TERTIARY HISTORY OF THE TENNESSEE RIVER 199 



of the old Cretaceous peneplain. In the broad valleys on either side 

 of this mountain was developed the Tertiary peneplain, remnants of 

 which are still distinctly visible in places, although post-Tertiary 

 erosion has destroyed much of its surface. Fig. 2 shows the sup- 

 posed former course of the Tennessee as given by those who support 

 the theory of capture. According to this theory, a great river, called 

 the Appalachian by Hayes and Campbell, flowed southward past 

 Chattanooga, across what is now the low divide near Lafayette, on 

 south through this valley to the Coosa River, and thence by way of 

 the Alabama River to the Gulf. In the Sequatchie valley, west of 



Fig. 3. — Present course of Tennessee River. 



Walden Ridge, a parallel, southward-flowing, subsequent stream, 

 the Sequatchie River, is believed to have occupied a level 100 feet 

 lower than its neighbor to the east, thus having some advantage over 

 the latter. It is conceived that near the close of the Tertiary period 

 a branch of the Sequatchie worked headward through the ridge, 

 finally tapping the Appalachian River at a point near the present 

 site of Chattanooga, and diverted its waters westward down through 

 the gorge to the lower level of the Sequatchie valley, thus giving 

 birth to the present Tennessee River. The broad valley southward 

 from Chattanooga, being thus deserted by the upper Appalachian 

 River, was left to the occupancy of the shrunken lower portion of 

 that beheaded stream, and a small tributary of the new Tennessee 

 River (Chicamauga Creek and its branches) succeeded in pushing 

 the low divide which was first established at the point of capture 

 southward along this valley nearly to Lafayette. 



Opposed to this theory, which has as its essential feature a grand 

 example of river-capture, is the conception that since the close of 



