116 Hayes and Campbell—Appalachian Geomorphology. 
on the line O P determined the location of the divide between 
the contending streams and held it stationary for a long time, 
neutralizing the advantage which local conditions would have 
given one or the other system and preventing consequent en- 
croachment. 
Figure 2 represents a restoration of the drainage as it probably 
existed when the Tertiary cycle was well advanced. The present 
course of the Tennessee river is represented by broken lines and 
the present relief by dotted contours. A rather large tributary, 
M M, joined the Sequatchie where that river now joins the Ten- 
SCALE OF MILES 
Z 2 x 5 ¢€ 
Figure 2.—Sketch Map of the Tennessee Gorge, showing the present Course of 
the Tennessee River through Walden Plateau and the probable Arrangement of the 
Drainageimmediately preceding the westward Diversion of the Appalachian River - 
nessee. It had numerous branches on the east heading against 
the divide along the axis O P. Flowing into the Clinch-Appa- 
lachian river on the east, the principal stream was LZ LZ, with the 
branches F, G, Hand K, also heading against the divide O P. 
At the points a and 0b streams were cutting backward toward 
the same part of the divide from opposite directions, and as the 
process continued the heavy sandstone capping the plateau was 
removed and deep cols formed on the limestone. Under such 
conditions the divides may have been cut very low at these points 
