TERTIARY HISTORY OF THE TENNESSEE RIVER 229 



able for the preservation of the gravels represented elsewhere so 

 abundantly on mere scattered remnants of the peneplain. But 

 not a trace of the gravels could be found over this area, nor on any 

 surface elsewhere south of Chattanooga which could be referred 

 to the Tertiary peneplain. It thus appears that the true Tertiary 

 gravels are wholly absent in the valley southward from Chattanooga 

 — a fact which forces us to the conclusion that this valley was not 

 occupied by the stream which left such abundant evidence of its 

 presence on the Tertiary peneplain elsewhere. 



SUMMARY AND CONCLUSIONS 



There are many features in the physiography of the Chattanooga 

 district which are of great interest and importance, to which it was 

 impossible to give special attention in the time at the writer's dis- 

 posal. A detailed discussion of these features will be found in the 

 reports by Dr. Hayes and Mr. Campbell. It may be said in general, 

 however, that it appears that all of these features may be interpreted 

 in accordance with the theory that the Tennessee River has held its 

 present course since near the close of the Cretaceous period. The 

 warping of the peneplains, which was supposed to determine the 

 point of the proposed capture, may doubtless be present ; and while 

 it is not believed that such a broad, gentle arching as marks that 

 region could sharply limit a series of divides to a given line repre- 

 senting the axis of the uplift, the presence of such warping is per- 

 fectly admissible on the basis of the conditions which are believed to 

 have existed. That the drainage on Walden Ridge north of the 

 gorge is to the eastward, while the drainage south of the gorge is to 

 the westward, seems wholly in accord with what we should expect 

 when the master-stream of the region is east of the ridge in the one 

 case, and west of the ridge in the other. Those streams flowing into 

 the master-stream by the most direct route would have a marked 

 advantage over their neighbors flowing in a longer, more round- 

 about course, and would in consequence gain control of a large 

 part of the area drained, pushing the divide to the western part of 

 the ridge north of the gorge, and to the eastern part of the ridge south 

 of the gorge. That the drainage in Cretaceous times may have 

 been very different in places from what it is now, and that parts of 



