120 Hayes and Camphell—Appalachian Geomorphology. 
limestones, sands and clays, so that it was able to keep pace 
with this uplift and retain its southward course unchanged to 
the Gulf. The Mississippi, by reason of its greater volume, was 
also able to keep near baselevel, and as the land rose cut a deep 
gorge through the Lafayette and well into or through the under- 
lying Tertiary and Cretaceous formations. 
The westward flowing stream which had diverted the Appa- 
lachian drainage occupied in its lower course about the position 
of Black river, and it probably continued in this course a short 
time after the post-Lafayette elevation began—long enough, at 
least, to cut through the mantle of Lafayette gravel down to the 
Grand gulf, which is the most indurated of all the Mississippi 
embayment formations. While the lower course of this river 
was thus held in check: by the elevation of the indurated beds, 
northward flowing streams were greatly stimulated by the tilt- 
ing of the surface in that direction. Small streams flowing north- 
ward to the Ohio along the strike of the easily erodible Creta- 
ceous beds therefore had a double advantage over those flowing 
westward or southwestward, and by cutting backward were able 
to capture and divert the Tennessee river to a northward course. 
After a comparatively short period of elevation the province 
was again depressed, though not so much as during the Lafay- 
ette epoch, and this depression was in turn followed by elevation 
to the presentaltitude. The record of these oscillations is found 
chiefly in the deposits and erosion forms of the region border- 
ing the Appalachian province, and hence is somewhat beyond 
the scope of this paper. The time was too short for permanent 
records to be inscribed on the land surface in the interior. Minor 
stream adjustments doubtless occurred, and the rivers sank their 
channels within the surface of the Tertiary peneplain, in some 
regions deeply dissecting that surface, as already described in 
Part I) 
SUMMARY OF THE DRAINAGE DEVELOPMENT AND LAND OSCILLA- 
TIONS. . 
It is seen from the foregoing that the present course of the 
Tennessee river is extremely complex, and that a history of its 
development is practically a history of the province in post- 
Paleozoic time. Different portions of the river course furnish a 
record of the various vicissitudes through which the province 
has passed, or at least confirm the record found in other physio- 
