See also:

• UNITED

The Pacific coast has been defined chiefly by relatively See also:

• RECENT

The invasion was wonderfully accelerated through the 19th See also:

• CENTURY (from Lat. centuria, a division of a hundred men)

Each of the disturbances altered the attitude of the mass with respect to the general See also:

• BASE

In a south-western section the crystalline belt again assumes importance in breadth and height, and the plateau member maintains the strength that it had in the middle section, but the intermediate stratified belt again has fewer ridges, 'because of the infrequence here of ridge-making strata as compared to their frequency in the middle section. The middle section of the Appalachians, rather arbitrarily limited by the Hudson and the James rivers, may be described first because it contains the best See also:

• REPRESENTATION

The relief is strong enough to make occupation difficult; the slopes are forested; the uplands are cleared and well occupied by farms and villages, but many of the valleys are wooded glens. With continued decrease of altitude south-eastward, the crystalline belt dips under the coastal plain, near a line marked by the Delaware river from Trenton to Philadelphia in Pennsylvania, and thence south-south-westward through Maryland and Virginia past the cities of See also:

• BALTIMORE
• BALTIMORE, GEORGE CALVERT, 1ST BARON (C. 1580—1632)

But the Hudson is stnkingly exceptional in this respect; it possesses a deep and navigable See also:

• TIDE (O. Eng. lid, cf. Ger. Zeit, time or season, connected with root of Sanskrit a-diti, endless)

A still larger example is seen in Mt Katandin (5200 ft.) in north-central Maine, the greatest of several similar isolated mountains thatare scattered over the interior uplands without apparent system. The See also:

• WHITE
• WHITE, ANDREW DICKSON (1832– )
• WHITE, GILBERT (1720–1793)
• WHITE, HENRY KIRKE (1785-1806)
• WHITE, HUGH LAWSON (1773-1840)
• WHITE, JOSEPH BLANCO (1775-1841)
• WHITE, RICHARD GRANT (1822-1885)
• WHITE, ROBERT (1645-1704)
• WHITE, SIR GEORGE STUART (1835– )
• WHITE, SIR THOMAS (1492-1567)
• WHITE, SIR WILLIAM ARTHUR (1824--1891)
• WHITE, SIR WILLIAM HENRY (1845– )
• WHITE, THOMAS (1628-1698)
• WHITE, THOMAS (c. 1550-1624)

The maturely dissected and recently glaciated uplands of New England are now somewhat depressed with respect to sea-level, so that the sea enters the valleys, forming bays and estuaries, while the interfluve uplands and hills stand forth in headlands and islands. See also:

• NARRAGANSETT

The rivers of the mountain belt, normally dividing and subdividing in apparently insequent See also:

• FASHION (adapted from Fr. facon, agon, Lat. factio, making, facere, to do or make)

There is one feature of the Appalachians that has greater continuity than any other; this is the Great Valley. It is determined The Great structurally by a belt of topographically weak limestones valley. and shales (or slates) next inland from the crystalline uplands; hence, whatever the direction of the rivers which drain the belt, it has been worn down by Tertiary erosion to a continuous lowland from the Gulf of St Lawrence to central Alabama. Through all this distance of 1500 m. the lowland is nowhere interrupted by a transverse ridge, although longitudinal ridges of moderate height occasionally diversify its surface. In the middle section, as already stated, the Great Valley is somewhat open on the east, by reason of the small height and broad interruptions of the narrow crystalline belt; on the west it is limited by the complex series of Alleghany ridges and valleys; in the north-east section the valley is strongly enclosed on the east by the New England uplands, and on the west by the Adirondacks and Catskills (see below) ; in the south-west section the valley broadens from the North Carolina highlands on the south-east almost to the Cumber-land plateau on the north-west, for here also the ridge-making formations weaken, although they do not entirely disappear. A striking contrast between New England and the See also:

• REST (O. Eng. rest, reste, bed, cognate with other Teutonic forms, e.g. Ger. Rast, Riiste, rest, and probably Gothic Rasta, league, i.e. resting or stopping place)

The coastal lowland between the sea arms is so See also:

• FLAT (a modification of O. Eng. flet, an obsolete word of Teutonic origin, meaning the ground beneath the feet)

The unity and continuity of the district, ex-pressed in the name Appalachian plateau, is seldom recognized in See also:

• LOCAL

Although composed chiefly of crystal-line rocks, which are commonly associated with a rugged landscape, and although possessing a greatly deformed structure, which must at some ancient period have been associated with strong relief, the upland as a whole is gently rolling, and the inter-stream surfaces are prevailing plateau-like in their evenness, with altitudes of 1400 to 1600 ft. in their higher areas. In this province, therefore, we find a part of one of those ancient mountain regions, initiated by crustal deformation, but reduced by long continued erosion to a peneplain of modern relief, with occasional surmounting monadnocks of moderate height not completely consumed during the peneplanation of the rest of the surface. The erosion of the region must have been far advanced, perhaps practically completed, in very ancient times, for the even surface of the peneplain is overlapped by fossiliferous marine strata of early geological date (See also:

• CAMBRIAN

When the oldland and its overlap of stratified deposits were elevated again, the overlapping strata must have had the appearance of a coastal plain; but that was long ago; the strata have since then been much eroded, and to-day possess neither the area nor the smooth form of their initial extent. Hence this district may be placed in the class of ancient coastal plains. As is always the See also:

• CASE
• CASE, JOHN (d. 1600)

This knob or ridge may be appropriately regarded as an ancient physiographic fossil, inasmuch as, being a monadnock of very remote origin, it has long been preserved from the destructive attack of the See also:

• WEATHER (O. Eng. weder; the word is common to Teutonic languages; cf. Du. weder, Dan. veir, Icel. ve8r, and Ger. Wetter and Gewitter, storm; the root is wa- to blow, from which is derived " wind ")

(rho ft. at the See also:

• CATARACT (from the Lat. form cataracta of the Gr. Karapplucrgss, a floodgate, or waterfall, properly something which rushes down)

The till plains, although sweeping in broad swells of slowly changing altitude, are often level to the See also:

• EYE
• EYE (O. Eng. edge, Ger. Auge; derived from an Indo-European root also seen in Lat. oc-ulus, the organ of vision (q.v.)

Later when the ice retreated farther and the unloaded streams returned to their earlier degrading habit, they more or less completely scoured out the valley deposits, the remains of which are now seen in terraces on either side of the present See also:

• FLOOD (in O. Eng. flod, a word common to Teutonic languages, cf. Ger. Flut, Dutch vloed, from the same root as is seen in " flow," " float ")
• FLOOD, HENRY (1732-1791)