DESCRIPTION OF THE ASHEVILLE QUADRANGLE By Arthur Keith. GEOGRAPHY. igneous rocks, such as granite and diabase, which general they flow in courses which for long dis­ feet at Asheville to less than 1200 feet at the point have solidified from a molten condition. tances are parallel to the sides of the Great Valley, GENERAL RELATIONS. where it passes out of the quadrangle. The western division of the Appalachian prov­ following the lesser valleys along the outcrops of Location. The Asheville quadrangle lies chiefly ince embraces the Cumberland Plateau, the Alle­ the softer rocks. These longitudinal streams empty GEOLOGY. in North Carolina, but includes also a portion of gheny Mountains, and the lowlands of Tennessee, into a number of larger, transverse rivers, which GENERAL GEOLOGIC EECOED. Tennessee. It is situated between parallels 35° 30' Kentucky, and Ohio. Its northwestern boundary cross one or the other of the barriers limiting the val­ and 36° and meridians 82° 30' and 83°, and con­ is indefinite, but may be regarded as an arbitrary ley. In the northern portion of the province they Nature of the formations. The formations which tains 968.70 square miles, divided between Madi­ line coinciding with the eastern boundary of the form Delaware, Susquehanna, Potomac, James, and appear at the surface of the Asheville quadrangle son, Buncombe, and Haywood counties in North Mississippi embayment as far up as Cairo, and Roanoke rivers, each of which passes through the and adjoining portions of the Appalachian prov­ Carolina and Greene, Cocke, and Unicoi counties then crossing the States of Illinois and Indiana. Appalachian Mountains in a narrow gap and flows ince comprise igneous, ancient metamorphic, and in Tennessee. Its eastern boundary is sharply defined along the eastward to the sea. In the central portion of the sedimentary bodies, all more or less altered since In its geographic and geologic relations this Appalachian Valley by the Allegheny front and province, in Kentucky and Virginia, these longi­ their materials were first brought together. Some quadrangle forms part of the Appalachian prov­ the Cumberland escarpment. *' The rocks of this tudinal streams form New (or Kanawha) River, of them are very ancient, going back to the earliest ince, which extends from the Atlantic coastal plain division are almost entirely of sedimentary origin which flows westward in a deep, narrow gorge known period. They consist mainly of two groups, on the east to the Mississippi lowlands on the west, and remain very nearly horizontal. The character through the Cumberland Plateau into Ohio of widely different age and character. These are (1) and from central Alabama to southern New York. of the surface, which is dependent on the character River. From New River southward to northern igneous and metamorphic rocks, including gneiss, All parts of the region thus defined have a common and attitude of the rocks, is that of a plateau more Georgia the Great Valley is drained by tributaries schist, granite, diorite, and similar formations; and history, recorded in its rocks, its geologic structure, or less completely worn down. In the southern of Tennessee River, which at Chattanooga leaves (2) sedimentary strata, of lower Cambrian age, and its topographic features. Only a part of this half of the province the Plateau is sometimes the broad valley and, entering a gorge through including conglomerate, sandstone, shale, limestone, history can be read from an area so small as that extensive and perfectly flat, but it is oftener much the Plateau, runs westward to the Ohio. South and their metamorphosed equivalents. Ordovician covered by a single atlas sheet; hence it is necessary divided by streams into large or small areas with of Chattanooga the streams flow directly to the rocks are also found in a small and unimportant to consider the individual area in its relations to flat tops. In West Virginia and portions of Penn­ Gulf of Mexico. area. The oldest of these groups occupies the the entire province. sylvania the Plateau is sharply cut by streams, leav­ greatest area, and the youngest the least. The GEOGRAPHY OF THE ASHEVILLE QUADRANGLE. Subdivisions of the Appalachian province. The ing in relief irregularly rounded knobs and ridges / materials of which the sedimentary rocks are Appalachian province is composed of three well- which bear but little resemblance to the original Geographic divisions. The area of the Ashe­ composed were originally gravel, sand, and mud, marked physiographic divisions, throughout each of surface. The western portion of the Plateau has ville quadrangle is nearly all included in the derived from the waste of older rocks, and the which certain forces have tended to produce similar .been completely removed by erosion, and the sur­ Mountain division of the Appalachian province. remains of plants and animals. All have been results in sedimentation, in geologic structure, and face is now comparatively low and level, or rolling. A few square miles in the extreme northwest cor­ greatly changed since their deposition, the altera­ in topography. These divisions extend the entire Altitude of the Appalachian province. The ner are situated in the Great Valley. The topog­ tion being so profound in some of the older gneisses length of the province, from northeast to southwest. Appalachian province as a whole is broadly dome raphy of this corner is of the kind which prevails and schists as to destroy their original nature. The central division is the Appalachian Valley. shaped, its surface rising from an altitude of about in the Great Valley, and consists of low, rounded From the relations of the formations to one It is the best defined and most uniform of the 500 feet along the eastern margin to the crest of hills and shallow valleys. Practically all of the another and from their internal structures many three. In its southern part it coincides with the the Appalachian Mountains and thence descending area of the quadrangle is occupied by a number of events in their history can be deduced. Whether belt of folded rocks which forms the Coosa Valley westward to about the same altitude on Ohio and mountain chains with broad plateaus and deep, the crystalline rocks were formed at great depth or of Georgia and Alabama and the Great Valley of Mississippi rivers. narrow intervening valleys. The most prominent at the surface is shown by their structures and tex­ East Tennessee and Virginia. Throughout its Each division of the province shows one or of these chains is the Newfound Mountains, which tures. The amount and the nature of the pressure central and northern portions the eastern side more culminating points. Thus the Appalachian extend in a general northerly direction between sustained by the rocks are indicated in a measure only is marked by great valleys such as the Mountains rise gradually from less than 1000 feet the valleys of Pigeon and French Broad rivers. by their folding and metamorphism. The com­ Shenandoah Valley of Virginia, the Cumberland in Alabama to more than 6700 feet in western In the northeast portion of the quadrangle rise the position and coarseness of the sediments show the Valley of Maryland and Pennsylvania, and the North Carolina. From this culminating point Bald Mountains, a group of disconnected ridges depth of water and the distance from shore at which Lebanon Valley of eastern Pennsylvania the they decrease to 4000 or 3000 feet in southern and peaks. The highest point in these, Big Bald they were produced. Cross bedding and ripple western side being a succession of ridges alter­ Virginia, rise to 4000 feet in central Virginia, and (5530 feet), lies about half a mile east of this quad­ marks in sandstones indicate strong and variable nating with narrow valleys. This division varies descend to 2000 or 1500 feet on the Maryland- rangle. The foothills of the Craggy Mountains currents. Mud cracks in shales show that their in width from 40 to 125 miles. It is sharply out­ Pennsylvania line. extend westward from the Mount Mitchell quad­ areas were at times above and at times below lined on the southeast by the Appalachian Moun­ The Appalachian Valley shows a uniform rangle nearly to French Broad River, just north of water. Red sandstones and shales like those of tains and on the northwest by the Cumberland increase in altitude from 500 feet or less in Asheville. The sides of these mountains are steep the Watauga formation were produced when ero­ Plateau and the Alleghenyo / Mountains. Its rocks Alabama to 900 feet in the vicinity of Chatta­ and made up of smooth, flowing slopes. The inter­ sion was revived on a land surface that had been are almost wholly sedimentary and are in large nooga, 2000 feet at the Tennessee-Virginia line, vening valleys are sharp and narrow at their heads long subject to decay and had become covered with measure calcareous. The strata must originally and 2600 or. 2700 feet at its culminating point, and descend rapidly to the altitudes of the differ­ a deep residual soil. Limestones show that the have been nearly horizontal, but they now intersect on the divide between New and Tennessee rivers. ent plateaus. At about these levels they quickly currents were too weak to carry sediment or that the surface at various angles and in narrow belts. From this point northward it descends to 2200 widen out into rounded valleys and plateaus. the land was low and furnished only fine clay and The surface differs with the outcrops of different feet in the valley of New River, 1500 to 1000 feet The most striking single feature in the region substances in solution. Coarse strata like those of kinds of rock, so that sharp ridges and narrow val­ in the James River basin and 1000 to 500 feet in is the plateau of French Broad River, which the Cochran conglomerate indicate strong currents leys of great length follow the narrow belts of hard the Potomac River basin, .remaining about the stands at elevations between 2100 and 2200 feet.