Description of the Greeneville Quadrangle

DESCRIPTION OF THE GREENEVILLE QUADRANGLE By Arthur Keith. GEOGRAPHY. by streams and is lower and less broken than the following the lesser valleys along the outcrops of the quadrangle, where the dolomite contains less divisions on either side. of the softer rocks. These longitudinal streams chert, its surface is reduced nearly as low as the GENERAL RELATIONS. The western division of the Appalachian prov empty into a number of larger, transverse rivers, surfaces of the other limestones. The least soluble Location. The Greeneville quadrangle lies ince embraces the Cumberland Plateau and Alle which cross one or the other of the barriers limit rocks are the quartzites, sandstones, and con chiefly in Tennessee, but comprises also a portion gheny Mountains and the lowlands of Tennessee, ing the valley. .In the northern portion of the glomerates, and, since most of their mass is left of North Carolina, It is included between paral Kentucky, and Ohio. Its northwestern boundary province they form Delaware, Susquehanna, Poto untouched by solution, they are the last to be lels 36° and 36° 30' and meridians 82° 30' and is indefinite, but may be regarded as extending mac, James, and Roanoke rivers, each of which reduced in height. Apparently the rocks of the 83°, and contains about 963 square miles, divided from the mouth of Tennessee River in a north passes through the Appalachian Mountains in a Cranberry granite form an exception to this rule, between Greene, Hawkins, Sullivan, Washington, easterly direction across the States of Illinois and narrow gap and flows eastward to the sea. In for they contain much soluble matter in feldspar, and Unicoi counties in Tennessee and Madison Indiana. Its eastern boundary is sharply defined the central portion of the province, in Kentucky and yet maintain great heights. For this result County in North Carolina. along the Appalachian Valley by the Allegheny and Virginia, these longitudinal streams form New the immense mass of the formation and the insolu In its geographic and geologic relations this front and the Cumberland escarpment. The rocks (or Kanawha) River, which flows westward in a bility of the quartz are largely responsible. quadrangle forms part of the Appalachian prov of this division are almost entirely of sedimentary deep, narrow gorge through the Cumberland Pla Erosion of the sedimentary formations has pro ince, which extends from the Atlantic coastal plain origin and remain very nearly horizontal. The teau into Ohio River. From New River south duced a series of long ridges separated by narrow on the east to the Mississippi lowlands on the west, character of the surface, which is dependent on the ward to northern Georgia the Great Valley is valleys, which closely follow the belts of rock. and from central Alabama to southern New York. character and attitude of the rocks, is that of a drained by tributaries of Tennessee River, which Where the formations spread out with a low dip All parts of the region thus defined have a com plateau more or less completely worn down. In at Chattanooga leaves the broad valley and, enter the valleys and ridges are broad, and where the mon history, recorded in its rocks, its geologic the southern half of the province the Plateau is ing a gorge through the Plateau, runs westward strata dip steeply the valleys are narrower. Each structure, and its topographic features. Only a sometimes extensive and perfectly flat, but it is to the Ohio. South of Chattanooga the streams turn in the course of a formation can be seen by part of this history can be read from an area so oftener much divided by streams into large or flow directly to the Gulf of Mexico. the turn of the ridge or valley which it causes. small as that covered by a single atlas sheet; hence small areas with flat tops. In West Virginia and Conspicuous examples of this are the various it* is necessary to consider the individual area in its portions of Pennsylvania the Plateau is sharply DETAILED GEOGRAPHY OF THE GREENEVILLE Clinch sandstone mountains. Each rock produces relations to the entire province. cut by streams, leaving in relief irregularly rounded QUADRANGLE. a uniform type of surface so long as its composi Subdivisions of the Appalachian province. The knobs and ridges which bear but little resemblance Geographic divisions. Within the limits of the tion remains the same, but with each change in Appalachian province is composed of three well- to the original surface. The western portion of Greeneville quadrangle two of the major divisions composition the surface changes form. The lime marked physiographic divisions, throughout each the Plateau has been completely removed by ero of the Appalachian Province are represented. The stones have disappeared through solution over of which certain forces have tended to produce sim sion, and the surface is now comparatively low and Appalachian Mountains occupy about 100 square much of each valley floor. Near the sandstone ilar results in sedimentation, in geologic structure, level, or rolling. miles in the southeastern portion of the quad and quartzite mountains the residual clays of the and in topography. These divisions extend the Altitude of the Appalachian province. The rangle, this being but a small section of the great limestone have been swept over with waste from entire length of the province, from northeast to Appalachian province as a whole is broadly dome mass lying farther east and south. The small por the mountain-making rocks. This material forms southwest. shaped, its surface rising from an altitude of about tions included within this quadrangle are called the terraces and flood plains which lie along the The eastern division of the province embraces 500 feet along the eastern margin to the crest of the Bald Mountains. The remainder of the quad streams that enter Nolichucky River on its south the Appalachian Mountains, a system which is the Appalachian Mountains, and thence descending rangle lies in the Great Valley and can be sub side, such as Camp Creek and Horse Creek. These made up of many minor ranges and which, under westward to about the same altitude on Ohio and divided into three topographic districts. In the deposits are very conspicuous and form practically various local names, extends from southern New Mississippi rivers. northwestern portion of the quadrangle lies the one plain, which slopes gradually away from the York to central Alabama. Some of its prominent Each division of the province shows one or ridge district, embracing the Bays Mountains and foot of the Bald Mountains. parts are the South Mountain of Pennsylvania, the more culminating points. Thus the Appalachian the region lying northwest of Holston River. The Bald Mountains consist of a high, irregular Blue Ridge and Catoctin Mountain of Maryland Mountains rise gradually from less than 1000 feet Between the Bays Mountains and the "Bald Moun range, much of it over 4000 feet in height, with and Virginia, the Great Smoky Mountains of Ten in Alabama to more than 6700 feet in western tains lies an open valley composed mainly of low, lesser mountains and spurs sloping away toward nessee and North Carolina, and the Cohutta Moun North Carolina. From this culminating point rolling ridges and shallow valleys, a part of the the streams in all directions. Where it borders the tains of Georgia. Also embraced in the eastern they decrease to 4000 or 3000 feet in southern Valley of East Tennessee. The northwestern part Great Valley it presents a steep front of ridges and division is the Piedmont Plateau, a vast upland Virginia, rise to 4000 feet in central Virginia, and of this is the valley of Lick Creek, a low, gently butts rising from 1000 to 1500 feet above the which, as its name implies, lies at the foot of the descend to 2000 or 1500 feet on the Maryland- rolling plain, varied here and thereby small knobs adjoining valley. Thus is seen in strongest con Appalachian Mountains. From New York to Ala Pennsylvania line. of slight relief. From the southeast border of this trast the results of erosion of soluble and insoluble bama it stretches eastward and southward from The Appalachian Valley shows a uniform valley to the foot of the Bald Mountains extends formations. The streams fall rapidly from their their foot and passes into the Coastal Plain, which increase in altitude from 500 feet or less in Ala the plateau traversed by Nolichucky River. sources until they emerge upon the valley at eleva borders the Atlantic Ocean. The Mountains and bama to 900 feet in the vicinity of Chattanooga, Drainage. The entire region is drained by trib tions varying from 1500 to 1800 feet. Their the Plateau are separated by no sharp boundary, 2000 feet at the Tennessee-Virginia line, and 2600 utaries of Tennessee River Nolichucky, French channels in the Cambrian quartzites and -slates, but merge into each other. The same rocks and or 2700 feet at its culminating point, on the divide Broad, and Holston rivers. All of them rise far which are wild, rocky, V-shaped gorges at their the same structures appear in each, and the form between New and Tennessee rivers. From this beyond the limits of this quadrangle, and they heads, suddenly open out on the limestone floor of of the surface varies largely in accordance with the point northward it descends to 2200 feet in the receive here a very small proportion of their water. the Great Valley. ability of the different streams to wear down the valley of New River, 1500 to 1000 feet in the The ridge district and practically all of the area In the ridge district, or northwestern portion of rocks.

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