Tistory of the Tennessee River. 121 
graphic features. We haye seen that most of the eastern tribu- 
taries are very old, having occupied approximately their present 
positions while the western portion of the province was still 
covered by the great inland sea. From the eastern highlands 
they brought down the vast Paleozoic sediments and built the 
floor of the future continent. As successive belts of these 
sediments were lifted to form dry land and the sea margin 
migrated westward, the streams extended their lower courses to 
the shrinking sea. Then during the long period of Appalachian 
folding and the longer period of degradation these westward- 
flowing streams were diverted to southward courses and collected 
in a single great stream, the Appalachian river. In the early 
part of this long cycle the southern portion of the province 
stood relatively higher, so that until the close of the Jurassic 
the materials carried down by the Appalachian river were swept 
to unknown distances and deeply buried beneath the later 
Mesozoic sediments. Early in the Cretaceous the land was tilted 
seaward and the water advanced to the present inner margin of 
the Cretaceous sediments. At the close of the cycle the Appa- 
lachian river wandered over a broad and nearly featureless plain. 
The second cycle began with uplift of the land, and broad valleys 
were cut by the streams nearly to their headwaters. Then came 
the Lafayette depression, accompanied by warping, which gave 
so great advantage to the streams flowing westward along the 
axis A B that the upper Appalachian drainage was captured 
and led off to the Mississippiembayment. The great river was 
scarcely adjusted to its new position before the tilting of the 
surface again changed it northward to its present cotrse into the 
Ohio. Thus the lower portion of the Tennessee river dates from 
the present cycle. The portion in northern Alabama and across 
Walden plateau was occupied at the close of the Tertiary cycle ; 
that in the Appalachian valley was adjusted during the long 
Cretaceous cycle; and, finally, the tributaries flowing from the 
present Smoky mountains have inherited their courses from the 
early Paleozoic continent. 
In conclusion, a graphic representation of this history will 
be given, in order to bring together the conclusions contained in 
the preceding portions of this paper. The oscillations of the 
surface have been so variable, accompanied by such diverse 
warping, that the relations of the surface of the whole region to 
sealevel cannot be represented diagramatically ; but if a single 
