Description of the Raleigh Quadrangle
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DESCRIPTION OF THE RALEIGH QUADRANGLE. By Marius R. Camplbell. GEOGRAPHY. the direction of Chicago, curves southward through and it has been completely dissected by the numer River becomes the Kanawha. Above Armstrong Cincinnati, Ohio, and Lexington, Kentucky, and ous streams which drain its surface, forming a Creek the grade is greater, and the river is narrow General relations. The Raleigh quadrangle then trends to the southwest, parallel cincinnati hilly region in the place of the plateau and a and is beset by falls and almost continuous rapids embraces an area of 944 square miles, extending with the Appalachian Valley, as far as anticline- broken margin of irregular hill slopes instead of throughout the coal field. from latitude 37° 30' on the south to 38° on the Nashville, Tennessee. Its maximum development an escarpment. North of Ohio River the distinc The New River portion of this trunk stream north, and from longitude 81° on the east to 81° is in the vicinity of Lexington, where the Trenton tion between the topographic features is less pro crosses the northeastern corner of the Raleigh 30' on the west. The quadrangle is located in limestone is exposed at the surface at an altitude nounced than farther south and there is more or quadrangle in a deep and narrow gorge, through the State of "West Virginia, and the Locationof of 1000 feet above sea level, but in Tennessee it less merging of the eastern plateaus into the low which the water rushes in its hurried descent to larger part of its surface is included in <iuadransle- again swells out into a dome-like structure which, plains of the Mississippi Valley. the more quiet stretches of Kanawha River. Its the County of Raleigh, from which the quadran being eroded, is represented topographically by From the foot of the escarpment which marks principal tributary streams in this quadrangle are gle derives its name. Within its boundaries are the great Central Basin of Tennessee. the western limit of the coal-field plateau there as follows: Clear Fork and Marsh Fork of Coal also included considerable territory belonging to Geographically this anticline separates the extends a second plain or plateau, which is a River, draining the extreme northwestern corner Fayette and Wyoming counties and small areas Allegheny Plateaus into two parts, or structural prominent feature of the topography of Kentucky and emptying into Kanawha River; Bluestone of Mercer, Summers, Boone, and Kanawha coun basins, which differ from each other in the charac and Tennessee. This plain stands at an altitude River, in the southeastern part of the territory; ties. ter of the rocks which they contain, in geologic of about 1000 feet throughout the and Paint, Piney, Glade, and Dunloup creeks, in In its geographic and geologic relations this structure, and in the topography developed upon " Blue-grass" region of Kentucky, and altitudePlain at of the central part of the quadrangle. quadrangle forms a part of the Appalachian prov them. The eastern basin, extending the entire can vbe traced4- * northward4.1 A into' 4. Unioro.- '°oofeet- ince, which extends from the Atlantic Coastal length of the province from northeast Divislons of and Indiana. In Tennessee it is beautifully Plain on the east to the Mississippi lowlands on to southwest, is well known as the gheny'pia- developed along the western front of the Cum the west, and from central Alabama to southern Appalachian coal field. The western berland Plateau, where it has approximately the New York. basin is more restricted, being the southeastern same altitude as in central Kentucky. Doubtless Subdivisions of the Appalachian province. part of the coal field of Illinois, Indiana, and Ken this surface once extended across the Central Respecting the attitude of the rocks, the Appala tucky. The rocks outcropping on the crest of the Basin, for the latter is bounded on the south by chian province may be divided into two nearly Cincinnati anticline are prevailingly calcareous, high land along the Tennessee-Alabama line, and equal parts by a line which follows the north hence the two coal fields are not only structur on the north by the great interior plain of Ken western side of the Appalachian Valley, along the ally distinct, but are separated by a wide band tucky. Allegheny Front and the eastern escarpment of of rocks which are lithologically very different The evidence indicates that this surface was the Cumberland Plateau. East of this line the from the sandy coal-bearing strata on either side. formed by subaerial erosion which operated so rocks are greatly disturbed by folds and faults, Topography of the Allegheny Plateaus. The extensively that it reduced the soft rocks nearly and in many places they are so metamorphosed altitude of this division is greatest along the to the level of the sea, forming a peneplain. Since that their original character can not be determined. southeastern margin, where the ridges and pla that time the surface has been elevated to its West of the division line the rocks are almost teaus attain suflicient elevation to be considered present position, 1000 feet above sea level, and wholly sedimentary and with few exceptions the mountains. They are not continuous, and in no streams have dissected it extensively. Owing to V. SOUTH \ CAROLINA strata lie nearly flat, in approximately the same sense can they be grouped into a mountain sys the softness of the rocks in Tennessee .GEORGIA N Central Basin attitude in which they were deposited. tem. In the northern part of the province the and to the geologic structure which is A L A B A M A \ \ The western division of the province is therefore general surface forms a plateau at an altitude of there developed, a second limited plain 7«« *^et ele- Fig. 1. Outline map showing the relation of the Raleigh sharply differentiated from the eastern division, from 2000 to 3000 feet above the sea. Upon this was formed, which was subsequently quadrangle to the Appalachian coal field. but it can not be so easily separated platform stand numerous ridges which elevated and now forms the floor of the Central Coal field is represented by the shaded area. Limits of the from the remaining portion of the Mis- Appalachian have been formed by partial erosion of Basin. This surface has a general altitude of Most of the small streams in this territory have . TT -11 T 1 province. sissippi Valley. In a geologic sense small anticlinal folds that traverse the from 500 to 700 feet, and it is separated from the their sources upon a plateau located near the it is a part of the Mississippi Valley. The char plateau in lines parallel with its eastern margin. higher surface by a steep slope or escarpment center of the quadrangle, and flow off in various acter and stratigraphic succession of the rocks are In the central part of the basin the plateau is not which is generally called the Highland Rim. directions. Upon the plateau the streams are the same, and the geologic structure which is so well marked nor so high, and it has been deeply Since the formation of the Central Basin the land somewhat sluggish and generally occupy characteristic of one is also found throughout the dissected by the streams which drain its surface, has been elevated several hundred feet and the broad, open valleys, but farther down- othe,r. On account of these facts it would be leaving a hilly, broken region in place of the even principal streams have carved deep and narrow stream they cut into this surface, and arbitrary, on geologic grounds, to separate the surface of the plateau. This region is also free valleys in its once even surface. their lower courses are marked by deep gorges, two, or, in other words, to assign a definite west from minor folds, hence there are no ridges rising In northern Kentucky the conditions were not the streams themselves being swift-flowing moun ern limit to the Appalachian province. above the general level. Farther south extensive so favorable for extensive erosion as in Tennessee, tain torrents. The major streams possess the same From a physiographic standpoint this division folds occur within the limits of this division, and consequently there is no feature exactly equivalent characteristics, and hence are useless for purposes is clearly a part of the Appalachian province, for parallel ridges are found which are similar to those to the Central Basin, but there are old high-level of navigation, but they present great possibilities its history can not be written apart from that of in the northern part of the province. In southern stream valleys, such as have been described in the in the way of undeveloped water power. New the whole province, and it has little or no relation Tennessee and northern Alabama,7 how- Anticlinal. ..,. , Richmond (Kentucky) folio, which indicate that River in particular is extremely rapid for a stream to the region west of Mississippi River, either in ever, the lithologic and structural con- valleys- similar, although not identical, conditions pre of its size, and it exhibits unmistakable evidence its physiographic history or in its present surface ditions have been such that the anticlines are vailed in the Ohio Valley during the same general of the youthf ulness of its present valley. features. This division is, therefore, physiograph- entirely eroded, leaving the central parts of the period. Relief. The surface features of any quadrangle ically limited on the east by the Allegheny Front broad synclines as elevated plateaus, which in are difficult of interpretation if the student is con TOPOGRAPHY OF THE RALEIGH QUADRANGLE. and the eastern escarpment of the Cumberland various places have received local names, but fined to the facts shown in that quadrangle, for Plateau and on the west by the flood plain of which may be grouped under the general name As shown in fig.