90 Hayes and Campbell—Appalachian Geomorphology. 
to be within 200 feet of each other in the vicinity of West Union, 
forty miles east of Parkersburg, West Virginia. On the eastern 
margin of the province the upper peneplain is completely oblit- 
erated, but the two probably coincide in the vicinity of Rich- 
mond, Virginia. Along the axes the descent was much less 
rapid. On the Pennsylvania line the uplift probably did not 
exceed 1,200 feet, while toward the southwest, along the axis EH F 
(plate 5), it extended certainly as far as the Tennessee line. 
South of this line the uplifts were much more irregular and dis- 
tributed over a broader area, so that their general effect has been 
to produce a broad fold extending from Greenville, South Caro- 
lina, to Nashville, Tennessee, and with an altitude not exceed- 
ing 1,000 feet. In this broad uplift can be traced several local 
orogenic disturbances, of which the uplift along the axis O P is 
quite prominent, but the greatest elevation occurred along the 
axis G H (plate 5). Many minor folds both of elevation and 
depression can be distinguished in this region, but their mean- 
ing is as yet obscure and we only know that they are intimately 
associated with the general warping of the surface of the proy- 
ince. In the vicinity of Atlanta the two baselevels are so near 
the same altitude that thejr peneplains cannot be discriminated, 
and the same is true along a line toward the northeast as far as 
Asheville. In the upper portion of the French Broad basin 
only one peneplain can be detected and it is ascribed to Cre- 
taceous time. The streams: have, however, barely sunk their 
channels through the mantle of disintegrated rock, although the 
present altitude of the region renders them extremely active. 
Westward from Asheville the two baselevels diverge under the 
influence of an uplift along the axis G H and indications of the 
two corresponding peneplains are found along the lower course 
of the French Broad river. 
DISSECTION OF THE TERTIARY PENEPLAIN. 
By far the larger part of the erosion of the Tertiary pene- 
plain was accomplished during the period of high level which 
preceded the Columbia depression, The streams were greatly 
stimulated, and where the elevation was considerable they carved 
deep gorges along their lower courses, giving rise to the numerous 
bays and broad-mouthed rivers now indenting the Atlantic coast. 
The distance these gorges were cut toward the interior yaries 
greatly, depending upon the elevation of the land and the char- 
