-bedded by currents, and hence it is necessary to consider the individual in Alabama to more than 6,600 feet in western lower ridges rise to 1,500 and 1,700 feet. The shales cracked by drying on mud flats, indicate sheet in its relations to the entire province. North Carolina. From this culminating point floors of the valleys range from 1,000 to 1,200 shallow water; while limestones, especially by the Subdivisions of the Appalachian province. they decrease to 4,000 or 3,000 feet in southern feet, becoming as low as 900 on the lower Hols- fossils they contain, indicate greater depth of The Appalachian province may be subdivided Virginia, rise to 4,000 feet in central Virginia, ton River. Lick Valley and its continuation, water and scarcity of sediment. The character of into three well-marked physiographic divisions, and descend to 2,000 or 1,500 feet on the Mary­ down the Nolichucky and French Broad rivers, the adjacent land is shown by the character of throughout each of which certain forces have pro­ land-Pennsylvania line. consists of flat or slightly rolling plains relieved the sediments derived from its waste. Coarse duced similar results in sedimentation, in geologic The Appalachian Valley shows a uniform by low hills and irregular knobs. The most of sandstones and conglomerates, such as are found structure, and in topography. These divisions increase in altitude from 500 feet or less in Ala­ its surface lies between 1,000 and 1,100 feet, and in the Coal Measures, were derived from high extend the entire length of the province, from bama to 900 feet in the vicinity of Chattanooga, the hills attain 100 or 200 feet above these eleva­ land on which stream grades were steep, or they northeast to southwest. 2,000 feet at the Tennessee-Virginia line, and tions. The knob belt lies southeast and east of may have resulted from wave action as the sea The central division is the Appalachian Valley. 2,600 or 2,700 feet at its culminating point, on Leadvale, and consists of a number of short, encroached upon a sinking coast. Red sandstones It is the best defined and most uniform of the the divide between the New and Tennessee irregular ridges and conical knobs, in which no and shales, such as make up some of the Cam­ three. In the southern part it coincides with the rivers. From this point it descends to 2,200 definite arrangement exists. The streams of this brian and Silurian formations, result from the belt of folded rocks which forms the Coosa Valley feet in the valley of New River, 1,500 to district flow in deep, narrow cuts, from which the revival of erosion on a land surface long exposed of Georgia and Alabama and the Great Valley of 1,000 feet in the James River basin, and 1,000 to knobs rise with exceedingly sharp slopes. Alti­ to rock decay and oxidation, and hence covered East Tennessee and Virginia. Throughout the 500 feet in the Potomac basin, remaining about tudes along the streams are from 1,000 to 1,100 by a deep residual soil. Limestones, on the other central and northern portions the eastern side the same through Pennsylvania. These figures feet, and the knobs rise from 100 to 400 feet hand, if deposited near the shore, indicate that only is marked by great valleys such as the represent the average elevation of the valley sur­ higher. the land was low and that its streams were too Shenandoah Valley of Virginia, the Cumberland face, below which the stream channels are sunk The entire region is drained by tributaries of sluggish to carry off coarse sediment, the sea Valley of Maryland and Pennsylvania, and the from 50 to 250 feet, and above which the valley the Tennessee River the Nolichucky, French receiving only fine sediment and substances in Lebanon Valley of northeastern Pennsylvania ridges rise from 500 to 2,000 feet. Broad, Holston, and Clinch rivers. All of them solution. the western side being a succession of ridges alter­ The plateau, or western, division increases in rise far beyond the limits of this area, and they The sea in which these sediments were laid nating with narrow valleys. This division varies altitude from 500 feet at the southern edge of the receive here a very small proportion of their down covered most of the Appalachian province in width from 40 to 125 miles. It is sharply out­ province to 1,500 feet in northern Alabama, 2,000 water. The Nolichucky falls from 1,100 to 1,000 and the Mississippi basin. The area of the lined on the southeast by the Appalachian Moun­ feet in central Tennessee, and 3,500 feet in south­ feet, the French Broad from about 1,000 nearly to Morristown sheet was near its eastern margin, tains and on the northwest by the Cumberland eastern Kentucky. It is between 3,000 and 4,000 900, the Holston from 1,000 to 850 feet, and the and the materials of which its rocks are composed Plateau and the Alleghany Mountains. Its rocks feet high in West Virginia, and decreases to about Clinch from nearly 1,100 to 1,000 feet. were therefore derived largely from the land to are almost wholly sedimentary and*in large meas­ 2,000 feet in Pennsylvania. From its greatest In this region the topography varies much, the east. The exact position of the eastern shore­ ure calcareous. The strata, which must originally altitude, along the eastern edge, the plateau slopes depending in all cases upon the influence of ero­ line of this ancient sea is not known, but it prob­ have been nearly horizontal, now intersect the gradually westward, although it is generally sepa­ sion on the different formations. Such rock- ably varied from time to time within rather wide surface at various angles and in narrow belts. rated from the interior lowlands by an abrupt forming minerals as carbonates of lime and mag­ limits. The surface differs with the outcrop of different escarpment.

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