105 Hayes and Campbell—Appalachian Geomorphology. 
some streams and started others upon careers of conquest. Only 
the larger streams continued across the axis, and the courses of 
these were shifted by the uplift. Thus the axis became a well 
marked divide between eastward and westward flowing streams. 
It crossed the present Tennessee gorge about midway from 
Chattanooga to the Sequatchie valley and determined the posi- 
tion of the divide against which streams of the Appalachian and 
Sequatchie systems worked during the whole of the second eycle. 
Northward from the Tennessee gorge it diagonally crossed Wal- 
den plateau, the Sequatchie anticline and the Cumberland 
plateau to the western escarpment of the latter, diverting to the 
eastward Appalachian system the heads of many streams which 
had previously flowed westward. The uplift on this axis was 
greatest in the vicinity of Chattanooga, from which it decreased 
in either direction. Toward the north the pitch of the axis was 
quite rapid, producing a marked effect upon the course of the 
Cumberland river. 
That stream, as stated above, probably flowed due westward 
near the present Kentucky-Tennessee line. It was too large to 
be diverted eastward to the Appalachian system, but it was so 
checked by the rising fold that a tributary crossing the axis 50 
miles further northward, where the uplift was less, had sufficient 
advantage over the main stream to carry off its headwaters to 
the more favorable position. 
As indicated above and shown upon plate 4, the streams of 
Sand mountain south of the Tennessee gorge flow westward 
from the extreme eastern edge of the plateau and have cut deep 
notches in its western side, in some cases even beyond the center 
of the basin. In Walden ridge, a continuation of the same 
plateau north of the Tennessee gorge, all the streams flow east- 
ward, heading in some cases only a few hundred yards from the 
western escarpment. These have cut deep notches in the eastern 
side of the plateau. This peculiar drainage is due chiefly to 
the axis of uplift O P, described above, but also in part to local 
conditions which continued from the preceding cycle. In the 
first place, the anticlinal valley west of the plateau was formed 
by a southward flowing stream, so that its southern portion was 
first excavated and erosion progressed toward the north ; hence 
the streams flowing from the plateau into the southern part of 
the valley had lower outlets, and so cut more rapidly than those 
toward the north. East of this southern part of the plateau is 
