The New International Encyclopædia/Appalachians

APPALACHIANS. The general name for the extensive mountain system in the eastern United States. It extends in a northeast-southwest direction from northern Alabama and Georgia, to the vicinity of Albany, N. Y. Some writers include the Adirondack Mountains, but these constitute an independent though comparatively small system, geologically distinct from the Appalachians. The Taconic, Green, and White mountains are often, and with more reason, considered a part of the general system, as also are the ranges stretching from northern Maine to the Gaspé Peninsula, and reappearing in Newfoundland. At its southern end the system curves slightly to the westward, and beyond the Mississippi Valley is resumed as the Ouachita uplift of southern Arkansas and Indian Territory.

General Character. The region proper may be described as a long, narrow plateau, from 70 to 200 miles in width, with an altitude of 1500 to 3000 feet. It is bordered on the east by the well-defined Blue Ridge, and on the west by the Alleghany Mountains, which two ridges lie approximately parallel, and 75 to 100 miles apart, throughout their lengths. Between these outer ranges lie a great number of smaller disconnected mountain ridges, chiefly parallel to the main axis of the system in the central and northern part, but much broken in the southern and southeastern Appalachians. These mountain ridges maintain a remarkably uniform altitude, gradually increasing from both directions toward the central mass in western North Carolina. Lying between the comparatively narrow and regular wall of the Blue Ridge and Alleghanian ranges, west of it, is the great Appalachian Valley, which is a characteristic feature of the topography, for it extends the entire length of the mountain system. Here and there it is broken by minor ridges into two or three parallel valleys, but the general nature of a trough between mountain ranges is maintained throughout. In New York it is known as the Wallkill Valley; in Pennsylvania, the Lebanon, Lancaster, and Cumberland valleys; in Virginia it is the historic Shenandoah Valley, or “Great Valley of Virginia”; and still farther south it is the Tennessee Valley, extending into Alabama and Georgia.

Divisions. The Appalachian region has not a uniform conformation throughout its extent, but is divided into two sections, the Northern and the Southern Appalachians, with the line of separation in western Virginia. This division is not merely of an arbitrary nature, but is founded on well-marked differences in the structural and physiographic features of the two regions. In the northern division the Blue Ridge range has gentle slopes, rising usually to rounded crests, which show a gently undulating sky line, with here and there a peak rising a little higher than the usual level. (See Blue Ridge.) To the west of this ridge is a more or less elevated northerly extension of the great Appalachian Valley, which in general presents a succession of depressions and heights, the former worn by streams to a depth, in some cases, of 200 feet, while the latter rise to a height of usually less than 1000 feet above the depressions. The Alleghany Mountains rise west of the valley in bolder sculpturing than that of the Blue Ridge, the side toward the great interior valley, the “Alleghany front,” being steep and rugged; but on the side of the Mississippi Valley the slope is gradual, descending westward in lessening ridges from the plateau which marks the summit region; this configuration is due to the fact that the stratified rocks (see below) incline westward, exhibiting their upturned edges in precipices toward the east. Beginning with the Catskills, the line is broken by the broad valley of the Delaware, but reappears in several prominent ranges in Pennsylvania. The westernmost, or ‘front’ range, is confusingly called First, or Blue Mountain, with Peter's, or Second Mountain, behind it, east of the Susquehanna. East of the Susquehanna, the Tuscarora, Blacklog, Jack's, Standing Stone, and Tussey's are well-defined ranges westward, filling the whole region with crowded heights to the long range distinctively termed Alleghany, which stretches from the border of New York down into West Virginia. In the Virginias both the Blue Ridge and the western ranges become loftier and better defined. The front range is here called the Great North Mountain, and west of it lie successively the Shenandoah and several broken ranges, rising to the continuation of the Alleghanies proper. These draw together at the southwest extremity of Virginia, where a new uplift, the Cumberland Mountains (q.v.), rises west of them, and terminates in the Clinch Mountains. The valley of the Tennessee makes a break, south of which the range reappears in the prolongations of the Cumberland Mountains in northern Alabama. In New Jersey the ‘Highlands’ of the Blue Ridge rise to heights of 1000 to 1500 feet; in Pennsylvania to 2000 feet; in Virginia from 2000 to 4000 feet (Hawk's Bill, 4066 feet), and with a breadth of 16 miles. In North Carolina, near the Virginia line, the Blue Ridge forks, the Unaka Mountains, of somewhat greater altitude, but of lesser continuity, branching off toward the southwest, while the Blue Ridge proper takes a more southerly course. The Alleghanies, which really begin with the Catskills, in New York State (highest 4200 feet), have in the northern part a general elevation of about 2000 feet, which increases to 4400 feet in Virginia and Kentucky, and still farther south decreases from 200 to 2500 feet. The absence of any isolated peaks is highly characteristic of the whole Alleghanian region; the mountains everywhere present the appearance of long, evenly topped ridges, and the name applies to the whole ridge.

The prominence of the Blue Ridge is the characteristic feature of the southern division of the Appalachians. This rises suddenly from the Piedmont tableland, east and south of it, to heights far greater than the Alleghanies attain. Beginning prominently in South Mountain, in southern Pennsylvania, it stretches Southwestward in greater and greater heights, through Virginia and western North Carolina, where it divides, the northern branch continuing westward to Georgia as the Unaka, or Great Smoky Mountains. These form a broad mass of mountains on the border between North Carolina and Tennessee, containing peaks exceeding those of the White Mountains of New Hampshire, and consequently the highest east of the Rocky Mountains. The culminating group, reaching in Mount Mitchell 6710 feet, is known as the Black Mountains (q.v.), and contains many peaks above 6000 feet in height. The Unaka Mountains are characterized by the great sharp-ridged spurs which leave the main chain and preserve its-height for a distance of several miles; between these spurs are deep valleys only wide enough at the bottom for the creek-beds which are invariably found there. The altitudes of the extended valleys in this great highland region are from 2000 to 3000 feet. To the west of the steep-sided Unaka ridge lies a valley, about 50 or 60 miles wide, in Tennessee, which contains the Tennessee River and its tributaries, the Clinch, Holston, and French Broad.

Geology. The Appalachian Mountains are folded mountains; that is, they have been formed by plications or, folds of the rock layers that make up the crust of the earth in this region, and the particular type of plication is so well developed in this region that it has received the name of the “Appalachian type” of folding. The Blue Ridge, along the eastern side, consists of layers of crystalline rocks, the oldest known in the Appalachians, that have suffered so great an amount of metamorphism as to render the determination of their exact age a matter of considerable difficulty. They are grouped under the term “fundamental complex,” and it is certain that they are in large part pre-Cambrian; and some are even Archæan on the eastern edge of the Blue Ridge. On the western edge isolated masses of Cambrian rocks are found. All these rocks of the Blue Ridge have been much folded and compressed, so that the layers now stand almost on end and are even overturned. Great faults and overthrusts are common, and add to the difficulty of unraveling the structure of the district. In the Appalachian Valley the geological structure is also quite complex, though the strata are not so intensely metamorphosed. The rocks are limestones, shales, and sandstones, and they lie in closed folds that become more open toward the western side of the valley. These folds are peculiar in that their eastward slopes are always steeper than the westward. When the folds are overturned the inversion is toward the east; and overthrusts are also toward the east, and often of considerable extent. This valley is largely the result of the erosion of a great limestone formation, of Cambro-Silurian age, that extends its entire length. The Alleghany Mountains consist of rocks of Paleozoic age, Cambrian to Carboniferous, inclusive, that have been elevated into folded ridges and then eroded to their present topography. The softer beds have been worn into valleys, and the harder beds, having resisted erosion, have been left to form the ridges and benches. In this limestone also have been eroded the wonderful series of caves of the Shenandoah Valley and elsewhere, of which that at Luray, Va., is a striking example (see Caves). Anticlinal and synclinal folds alternate in diminishing intensity toward the west, where they disappear in the nearly horizontal beds of the Cumberland Plateau, which is made up of carboniferous rocks.

Drainage Development. The region now occupied by the Appalachian Mountains has been the scene of many physiographical changes too complex to explain here. At a comparatively recent time, however, the whole of the Appalachian system consisted of a great rounded plateau with an elevation of perhaps 4000 feet, the surface of which is called by geologists the Kittatinny Plain. Above this plain arose to a moderate height the now high mountains of western North Carolina. Along a central zone the land increased in altitude to a region in Virginia which thus became the watershed. The rain now did its work, and the great rivers—the New, the Roanoke, James, Potomac, and Susquehanna—cut out their paths through the then nearly level region, and a well-developed system of highlands and drainage was established. However, the subsequent elevation of land in this region by amounts ranging from 200 feet in the north to 1700 feet in Virginia, once more disturbed the adjustment of the water systems, and gave a new impetus to the work of the flowing waters.

While the Appalachian Mountains form the watershed between the Atlantic Slope and the Mississippi Valley, yet throughout there is no definite watershed line on one side of which the rivers flow to the west, and on the other toward the east. In the northern part the streams chiefly break through the mountains from the western side to the east. In the middle part, some escape toward the east and some toward the west; while at the south the eastern mountain range of the Blue Ridge forms the watershed. The water-courses appear to be independent of the direction of the mountain ranges, and instead of pursuing what appear to be the natural directions along the present great valleys, they flow across the ridges through deep gaps in them. This peculiar circumstance is due to the fact that these gaps were cut by the streams before the intervening ridges were upheaved.

The chief streams draining the eastern slope of the Appalachian into the Atlantic are the Hudson and its branches on the west, the Delaware, Schuylkill, Susquehanna, Potomac, and the James, which cut their way eastward through the mountain ranges; and the Rappahannock, Dan, Yadkin (Pedee), Catawba, Broad, Saluda (branches of the Santee), and the Savannah, which rise from the eastern slope of the Blue Ridge, whose western slopes drain into the Susquehanna, Shenandoah (Potomac), James or Tennessee. On the south are the Chattahoochee (head stream of the Apalachicola ) and the Coosa (head stream of the Alabama), flowing into the Gulf of Mexico. The streams draining the Appalachian region on the west are tributary to the Ohio River. They are they Hiwassee, the Little Tennessee, and the French Broad, which flow from the Blue Ridge through a network of high mountains, and break through the great Unaka range to the Tennessee; the Holston and Clinch rivers, also tributaries of the Tennessee; the Cumberland, the New (head of the Kanawha), the Little Kanawha, Allegheny, and Monongahela. The last two join to form the Ohio.

Climate. The climate of the Appalachian Mountains must be characterized as temperate, as they extend from a region in which the average annual temperature is 46° F. southward to a region of 61° F. The region, therefore, partakes of the general climatic conditions of its latitude, modified by its altitude. As the prevailing winds come from the southwest, they do not bring much moisture, and the rainfall and snowfall are not excessive, though greater upon the heights of the central ranges than in the lower areas outside. The rainfall for the year averages about 40 inches throughout most of the Appalachian region, but in the southern section increases to 60 or 70 inches. Droughts frequently occur at the north, but seldom at the south. On the whole, the summer climate of the Appalachian region is delightful, and its charms are becoming more and more appreciated by summer visitors. This attractiveness is increased by the abundance of vegetation, the beautiful scenery, in which grandeur may often be found, and particularly by the presence in many parts of the mountains of springs of saline, chalybeate, and other mineral-bearing waters, both hot and cold. These medicinal waters, together with the purity and energizing character of the air, has long given the mountains, especially in North Carolina and Virginia, a high repute as a health resort.

Vegetation and Fauna. The Appalachian region is covered with a dense forest growth where it has not been removed by man, forest trees covering the mountain slopes practically to their summits, except where the barren rocks furnish no soil. The chief trees in the north are the sugar maple, white birch, beech, ash, pine, and hemlock: in the south, oaks of various kinds, chestnut, hickory, poplar, tulip, ash, beech, maple, linden, red birch, cherry, with a sprinkling of a dozen other varieties. Especially at the south extensive thickets of laurel and rhododendron border the water-courses. Ferns, wild flowers, wild grasses, and the wild pea vine furnish an abundant herbage. In the northern section most of the valuable timber has been removed and vast areas desolated to secure tree bark for tanning purposes. At the South, however, the forests retain much of their primeval character and magnificence, some of the trees being of gigantic size. Of the larger mammalia bears, deer, wildcats, are still common, but by no means plentiful. Wolves and panthers have practically disappeared. Small game birds and, at the South, wild turkeys are plentiful. Unfortunately, rattlesnakes and copperheads are to be found all over the mountains, yet rarely in dangerous numbers. The woods and streams abound, beyond almost any other part of the Temperate Zone, in fresh-water mollusks.

Mineral Resources. Economic products of considerable importance are found in the Appalachian region. Coal (q.v.) is far the most important; the entire anthracite field and part of the bituminous field of Pennsylvania and other States lie in the Alleghany Mountains and the Cumberland plateau or its northern extension. The petroleum and oil fields of New York, western Pennsylvania, and southward, barely touch the edge of the Appalachian region. Of the metals, iron occurs as hematite, limonite, and magnetite at many localities; zinc is found in association with magnetite at the well-known localities of Franklin Furnace and Ogdensburg, N. J., and as blende, calamine, etc., associated with lead, at the Bertha Mines in Wythe County, Va. Lead has been found in small amounts at many points, but does not occur in sufficient quantity to constitute an independent industry. Copper is found native in the crystalline rocks of Virginia, and as chaleopyrite often in large masses, as at Ducktown, eastern Tennessee. Gold and silver occur in small amounts chiefly in Georgia and North Carolina; nickel and cobalt are also found sparingly. Bauxite, one of the ores of aluminum, has assmned great importance in Alabama, and manganese has been mined in large quantities in Tennessee and Virginia. Natural cement, of such high grade as to make it a rival of Portland cement, is found at many outcrops of the Upper Silurian formations in New York, New Jersey, Pennsylvania, and Maryland, and lime is burned throughout the region. Building stone of good quality is abundant, and slate of excellent grade is quarried in New Jersey and Pennsylvania. Asbestos, mica, garnet, and emery are mined in Virginia, the Carolinas, and Georgia, and gems of many kinds are found in the Blue Ridge.

Bibliography. A. Guyot, “The Appalachian Mountain System,” American Journal of Science, second series, Volume XXXI. (New Haven, 1861); C. W. Hayes, “The Mechanics of Appalachian Mountain Structure,” Annual Report United States Geological Survey, Volume XIII., Part II. (Washington, 1892); B. Willis, “The Northern Appalachians,” National Geographic Monographs, Volume I. (New York, 1895); C. W. Hayes, “The Southern Appalachians,” National Geographic Monographs, Volume I. (New York, 1895); C. W. Hayes and M. R. Campbell, “Geomorphology of the Southern Appalachians,” National Geographic Magazine, Volume VI. (Washington, 1894); C. W. Hayes, “Physiography of the Chattanooga District in Tennessee, Georgia, and Alabama,” Annual Report United States Geological Survey, Volume XIX., Part II. (Washington, 1899); B. Willis, “Paleozoic Appalachia, or a History of Maryland During Paleozoic Time,” Maryland Geological Survey, Special Publication, Volume VI., Part I. (Baltimore, Md., 1900); Chapman, Flora of the Southern States (New York, 1883); Lounsberry, Southern Wildflowers and Trees (New York, 1901).

See Mountain; Anticline; Physiography; Geology; United States.