National Geographic : 1894 May 23
Drainageof the Province. 95 extended southwestward along the axis M N, so that in very recent geologic time the Tertiary peneplain from Asheville to Atlanta and southwestward has been elevated to its present position. Movements have occurred along some minor axes chiefly of subsidence, but their exact date cannot be fixed. The latest movements which can be detected in the province are along the axes K L and 0 P. That along K L has resulted in a slight ponding of the Tennessee river in the vicinity of Huntsville, Alabama, while the uplift along 0 P has affected the Cumberland river above point Burnside, Kentucky, in a similar manner. PART II. - DRAINAGE DEVELOPMENT. SUBDIVISIONS OF THE PROVINCE. Geologically, and topographically as well, the southern Appa lachian province falls into four well-marked divisions. These are (1) an eastern piedmont plain, sloping gently seaward and composed of metamorphic and crystalline rocks; (2) a montanic tract, embracing the Blue ridge and the Great Smoky range with its many outliers and containing chiefly crystalline rocks with sediments which have undergone various degrees of metamor phism; (3) a central broad valley with numerous parallel ridges of Paleozoic sediments; (4) a western dissected plateau of upper Silurian and Carboniferous rocks. OUTLINE OF THE PRESENT DRAINAGE. In the northern portion of the province the water parting be tween the Atlantic and Gulf drainage is westward of the Appa lachian valley. The Potomac heads upon the edge of the plateau and flows eastward across the Appalachian valley, the montanic tract and the piedmont plain. From the western point of Mary land the divide passes nearly due southward, crossing the Appa lachian valley diagonally, so that the James and Roanoke drain only the eastern part of the valley, but, like the Potomac, flow east ward across the montanic tract and the piedmont plain. South of these streams the divide follows near the eastern margin of the montanic tract to its southern extremity, only the eastern slope being drained by streams crossing the piedmont plain to 14-NAT. GEoa. MAO., VOL. VI, 1894.
1894 Jun 22
1894 Apr 25